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Sample records for pupation

  1. Gregarious pupation act as a defensive mechanism against cannibalism and intraguild predation.

    Science.gov (United States)

    Roberge, Claudia; Fréchette, Bruno; Labrie, Geneviève; Dumont, François; Lucas, Eric

    2016-08-01

    Coccinellid pupae use an array of defensive strategies against their natural enemies. This study aims to assess the efficiency of gregarious pupation as a defensive mechanism against intraguild predators and cannibals in coccinellid. The study was designed specifically (i) to determine the natural occurrence of gregarious pupation in the field for different coccinellid species, and (ii) to evaluate the adaptive value of gregarious pupation as a defensive mechanism against 2 types of predators (i.e., cannibals and intraguild predators). In the field, gregarious pupation consisted of a group of 2-5 pupae. The proportion of gregarious pupation observed varied according to species, the highest rate being observed with Harmonia axyridis Pallas (Coccinellidae; 14.17%). Gregarious pupation had no impact on the probability that intraguild predators and cannibals locate pupae. Intraguild predation occurred more often in site with gregarious pupation, while cannibalism occurred as often in site with gregarious pupation as in site with isolated pupa. However, for a specific pupa, the mortality rate was higher for isolated pupae than for pupae located in a gregarious pupation site both in the presence of intraguild predators and in the presence of cannibals. The spatial location of pupae within the group had no impact on mortality rate. Since it reduces the risk of predation, it is proposed that gregarious pupation act as a defensive mechanism for H. axyridis pupae. © 2015 Institute of Zoology, Chinese Academy of Sciences.

  2. Seasonal change in pupation behaviour and pupal mortality in a swallowtail butterfly

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    Stefanescu, C.

    2004-01-01

    Full Text Available Phenotypic plasticity in pupal colour has evolved to render cryptic pupae. Apart from characteristics of the pupation site, the photoperiod experienced by larvae is important in determining pupal colour, long and short photophases eliciting the formation of green and brown pupae, respectively. This seasonal polyphenismis often correlated with developmental pathway, green pupae developing directly and brown pupae entering into diapause. From 1996 to 2000, immature stages of Iphiclides podalirius were monitored on natural hostplants in NE Spain. Larvae were followed to the pupation site and pupal colour, characteristics of the pupation site and the fate of pupae were recorded. Before August, pupae were non-diapausing green while in early August they were dimorphic, after which, they were brown and overwintered. As theory predicts, differences in pupation sites in successive generations were found in relation to pupal colour. Green pupae occurred on the hostplants and brown pupae were found among the leaf litter. Mortality ranged from 14.3 to 100%. Bird predation was the major mortality factor for green pupae and was also important for brown pupae. Results suggest that preference for pupation sites in the litter in diapausing broods evolved to avoid strong bird predation on the hostplants. Preference for sites above ground level in summer generations may have evolved in response to both non-visual (small mammals and visual (avian predators.

  3. Circadian clocks and life-history related traits: is pupation height affected by circadian organization in Drosophila melanogaster?

    Indian Academy of Sciences (India)

    Dhanashree A. Paranjpe; D. Anitha; Vijay Kumar Sharma; Amitabh Joshi

    2004-04-01

    In D. melanogaster, the observation of greater pupation height under constant darkness than under constant light has been explained by the hypothesis that light has an inhibitory effect on larval wandering behaviour, preventing larvae from crawling higher up the walls of culture vials prior to pupation. If this is the only role of light in affecting pupation height, then various light : dark regimes would be predicted to yield pupation heights intermediate between those seen in constant light and constant darkness. We tested this hypothesis by measuring pupation height under various light : dark regimes in four laboratory populations of Drosophila melanogaster. Pupation height was the greatest in constant darkness, intermediate in constant light, and the least in a light / dark regime of LD 14:14 h. The results clearly suggest that there is more to light regime effects on pupation height than mere behavioural inhibition of wandering larvae, and that circadian organization may play some role in determining pupation height, although the details of this role are not yet clear. We briefly discuss these results in the context of the possible involvement of circadian clocks in life-history evolution.

  4. Chemical Cues Influence Pupation Behavior of Drosophila simulans and Drosophila buzzatii in Nature and in the Laboratory

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    Beltramí, Marcial; Medina-Muñoz, María Cristina; Del Pino, Francisco; Ferveur, Jean-Francois; Godoy-Herrera, Raúl

    2012-01-01

    In the wild, larvae of several species of Drosophila develop in heterogeneous and rapidly changing environments sharing resources as food and space. In this scenario, sensory systems contribute to detect, localize and recognize congeners and heterospecifics, and provide information about the availability of food and chemical features of environments where animals live. We investigated the behavior of D. simulans and D. buzzatii larvae to chemicals emitted by conspecific and heterospecific larvae. Our goal was to understand the role of these substances in the selection of pupation sites in the two species that cohabit within decaying prickly pear fruits (Opuntia ficus-indica). In these breeding sites, larvae of D. simulans and D. buzzatii detect larvae of the other species changing their pupation site preferences. Larvae of the two species pupated in the part of the fruit containing no or few heterospecifics, and spent a longer time in/on spots marked by conspecifics rather than heterospecifics. In contrast, larvae of the two species reared in isolation from conspecifics pupated randomly over the substrate and spent a similar amount of time on spots marked by conspecifics and by heterospecifics. Our results indicate that early chemically-based experience with conspecific larvae is critical for the selection of the pupation sites in D. simulans and D. buzzatii, and that pupation site preferences of Drosophila larvae depend on species-specific chemical cues. These preferences can be modulate by the presence of larvae of the same or another species. PMID:22737236

  5. Chemical cues influence pupation behavior of Drosophila simulans and Drosophila buzzatii in nature and in the laboratory.

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    Marcial Beltramí

    Full Text Available In the wild, larvae of several species of Drosophila develop in heterogeneous and rapidly changing environments sharing resources as food and space. In this scenario, sensory systems contribute to detect, localize and recognize congeners and heterospecifics, and provide information about the availability of food and chemical features of environments where animals live. We investigated the behavior of D. simulans and D. buzzatii larvae to chemicals emitted by conspecific and heterospecific larvae. Our goal was to understand the role of these substances in the selection of pupation sites in the two species that cohabit within decaying prickly pear fruits (Opuntia ficus-indica. In these breeding sites, larvae of D. simulans and D. buzzatii detect larvae of the other species changing their pupation site preferences. Larvae of the two species pupated in the part of the fruit containing no or few heterospecifics, and spent a longer time in/on spots marked by conspecifics rather than heterospecifics. In contrast, larvae of the two species reared in isolation from conspecifics pupated randomly over the substrate and spent a similar amount of time on spots marked by conspecifics and by heterospecifics. Our results indicate that early chemically-based experience with conspecific larvae is critical for the selection of the pupation sites in D. simulans and D. buzzatii, and that pupation site preferences of Drosophila larvae depend on species-specific chemical cues. These preferences can be modulate by the presence of larvae of the same or another species.

  6. Chemical cues influence pupation behavior of Drosophila simulans and Drosophila buzzatii in nature and in the laboratory.

    Science.gov (United States)

    Beltramí, Marcial; Medina-Muñoz, María Cristina; Del Pino, Francisco; Ferveur, Jean-Francois; Godoy-Herrera, Raúl

    2012-01-01

    In the wild, larvae of several species of Drosophila develop in heterogeneous and rapidly changing environments sharing resources as food and space. In this scenario, sensory systems contribute to detect, localize and recognize congeners and heterospecifics, and provide information about the availability of food and chemical features of environments where animals live. We investigated the behavior of D. simulans and D. buzzatii larvae to chemicals emitted by conspecific and heterospecific larvae. Our goal was to understand the role of these substances in the selection of pupation sites in the two species that cohabit within decaying prickly pear fruits (Opuntia ficus-indica). In these breeding sites, larvae of D. simulans and D. buzzatii detect larvae of the other species changing their pupation site preferences. Larvae of the two species pupated in the part of the fruit containing no or few heterospecifics, and spent a longer time in/on spots marked by conspecifics rather than heterospecifics. In contrast, larvae of the two species reared in isolation from conspecifics pupated randomly over the substrate and spent a similar amount of time on spots marked by conspecifics and by heterospecifics. Our results indicate that early chemically-based experience with conspecific larvae is critical for the selection of the pupation sites in D. simulans and D. buzzatii, and that pupation site preferences of Drosophila larvae depend on species-specific chemical cues. These preferences can be modulate by the presence of larvae of the same or another species.

  7. A new species of Longitarsus Latreille, 1829 (Coleoptera, Chrysomelidae, Galerucinae pupating inside stem aerenchyma of the hydrophyte host from the Oriental Region

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    Kaniyarikkal Prathapan

    2011-03-01

    Full Text Available A new species of subaquatic Longitarsus pupating inside the stem aerenchyma of its hydrophyte host plant is described. Eggs are laid on tender leaves and buds and the larvae are open feeders. This is the first report of an Oriental flea beetle pupating inside the stem of its hydrophyte host. A key to the species of southern Indian Longitarsus is provided.

  8. The evolution of host associations in the parasitic wasp genus Ichneumon (Hymenoptera: Ichneumonidae): convergent adaptations to host pupation sites.

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    Tschopp, Andreas; Riedel, Matthias; Kropf, Christian; Nentwig, Wolfgang; Klopfstein, Seraina

    2013-03-27

    The diversification of organisms with a parasitic lifestyle is often tightly linked to the evolution of their host associations. If a tight host association exists, closely related species tend to attack closely related hosts; host associations are less stable if associations are determined by more plastic traits like parasitoid searching and oviposition behaviour. The pupal-parasitoids of the genus Ichneumon attack a variety of macrolepidopteran hosts. They are either monophagous or polyphagous, and therefore offer a promissing system to investigate the evolution of host associations. Ichneumon was previously divided into two groups based on general body shape; however, a stout shape has been suggested as an adaptation to buried host pupation sites, and might thus not represent a reliable phylogenetic character. We here reconstruct the first molecular phylogeny of the genus Ichneumon using two mitochondrial (CO1 and NADH1) and one nuclear marker (28S). The resulting phylogeny only supports monophyly of Ichneumon when Ichneumon lugens Gravenhorst, 1829 (formerly in Chasmias, stat. rev.) and Ichneumon deliratorius Linnaeus, 1758 (formerly Coelichneumon) are included. Neither parasitoid species that attack hosts belonging to one family nor those attacking butterflies (Rhopalocera) form monophyletic clades. Ancestral state reconstructions suggest multiple transitions between searching for hosts above versus below ground and between a stout versus elongated body shape. A model assuming correlated evolution between the two characters was preferred over independent evolution of host-searching niche and body shape. Host relations, both in terms of phylogeny and ecology, evolved at a high pace in the genus Ichneumon. Numerous switches between hosts of different lepidopteran families have occurred, a pattern that seems to be the rule among idiobiont parasitoids. A stout body and antennal shape in the parasitoid female is confirmed as an ecological adaptation to host

  9. A biological timer in the fat body comprising Blimp-1, βFtz-f1 and Shade regulates pupation timing in Drosophila melanogaster.

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    Akagi, Kazutaka; Sarhan, Moustafa; Sultan, Abdel-Rahman S; Nishida, Haruka; Koie, Azusa; Nakayama, Takumi; Ueda, Hitoshi

    2016-07-01

    During the development of multicellular organisms, many events occur with precise timing. In Drosophila melanogaster, pupation occurs about 12 h after puparium formation and its timing is believed to be determined by the release of a steroid hormone, ecdysone (E), from the prothoracic gland. Here, we demonstrate that the ecdysone-20-monooxygenase Shade determines pupation timing by converting E to 20-hydroxyecdysone (20E) in the fat body, which is the organ that senses nutritional status. The timing of shade expression is determined by its transcriptional activator βFtz-f1. The βftz-f1 gene is activated after a decline in the expression of its transcriptional repressor Blimp-1, which is temporally expressed around puparium formation in response to a high titer of 20E. The expression level and stability of Blimp-1 is critical for the precise timing of pupation. Thus, we propose that Blimp-1 molecules function like sand in an hourglass in this precise developmental timer system. Furthermore, our data suggest that a biological advantage results from both the use of a transcriptional repressor for time determination and the association of developmental timing with nutritional status of the organism. © 2016. Published by The Company of Biologists Ltd.

  10. Effects of human food grade titanium dioxide nanoparticle dietary exposure on Drosophila melanogaster survival, fecundity, pupation and expression of antioxidant genes.

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    Jovanović, Boris; Cvetković, Vladimir J; Mitrović, Tatjana Lj

    2016-02-01

    The fruitfly, Drosophila melanogaster was exposed to the human food grade of E171 titanium dioxide (TiO2). This is a special grade of TiO2 which is frequently omitted in nanotoxicology studies dealing with TiO2, yet it is the most relevant grade regarding oral exposure of humans. D. melanogaster larvae were exposed to 0.002 mg mL(-1), 0.02 mg mL(-1), 0.2 mg mL(-1), and 2 mg mL(-1) of TiO2 in feeding medium, and the survival, fecundity, pupation time, and expression of genes involved in oxidative stress response were monitored. TiO2 did not affect survival but significantly increased time to pupation (p < 0.001). Fecundity of D. melanogaster was unaffected by the treatment. Expression of the gene for catalase was markedly downregulated by the treatment, while the effect on the downregulation of superoxide dismutase 2 was less pronounced. After four days of dietary exposure TiO2 was present in a significant amount in larvae, but was not transferred to adults during metamorphosis. Two individuals with aberrant phenotype similar to previously described gold nanoparticles induced mutant phenotypes were detected in the group exposed to TiO2. In general, TiO2 showed little toxicity toward D. melanogaster at concentrations relevant to oral exposure of humans.

  11. Genome-wide analysis of chitinase genes and their varied functions in larval moult, pupation and eclosion in the rice striped stem borer, Chilo suppressalis.

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    Su, C; Tu, G; Huang, S; Yang, Q; Shahzad, M F; Li, F

    2016-08-01

    Some insect chitinases are required to degrade chitin and ensure successful metamorphosis. Although chitinase genes have been well characterized in several model insects, no reports exist for the rice striped stem borer, Chilo suppressalis, a highly destructive pest that causes huge yield losses in rice production. Here, we conducted a genome-level analysis of chitinase genes in C. suppressalis. After amplification of full-length transcripts with rapid amplification of cDNA ends, we identified 12 chitinase genes in C. suppressalis. All these genes had the conserved domains and motifs of glycoside hydrolase family 18 and grouped phylogenetically into five subgroups. C. suppressalis chitinase 1 (CsCht1) was highly expressed in late pupae, whereas CsCht3 was abundant in early pupae. Both CsCht2 and CsCht4 were highly expressed in larvae. CsCht2 was abundant specifically in the third-instar larvae and CsCht4 showed periodic high expression in 2- to 5-day-old larvae in each instar. Tissue specific expression analysis indicated that CsCht1 and CsCht3 were highly expressed in epidermis whereas CsCht2 and CsCht4 were specifically abundant in the midgut. Knockdown of CsCht1 resulted in adults with curled wings, indicating that CsCht1 might have an important role in wing expansion. Silencing of CsCht2 or CsCht4 arrested moulting, suggesting essential roles in larval development. When the expression of CsCht3 was interfered, defects in pupation occurred. Overall, we provide here the first catalogue of chitinase genes in the rice striped stem borer and have elucidated the functions of four chitinases in metamorphosis.

  12. Downregulation of the Musca domestica peptidoglycan recognition protein SC (PGRP-SC) leads to overexpression of antimicrobial peptides and tardy pupation.

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    Gao, Yifu; Tang, Ting; Gu, Jihai; Sun, Lingling; Gao, Xiaobin; Ma, Xianyong; Wang, Xiaochun; Liu, Fengsong; Wang, Jianhui

    2015-10-01

    PGRP (peptidoglycan recognition protein) is a conserved protein family that recognizes the peptidoglycan in bacterial cell wall and causes the activation of various innate immune responses. Previous studies have reported that PGRP-SCs in Drosophila dampen the activation of Immune Deficiency (Imd) pathway to microbial infection, and participate in the lifespan extension of the insects. To facilitate understanding the function of PGRP-SCs from an evolutionary angle, we identified and functionally characterized the PGRP-SC gene in the housefly Musca domestica, a species that has adapted to a septic environment much harsher than the natural habitat of Drosophila. The gene designated as MdPGRP-SC was found most abundantly expressed in the 3rd instar larvae, and is expressed at this developmental stage predominantly in the gut. MdPGRP-SC was virtually unchanged in whole larvae after a septic injury at the second larval instar, while two antimicrobial peptides (AMPs), diptericin and attacin, were upregulated in the first 24h but not later. Through dsRNA microinjection, MdPGRP-SC was knocked down by RNA interference (RNAi), and caused the significant increased expression of diptericin and attacin. The pupation of MdPGRP-SC-depleted larvae was severely suppressed compared to controls. Opposite to the expression trend of MdPGRP-SC, a spontaneous active expression of diptericin and attacin was found in pre-pupae but not in third instar larvae. Taken together, our study reveals that downregulation of MdPGRP-SC leads to the overexpression of the AMPs, and is involved in the larvae-to-pupa transition of housefly.

  13. The effect of sublethal exposure to temephos and propoxur on reproductive fitness and its influence on circadian rhythms of pupation and adult emergence in Anopheles stephensi Liston-a malaria vector.

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    Sanil, Deepak; Shetty, Nadikere Jaya

    2012-07-01

    The present study was undertaken to investigate the effects of organophosphate and carbamate insecticides namely, temephos and propoxur respectively, on the life history of Anopheles stephensi Liston (Culicidae) under laboratory conditions. The late third instar larvae of the mosquito were exposed to sublethal concentrations of temephos and propoxur at LC(10), LC(30) and LC(50), respectively, and adult survivors were evaluated for fitness parameters. Sublethal effects were also evaluated in subsequent generations. Fecundity, egg hatchability, sex ratio, adult longevity and morphology of gonads were the end points studied and compared to the untreated control. Adverse changes in developmental traits were mainly observed in fecundity, egg hatchability and sex ratio. However, significant differences in adult longevity were observed in the insecticide-exposed population. Pleiotropic effects through prolonged larval duration and enhanced longevity of adults were observed. Morphology of gonads in the insecticide-exposed population was severely affected and is represented by rudimentary and atrophied testes, and the size of the vas deferens was very much reduced when compared to that of the control. In another set of experiments, circadian rhythm (for pupation and adult emergence) of LC(10), LC(30) and LC(50) values to abovementioned insecticides exposed to late third instar larvae was studied. Pupation and adult emergence rhythms were found to be disturbed with an increase in concentrations of insecticides when compared to that of untreated control.

  14. Decrease in Pupation and Adult Emergence of Plutella xylostella (L. treated with Hexaflumuron Disminución en Pupación y Emergencia de Adultos de Plutella xylostella (L. tratados por Hexaflumuron

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    Mohammad Mahmoudvand

    2012-06-01

    Full Text Available The oligophagous pest Plutella xylostella (L. is a major crucifer pest in Tehran Province, Iran. Hexaflumuron is an insect growth regulator insecticide with good effects on immature insect stages. The objective of this study was to investigate the effects of two sublethal concentrations (LC10 and LC25 of hexaflumuron on some biological parameters of P. xylostella larvae, such as birth rate (b, death rate (d, finite rate of increase (λ, generation time (T, sex ratio, pupation rate, and adult emergence. Results showed that hexaflumuron decreased the total number of eggs and oviposition and post-oviposition periods, pupation, and adult emergence in the treated generation, b, and λ. Hexaflumuron also increased T, d, and the pre-oviposition period. However, sex ratio, percentage of pupation, and adult emergence in the offspring generation were not affected by hexaflumuron. Overall, these results indicated that sublethal concentrations of hexaflumuron can affect the biological parameters of P. xylostella.Plutella xylostella (L., una plaga oligofaga, es una importante plaga de crucíferas en la provincia de Teherán, Irán. Hexaflumuron, un insecticida regulador de crecimiento de insectos, tiene buenos efectos sobre estados inmaduros de insectos. El objetivo de este estudio es investigar los efectos de dos concentraciones subletales (LC10 y LC25 de hexaflumuron sobre algunos parámetros de larvas de P. xylostella tales como tasa de nacimiento (b y tasa de mortalidad (d, tasa finita de aumento (λ, tiempo de generación (T, proporción de sexos, tasa de pupación, emergencia de adultos, y algunos otros parámetros. Los resultados mostraron que hexaflumuron redujo el número total de huevos y ovipostura y períodos de post-ovipostura, pupación, y emergencia de adultos en la generación tratada, b y λ. Hexaflumuron además aumentó T, d y el período pre-ovipostura. Sin embargo, la proporción de sexos, porcentaje de pupación, y emergencia de adultos

  15. Dispersão larval radial pós-alimentar em Lucilia cuprina (Diptera, Calliphoridae: profundidade, peso e distância de enterramento para pupação Postfeeding radial larval dispersion in Lucilia cuprina (Diptera, Calliphoridae: depth, weight and distance of burying for pupation

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    Leonardo Gomes

    2004-06-01

    Full Text Available Blowflies utilize discrete and ephemeral sites for breeding and larval nutrition. After the exhaustion of food, the larvae begin dispersing to search for sites to pupate or for additional food source, process referred as postfeeding larval dispersal. Some aspects of this process were investigated in Lucilia cuprina (Wiedemann, 1830, utilizing a circular arena to permit the radial dispersion of larvae from the food source in the center. To determine the localization of each pupa, the arena was split into 72 equal sectors from the center. For each pupa, distance from the center of arena, weight and depth were determined. Statistical tests were performed to verify the relation among weight, depth and distance of burying for pupation. It was verified that the larvae that disperse farthest are those with lowest weights. The majority of individuals reached the depth of burying for pupation between 7 and 18 cm. The study of this process of dispersion can be utilized in the estimation of postmortem interval (PMI for human corpses in medico-criminal investigations.

  16. Indoor breeding Zhou Tetrastichus white moth pupation (former) cryopreservation of%室内繁育白蛾周氏啮小蜂化蛹(前)低温保存的探讨

    Institute of Scientific and Technical Information of China (English)

    钮效东; 刘发邦; 王绍文; 冯敬奎; 谢广科; 李增磊; 谭翠朋

    2012-01-01

    Zhou Nie small white moth colony set in the fall webworm pupae in parasitic, their eggs, larvae, pupae and eggs are in the early pupa inside the host spent. In nature, the mature larvae overwinter in the host pupa. After many years of research we learned that the local white moth Zhou Tetrastichus developmental threshold temperature: 6.28℃ (6.28 ± 0.60) effective temperature is: 365.12 day--degrees (365.12 ± 15.56). Zhou Tetrastichus white moth pupation (front), 6 degrees of cold storage in the next, after 30 days; a bee on the effective temperature of 436.6 degrees.%白蛾周氏啮小蜂群集内寄生于美国白蛾蛹中,其卵、幼虫、蛹及产卵前期均在寄主蛹内度过。在自然界中,以老熟幼虫在寄主蛹内越冬。作者经多年研究得知,在当地白蛾周氏啮小蜂发育起点温度是:6.28℃(6.28±0.60);有效积温是:365.12日度(365.12±15.56)。白蛾周氏啮小蜂化蛹(前),在6℃的低温保存下,历经30天的时间;出蜂的有效积温为436.6日度。

  17. Efeito do tipo de substrato para pupação na dispersão larval pós-alimentar de Chrysomya albiceps (Diptera, Calliphoridae Effect of the substrate for pupation in the postfeeding larval dispersal of Chrysomya albiceps (Diptera: Calliphoridae

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    Leonardo Gomes

    Full Text Available As moscas-varejeiras utilizam substratos discretos e efêmeros para posturas dos ovos e para alimentação das larvas. Após a exaustão de recursos, as larvas começam a procurar por um sítio de pupação no habitat ou por mais fonte de alimento adicional (dispersão larval pós-alimentar. No entanto, o tipo de substrato de dispersão pode afetar este processo; assim, procurou-se avaliar o comportamento de dispersão de Chrysomya albiceps (Wiedemann 1819 por meio da localização das pupas em arenas circulares preenchidas com vermiculita, comparando-se com outros estudos feitos em serragem. As arenas foram dividas em 72 setores iguais a partir do centro de dispersão para facilitar a localização das pupas no substrato. A massa, a distância de dispersão do centro de arena, e a profundidade de cada pupa foram determinadas e verificou-se a relação entre peso, profundidade e distância do centro de dispersão. Pôde-se constatar que as larvas com menor massa foram as que percorreram maior distância do centro de dispersão, como também foi observado em estudos anteriores que empregaram outros substratos. O sítio de pupação da maioria dos indivíduos foi entre 2 e 8 cm de profundidade (média 4,96±2,97 cm. Tal estudo do processo de dispersão pode ser útil na estimativa do intervalo pós-morte (IPM para corpos humanos em investigações médico-criminais.Blowflies utilize discrete and ephemeral sites for breeding and larval nutrition. After the exhaustion of food, the larvae begin dispersing to search for pupation sites or for additional food sources, a process referred to as postfeeding larval dispersal. However the nature of the substrate can affect this process. Some of the most important aspects of this behavior were here investigated in Chrysomya albiceps (Wiedemann, 1819, utilizing a circular arena covered with vermiculite allowing the post-feeding larval dispersal from the center and to comparing with others studies that used

  18. 沙丁胺醇对果蝇的化蛹、羽化、寿命及抗氧化能力和DNA损伤的影响%Effect of Salbutamol on the Pupation, Emergence, Life Span, Antioxidative Capacity and DNA Damage in Drosophila melanogaster

    Institute of Scientific and Technical Information of China (English)

    孙冰; 林欣大; 张春红

    2014-01-01

    蝇寿命呈现增加的趋势。对果蝇DNA损伤检测的试验表明,经沙丁胺醇处理之后,果蝇细胞就出现损伤,在SCGE的检测下可以观察到DNA损伤形成的拖尾,并且随着浓度的增加损伤情况也越严重,但是彗星图片中没有出现细胞核首尾分离的情况,可知沙丁胺醇并没有引起细胞凋亡。经统计分析,各处理浓度组的“彗星”尾长(Tail length, TL)、尾距(Olive tail moment, OTM)和尾部DNA百分含量(%DNA in tail),与对照组相比,均有显著差异(P<0.05)。【结论】沙丁胺醇对果蝇化蛹和羽化没有显著影响;对果蝇抗氧化系统产生作用,抑制CAT活力,使SOD活力显著增加,使得在较高浓度处理时出现显著延长果蝇的寿命的情况;经沙丁胺醇处理之后,就会引起果蝇DNA损伤并且与对照组存在显著差异,但是并没有出现细胞凋亡的情况。%The objective of this study is to explore the effect of salbutamol on the growth, development, life span, anti-oxidative capacity and DNA damage in Drosophila melanogaster, to further provide the basis for improvement of the more effective detection method.[Method]The 1st-instar larvae were fed with salbutamol and the pupate and emergence of flies were recorded, the pupation rate and the eclosion rate as well as pupation and eclosion time were counted. One day after eclosed, adult flies were fed up with normal medium and salbutamol medium, in which the concentrations of salbutamol were 0.48, 2.4,12 and 24μg·mL-1. Fifty flies for each medium(1﹕1 for male﹕female) and the experiment was repeated for 4 times. The number of lived flies was recorded every day. The medium was replaced every three days until all of the flies died. The 50%lethal time, average longevity and average maximum time were recorded and calculated, respectively. The 3-day old adult flies which feed up with salbutamol or minimum medium were collected. Tissue

  19. Pupation behavior and larval and pupal biocontrol of Drosophila suzukii in the field

    Science.gov (United States)

    Drosophila suzukii is a worldwide pest of fruit crops. Biological control may play an important role in D. suzukii IPM, and suppressing populations in unmanaged areas. While predation has been observed in the field, nothing is known about the potential for natural enemies to reduce D. suzukii popula...

  20. Chemical Cues Influence Pupation Behavior of Drosophila simulans and Drosophila buzzatii in Nature and in the Laboratory.

    OpenAIRE

    Marcial Beltramí; María Cristina Medina-Muñoz; Francisco Del Pino; Jean-Francois Ferveur; Raúl Godoy-Herrera

    2012-01-01

    International audience; In the wild, larvae of several species of Drosophila develop in heterogeneous and rapidly changing environments sharing resources as food and space. In this scenario, sensory systems contribute to detect, localize and recognize congeners and heterospecifics, and provide information about the availability of food and chemical features of environments where animals live. We investigated the behavior of D. simulans and D. buzzatii larvae to chemicals emitted by conspecifi...

  1. X射线辐照对舞毒蛾幼虫死亡率和化蛹率的影响%Influence of X-ray irradiation on mortality and pupation rate of gypsy moth larvae

    Institute of Scientific and Technical Information of China (English)

    韩书霞; 戚大伟; 李景奎; 李花顺

    2007-01-01

    为了给物理辐照灭虫的研究和实际应用提供理论依据,文章分别用不同剂量的X射线照射舞毒蛾虫卵,观察照射后虫卵孵化、幼早死亡、化蛹等变化情况.实验表明,随着X射线辐剂量增大幼虫的死亡率有明显上升的趋势,而化蛹率有明显下降趋势.

  2. Influence of plant extracts on the pupation rate and pupal weight of Plutella xylostella%植物提取物对小菜蛾化蛹率和蛹重的影响

    Institute of Scientific and Technical Information of China (English)

    魏辉; 尤民生; 王前梁; 侯有明; 林泽燕

    2004-01-01

    分别用35种植物乙醇提取物处理的叶片饲养小菜蛾幼虫,研究非嗜食植物提取物对小菜蛾化蛹率和蛹重的影响.研究表明,茶枯(Camellia oleifera)、番石榴(Psidium guajava)、飞扬草(Euphorbia hirta)、南洋楹(Albizia falcataria)、薄荷(Mentha haplocalyx)、蓖麻(Ricinus communis)、假连翘(Duranta repens)的乙醇提取物对小菜蛾化蛹有显著的抑制作用(P<0.01,DMRT),化蛹率都低于30.00%;从蛹重来看,经积雪草(Centella asiatica)、芒果(Mangifera indica)、构树(Broussonetia papyrifera)、细叶桉(Eucalyptus tereticornis)的乙醇提取物处理,小菜蛾蛹重显著减轻(P<0.01,DMRT),蛹重(10只蛹)都低于0.0300g.

  3. Preliminary assessment of insecticidal activity of Moroccan ...

    African Journals Online (AJOL)

    aghomotsegin

    2015-03-11

    Mar 11, 2015 ... capitata, and the most important pupation reduction was obtained for isolates 37 ... Key words: Moroccan actinobacteria, insecticidal activity, biological screening, ..... extracts against culex tritaeniorhynchus and culex gelidus.

  4. Effects of in situ climate warming on monarch caterpillar (Danaus plexippus) development.

    Science.gov (United States)

    Lemoine, Nathan P; Capdevielle, Jillian N; Parker, John D

    2015-01-01

    Climate warming will fundamentally alter basic life history strategies of many ectothermic insects. In the lab, rising temperatures increase growth rates of lepidopteran larvae but also reduce final pupal mass and increase mortality. Using in situ field warming experiments on their natural host plants, we assessed the impact of climate warming on development of monarch (Danaus plexippus) larvae. Monarchs were reared on Asclepias tuberosa grown under 'Ambient' and 'Warmed' conditions. We quantified time to pupation, final pupal mass, and survivorship. Warming significantly decreased time to pupation, such that an increase of 1 °C corresponded to a 0.5 day decrease in pupation time. In contrast, survivorship and pupal mass were not affected by warming. Our results indicate that climate warming will speed the developmental rate of monarchs, influencing their ecological and evolutionary dynamics. However, the effects of climate warming on larval development in other monarch populations and at different times of year should be investigated.

  5. Odontopus brevirostris (Hustache, 1936 (Coleoptera, Curculionidae associated with new host plants belonging to Annona (Annonaceae

    Directory of Open Access Journals (Sweden)

    Germano H. Rosado-Neto

    2002-01-01

    Full Text Available Odontopus brevirostris (Hustache, 1936 feeding on Annona squamosa L., A. cherimola Mill., A. glabra L., and A. muricata L. was observed. The last three host plants are recorded for the first time. The endophitic oviposition occurs in the veins of the ventral surface of the young leaves. The larvae, leaf miners, eat the parenchyma and the adults make small holes in the leaves. The pupation occurs in spherical cocoons protected by a sort of nest (pupation chamber between the two epidermal layers.

  6. Obtenção de uma dieta artificial para Bradysia hygida (Diptera, Sciaridae

    Directory of Open Access Journals (Sweden)

    Angelo de Lima Francisco

    1984-01-01

    Full Text Available Some artificial diets were tested and their efficiency assessed from percentage of pupation and emergence, time to emergence, pupal weight, ovary development and maintenance of generation. The best results were obtained with a yeast and starch basal diet. The other products tested were: wheat germ, soybean, fish flour, blood flour and meat flour.

  7. Costly nutritious diets do not necessarily translate into better performance of artificaially reared fruit files (Diptera: Tephritidae)

    Science.gov (United States)

    Protein, lipid, carbohydrate and energy contents of three artificial diets (Xal2, Met1 and Met2) used for laboratory-rearing and mass-rearing the Mexican fruit fly, Anastrepha ludens (Loew), for a sterile insect technique (SIT) program were measured. The larval survival, pupation, pupal weight, adu...

  8. Hormonal mechanisms underlying termination of larval diapause by juvenile hormone in the bamboo borer, Omphisa fuscidentalis.

    Science.gov (United States)

    Singtripop, Tippawan; Manaboon, Manaporn; Tatun, Nujira; Kaneko, Yu; Sakurai, Sho

    2008-01-01

    Topical application of methoprene, a juvenile hormone analogue (JHA), induces pupation by activating the prothoracic glands (PGs) in diapausing larvae of the bamboo borer, Omphisa fuscidentalis. To determine the minimum stimulation period for PG activation, we transplanted PGs of JHA-treated larvae (donors) into non-treated larvae (recipients) on successive days after JHA treatment and observed the recipients for pupation. JHA stimulation for 1 day was sufficient to induce pupation. In recipient larvae, the hemolymph ecdysteroid titer increased transiently on day 18 after transplantation and significantly on days 24-28, prior to pupation. Secretory activity of recipient PGs increased transiently on day 16 and days 22-28. Because the recipient PG activity was too low to account for an increased ecdysteroid titer, the JHA-stimulated donor PGs must produce the major part of hemolymph ecdysteroids. In addition, the ecdysteroid produced by the donor PGs might have stimulated the recipient PGs. We examined the possible involvement of two ecdysone receptor (EcR) isoforms, OfEcR-A and OfEcR-B1, in PG activation by JHA, and found that although both isoforms were up-regulated, accompanied by an increased ecdysteroid titer in the hemolymph, the isoform mRNA levels were not altered at all before the increase in PG secretory activity. Thus, EcR expression might not be involved in feedback activation of PGs.

  9. Prothoracicotropic hormone acts as a neuroendocrine switch between pupal diapause and adult development.

    Science.gov (United States)

    Mizoguchi, Akira; Ohsumi, Shintaro; Kobayashi, Katuji; Okamoto, Naoki; Yamada, Nobuto; Tateishi, Ken; Fujimoto, Yoshinori; Kataoka, Hiroshi

    2013-01-01

    Diapause is a programmed developmental arrest that has evolved in a wide variety of organisms and allows them survive unfavorable seasons. This developmental state is particularly common in insects. Based on circumstantial evidence, pupal diapause has been hypothesized to result from a cessation of prothoracicotropic hormone (PTTH) secretion from the brain. Here, we provide direct evidence for this classical hypothesis by determining both the PTTH titer in the hemolymph and the PTTH content in the brain of diapause pupae in the cabbage army moth Mamestra brassicae. For this purpose, we cloned the PTTH gene, produced PTTH-specific antibodies, and developed a highly sensitive immunoassay for PTTH. While the hemolymph PTTH titer in non-diapause pupae was maintained at high levels after pupation, the titer in diapause pupae dropped to an undetectable level. In contrast, the PTTH content of the post-pupation brain was higher in diapause animals than in non-diapause animals. These results clearly demonstrate that diapause pupae have sufficient PTTH in their brain, but they do not release it into the hemolymph. Injecting PTTH into diapause pupae immediately after pupation induced adult development, showing that a lack of PTTH is a necessary and sufficient condition for inducing pupal diapause. Most interestingly, in diapause-destined larvae, lower hemolymph titers of PTTH and reduced PTTH gene expression were observed for 4 and 2 days, respectively, prior to pupation. This discovery demonstrates that the diapause program is already manifested in the PTTH neurons as early as the mid final instar stage.

  10. Differing Success of Defense Strategies in Two Parasitoid Wasps in Protecting Their Pupae Against a Secondary Hyperparasitoid

    NARCIS (Netherlands)

    Harvey, J.A.; Gols, R.; Tanaka, T.

    2011-01-01

    During their larval development, endoparasitoids are known to dispose of host resources in several different ways. Some parasitoid wasps consume most or all tissues of the host, whereas others consume a small fraction of host resources and either ensure that the host moves away from the pupation sit

  11. Patterns of host ant use by sympatric populations of Maculinea alcon and M. 'rebeli' in the Carpathian Basin

    DEFF Research Database (Denmark)

    Tartally, A.; Nash, David Richard; Lengyel, S.

    2008-01-01

    Maculinea butterflies show social parasitism via obligatory myrmecophily as their larvae are adopted and raised to pupation by Myrmica ants. Suitable hosts differ for different Maculinea species, and host ant specificity can further differ at the population-level. Although early studies suggested...

  12. The effect of Erynia radicans on food consumption, utilization and fecundity by the spruce budworm, Choristoneura fumiferana.

    Science.gov (United States)

    Abdul K. A. Mohamed; Lucius Lewis; Denise Lewis

    1985-01-01

    In food consumption and utilization studies, observations were confined to a period of 5 days after which mortality of Erynia radicans larvae began to occur. Mortality due to the fungus was 76 and 83% in male and female larvae, respectively. In control larvae the pupation rate was over 95%. Control larvae of both sexes consumed significantly (P = 0....

  13. Effects of gamma irradiation on the grape vine moth, Lobesia botrana, mature larvae

    Science.gov (United States)

    Mansour, M.; Al-Attar, J.

    2014-04-01

    Mature 5th instars of the grape vine moth, Lobesia botrana (Denis and Schiffermuller) were exposed to gamma radiation dosages ranging from 50 to 250 Gy. The effects of gamma radiation on pupation, adult emergence, sex ratio and rate of development were examined. Results showed that the radiosensitivity of the grape vine moth larvae increased with increasing radiation dose. The severity of the effect, however, depends on the criterion used for measuring effectiveness; adult emergence was more severely affected than pupation. Pupation was significantly affected at 150 Gy and decreased by about 25% at 250 Gy. Adult emergence, on the other hand, was significantly affected at 100 Gy and completely prevented at 200 Gy. Probit analysis of dose mortality data for pupation and adult emergence show that the LD99 for preventing subsequent development to pupae and adults was 2668 and 195 Gy, respectively. In addition, the rate of development of mature larvae to the adult stage was negatively affected and sex ratio was skewed in favor of males.

  14. Modification of Tetragnata montana (Araneae, Tetrafnathidae) web architecture induced by larva of the parasitoid Acrodactyla quadrisculpta (Hymenopteram Ichneumonidae, Polysphincta genus-group)

    NARCIS (Netherlands)

    Korenko, S.; Korenkova, B.; Satrapova, J.; Hamouzova, K.; Belgers, J.D.M.

    2015-01-01

    Background: The polysphinctine wasp, Acrodactyla quadrisculpta, is a koinobiont ecto-parasitoid of spiders and is narrowly associated with the biology of its spider hosts. The larva, attached to the dorsal side of the abdomen, develops while the spider continues foraging. Shortly before pupation, th

  15. Pupal colour plasticity in a tropical butterfly, Mycalesis mineus (Nymphalidae: Satyrinae).

    Science.gov (United States)

    Mayekar, Harshad Vijay; Kodandaramaiah, Ullasa

    2017-01-01

    Lepidopteran insects have provided excellent study systems for understanding adaptive phenotypic plasticity. Although there are a few well-studied examples of adult plasticity among tropical butterflies, our understanding of plasticity of larval and pupal stages is largely restricted to temperate butterflies. The environmental parameters inducing phenotypic plasticity and the selective pressures acting on phenotypes are likely to differ across tropical and temperate climate regimes. We tested the influence of relative humidity (RH), a prominent yet under-appreciated tropical climatic component, along with pupation substrate, larval development time, pupal sex and weight in determining pupal colour in the tropical satyrine butterfly Mycalesis mineus. Pupae of this butterfly are either brown or green or very rarely intermediate. Larvae were reared at high (85%) and low (60%) RH at a constant temperature. Proportions of green and brown pupae were expected to vary across low and high RH and pupation substrates in order to enhance crypsis. Brown pupae were more common at low RH than at high RH, as predicted, and developed faster than green pupae. Pupal colour was correlated with pupation substrate. Choice of pupation substrate differed across RH treatments. It is unclear whether pupal colour influences substrate selection or whether substrate influences pupal colour. Our study underscores the need for further work to understand the basis of pupal plasticity in tropical butterflies.

  16. Pupal colour plasticity in a tropical butterfly, Mycalesis mineus (Nymphalidae: Satyrinae)

    Science.gov (United States)

    Kodandaramaiah, Ullasa

    2017-01-01

    Lepidopteran insects have provided excellent study systems for understanding adaptive phenotypic plasticity. Although there are a few well-studied examples of adult plasticity among tropical butterflies, our understanding of plasticity of larval and pupal stages is largely restricted to temperate butterflies. The environmental parameters inducing phenotypic plasticity and the selective pressures acting on phenotypes are likely to differ across tropical and temperate climate regimes. We tested the influence of relative humidity (RH), a prominent yet under-appreciated tropical climatic component, along with pupation substrate, larval development time, pupal sex and weight in determining pupal colour in the tropical satyrine butterfly Mycalesis mineus. Pupae of this butterfly are either brown or green or very rarely intermediate. Larvae were reared at high (85%) and low (60%) RH at a constant temperature. Proportions of green and brown pupae were expected to vary across low and high RH and pupation substrates in order to enhance crypsis. Brown pupae were more common at low RH than at high RH, as predicted, and developed faster than green pupae. Pupal colour was correlated with pupation substrate. Choice of pupation substrate differed across RH treatments. It is unclear whether pupal colour influences substrate selection or whether substrate influences pupal colour. Our study underscores the need for further work to understand the basis of pupal plasticity in tropical butterflies. PMID:28158254

  17. Modification of Tetragnata montana (Araneae, Tetrafnathidae) web architecture induced by larva of the parasitoid Acrodactyla quadrisculpta (Hymenopteram Ichneumonidae, Polysphincta genus-group)

    NARCIS (Netherlands)

    Korenko, S.; Korenkova, B.; Satrapova, J.; Hamouzova, K.; Belgers, J.D.M.

    2015-01-01

    Background: The polysphinctine wasp, Acrodactyla quadrisculpta, is a koinobiont ecto-parasitoid of spiders and is narrowly associated with the biology of its spider hosts. The larva, attached to the dorsal side of the abdomen, develops while the spider continues foraging. Shortly before pupation,

  18. The lethal giant larvae Gene in Tribolium castaneum: Molecular Properties and Roles in Larval and Pupal Development as Revealed by RNA Interference

    Directory of Open Access Journals (Sweden)

    Da Xiao

    2014-04-01

    Full Text Available We identified and characterized the TcLgl gene putatively encoding lethal giant larvae (Lgl protein from the red flour beetle (Tribolium castaneum. Analyses of developmental stage and tissue-specific expression patterns revealed that TcLgl was constitutively expressed. To examine the role of TcLgl in insect development, RNA interference was performed in early (1-day larvae, late (20-day larvae, and early (1-day pupae. The early larvae injected with double-stranded RNA of TcLgl (dsTcLgl at 100, 200, and 400 ng/larva failed to pupate, and 100% mortality was achieved within 20 days after the injection or before the pupation. The late larvae injected with dsTcLgl at these doses reduced the pupation rates to only 50.3%, 36.0%, and 18.2%, respectively. The un-pupated larvae gradually died after one week, and visually unaffected pupae failed to emerge into adults and died during the pupal stage. Similarly, when early pupae were injected with dsTcLgl at these doses, the normal eclosion rates were reduced to only 22.5%, 18.0%, and 11.2%, respectively, on day 7 after the injection, and all the adults with abnormal eclosion died in two days after the eclosion. These results indicate that TcLgl plays an essential role in insect development, especially during their metamorphosis.

  19. Control of larval-pupal-adult molt in the moth Sesamia nonagrioides by juvenile hormone and ecdysteroids.

    Science.gov (United States)

    Pérez-Hedo, Meritxell; Goodman, Walter G; Schafellner, Christa; Martini, Antonio; Sehnal, Frantisek; Eizaguirre, Matilde

    2011-05-01

    Sesamia nonagrioides (Lepidoptera: Noctuidae) larvae reared under long day (LD; 16L:8D) conditions pupate after 5 or 6 larval instars, whereas under short day (SD; 12L:12D) conditions they undergo up to 12 additional molts before pupating. This extended period of repeated molting is maintained by high levels of juvenile hormone (JH). Previous work demonstrated that both LD and SD larvae decapitated in the 6th instar pupate but further development is halted. By contrast, about one-third of SD larvae from which only the brain has been removed, undergo first a larval molt, then pupate and subsequently developed to the adult stage. Debrained LD larvae molt to larvae exceptionally but regularly pupate and produce adults. Implanted brains may induce several larval molts in debrained recipient larvae irrespectively of the photoperiodic conditions. The results of present work demonstrate that the prothoracic glands (PGs) and the corpora allata (CA) of debrained larvae continue to produce ecdysteroids and JHs, respectively. PGs are active also in the decapitated larvae that lack JH, consistent with the paradigm that CA, which are absent in the decapitated larvae, are the only source of this hormone. Completion of the pupal-adult transformation in both LD and SD debrained insects demonstrates that brain is not crucial for the development of S. nonagrioides but is required for diapause maintenance. Application of JH to headless pupae induces molting, presumably by activating their PGs. It is likely that JH plays this role also in the induction of pupal-adult transformation in debrained insects. Application of the ecdysteroid agonist RH 2485 (methoxyfenozide) to headless pupae also elicits molting: newly secreted cuticle is in some cases thin and indifferent, in other cases it bears distinct pupal or adult features.

  20. Morphology, Biology and Control Possibilities of Two Argyresthia species – A. thuiella and A. trifasciata (Lepidoptera: Argyresthiidae

    Directory of Open Access Journals (Sweden)

    Hana Konečná

    2014-01-01

    Full Text Available The bionomics of Argyresthia thuiella (Packard, 1871 and A. trifasciata Staudinger, 1871 was studied on ornamental conifers in southern Moravia, Czech Republic. Argyresthia thuiella overwinters as caterpillar inside twigs and pupates the following spring there. Moths are on the wing during June until the beginning of July. Argyresthia trifasciata adults were observed from mid May till the beginning of June. Its larvae reach the stage of maturity from October to December. They pupate in the debris under trees. Both species develop one generation annually. Argyresthia thuiella was found on Thuja occidentalis, T. plicata and Chamaecyparis lawsoniana; A. trifasciata on Juniperus virginiana, J. chinensis, J. sabina, J. × media, J. squamata and J. horizontalis. Both species cause mainly aesthetic damage to plants. Stronger attack of Argyresthia may cause damage to trees. Control possibilities were tested on both species. The chaetotaxy of these species was first done in this experiment.

  1. Changing the pupal- case architecture as a survival strategy in the caddisfly, Annitella amelia Sipahiler, 1998 (Insecta, Trichoptera)

    Energy Technology Data Exchange (ETDEWEB)

    Alba-Tercedor, J.; SAinz-Bariain, M.; Zamora-Muñoz, C.

    2016-07-01

    In early autumn, pupal cases of the scarce caddisfly species, Annitella amelia Sipahiler, 1998 were collected on the shore of a narrow, shallow brook from the northwestern Iberian peninsula, in Spain. Some of the pupal cases had been built as a new tube inside an existing tubular case. Moreover, for pupation, the last instar larvae clearly changed the architecture of the cases by adding internal and/or external grains of substrate at the tips. An architectural study with microCT techniques made it possible to divide each case into equal halves and to indirectly measure the weight of each. As no significant differences were found, it was concluded that pupa equilibrates its case, ensuring that it will lie horizontally on the substrate of the brook and thus avoid more vertical positions that might risk air exposure. The architectural changes could represent a survival strategy during pupation, in which the pupae remain in shallow channels ditches of the small brooks. (Author)

  2. Influence of rain and malathion on the oviposition and development of blowflies (Diptera: Calliphoridae) infesting rabbit carcasses in Kelantan, Malaysia.

    Science.gov (United States)

    Mahat, N A; Zafarina, Z; Jayaprakash, P T

    2009-11-20

    The influence of rain and malathion on the initial oviposition as well as development of blowfly species infesting rabbit carcasses decomposing in sunlit and shaded habitats were studied over a period of 1 year in Kelantan, Malaysia. Chrysomya megacephala (Fabricius) was the most dominant species that infested the carcasses, followed by Chrysomya rufifacies (Macquart). In general, rain, depending on its intensity, delayed initial oviposition by 1-2 days and prolonged the pupation period by 1-3 days. The presence of malathion in the carcasses delayed initial oviposition by 1-3 days and prolonged the pupation period by 2-3 days. These findings deserve consideration while estimating postmortem interval since rain is a commonplace occurrence in Malaysia and malathion is one of the common poisons as an agent for choice to commit suicide.

  3. Endocrine changes associated with metamorphosis and diapause induction in the yellow-spotted longicorn beetle, Psacothea hilaris.

    Science.gov (United States)

    Munyiri, Florence N; Ishikawa, Yukio

    2004-11-01

    At 25 degrees C and under a long-day photoperiod, all 5th instar Psacothea hilaris larvae pupate at the next molt. Under a short-day photoperiod, in contrast, they undergo one or two additional larval molts and enter diapause; the 7th instar larvae enter diapause without further molt. The changes in hemolymph juvenile hormone (JH III) titers, JH esterase activity, and ecdysteroid titers in pupation-destined, pre-diapause, and diapause-destined larvae were examined. JH titers of the 5th instar pupation-destined larvae decreased continuously from 1.3 ng/ml and became virtually undetectable on day 13, when JH esterase activity peaked. Ecdysteroids exhibited a small peak on day 8, 1 day before gut purge, and a large peak on day 11, 2 days before the larvae became pre-pupae. The two ecdysteroid peaks are suggested to be associated with pupal commitment and pupation, respectively. JH titers of the 5th instar pre-diapause larvae were maintained at approximately 1.5 ng/ml for 5 days and then increased to form a peak (3.3 ng/ml) on day 11. JH esterase activity remained at a low level throughout. Ecdysteroid levels exhibited a large peak of 40 ng/ml on day 18, coincident with the larval molt to the 6th instar. JH titers of the 7th instar diapause-destined larvae peaked at 1.9 ng/ml on day 3, and a level of approximately 1.1 ng/ml was maintained even 30-60 days into the instar, when they were in diapause. Ecdysteroid titers remained approximately 0.02 ng/ml. Diapause induction in this species was suggested to be a consequence of high JH and low ecdysteroid titers.

  4. Juvenile hormone changes associated with diapause induction, maintenance, and termination in the beet webworm, Loxostege sticticalis (Lepidoptera: Pyralidae).

    Science.gov (United States)

    Jiang, Xingfu; Huang, Shaohong; Luo, Lizhi

    2011-07-01

    At 22°C and under a long-day photoperiod of L:D 16:8, all the last fifth instar Loxostege sticticalis larvae undergo prepupal stage and pupate without diapause. Under a short-day photoperiod of L:D 12:12, in contrast, they all enter diapause with approximately 36 days diapause maintenance and then terminate diapause spontaneously, although only 44% of the larvae terminated diapause successfully. Changes in hemolymph juvenile hormone (JH I) titers of diapause-destined larvae across diapause induction, maintenance and termination were examined using HPLC, and were compared with those of non-diapause-destined larvae from the fifth instar through pupation. JH I titer of the earliest fifth instar diapause-destined larvae remained at a high level with a peak of 220.4 ng/ml, though it decreased continuously to a minimum of 69.0 ng/ml on day 5 in the fifth instar when the larvae stopped feeding to enter diapause. During the diapause maintenance, JH I titer of the mature larvae increased significantly and maintained a high level until day 31 in prepupae. JH I titer declined and fluctuated at low level from 5 days before pupation. In contrast, JH I titer of both the fifth instar non-diapause-destined larvae and prepupae remained and fluctuated at low level consistently, as well as decreased before pupation. These results indicate that diapause induction and maintenance in this species might be a consequence of high JH, whereas diapause termination can be attributed to low JH titer, which was in agreement with the hormonal regulation observed in many other larval-diapausing insects.

  5. Brain-independent development in the moth Sesamia nonagrioides.

    Science.gov (United States)

    Pérez-Hedo, Meritxell; Eizaguirre, Matilde; Sehnal, Frantisek

    2010-06-01

    The caterpillars of Sesamia nonagrioides developing under long-day (LD) photoperiod pupate in the 5th or 6th instar whereas under short day (SD) conditions they enter diapause and undergo several extra larval molts. The diapause is terminated within 1-3 instars upon transfer of SD larvae to the LD conditions. Brain removal from the 6th instar larvae promotes pupation followed by imaginal development; however, one third of the SD larvae and 12% of the LD larvae debrained at the start of the instar first undergo 1-2 larval molts. The incidence of larval molts is enhanced by the brain implants. Exclusively pupal molts occur in the LD larvae debrained late in the 6th instar. Decapitation elicits pupation in both LD and SD larvae, except for some of the 4th and 5th and rarely 6th instar that are induced to a fast larval molt. The pupation of decapitated larvae is reverted to a larval molt by application of a juvenile hormone (JH) agonist. No molts occur in abdomens isolated from the head and thorax prior to the wandering stage. Abdomens isolated later undergo a larval (SD insects) or a pupal (LD insects) molt. Taken together the data reveal that in S. nonagrioides (1) several larval molts followed by a pupal and imaginal molt can occur without brain; (2) an unknown head factor outside the brain is needed for the pupal-adult molt; (3) brain exerts both stimulatory and inhibitory effect on the corpora allata (CA); (4) larval molts induced in CA absence suggest considerable JH persistence.

  6. Effect of electron beam irradiation on developmental stages of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae)

    Science.gov (United States)

    Kim, Junheon; Chung, Soon-Oh; Jang, Sin Ae; Jang, Miyeon; Park, Chung Gyoo

    2015-07-01

    Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), is an economically important and polyphagous pest, which harms various kinds of food crops and important agricultural plants, such as cotton and paprika. Effects of electron beam irradiation at six dose levels between 50 and 350 Gy on the egg (24-48 h old), the larval (4-5th instar), and the pupal (7-d old for female, 5-d old for male) development, and on the adult (1-d old) reproduction were tested to identify a potential quarantine treatment dose. Increased doses of irradiation on eggs decreased egg hatchability, pupation and adult emergence and increased larval period. ED99 values for inhibition of hatching, pupation and emergence were 460.6, 236.9 and 197.8 Gy, respectively. When larvae were irradiated with more than 280 Gy, no larvae could develop into pupae. ED99 values for inhibition of pupation and adult emergence were 265.6 and 189.6 Gy, respectively. Even though the irradiation on pupa did not completely inhibit adult emergence, most of the pupae emerged to deformed adults. When adults were irradiated, fecundity was not affected. However, F1 egg hatching was completely inhibited at the dose of 350 Gy. ED99 value for inhibition of adult emergence was estimated at 366.5 Gy. Our results suggest that electron beam irradiation could be recommendable as an alternative to MB and as a phytosanitary treatment for quarantine. A treatment dose of less than or equal to 220 Gy is suggested as a potential quarantine treatment to H. armigera egg for prevention of pupation and to larva for prevention of adult emerge.

  7. Comparison of life history characteristics of the genetically modified OX513A line and a wild type strain of Aedes aegypti.

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    Irka Bargielowski

    Full Text Available The idea of implementing genetics-based insect control strategies modelled on the traditional SIT (Sterile Insect Technique, such as RIDL (Release of Insects carrying a Dominant Lethal, is becoming increasingly popular. In this paper, we compare a genetically modified line of Aedes aegypti carrying a tetracycline repressible, lethal positive feedback system (OX513A with a genetically similar, unmodified counterpart and their respective responses to increasing larval rearing density using a constant amount of food per larva. The parameters that we examined were larval mortality, developmental rate (i.e., time to pupation, adult size and longevity. Analysis revealed some statistically significant differences between the life history traits we examined. The genetically modified OX513A line overall showed 5% lower larval survival as well as reduced adult longevity (20 vs 24 days mean lifespan compared to the unmodified line. Furthermore, the OX513A line pupated about one day sooner, which could be advantageous in mass-rearing, but produced somewhat smaller adults than the unmodified line; this effect was more pronounced in females than in males. Increasing the larval rearing density delayed pupation, decreased adult longevity and reduced adult size in both lines. While the delay in pupation and the decrease in longevity were similar between the two lines, the decrease in adult size was more pronounced for OX513A males.Our study shows that in a controlled laboratory situation the transgenic sterile OX513A line may have somewhat reduced performance compared to its unmodified counterpart and that high rearing densities may further reduce performance. Laboratory-based cage trials as well as field trials are necessary to assess how the differences in life history traits documented here impact the males' success upon release. Furthermore, this paper highlights the potential value of optimisation of mass-rearing systems as optimised rearing methods may be

  8. Comparison of life history characteristics of the genetically modified OX513A line and a wild type strain of Aedes aegypti.

    Science.gov (United States)

    Bargielowski, Irka; Nimmo, Derric; Alphey, Luke; Koella, Jacob C

    2011-01-01

    The idea of implementing genetics-based insect control strategies modelled on the traditional SIT (Sterile Insect Technique), such as RIDL (Release of Insects carrying a Dominant Lethal), is becoming increasingly popular. In this paper, we compare a genetically modified line of Aedes aegypti carrying a tetracycline repressible, lethal positive feedback system (OX513A) with a genetically similar, unmodified counterpart and their respective responses to increasing larval rearing density using a constant amount of food per larva. The parameters that we examined were larval mortality, developmental rate (i.e., time to pupation), adult size and longevity. Analysis revealed some statistically significant differences between the life history traits we examined. The genetically modified OX513A line overall showed 5% lower larval survival as well as reduced adult longevity (20 vs 24 days mean lifespan) compared to the unmodified line. Furthermore, the OX513A line pupated about one day sooner, which could be advantageous in mass-rearing, but produced somewhat smaller adults than the unmodified line; this effect was more pronounced in females than in males. Increasing the larval rearing density delayed pupation, decreased adult longevity and reduced adult size in both lines. While the delay in pupation and the decrease in longevity were similar between the two lines, the decrease in adult size was more pronounced for OX513A males.Our study shows that in a controlled laboratory situation the transgenic sterile OX513A line may have somewhat reduced performance compared to its unmodified counterpart and that high rearing densities may further reduce performance. Laboratory-based cage trials as well as field trials are necessary to assess how the differences in life history traits documented here impact the males' success upon release. Furthermore, this paper highlights the potential value of optimisation of mass-rearing systems as optimised rearing methods may be able to

  9. Compilation of 1992 Annual Reports of the Navy ELF Communications System Ecological Monitoring Program. Volume 2. Tabs C - F

    Science.gov (United States)

    1993-08-01

    1985-1992 ....... .... ... ... 74 FIGURE 13. Cumulative precipitation at KTU pine planta - tions. i . . . 75 FIGURE 14a. Cmulative number of nests of M...Pupation occurs in spring, and adults emerge soon after, in June and July at our study sites. A variety of parasites may emerge from the cell instead of...the original bee. Oviposition by parasites of the genus Coelioxys (Megachilidae) often occurs I while the cell is being provisioned, when the mother

  10. Effects of gamma irradiation on the grape vine moth, Lobesia botrana, eggs

    Science.gov (United States)

    Mansour, M.; Al-Attar, J.

    2012-11-01

    Eggs of the grape vine moth, Lobesia botrana (Denis and Schiffermuller), ranging in age from 1-24 to 73-96 h, were exposed, at 24 h intervals, to gamma radiation ranging from 25-600 Gy. The effects of gamma radiation on egg hatch, pupation, adult emergence, sex ratio and rate of development were examined. Results showed that the radiosensitivity of the grape vine moth eggs decreased with increasing age and increased with increasing radiation dose. Egg hatch in 1-24 h old eggs was significantly affected at 25 Gy and completely prevented at 100 Gy. At the age of 25-48 h, radiation sensitivity was only a little lower; egg hatch at 100 Gy was <1% and at 125 Gy no egg hatch was observed. Egg sensitivity to gamma irradiation decreased significantly in the 49-72 h age group; egg hatch was 66% at 100 Gy, and 500 Gy did not completely stop egg hatch (<1%). Eggs irradiated a few hours before egg hatch (73-96 h old) were the most resistant; 150 Gy had no significant effect on egg hatch and at 600 Gy over 33% of the eggs hatched. When pupation or adult emergence was used as a criterion for measuring effectiveness, however, the effects of gamma radiation were very severe. In the most resistant age group (73-96 h old), 150 Gy completely prevented pupation and adult emergence and all larvae resulting from eggs irradiated <49 h old died before pupation. In addition, the rate of development of immature stages resulting from irradiated eggs was negatively affected and sex ratio was skewed in favor of males.

  11. Comparison of Life History Characteristics of the Genetically Modified OX513A Line and a Wild Type Strain of Aedes aegypti

    Science.gov (United States)

    Bargielowski, Irka; Nimmo, Derric; Alphey, Luke; Koella, Jacob C.

    2011-01-01

    The idea of implementing genetics-based insect control strategies modelled on the traditional SIT (Sterile Insect Technique), such as RIDL (Release of Insects carrying a Dominant Lethal), is becoming increasingly popular. In this paper, we compare a genetically modified line of Aedes aegypti carrying a tetracycline repressible, lethal positive feedback system (OX513A) with a genetically similar, unmodified counterpart and their respective responses to increasing larval rearing density using a constant amount of food per larva. The parameters that we examined were larval mortality, developmental rate (i.e., time to pupation), adult size and longevity. Analysis revealed some statistically significant differences between the life history traits we examined. The genetically modified OX513A line overall showed 5% lower larval survival as well as reduced adult longevity (20 vs 24 days mean lifespan) compared to the unmodified line. Furthermore, the OX513A line pupated about one day sooner, which could be advantageous in mass-rearing, but produced somewhat smaller adults than the unmodified line; this effect was more pronounced in females than in males. Increasing the larval rearing density delayed pupation, decreased adult longevity and reduced adult size in both lines. While the delay in pupation and the decrease in longevity were similar between the two lines, the decrease in adult size was more pronounced for OX513A males. Our study shows that in a controlled laboratory situation the transgenic sterile OX513A line may have somewhat reduced performance compared to its unmodified counterpart and that high rearing densities may further reduce performance. Laboratory-based cage trials as well as field trials are necessary to assess how the differences in life history traits documented here impact the males' success upon release. Furthermore, this paper highlights the potential value of optimisation of mass-rearing systems as optimised rearing methods may be able to

  12. Susceptibility of the leaf-eating beetle, Galerucella calmariensis, a biological control agent for purple loosestrife (Lythrum salcaria), to three mosquito control larvicides

    Science.gov (United States)

    Lowe, T.P.; Hershberger, T.D.

    2004-01-01

    We evaluated the susceptibility of Galerucella calmariensis, a species used to control purple loosestrife (Lythrum salicaria), to three mosquito control larvicides. Larvae and adults were fed loosestrife cuttings dipped in Abate? (3.75 g?L-1) was reduced significantly and survival was significantly lower among larvae and adults eating cuttings dipped in Abate (>0.17 g?L-1 and >2.27 g?L-1, respectively). Hatching success of eggs dipped in Altosid (>2.52 g?L-1) was reduced significantly. With exposure to Altosid, larval survival to pupation and adult emergence was reduced significantly at concentrations of >2.92 g?L-1 and >0.63 g?L-1, respectively. Altosid (>0.23 g?L-1) also delayed the onset of pupation and adult emergence among larvae that survived to pupate. Larvae that survived with exposure to Altosid (>1.72 g?L-1) grew to 70% larger than those exposed to lower concentrations. Pupal survival was unaffected with exposure to Abate and Altosid and adult survival was unaffected with exposure to Altosid. Bacillus thuringiensis var israeliensis did not adversely affect any life stage of G. calmariensis. The mean Abate concentration on cuttings exposed to operational spraying was in the range that reduced egg hatchability and adult survival but was higher than concentrations that caused complete mortality of larvae. The mean Altosid concentration on cuttings exposed to operational spraying was in the range that reduced hatching success in eggs and delayed pupation and adult emergence of larvae.

  13. The Toxicology, Environmental Fate, and Human Risk of Herbicide Orange and Its Associated Dioxin

    Science.gov (United States)

    1978-10-01

    TCDD VI-6 C. Trichlorophenol (TCP), 2,4,5-T and TCDD VI-12 D. Cancer VI-27 IV. CONCLUSIONS VI-28 A. Pharmacodynamics VI-28 B. Effects of the Herbicides...effect on pupation of the mosquito larvae, but reduced the reproductive successes of the pulmonate snail and the oligochaete worm. Norris and Miller (48...Dalgaard-Mikkelsen and Poulsen (29); and the International Agency For Research on Cancer (IARC) Monograph, Vol 15 (66) although other recent

  14. Desenvolvimento pós-embrionário do intestino médio de Dermatobia hominis (Linnaeus Jr. (Diptera, Cuterebridae Post-embryonic development of Dermatobia hominis (Linnaeus Jr. (Diptera, Cuterebridae midgut

    Directory of Open Access Journals (Sweden)

    Edy de Lello

    2001-03-01

    Full Text Available Dermatobia hominis (Linnaeus, 1781 midgut is internally lined by an epithelium of polytenic cells, some low others prismatic with well developed brush border. Their apical portion are enlarged by secretory vesicles, forming button-like structures that are pinched off to the lumen, some accompained by the nucleus characterizing apocrine and holocrine secretions. This epithelium is gradually renewed by small, non polytenic regenerative cells, found scattered at its basal portion. At the end of the third instar the metamorphosis begins. The epithelial cells present signs of degeneration and at the first day of pupation the regenerative cells increase in number. By the 5th day of pupation these regenerative cells, besides being increased in number, differentiate themselves into two layers: one similar to the dense conective tissue that sustainning the larval epithelium is pinched off to the midgut lumen forming the "yellow bodies"; the other, develops right under it as the imaginal epitelium. The disorganized muscles bundles of the midgut wall, are invaded by phagocytes. At the end of pupation the midgut has a low prismatic epithelium with brush-border. In the adult, the torax portion of the midgut has prismatic homogeneously basophilic epithelium while in the abdominal portion the epithelium is made of high prismatic cells full of small vacuoles. The larval midgut epithelium suffers programmed cell death non compatible with apoptose. During the metamorphosis the midgut lenght diminishes from 31mm in the larva to 14mm in the adult.

  15. Adopting Bacteria in Order to Adapt to Water—How Reed Beetles Colonized the Wetlands (Coleoptera, Chrysomelidae, Donaciinae

    Directory of Open Access Journals (Sweden)

    Birgit Kleinschmidt

    2011-12-01

    Full Text Available The present paper reviews the biology of reed beetles (Donaciinae, presents experimental data on the role of specific symbiotic bacteria, and describes a molecular method for the detection of those bacteria. Reed beetles are herbivores living on wetland plants, each species being mono- or oligo-phagous. They lay their eggs on the host plant and the larvae live underwater in the sediment attached to its roots. The larvae pupate there in a water-tight cocoon, which they build using a secretion that is produced by symbiotic bacteria. The bacteria are located in four blind sacs at the foregut of the larvae; in (female adults they colonize two out of the six Malpighian tubules. Tetracycline treatment of larvae reduced their pupation rate, although the bacteria could not be fully eliminated. When the small amount of bacterial mass attached to eggs was experimentally removed before hatching, symbiont free larvae resulted, showing the external transmission of the bacteria to the offspring. Specific primers were designed to detect the bacteria, and to confirm their absence in manipulated larvae. The pupation underwater enabled the reed beetles to permanently colonize the wetlands and to diversify in this habitat underexploited by herbivorous insects (adaptive radiation.

  16. Estudo da dispersão larval radial pós-alimentar em Chrysomya megacephala (Fabricius (Diptera, Calliphoridae

    Directory of Open Access Journals (Sweden)

    Gomes Leonardo

    2003-01-01

    Full Text Available Blowflies utilize discrete and ephemeral sites for breeding and larval nutrition. After the exhaustion of food, the larvae begin dispersing to search for sites to pupate or to additional food source, process referred as postfeeding larval dispersal. Some of the most important aspects of this process were investigated in Chrysomya megacephala, utilizing a circular arena to permit the radial dispersion of larvae from the center. To determinate the localization of each pupa, the arena was split in 72 equal sectors from the center. For each pupa, distance from the center of arena, weight and depth were determined. Statistical tests were performed to verify the relation among weight, depth and distance of burying for pupation. It was verified that the larvae that disperse farther are those with higher weights. The majority of individuals reached the depth of burying for pupation between 7 and 18 cm. The study of this process of dispersion can be utilized in the estimation of postmortem interval (PMI for human corpses in medico-criminal investigations.

  17. Aconitase and Developmental End Points as Early Indicators of

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    Oleksandr Vasyliovuch Lozinsky

    2014-03-01

    Full Text Available Background: In this study, the toxicity of the different xenobiotics was tested on the fruit fly Drosophila melanogaster model system. Methods: Fly larvae were raised on food supplemented with xenobiotics at different concentrations (sodium nitroprusside (0.1-1.5 mM, S-nitrosoglutathione (0.5-4 mM, and potassium ferrocyanide (1 mM. Emergence of flies, food intake by larvae, and pupation height preference as well as aconitase activity (in 2-day old flies were measured. Results: Food supplementation with xenobiotics caused a developmental delay in the flies and decreased pupation height. Biochemical analyses of oxidative stress markers and activities of antioxidants and their associated enzymes were carried out on 2-day-old flies emerged from control larvae and larvae fed on food supplemented with chemicals. Larval exposure to chemicals resulted in lower activities of aconitase in flies of both sexes and perturbation in activities of antioxidant enzymes. Conclusions: The results of this study showed that among a variety of parameters tested, aconitase activity, developmental endpoints, and pupation height may be used as reliable early indicators of toxicity caused by different chemicals.

  18. Sexual selection drives the evolution of limb regeneration in Harmonia axyridis (Coleoptera: Coccinellidae).

    Science.gov (United States)

    Wang, S; Tan, X L; Michaud, J P; Shi, Z K; Zhang, F

    2015-04-01

    When Harmonia axyridis larvae were subjected to amputation of a foreleg in the fourth instar, 83% survived and, of these, 75% regenerated the leg during pupation. Regenerators pupated at heavier weights than controls (unoperated) or non-regenerators, and spent longer in pupation. Regenerated males were preferred by females in choice tests and produced more viable progeny than control males. Unregenerated males were less preferred by females, copulated for shorter periods than control males, and reduced female fecundity. Amputation diminished beneficial paternal effects, whether males regenerated or not, resulting in progeny with slower development and smaller adult body mass relative to control paternity. Progeny of unregenerated males had lower survival and body mass, whether male or female, confirming that regeneration was an honest signal of mate quality. When offspring had a foreleg amputated, a regenerated paternity yielded higher survival than control paternity, but similar rates of regeneration, whereas an unregenerated paternity yielded lower rates of survival and leg regeneration than control paternity. Regenerating beetles were twice as likely to be melanic as non-regenerating or control beetles, suggesting pleiotropic effects of melanism on processes involved in regeneration. This is the first report of complete limb regeneration by a holometabolous insect in the pupal stage, and the first example of sexual selection for regenerative capacity.

  19. Variability in development of the striped rice borer, Chilo suppressalis (Lepidoptera: Pyralidae), due to instar number and last instar duration

    Science.gov (United States)

    Luo, Guang-Hua; Yao, Jing; Yang, Qiong; Zhang, Zhi-Chun; Hoffmann, Ary A.; Fang, Ji-Chao

    2016-01-01

    The striped stem borer, Chilo suppressalis (Walker), is an important insect pest of rice which shows substantial variation in developmental duration among individuals. This variation is currently poorly characterized but it is important from a control perspective because pesticides can only target early sensitive instars. It is unclear whether there are key stages that determine the length of developmental duration of individuals and/or whether variation in instar number contributes to this variation. In this study, a laboratory population and a population recently established from the field were used to test variation in development time across instar stages. The duration of developmental time of C. suppressalis started to diverge from the 5th instar onward. Individuals pupated at the 5th, 6th, 7th or even 8th instar stage. In both populations, both the instar at which the larva pupated and the duration of the last larval instar stage determined total developmental time of an individual. There was little impact of the developmental time of early instars on total developmental duration or on instar number prior to pupation. Sex influenced the number of instars but not development time within this number. The biological and applied significance of uneven development in C. suppressalis are discussed. PMID:27731388

  20. A parasitoid wasp induces overwintering behaviour in its spider host.

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    Stanislav Korenko

    Full Text Available Parasites and parasitoids control behaviors of their hosts. However, the origin of the behavior evoked by the parasitic organism has been rarely identified. It is also not known whether the manipulation is universal or host-specific. Polysphinctine wasps, koinobiont ectoparasitoids of several spider species that manipulate host web-spinning activity for their own protection during pupation, provide an ideal system to reveal the origin of the evoked behavior. Larva of Zatypota percontatoria performed species-specific manipulation of theridiid spiders, Neottiura bimaculata and Theridion varians, shortly before pupation. Parasitized N. bimaculata produced a dense web, whereas parasitized T. varians built a cupola-like structure. The larva pupated inside of either the dense web or the cupola-like structure. We discovered that unparasitized N. bimaculata produce an analogous dense web around their eggsacs and for themselves during winter, while T. varians construct an analogous 'cupola' only for overwintering. We induced analogous manipulation in unparasitized hosts by altering ambient conditions. We discovered that the behavior evoked by larvae in two hosts was functionally similar. The larva evoked protective behaviors that occur in unparasitized hosts only during specific life-history periods.

  1. Potential of biologically active plant oils to control mosquito larvae (Culex pipiens, Diptera: Culicidae) from an Egyptian locality.

    Science.gov (United States)

    Khater, Hanem Fathy; Shalaby, Afaf Abdel-Salam

    2008-01-01

    The insecticidal effect of six commercially available plant oils was tested against 4th larval instars of Culex pipiens. Larvae were originally collected from Meit El-Attar, Qalyubia Governorate, Egypt, and then reared in the laboratory until F1 generation. The LC50 values were 32.42, 47.17, 71.37, 83.36, 86.06, and 152.94 ppm for fenugreek (Trigonella foenum-grecum), earth almond (Cyperus esculentus), mustard (Brassica compestris), olibanum (Boswellia serrata), rocket (Eruca sativa), and parsley (Carum ptroselinum), respectively. The tested oils altered some biological aspects of C. pipiens, for instance, developmental periods, pupation rates, and adult emergences. The lowest concentrations of olibanum and fenugreek oils caused remarkable prolongation of larval and pupal durations. Data also showed that the increase of concentrations was directly proportional to reduction in pupation rates and adult emergences. Remarkable decrease in pupation rate was achieved by mustard oil at 1000 ppm. Adult emergence was suppressed by earth almond and fenugreek oils at 25 ppm. In addition, the tested plant oils exhibited various morphological abnormalities on larvae, pupae, and adult stages. Consequently, fenugreek was the most potent oil and the major cause of malformation of both larval and pupal stages. Potency of the applied plant oils provided an excellent potential for controlling C. pipiens.

  2. Effects of in situ climate warming on monarch caterpillar (Danaus plexippus) development

    Science.gov (United States)

    Capdevielle, Jillian N.; Parker, John D.

    2015-01-01

    Climate warming will fundamentally alter basic life history strategies of many ectothermic insects. In the lab, rising temperatures increase growth rates of lepidopteran larvae but also reduce final pupal mass and increase mortality. Using in situ field warming experiments on their natural host plants, we assessed the impact of climate warming on development of monarch (Danaus plexippus) larvae. Monarchs were reared on Asclepias tuberosa grown under ‘Ambient’ and ‘Warmed’ conditions. We quantified time to pupation, final pupal mass, and survivorship. Warming significantly decreased time to pupation, such that an increase of 1 °C corresponded to a 0.5 day decrease in pupation time. In contrast, survivorship and pupal mass were not affected by warming. Our results indicate that climate warming will speed the developmental rate of monarchs, influencing their ecological and evolutionary dynamics. However, the effects of climate warming on larval development in other monarch populations and at different times of year should be investigated. PMID:26528403

  3. Atrazine exposure affects longevity, development time and body size in Drosophila melanogaster.

    Science.gov (United States)

    Marcus, Sarah R; Fiumera, Anthony C

    2016-01-01

    Atrazine is the one of the most widely used herbicides in the United States and non-target organisms may encounter it in the environment. Atrazine is known to affect male reproduction in both vertebrates and invertebrates but less is known about its effects on other fitness traits. Here we assessed the effects of five different chronic exposure levels on a variety of fitness traits in Drosophila melanogaster. We measured male and female longevity, development time, proportion pupated, proportion emerged, body size, female mating rate, fertility and fecundity. Atrazine exposure decreased the proportion pupated, the proportion emerged and adult survival. Development time was also affected by atrazine and exposed flies pupated and emerged earlier than controls. Although development time was accelerated, body size was actually larger in some of the exposures. Atrazine exposure had no effect on female mating rate and the effects on female fertility and fecundity were only observed in one of the two independent experimental blocks. Many of the traits showed non-monotonic dose response curves, where the intermediate concentrations showed the largest effects. Overall this study shows that atrazine influences a variety of life history traits in the model genetic system, D. melanogaster, and future studies should aim to identify the molecular mechanisms of toxicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Reusing larval rearing water and its effect on development and quality of Anopheles arabiensis mosquitoes.

    Science.gov (United States)

    Mamai, Wadaka; Lees, Rosemary Susan; Maiga, Hamidou; Gilles, Jeremie R L

    2016-03-16

    There is growing interest in applying the sterile insect technique (SIT) against mosquitoes. Mass production of mosquitoes for large-scale releases demands a huge amount of water. Yet, many arid and/or seasonally arid countries face the difficulties of acute water shortage, deterioration of water quality and environmental constraints. The re-use of water to rear successive generations of larvae is attractive as a way to reduce water usage and running costs, and help to make this control method viable. To determine whether dirty larval water was a suitable rearing medium for Anopheles arabiensis, in place of the 'clean' dechlorinated water routinely used, a series of three experiments was carried out to evaluate the effect of dirty water or mixed clean and dirty water on several parameters of insect quality. Batches of 100 fresh eggs were distributed in dirty water or added to clean water to test the effect of dirty water on egg hatching, whereas first-instar larvae were used to determine the effect on immature development time, pupation, adult emergence, body size, and longevity. Moreover, to assess the effect of dirty water on larval mortality, pupation rate, adult emergence, and longevity, L4 larvae collected after the tilting or larvae/pupae separation events were returned either to the dirty water or added to clean water. Results indicated that reusing dirty water or using a 50:50 mix of clean and dirty water did not affect egg hatching. Moreover, no difference was found in time to pupation, larval mortality or sex ratio when first-instar larvae were added to clean water, dirty water, or a 75:25, 50:50 or 25:75 mix of clean and dirty water and reared until emergence. When late-instar larvae were put back into their own rearing water, there was no effect on pupation rate, emergence rate or female longevity, though male longevity was reduced. When reared from first-instar larvae, however, dirty water decreased pupation rate, emergence rate, body size, and adult

  5. Drosophila nociceptors mediate larval aversion to dry surface environments utilizing both the painless TRP channel and the DEG/ENaC subunit, PPK1.

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    Wayne A Johnson

    Full Text Available A subset of sensory neurons embedded within the Drosophila larval body wall have been characterized as high-threshold polymodal nociceptors capable of responding to noxious heat and noxious mechanical stimulation. They are also sensitized by UV-induced tissue damage leading to both thermal hyperalgesia and allodynia very similar to that observed in vertebrate nociceptors. We show that the class IV multiple-dendritic(mdIV nociceptors are also required for a normal larval aversion to locomotion on to a dry surface environment. Drosophila melanogaster larvae are acutely susceptible to desiccation displaying a strong aversion to locomotion on dry surfaces severely limiting the distance of movement away from a moist food source. Transgenic inactivation of mdIV nociceptor neurons resulted in larvae moving inappropriately into regions of low humidity at the top of the vial reflected as an increased overall pupation height and larval desiccation. This larval lethal desiccation phenotype was not observed in wild-type controls and was completely suppressed by growth in conditions of high humidity. Transgenic hyperactivation of mdIV nociceptors caused a reciprocal hypersensitivity to dry surfaces resulting in drastically decreased pupation height but did not induce the writhing nocifensive response previously associated with mdIV nociceptor activation by noxious heat or harsh mechanical stimuli. Larvae carrying mutations in either the Drosophila TRP channel, Painless, or the degenerin/epithelial sodium channel subunit Pickpocket1(PPK1, both expressed in mdIV nociceptors, showed the same inappropriate increased pupation height and lethal desiccation observed with mdIV nociceptor inactivation. Larval aversion to dry surfaces appears to utilize the same or overlapping sensory transduction pathways activated by noxious heat and harsh mechanical stimulation but with strikingly different sensitivities and disparate physiological responses.

  6. Efifciency of Different Methods for dsRNA Delivery in Cotton Bollworm (Helicoverpa armigera)

    Institute of Scientific and Technical Information of China (English)

    YANG Jing; HAN Zhao-jun

    2014-01-01

    RNAi trigged by dsRNA not only facilitates the development of molecular biology, but also initiates a new way for pest control by silence of fatal genes. However, one of the key limitations in pest control is lack of the convenient and efifcient method for dsRNA delivery. In this study, different dsRNA delivery methods at their own optimum conditions were evaluated comparatively for their efifciency with Helicoverpa armigera as test animal. It was found that the popular one-time injection of larvae with dsRNA could reduce the pupation rate by 43.0%and enhance larva mortality by 11.7%. One-time ingestion of dsRNA did not result in any signiifcant effect on phenotype. Continuous ingestion of in vitro synthesized dsRNA by refreshing the bait diet every day caused 40.4% decrease in successful pupation and 10.0% increase in larval mortality, which was similar as one-time injection. The most efifcient method was found to be the continuous ingestion of the bacteria containing dsRNA expressed, which reduced the rate of pupation by 68.7%and enhanced the larval mortality by 34.1%. Further analysis found that dsRNA was degraded faster in midgut juice than in hemolymph. However, the cell of bacteria could protect dsRNA and delay the degradation in the midgut juice of H. armigera. These results throw light on the application of dsRNA in pest management with proper ways.

  7. Multi-year survival of sugarbeet root maggot (Tetanops myopaeformis) larvae in cold storage.

    Science.gov (United States)

    Chirumamilla, Anitha; Yocum, George D; Boetel, Mark A; Dregseth, Robert J

    2008-04-01

    To test the hypothesis that long-term survival of sugarbeet root maggot in storage is facilitated by larvae undergoing prolonged diapause, respiration and gene expression patterns of field-collected diapausing larvae were compared with those of 1-, 2-, and 5-year laboratory-stored larvae. Additional assessments were made on post-storage survival, emergence, and reproductive fitness of stored larvae. Respirometry, carried out at 5 and 20 degrees C revealed no differences among respiration rates of initially diapausing and long-term stored larvae. A 15 degrees increase in temperature elevated respiration in both diapausing and stored larvae, with levels of CO2 release ranging between 8- and 14-fold higher at 20 degrees C than at 5 degrees C. Similarly, 6-10-fold increases in O2 consumption levels were observed at the higher temperature. A transcript with sequence similarity to the fat body protein 2 (Fbp2) gene was highly expressed in diapausing larvae, and trace levels were expressed in some samples of 1-year stored larvae. However, no expression was detected in 2- and 5-year stored larvae. Survival and emergence studies of stored larvae revealed mixed populations of diapausing (i.e., the 5-17% of larvae that did not pupate) and post-diapausing (62-84% of larvae pupated) insects, with a high incidence of pupation (62%) and emergence (47%), even after 4 years in cold storage. Therefore, extended survival of Tetanops myopaeformis larvae in long-term cold storage is facilitated by two mechanisms, with a majority of larvae in post-diapause quiescence and a smaller fraction in a state of prolonged diapause.

  8. Host exploitation strategies of the social parasite Maculinea alcon

    DEFF Research Database (Denmark)

    Fürst, Matthias Alois

    . Throughout the first instars M. alcon lives on a specific food plant, however, in the last instar before pupation it develops into an obligate social parasite, posing a considerably cost to its host ant colony. I here focus on the different exploitation strategies of M. alcon throughout its lifecycle...... into the nest where it will feed on ant regurgitations and ant brood. It is thus crucial for the caterpillar's survival to attract the host ant, get picked up and brought back to the ant's colony. My study shows that 3rd and 4th instar caterpillars are distinct from each other not only morphologically but also...

  9. The contribution of ancestry, chance, and past and ongoing selection to adaptive evolution

    Indian Academy of Sciences (India)

    Amitabh Joshi; Robinson B. Castillo; Laurence D. Mueller

    2003-12-01

    The relative contributions of ancestry, chance, and past and ongoing selection to variation in one adaptive (larval feeding rate) and one seemingly nonadaptive (pupation height) trait were determined in populations of Drosophila melanogaster adapting to either low or high larval densities in the laboratory. Larval feeding rates increased rapidly in response to high density, and the effects of ancestry, past selection and chance were ameliorated by ongoing selection within 15–20 generations. Similarly, in populations previously kept at high larval density, and then switched to low larval density, the decline of larval feeding rate to ancestral levels was rapid (15–20 generations) and complete, providing support for a previously stated hypothesis regarding the costs of faster feeding in Drosophila larvae. Variation among individuals was the major contributor to variation in pupation height, a trait that would superficially appear to be nonadaptive in the environmental context of the populations used in this study because it did not diverge between sets of populations kept at low versus high larval density for many generations. However, the degree of divergence among populations ($F_{\\text{ST}}$) for pupation height was significantly less than expected for a selectively neutral trait, and we integrate results from previous studies to suggest that the variation for pupation height among populations is constrained by stabilizing selection, with a flat, plateau-like fitness function that, consequently, allows for substantial phenotypic variation within populations. Our results support the view that the genetic imprints of history (ancestry and past selection) in outbreeding sexual populations are typically likely to be transient in the face of ongoing selection and recombination. The results also illustrate the heuristic point that different forms of selection—for example directional versus stabilizing selection—acting on a trait in different populations may

  10. Irradiation of Ceratitis capitata, Anastrepha fraterculus and Anastrepha obliqua larvae (Diptera: Tephritidae) on an artificial diet; Irradiacao de larvas de Ceratitis capitata, Anastrepha fraterculus e Anastrepha obliqua (Diptera: Tephritidae) em dieta artificial

    Energy Technology Data Exchange (ETDEWEB)

    Raga, A.; Sato, M.E.; Suplicy Filho, N.; Potenza, M.R. [Instituto Biologico, Sao Paulo, SP (Brazil); Yamazaki, M.C.R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1992-01-01

    The aim of the experiment was to establish gamma radiation dose levels sufficient to prevent the emergence of adults, and thus to serve as parameters for disinfestation of hosts of the fruit-flies Ceratitis capitata, Anastrepha fraterculus, and Anastrepha obliqua. Four-, 5,6-, and 7-day-old larvae of the 3 species were tested. Pupation was unaffected by 40 Gy for C. capitata, and by 100 Gy for A. fraterculus and A. obliqua. Gamma radiation doses necessary to prevent development of adults from larvae were 30 Gy, 20 Gy and 20 Gy for C. capitata, A. obliqua respectively. (author). 10 refs, 6 tabs.

  11. Immature stages of the butterfly Diaethria clymena janeira (Lepidoptera: Nymphalidae: Biblidinae

    Directory of Open Access Journals (Sweden)

    Eduardo P. Barbosa

    2010-10-01

    Full Text Available The immature stages (egg, larva, and pupa morphology, larval and oviposition behavior, and host plant of the "eighty-eight" butterfly Diaethria clymena janeira (C. Felder, 1862 are described. Eggs are laid singly under leaf, and have pronounced vertical ribs ending up in a crown. Larvae of early instars construct stick-like frass chains where they rest when not feeding. Late instars are green with reduced body scoli and long branched head scoli. Pupae are entirely green, and pupation occurs on the upper leaf surface. In general, morphology and behavior of immature stages are similar to those of related species in the tribe Callicorini.

  12. Study on the biological characteristics of Homalotglus flaminus

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Homalotglus flaminus (Dalman) is an important natural enemy of the Chilocorus kuwanae. Its biological characteristic, life history, the action style on hosts were studied at Hongqi Forest Farm, Daqing City, Heilongjiang Province from June 1998 to October 2000, in order to control H. flaminus and raise the control ability of Chilocorus kuwanae to Quadraspidiotus gigas pest. The observed results indicated that H. flaminus has two generation one year in study area, the pupating span is 12.7 d, life span of females and males is 17.6 d and 10.8 d respectively, egg span is 10 d, and the sex ratio of females to males is 1:3.

  13. Postfeeding radial dispersal in larvae of Chrysomya albiceps (Diptera: Calliphoridae): implications for forensic entomology.

    Science.gov (United States)

    Gomes, Leonardo; Zuben, Claudio José Von

    2005-12-01

    Blowflies utilize discrete and ephemeral breeding sites for larval nutrition. After the exhaustion of food, larvae begin dispersing in search of sites to pupate or additional food sources, a process referred as postfeeding larval dispersal. Some of the most important aspects of this process were investigated in the blowfly Chrysomya albiceps, employing a circular arena to allow radial dispersion of larvae from the center. The results showed a positive correlation between burial depth and distance, and a negative correlation between distance and pupal weight. These results can be used in forensic entomology for the postmortem interval estimation of human corpses in medico-criminal investigations.

  14. Molecular cloning, genomic organization, and developmental regulation of a novel receptor from Drosophila melanogaster structurally related to members of the thyroid-stimulating hormone, follicle-stimulating hormone, luteinizing hormone/choriogonadotropin receptor family from mammals

    DEFF Research Database (Denmark)

    Hauser, F; Nothacker, H P; Grimmelikhuijzen, C J

    1997-01-01

    Using oligonucleotide probes derived from consensus sequences for glycoprotein hormone receptors, we have cloned an 831-amino acid residue-long receptor from Drosophila melanogaster that shows a striking structural homology with members of the glycoprotein hormone (thyroid-stimulating hormone (TSH...... until after pupation. Adult male flies express high levels of receptor mRNA, but female flies express about 6 times less. The expression pattern in embryos and larvae suggests that the receptor is involved in insect development. This is the first report on the molecular cloning of a glycoprotein hormone...

  15. Effect of some botanical materials on certain biological aspects of the house fly, Musca domestica L

    Directory of Open Access Journals (Sweden)

    Nabawy A. I. Elkattan, Khalafalla S. Ahmed, Saadya M. Elbermawy and Rabab

    2011-04-01

    Full Text Available The effects of Lantana camara (leaves, Pelargonium zonale (leaves, Cupressus macrocarpa (leaves, Cyperus rotundus (whole plant and Acacia nilotica (seeds powders on some biological aspects of house fly, M. domestica L. were tested. The effects of three lethal concentrations LC25, LC50 and LC75 on the larval duration, pupation percent, pupal weight, pupal duration, adult emergence percent, sex ratio, adult longevity, and fecundity were determined. The induced malformed larvae, pupae and adults were recorded and photographed. The powders of the five plants were found to have promising effects in controlling this insect.

  16. Reproducción de Oenomaus ortignus (Lepidoptera: Lycaenidae en Barva, Heredia, Costa Rica

    Directory of Open Access Journals (Sweden)

    Renán Calvo

    1998-03-01

    Full Text Available A group of Annona cherimolia (Mill:Annonaceae trees was studied in Barva, Heredia, Costa Rica (June 1991-August 1992 to record egg-laying sites of the butterfly Oenomaus ortignus (Lepidoptera: Lycaenidae. Used fruits often dehydrated and fell before maturity. Eggs are laid in fruits independently of fruit ontologic state and of height above ground. Tree parts less frequently used to lay eggs are flower primordia, leaves and stems, but the larvae move to fruits when food reserves are depleted. Pupation occurs outside the fruit. Pupae emit sound, possible for defence.

  17. Report of the Insect Development Group

    Science.gov (United States)

    Rockstein, M.

    1985-01-01

    Drosophila metanogaster was chosen as the insect species of choice, in regard to gravity response experiments involving normal reproduction and develop different strains. The specific gravity responses which might be affected by microgravity and are exhibited in normal reproduction and development include normal flight for courtship, mating and oviposition, tropisms for pupating or emergency of the adult, and crawling for gettering food by the larval instars at the organismic level. At the suborganismic elevel, it is believed that maturation of developing eggs in the virgin female and embryonic development of the developing egg could be affected by microgravity and warrant study.

  18. Ovis aries (Artiodactyla: Bovidae e Capra hircus (Artiodactyla: Bovidae parasitados por Oestrus ovis (Diptera: Oestridae no Distrito Federal, Brasil

    Directory of Open Access Journals (Sweden)

    Edison Cansi

    2011-12-01

    Abstract. The Oestrosis is an obligatory and cavitary myiasis of sheep and goat, wild and domestic, caused by the larvae of Oestrus ovis (Linnaeus fly. This study records the presence of O. ovis in the West Central region of Brazil as parasites of goats and sheep. We obtained six larvae from sheep and goats with suspects of oestrosis in Brasília (Brazil originate two females adult of O. ovis, after 20 and 23 days respectively of pupation. This finding is probably associated with expansion and diversification of farming in the Cerrado of the Brazilian central plateau.

  19. Snowdrop lectin (GNA) has no acute toxic effects on a beneficial insect predator, the 2-spot ladybird (Adalia bipunctata L.).

    Science.gov (United States)

    Down, R E.; Ford, L; Woodhouse, S D.; Raemaekers, R J.M.; Leitch, B; Gatehouse, J A.; Gatehouse, A M.R.

    2000-04-01

    Two-spot ladybird (Adalia bipunctata L.) larvae were fed on aphids (Myzus persicae (Sulz.)) which had been loaded with snowdrop lectin (Galanthus nivalis agglutinin; GNA) by feeding on artificial diet containing the protein. Treatment with GNA significantly decreased the growth of aphids. No acute toxicity of GNA-containing aphids towards the ladybird larvae was observed, although there were small effects on development. When fed a fixed number of aphids, larvae exposed to GNA spent longer in the 4th instar, taking 6 extra days to reach pupation; however, retardation of development was not observed in ladybird larvae fed equal weights of aphids. Ladybird larvae fed GNA-containing aphids were found to be 8-15% smaller than controls, but ate a significantly greater number of aphids (approx. 40% to pupation). GNA was shown to be present on the microvilli of the midgut brush border membrane and within gut epithelial cells in ladybird larvae fed on GNA-dosed aphids, although disruption of the brush border was not observed. It is hypothesised that GNA does not have significant direct toxic or adverse effects on developing ladybird larvae, but that the effects observed may be due to the fact that the aphids fed on GNA are compromised and are thus a suboptimal food.

  20. Cannibalism of Helicoverpa zea (Lepidoptera: Noctuidae) from Bacillus thuringiensis (Bt) transgenic corn versus non-Bt corn.

    Science.gov (United States)

    Chilcutt, Charles F

    2006-06-01

    Because of the importance of cannibalism in population regulation of Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) in corn, Zea mays L., it is useful to understand the interactions between Bacillus thuringiensis (Bt) transgenic corn and cannibalism. To determine the effects of Bt corn on cannibalism in H. zea, pairs of the same or different instars were taken from Bt or non-Bt corn and placed on artificial diet in proximity. Cannibalism occurred in 91% of pairs and was approximately 7% greater for pairs of larvae reared from Bt transgenic corn (95%) than from non-Bt corn (88%). Also, first instar by first instar pairs had a lower rate of cannibalism than other pairs. Time until cannibalism was not different for larvae from Bt corn versus non-Bt corn. Pupation rate of cannibals and surviving victims was not different for pairs from Bt corn versus non-Bt corn. Finally, cannibalism increased pupation rate of cannibals from both Bt and non-Bt corn by approximately 23 and 12%, respectively, although the increases were not significant. Thus, negative effects of Bt on larvae were compensated by increased cannibalism in comparison with larvae reared on non-Bt corn, which increased larval survival to levels comparable with larvae reared on non-Bt plants.

  1. Chemically mediated group formation in soil-dwelling larvae and pupae of the beetle Trypoxylus dichotomus

    Science.gov (United States)

    Kojima, Wataru; Ishikawa, Yukio; Takanashi, Takuma

    2014-09-01

    Many insects form groups through interactions among individuals, and these are often mediated by chemical, acoustic, or visual cues and signals. In spite of the diversity of soil-dwelling insects, their aggregation behaviour has not been examined as extensively as that of aboveground species. We investigated the aggregation mechanisms of larvae of the Japanese rhinoceros beetle Trypoxylus dichotomus, which live in groups in humus soil. In two-choice laboratory tests, 2nd- and 3rd-instar larvae gathered at conspecific larvae irrespective of the kinship. The ablation of maxillae, which bear chemosensilla, abolished aggregation behaviour. Intact larvae also exhibited aggregation behaviour towards a larval homogenate. These results suggest that larval aggregation is mediated by chemical cues. We also demonstrated that the mature larvae of T. dichotomus built their pupal cells close to a mesh bag containing a conspecific pupal cell, which indicated that larvae utilize chemical cues emanating from these cells to select the pupation site. Thus, the larvae of T. dichotomus may use chemical cues from the conspecifics in two different contexts, i.e. larval aggregation and pupation site selection. Using conspecific cues, larvae may be able to choose suitable locations for foraging or building pupal cells. The results of the present study highlight the importance of chemical information in belowground ecology.

  2. Insulin-like growth factor (IGF)-like peptide and 20-hydroxyecdysone regulate the growth and development of the male genital disk through different mechanisms in the silkmoth, Bombyx mori.

    Science.gov (United States)

    Fujinaga, Daiki; Kohmura, Yusuke; Okamoto, Naoki; Kataoka, Hiroshi; Mizoguchi, Akira

    2017-08-01

    It is well established that ecdysteroids play pivotal roles in the regulation of insect molting and metamorphosis. However, the mechanisms by which ecdysteroids regulate the growth and development of adult organs after pupation are poorly understood. Recently, we have identified insulin-like growth factor (IGF)-like peptides (IGFLPs), which are secreted after pupation under the control of 20-hydroxyecdysone (20E). In the silkmoth, Bombyx mori, massive amounts of Bombyx-IGFLP (BIGFLP) are present in the hemolymph during pupal-adult development, suggesting its importance in the regulation of adult tissue growth. Thus, we hypothesized that the growth and development of adult tissues including imaginal disks are regulated by the combined effects of BIGFLP and 20E. In this study, we investigated the growth-promoting effects of BIGFLP and 20E using the male genital disks of B. mori cultured ex vivo, and further analyzed the cell signaling pathways mediating hormone actions. We demonstrate that 20E induces the elongation of genital disks, that both hormones stimulate protein synthesis in an additive manner, and that BIGFLP and 20E exert their effects through the insulin/IGF signaling pathway and mitogen-activated protein kinase pathway, respectively. These results show that the growth and development of the genital disk are coordinately regulated by both BIGFLP and 20E. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Mitosis and cell death in the optic lobes of workers, queens and drones of the honey bee (Apis mellifera) during metamorphosis

    Indian Academy of Sciences (India)

    Thaisa Cristina Roat; Carminda Da Cruz Landim

    2010-09-01

    Colonies of the honey bee, Apis mellifera, consist of males and two female castes: workers and queens. The castes and males from A. mellifera have a distinct morphology, physiology and behaviour that correlate with their roles in the society and are characterized by some brain polymorphisms. Compound eyes are one of the characteristics that differ among the castes and sexes. A. mellifera is a holometabolous insect; therefore, the development of adult organs during metamorphosis, which will produce these differences, requires the precise coordination of three main programmed cellular processes: proliferation, differentiation and death. These processes take place simultaneously during pupation. Our purpose was to investigate cell division and death in the optic lobes (OL) of workers, queens and males during pupation to identify how the differences in the compound eyes in adults of these classes are achieved. The results showed that OL differentiation follows a similar pattern in the three classes of individuals studied, without structural differences in their development. The main non-structural differences involve cell division, mortality rates and timing. The results suggest a modelling of the brain during differentiation, which contributes to the specific functions of each individual class.

  4. Adaptation to larval crowding in Drosophila ananassae and Drosophila nasuta nasuta : increased larval competitive ability without increased larval feeding rate

    Indian Academy of Sciences (India)

    ARCHANA NAGARAJAN; SHARMILA BHARATHI NATARAJAN; MOHAN JAYARAM; ANANDA THAMMANNA; SUDARSHAN CHARI; JOY BOSE; SHREYAS V. JOIS; AMITABH JOSHI

    2016-06-01

    The standard view of adaptation to larval crowding in fruitflies, built on results from 25 years of multiple experimental evo-lution studies onDrosophila melanogaster , was that enhanced competitive ability evolves primarily through increased larvalfeeding and foraging rate, and increased larval tolerance to nitrogenous wastes, at the cost of efficiency of food conversion tobiomass. These results were at odds from the predictions of classicalK -selection theory, notably the expectation that selec-tion at high density should result in the increase of efficiency of conversion of food to biomass, and were better interpretedthrough the lens of α -selection. We show here that populations ofD. ananassaeandD. n. nasutasubjected to extreme larvalcrowding evolve greater competitive ability and pre-adult survivorship at high density, primarily through a combination ofreduced larval duration, faster attainment of minimum critical size for pupation, greater time efficiency of food conversion tobiomass and increased pupation height, with a relatively small role of increased urea/ammonia tolerance, if at all. This is avery different suite of traits than that seen to evolve under similar selection inD .melanogaster ,andseemstobeclosertotheexpectations from the canonical theory ofK -selection. We also discuss possible reasons for these differences in results acrossthe three species. Overall, the results reinforce the view that our understanding of the evolution of competitive ability in fruit-flies needs to be more nuanced than before, with an appreciation that there may be multiple evolutionary routes through whichhigher competitive ability can be attained.

  5. Use of grafting to prevent Hypsipyla grandella (Zeller) (Lepidoptera: Pyralidae) damage to new world Meliaceae species.

    Science.gov (United States)

    Perez, Julian; Eigenbrode, Sanford D; Hilje, Luko; Tripepi, Robert R; Aguilar, Maria E; Mesen, Francisco

    2010-01-01

    The susceptible species Cedrela odorata and Swietenia macrophylla to attack by Hypsipyla grandella (Zeller) larvae were grafted onto the resistant species Khaya senegalensis and Toona ciliata. Six-month-old grafted plants were then compared to their reciprocal grafts and to both intact (non-grafted) and autografted plants for damage due to H. grandella larvae and for their effects on larval performance. Two experiments were conducted: one in which the apical bud of the main plant shoot was inoculated with H. grandella eggs, and the other in which the bud was inoculated with third instars. Damage in each experiment was assessed by the number of frass piles, number and length of tunnels, number of damaged leaves, and damage to the apical bud. Larval performance was evaluated in terms of time to reach pupation and pupal weight and length. In both experiments, plant damage differed significantly among treatments (P grandella larvae. Scions of autografted susceptible species had similar resistance to susceptible scions grafted on resistant rootstocks. Few larvae reached pupation, and their pupal weight and length were similar.

  6. Intrapopulation Genome Size Variation in D. melanogaster Reflects Life History Variation and Plasticity

    Science.gov (United States)

    Ellis, Lisa L.; Huang, Wen; Quinn, Andrew M.; Ahuja, Astha; Alfrejd, Ben; Gomez, Francisco E.; Hjelmen, Carl E.; Moore, Kristi L.; Mackay, Trudy F. C.; Johnston, J. Spencer; Tarone, Aaron M.

    2014-01-01

    We determined female genome sizes using flow cytometry for 211 Drosophila melanogaster sequenced inbred strains from the Drosophila Genetic Reference Panel, and found significant conspecific and intrapopulation variation in genome size. We also compared several life history traits for 25 lines with large and 25 lines with small genomes in three thermal environments, and found that genome size as well as genome size by temperature interactions significantly correlated with survival to pupation and adulthood, time to pupation, female pupal mass, and female eclosion rates. Genome size accounted for up to 23% of the variation in developmental phenotypes, but the contribution of genome size to variation in life history traits was plastic and varied according to the thermal environment. Expression data implicate differences in metabolism that correspond to genome size variation. These results indicate that significant genome size variation exists within D. melanogaster and this variation may impact the evolutionary ecology of the species. Genome size variation accounts for a significant portion of life history variation in an environmentally dependent manner, suggesting that potential fitness effects associated with genome size variation also depend on environmental conditions. PMID:25057905

  7. Indirect evidence that agricultural pesticides select for insecticide resistance in the malaria vector Anopheles gambiae.

    Science.gov (United States)

    Luc, Djogbénou S; Benoit, Assogba; Laurette, Djossou; Michel, Makoutode

    2016-06-01

    We investigated the possible relationship between the agricultural use of insecticides and the emergence of insecticide resistance. Bioassays were conducted using simulated mosquito larval habitats and well known Anopheles gambiae strains. Soil samples were collected from vegetable production areas in Benin, including one site with insecticide use, one site where insecticides had not been used for two months, and a third where insecticides had not been used. Pupation and emergence rates were very low in pyrethroid-susceptible strains when exposed to soil that had been recently exposed to insecticides. Pupation and emergence rates in strains with the kdr mutation alone or both the kdr and Ace-1 mutations were much higher. Overall, strains with the kdr mutation survived at higher rates compared to that without kdr mutation. Although this study is observational, we provide indirect evidence indicating that soils from agricultural areas contain insecticide residues that can play a role in the emergence of insecticide resistance in Anopheles. This aspect should be taken into account to better utilize the insecticide in the context of integrated pest management programs.

  8. Juvenile hormone-mediated termination of larval diapause in the bamboo borer, Omphisa fuscidentalis.

    Science.gov (United States)

    Singtripop, T; Wanichacheewa, S; Sakurai, S

    2000-01-01

    Larvae of the bamboo borer, Omphisa fuscidentalis are in diapause for more than nine months (Singtripop, T., Wanichaneewa, S., Tsuzuki, S., Sakurai, S. 1999. Larval growth and diapause in a tropical moth, Omphisa fuscidentalis Hampson. Zool. Sci. 16, 725-733). To examine the endocrine mechanisms underlying this larval diapause, we assayed the responsiveness of the diapausing larvae to 20-hydroxyecdysone (20E) and a juvenile hormone analogue (JHA: S-methoprene). 20E injection caused the larvae to halt movement, followed by deposition of a pupal cuticle. Topical application of JHA induced pupation in a dose-dependent manner. JHA also induced pupation of the larvae whose brains were removed before JHA application. In those larvae, the prothoracic glands became active and competent to respond to brain extracts within seven days after JHA treatment, and the hemolymph ecdysteroid concentration began to increase 12 days after JHA application. These results indicate that JHA stimulates the prothoracic glands of diapausing Omphisa larvae, terminating larval diapause, in contrast with previous findings that JH inhibits the brain-prothoracic gland axis and thus maintains the larval diapause. Current results therefore suggest a novel regulatory mechanism for larval diapause in this species.

  9. X-ray radiation and development inhibition of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae)

    Science.gov (United States)

    Kim, Junheon; Jung, Soon-Oh; Jang, Sin Ae; Kim, Jeongmin; Park, Chung Gyoo

    2015-10-01

    Effect of X-ray radiation on the development inhibition was evaluated for all stages of the life cycle of Helicoverpa armigera to determine a radiation dose for potential quarantine treatment against the insect. ED99 values for inhibition of hatching, pupation, and adult emergence from irradiated eggs were 413, 210, and 154 Gy, respectively. ED99 values for inhibition of pupation and adult emergence from irradiated larvae were 221 and 167 Gy, respectively. Pupa was the most tolerant to X-ray radiation. ED99 value for inhibition of adult emergence from irradiated pupae was as high as 2310 Gy, whereas that for inhibition of F1 egg hatching was only 66 Gy. ED99 value for inhibition of hatching of F1 eggs which were laid by irradiated adults was estimated to 194 Gy. X-ray irradiation against H. armigera is recommended as an alternative method to methyl bromide fumigation for phytosanitary treatments during quarantine. X-ray radiation dose of 200 Gy is proposed as a potential quarantine treatment dose for H. armigera eggs and larvae.

  10. Minocycline treatment suppresses juvenile development and growth by attenuating insulin/TOR signaling in Drosophila animal model

    Science.gov (United States)

    Yun, Hyun Myoung; Noh, Sujin; Hyun, Seogang

    2017-01-01

    Minocycline is a broad spectrum, semi-synthetic tetracycline analog that is used to treat bacterial infection. Recently, this drug has been receiving increasing attention for its non-antibiotic properties, including anti-inflammatory, tumor suppressive, and neuroprotective effects. Drosophila is a useful model organism for studying human metabolism and disease. In this study, we investigated the effects of minocycline on juvenile development and growth in Drosophila. Feeding minocycline to Drosophila larvae suppresses larval body growth and delays the timing of pupation in a dose-dependent manner. We found that the drug treatment decreased the activated form of Akt and S6K in peripheral tissues, which suggested that the insulin/target of rapamycin (TOR) signaling had been attenuated. Specifically enhancing TOR activity in the prothoracic gland (PG), the ecdysone-generating organ, attenuated the drug-induced developmental delay, which is consistent with the critical role of PG’s TOR signaling in determining pupation time. Our results reveal previously unrecognized effects of minocycline and offer a new potential therapeutic opportunity for various pathological conditions associated with insulin/TOR signaling. PMID:28317899

  11. Foliage maturity of Quercus ilex affects the larval development of a Croatian coastal population of Lymantria dispar (Lepidoptera: Erebidae

    Directory of Open Access Journals (Sweden)

    Lukić Ivan

    2017-02-01

    Full Text Available Gypsy moth (Lymantria dispar is one of the most important forest pests in the world. Numerous previous studies focused only on different host tree species, but small number of them on foliage age. Since recent genetic analyses showed that there are significant differences between Croatian continental and coastal population we investigated coastal population since there was no previous research. For this research juvenile and mature foliage of Holm oak (Quercus ilex was used. Larval development was investigated in two laboratory experiments. One experiment involved rearing trials consisting of 50 individual larvae per treatment while a parallel experiment investigated gregarious feeding conditions using 120 larvae in a rearing treatment. Larval mortality was lower and development time shorter for individuals reared on juvenile foliage. High pupation success in both the individual and group rearing experiment for larvae reared on juvenile foliage was also observed. To conclude, our results showed high mortality, poor larval development and low pupation success in larvae reared on mature foliage. This research is significant because in the aspect of ongoing climate changes there is a possibility that gypsy moth will move to the north and shift its distribution by expanding into new climatic area.

  12. Resource depletion in Aedes aegypti mosquitoes infected by the microsporidia Vavraia culicis.

    Science.gov (United States)

    Rivero, A; Agnew, P; Bedhomme, S; Sidobre, C; Michalakis, Y

    2007-09-01

    SUMMARYParasitic infection is often associated with changes in host life-history traits, such as host development. Many of these life-history changes are ultimately thought to be the result of a depletion or reallocation of the host's resources driven either by the host (to minimize the effects of infection) or by the parasite (to maximize its growth rate). In this paper we investigate the energetic budget of Aedes aegypti mosquito larvae infected by Vavraia culicis, a microsporidian parasite that transmits horizontally between larvae, and which has been previously shown to reduce the probability of pupation of its host. Our results show that infected larvae have significantly less lipids, sugars and glycogen than uninfected larvae. These differences in resources were not due to differences in larval energy intake (feeding rate) or expenditure (metabolic rate). We conclude that the lower energetic resources of infected mosquitoes are the result of the high metabolic demands that microsporidian parasites impose on their hosts. Given the fitness advantages for the parasite of maintaining the host in a larval stage, we discuss whether resource depletion may also be a parasite mechanism to prevent the pupation of the larvae and thus maximize its own transmission.

  13. Impact of UV radiation on activity of linear furanocoumarins and Bacillus thuringiensis var. kurstaki against Spodoptera exigua: Implications for tritrophic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Trumble, J.T.; Moar, W.J.; Brewer, M.J.; Carson, W.G. (Univ. of California, Riverside (United States))

    1991-05-01

    Acidic fogs with a pH of 2.0 and duration of 2 hr did not reduce the efficacy of Bacillus thuringiensis var. kurstaki. Therefore, the impact of UV radiation was investigated on the interactions between (1) levels of the antibacterial linear furanocoumarins psoralen, bergapten, and xanthotoxin in Apium graveolens (L.) occurring following a 2.0 pH acidic fog episode, (2) the noctuid Spodoptera exigua, and (3) a sublethal dosage of the microbial pathogen B. thuringiensis var. kurstaki. Mean time to pupation in the absence of UV radiation was significantly extended by the addition of either psoralens or B. thuringiensis. Larvae developing on diets containing B. thuringiensis plus psoralens required nearly 40% longer to pupate than controls, but their effects were additive as the interaction was not significant. Mean time to mortality, a weighted average time of death, was not significantly affected by any of the treatments. In a 2 {times} 2 {times} 2 factorial analysis, all main effects reduced survival significantly, as did the three-way interaction. Thus, antagonistic interactions with psoralens that would reduce the effectiveness of B. thuringiensis in the field were not observed. When pairs of main effects were nested within the two levels of the third factor, several two-way interactions were found. Interestingly, the activity of B. thuringiensis and the psoralens, individually or in combination, was enhanced by exposure to UV radiation. Implications of this research are discussed for both natural and agricultural ecosystems.

  14. Relevance of the endosymbiosis of Blochmannia floridanus and carpenter ants at different stages of the life cycle of the host.

    Science.gov (United States)

    Zientz, Evelyn; Beyaert, Ivo; Gross, Roy; Feldhaar, Heike

    2006-09-01

    Expression of several genes possibly involved in the symbiotic relationship between the obligate intracellular endosymbiont Blochmannia floridanus and its ant host Camponotus floridanus was investigated at different developmental stages of the host by real-time quantitative PCR. These included a set of genes related to nitrogen metabolism (ureC, ureF, glnA, and speB) as well as genes involved in the synthesis of the aromatic amino acid tyrosine (tyrA, aspC, and hisC). The overall transcriptional activity of Blochmannia was found to be quite low during early developmental stages and to increase steadily with host age. However, a concerted peak of gene expression related to nitrogen recycling could be detected around the entire process of pupation, while expression of biosynthesis pathways for aromatic amino acids was elevated only during a short phase in pupation. These data suggest an important role of certain metabolic functions for the symbiotic interactions of the bacteria and an individual host organism in early phases of development. General relevance of Blochmannia for its ant host was tested in fostering experiments with worker groups of Camponotus floridanus, and their success in raising pupae from first-instar larvae was used as a fitness measure. Groups treated with antibiotics had a significantly reduced success in raising the brood in comparison to untreated control groups, indicating that the symbiosis is relevant for the development of the entire colony.

  15. Can butterflies evade fire? Pupa location and heat tolerance in fire prone habitats of Florida.

    Directory of Open Access Journals (Sweden)

    Matthew D Thom

    Full Text Available Butterflies such as the atala hairstreak, Eumaeus atala Poey, and the frosted elfin, Callophrys irus Godart, are restricted to frequently disturbed habitats where their larval host plants occur. Pupae of these butterflies are noted to reside at the base of host plants or in the leaf litter and soil, which may allow them to escape direct mortality by fire, a prominent disturbance in many areas they inhabit. The capacity of these species to cope with fire is a critical consideration for land management and conservation strategies in the locations where they are found. Survival of E. atala pupae in relation to temperature and duration of heat pulse was tested using controlled water bath experiments and a series of prescribed fire field experiments. Survival of E. atala pupae was correlated to peak temperature and heat exposure in both laboratory and field trials. In addition, E. atala survival following field trials was correlated to depth of burial; complete mortality was observed for pupae at the soil surface. Fifty percent of E. atala survived the heat generated by prescribed fire when experimentally placed at depths ≥ 1.75 cm, suggesting that pupation of butterflies in the soil at depth can protect from fatal temperatures caused by fire. For a species such as E. atala that pupates above ground, a population reduction from a burn event is a significant loss, and so decreasing the impact of prescribed fire on populations is critical.

  16. Biological characteristics of Acanthocinus carinulatus, a new record insect pest in Aershan, Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    YUAN Fei; LUO You-qing; SHI Juan; Kari KELI(O)VAARA; QI Guo-xin; CHEN Yu-jie; MA Ling-yun

    2008-01-01

    Biological characteristics of a new record pest insect Acanthocinus carinulatus Gebler has been reported in China. During the last few years, outbreaks of this insect in larch (Larix gmelinii Rupr.) plantations of Aershan, Inner Mongolia have occurred. Each year one generation is born. The insects only damage the phloem in L. gmelinii, overwinter in galleries as larvae and pupate in May of the following year. The pupation culminates in late May. The pupal phase lasts about 45 d. Adults emerge in early June and require nutrition after emergence. Mating and oviposition occur from late June to early August and the adult males and females and may copulate many times in their lifetime. The female adults lay eggs in bark crevices. Oviposition sites with one egg occupy 70.5% of all sites, sites with three eggs occupy 6.8% and 22.7% of all crevices are without eggs. Eggs stay in this stage for a period of 7 to 11 d.Larvae hatch in early July and hibernate in early September. The rate of successful hatching is only 37.8%.

  17. Lethal and sublethal effects of methoxyphenozide on the development, survival and reproduction of the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

    Energy Technology Data Exchange (ETDEWEB)

    Zarate, N.; Diaz, O. [Universidad Autonoma de San Luis Potosi (Mexico). Facultad de Agronomia; Martinez, A.M.; Figueroa, J.I.; Pineda, S., E-mail: spineda_us@yahoo.co [Universidad Michoacana de San Nicolas de Hidalgo, Tarimbaro, Michoacan (Mexico). Inst. de Investigaciones Agropecuarias y Forestales; Schneider, M.I. [National Council of Scientific and Technical Research (CEPAVE/CCT/CONICET), La Plata (Argentina). Centro de Estudios Parasitologicos y de Vectores. Centro Cientifico Tecnologico; Smagghe, G. [Ghent University, Ghent (Belgium). Faculty of Bioscience Engineering. Lab of Agrozoology; Vinuela, E.; Budia, F. [Escuela Tecnica Superior de Ingenieros Agronomos, Madrid (Spain). Escuela Tecnica Superior de Ingenieros Agronomos. Proteccion de Cultivos

    2011-01-15

    The lethal and sublethal effects of the ecdysone agonist methoxyphenozide on the fall armyworm, Spodoptera frugiperda (J. E. Smith), were investigated by feeding a methoxyphenozide-treated diet to fifth instars until pupation in doses corresponding to the LC{sub 10} and LC{sub 25} for the compound. Larval mortality reached 8% and 26% in the low and high concentration groups, respectively, on the seventh day of the experiment. A progressive larval mortality of 12% for the LC{sub 10} and 60% for the LC{sub 25} was observed before pupation. Treated larvae exhibited lower pupal weights, higher pupal mortality, presence of deformed pupae, and more deformed adults than untreated larvae. The incorporation of methoxyfenozide into the diet had a significant effect on the timing of larval development. The development period for males and females was about seven days longer than the controls for both concentrations tested. In contrast, the compound affected neither pupae nor adult longevity. Finally, S. frugiperda adults that resulted from fifth instars treated with methoxyfenozide were not affected in their mean cumulative number of eggs laid per female (fecundity), nor percentages of eggs hatched (fertility), or the sex ratio. Our results suggest that the combination of lethal and sublethal effects of methoxyfenozide may have important implications for the population dynamics of the fall armyworm. (author)

  18. Intrapopulation genome size variation in D. melanogaster reflects life history variation and plasticity.

    Directory of Open Access Journals (Sweden)

    Lisa L Ellis

    2014-07-01

    Full Text Available We determined female genome sizes using flow cytometry for 211 Drosophila melanogaster sequenced inbred strains from the Drosophila Genetic Reference Panel, and found significant conspecific and intrapopulation variation in genome size. We also compared several life history traits for 25 lines with large and 25 lines with small genomes in three thermal environments, and found that genome size as well as genome size by temperature interactions significantly correlated with survival to pupation and adulthood, time to pupation, female pupal mass, and female eclosion rates. Genome size accounted for up to 23% of the variation in developmental phenotypes, but the contribution of genome size to variation in life history traits was plastic and varied according to the thermal environment. Expression data implicate differences in metabolism that correspond to genome size variation. These results indicate that significant genome size variation exists within D. melanogaster and this variation may impact the evolutionary ecology of the species. Genome size variation accounts for a significant portion of life history variation in an environmentally dependent manner, suggesting that potential fitness effects associated with genome size variation also depend on environmental conditions.

  19. Life cycle and secondary production of two mayflies Leptophlebia sp. And Ephemera sp. In Heizhuchong stream, Hubei, China

    Institute of Scientific and Technical Information of China (English)

    LI Xiaoyu; YAN Yunjun

    2008-01-01

    From June 2003 to June 2004,an investigation on the life cycle,production and trophic basis of dominant species of macrozoobenthos community in a second-order river of the Hanjiang River basin,Hubei,China was carried out.The results showed that the dominant species Leptophlebia sp.and Ephemera sp.appeared to develop two generations per year,and there was a small overlap in the two generations of both species.The pupation of Leptophlebia sp.mainly occurred in autumn and winter,while pupation of Ephemera sp.mainly took place in summer and winter.The standing stocks of the Leptophlebia sp.population and Ephemera sp.population had two peaks in a year.The cohort production and cohort P/B ratio of the Leptophlebia sp.population estimated by size frequency method were 19.018 1 g/m2.a and 5.7 respectively,while its annual production and P/B ratio were 38.036 2 g/m2.a and 11.4.The cohort production and cohort P/B ratio of the Ephemera sp.population were 38.015 9 g/m2.a and 5.9,while its annual production and P/B ratio were 76.0318 g/m2.a and 11.8.

  20. Comparing the emergence of northern strain plum Curculio larvae from multiple fruit varieties.

    Science.gov (United States)

    Selby, R D; Whalon, M E

    2014-08-01

    Increasing restrictions on chemical pesticide use in orchards have encouraged the use of alternative strategies to control the northern strain of the plum curculio, Conotrachelus nenuphar (Herbst). Some of these strategies target larvae as they emerge from fruit, so existing models for larval emergence from fruit were evaluated for accuracy while examining the effect of multiple larvae and fruit type on emergence timing. Larval head width growth rate was established and used to gauge larval development. Larval emergence timing, quantified as degree-days (base 11.1 degrees C), was recorded in tart cherries on trees, and emergence timing was recorded in multiple apple varieties both in cyclical field conditions and in constant laboratory conditions. Ovipositing females and fruit were isolated, so larvae in a fruit were all siblings. Adult emergences from pupation in soil were recorded in the laboratory and compared with existing model predictions. Model predictions did not accurately reflect the timing of larval or adult emergence, and future incorporation of factors that could improve models are discussed. Colder conditions and changing host fruit type had no significant effect on larval emergence timing but changing host fruit type correlated with a shorter pupation interval. Results suggested that females preferred to oviposit on multiple fruit rather than lay multiple eggs in one fruit. Higher numbers of larvae per fruit did not significantly alter the timing of first larval emergence, although more larvae per fruit resulted in a significantly longer emergence period in apples.

  1. Aflatoxin B1: Toxicity, bioactivation and detoxification in the polyphagous caterpillar Trichoplusia ni

    Institute of Scientific and Technical Information of China (English)

    Ren Sen Zeng; Zhimou Wen; Guodong Niu; May R.Berenbaum

    2013-01-01

    Trichoplusia ni caterpillars are polyphagous foliage-feeders and rarely likely to encounter aflatoxin B1 (AFB1),a mycotoxin produced by Aspergillus flavus and A.parasiticus,in their host plants.To determine how T.ni copes with AFB1,we evaluated the toxicity ofAFB1 to T.ni caterpillars at different developmental stages and found that AFB1 tolerance significantly increases with larval development.Diet incorporation of AFB1 at 1μg/g completely inhibited larval growth and pupation of newly hatched larvae,but 3μg/g AFB1 did not have apparent toxic effects on larval growth and pupation of caterpillars that first consume this compound 10 days after hatching.Piperonyl butoxide,a general inhibitor of cytochrome P450 monooxygenases (P450s),reduced the toxicity of AFB1,suggesting that AFB1 is bioactivated in T.ni and this bioactivation is mediated by P450s.Some plant allelochemicals,including flavonoids such as flavones,furanocoumarins such as xanthotoxin and imperatorin,and furanochromones such as visnagin,that induce P450s in other lepidopteran larvae ameliorated AFB1 toxicity,suggesting that P450s are also involved in AFB1 detoxification in T.ni.

  2. Light conditions affect the performance of Yponomeuta evonymellus on its native host Prunus padus and the alien Prunus serotina.

    Science.gov (United States)

    Łukowski, A; Giertych, M J; Walczak, U; Baraniak, E; Karolewski, P

    2017-04-01

    The bird cherry ermine moth, Yponomeuta evonymellus L., is considered an obligatory monophagous insect pest that feeds only on native European Prunus padus L. In recent years, however, increased larval feeding on alien P. serotina Ehrh. has been observed. In both species, general defoliation is extensive for shade grown trees, whereas it is high in P. padus, but very low in P. serotina, when trees are grown in full light conditions. The aim of the present study was to identify how the plant host species and light conditions affect the performance of Y. evonymellus. The influence of host species and light condition on their growth and development, characterized by the parameters of pupation, adult eclosion, body mass, potential fecundity, and wing size, was measured in a 2 × 2 experimental design (two light treatments, two hosts). In comparison with high light (HL) conditions, a greater percentage of pupation and a longer period and less dynamic adult emerge was observed under low light (LL) conditions. The effect of host species on these parameters was not significant. In contrast, mass, fecundity and all of the studied wing parameters were higher in larvae that grazed on P. padus than on P. serotina. Similarly the same parameters were also higher on shrubs in HL as compared with those grown under LL conditions. In general, light conditions, rather than plant species, were more often and to a greater extent, responsible for differences in the observed parameters of insect development and potential fecundity.

  3. Determinação das castas em Scaptotrigona postica (Latreille (Hymenoptera, Apidae, Meliponini: diferenciação do ovário Caste determination in Scaptotrigona postica (Latreille (Hymenoptera, Apidae, Meliponini: the ovarian differentiation

    Directory of Open Access Journals (Sweden)

    Thaís da Cruz Alves dos Santos

    2002-09-01

    Full Text Available Both castes of Scaptotrigolia postica (Latreille, 1804 possess four ovarioles in each ovary. Queen and workers have the same ovarian development during the larvallife, but in lhe late larval stage the queen ovary beco me larger. During pupation a higher rate of cell division is observed in queen ovarioles and a higher rale of cell death in workers. Newly emerged workers have short ovarioles with differenriatcd germarium and vitellarium while queens have very long ovarioles with only germarium. Caste deterrnination in rhis species of bee is trophic, but lhe food does not differ in quality, only in quantiry. The food differences only beco me effecri ve by the end of larval stage when the queen larvae have lhe opportunity of eat more. In this way lhe ovary differentiation, between workers and queens. In this species, only occurs frorn lhe end of larval stage, mainly during pupation. Although the ovaries of workers are smaller, they are precocious in relation to queens, since nurse workers, 5 10 20 days, old may lay eggs. The eggs laid by the workers may be trophic or functional. These eggs may be distinguished by lhe aspect ofthe yolk. Older forager workers have degenerated ovaries.

  4. Mitosis and cell death in the optic lobes of workers, queens and drones of the honey bee (Apis mellifera) during metamorphosis.

    Science.gov (United States)

    Roat, Thaisa Cristina; Landim, Carminda da Cruz

    2010-09-01

    Colonies of the honey bee, Apis mellifera, consist of males and two female castes: workers and queens. The castes and males from A. mellifera have a distinct morphology, physiology and behaviour that correlate with their roles in the society and are characterized by some brain polymorphisms. Compound eyes are one of the characteristics that differ among the castes and sexes. A. mellifera is a holometabolous insect; therefore, the development of adult organs during metamorphosis, which will produce these differences, requires the precise coordination of three main programmed cellular processes: proliferation, differentiation and death. These processes take place simultaneously during pupation. Our purpose was to investigate cell division and death in the optic lobes (OL) of workers, queens and males during pupation to identify how the differences in the compound eyes in adults of these classes are achieved. The results showed that OL differentiation follows a similar pattern in the three classes of individuals studied, without structural differences in their development. The main non-structural differences involve cell division, mortality rates and timing. The results suggest a modelling of the brain during differentiation, which contributes to the specific functions of each individual class.

  5. Predation by odonates depresses mosquito abundance in water-filled tree holes in Panama.

    Science.gov (United States)

    Fincke, Ola M; Yanoviak, Stephen P; Hanschu, Richard D

    1997-10-01

    In the lowland moist forest of Barro Colorado Island (BCI), Panama, larvae of four common species of odonates, a mosquito, and a tadpole are the major predators in water-filled tree holes. Mosquito larvae are their most common prey. Holes colonized naturally by predators and prey had lower densities of mosquitoes if odonates were present than if they were absent. Using artificial tree holes placed in the field, we tested the effects of odonates on their mosquito prey while controlling for the quantity and species of predator, hole volume, and nutrient input. In large and small holes with low nutrient input, odonates depressed the number of mosquitoes present and the number that survived to pupation. Increasing nutrient input (and consequently, mosquito abundance) to abnormally high levels dampened the effect of predation when odonates were relatively small. However, the predators grew faster with higher nutrients, and large larvae in all three genera reduced the number of mosquitoes surviving to pupation, even though the abundance of mosquito larvae remained high. Size-selective predation by the odonates is a likely explanation for this result; large mosquito larvae were less abundant in the predator treatment than in the controls. Because species assemblages were similar between natural and artificial tree holes, our results suggest that odonates are keystone species in tree holes on BCI, where they are the most common large predators.

  6. Can butterflies evade fire? Pupa location and heat tolerance in fire prone habitats of Florida.

    Science.gov (United States)

    Thom, Matthew D; Daniels, Jaret C; Kobziar, Leda N; Colburn, Jonathan R

    2015-01-01

    Butterflies such as the atala hairstreak, Eumaeus atala Poey, and the frosted elfin, Callophrys irus Godart, are restricted to frequently disturbed habitats where their larval host plants occur. Pupae of these butterflies are noted to reside at the base of host plants or in the leaf litter and soil, which may allow them to escape direct mortality by fire, a prominent disturbance in many areas they inhabit. The capacity of these species to cope with fire is a critical consideration for land management and conservation strategies in the locations where they are found. Survival of E. atala pupae in relation to temperature and duration of heat pulse was tested using controlled water bath experiments and a series of prescribed fire field experiments. Survival of E. atala pupae was correlated to peak temperature and heat exposure in both laboratory and field trials. In addition, E. atala survival following field trials was correlated to depth of burial; complete mortality was observed for pupae at the soil surface. Fifty percent of E. atala survived the heat generated by prescribed fire when experimentally placed at depths ≥ 1.75 cm, suggesting that pupation of butterflies in the soil at depth can protect from fatal temperatures caused by fire. For a species such as E. atala that pupates above ground, a population reduction from a burn event is a significant loss, and so decreasing the impact of prescribed fire on populations is critical.

  7. Embryo-larval exposure to atrazine reduces viability and alters oxidative stress parameters in Drosophila melanogaster.

    Science.gov (United States)

    Figueira, Fernanda Hernandes; Aguiar, Lais Mattos de; Rosa, Carlos Eduardo da

    2017-01-01

    The herbicide atrazine has been used worldwide with subsequent residual contamination of water and food, which may cause adverse effects on non-target organisms. Animal exposure to this herbicide may affect development, reproduction and energy metabolism. Here, the effects of atrazine regarding survival and redox metabolism were assessed in the fruit fly D. melanogaster exposed during embryonic and larval development. The embryos (newly fertilized eggs) were exposed to different atrazine concentrations (10μM and 100μM) in the diet until the adult fly emerged. Pupation and emergence rates, developmental time and sex ratio were determined as well as oxidative stress parameters and gene expression of the antioxidant defence system were evaluated in newly emerged male and female flies. Atrazine exposure reduced pupation and emergence rates in fruit flies without alterations to developmental time and sex ratio. Different redox imbalance patterns were observed between males and females exposed to atrazine. Atrazine caused an increase in oxidative damage, reactive oxygen species generation and antioxidant capacity and decreased thiol-containing molecules. Further, atrazine exposure altered the mRNA expression of antioxidant genes (keap1, sod, sod2, cat, irc, gss, gclm, gclc, trxt, trxr-1 and trxr-2). Reductions in fruit fly larval and pupal viability observed here are likely consequences of the oxidative stress induced by atrazine exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Effects of X-ray irradiation on different stages of Sesamia nonagrioides Lefebvre (Lepidoptera: Noctuidae) and DNA damage

    Science.gov (United States)

    Avan Aksoy, Hatice; Yazıcı, Nizamettin; Erel, Yakup

    2017-01-01

    The corn stalk borer, Sesamia nonagrioides Lefebvre (Lepidoptera: Noctuidae) is an important corn pest in the Mediterranean countries. In this study, we investigated the influence of X-ray irradiation on different developmental stages, reproduction and DNA damage to the insect. Eggs (0-24 h old), larvae (5th instar), pupae (5 days after pupation) and adults (24 h after emergence) were irradiated with X-ray irradiation at target doses of 0 (control), 50, 100, 150 and 200 Gy. Eggs irradiated at all doses did not hatch. When 5th instar were irradiated pupation and adult emergence significantly decreased. Fecundity of adults from irradiated pupae was inhibited and no eggs were laid. Moreover, adult longevity decreased after irradiation compared to control. Larvae, pupae, and adults of S. nonagrioides were studied using the single-cell gel electrophoresis (DNA comet) directly after irradiation. X-ray irradiated larvae, pupae, and adults showed typical DNA fragmentation in a dose-dependent manner compared with cells from non-irradiated groups. The amount of DNA damage increased as doses increased and possibly could be used to estimate dose applied in commercial phytosanitary irradiation treatments. Furthermore, irradiation would be an effective phytosanitary treatment for shipped commodities at risk infestation with S. nonagrioides.

  9. Inhibiting the Mitochondrial Calcium Uniporter during Development Impairs Memory in Adult Drosophila

    Directory of Open Access Journals (Sweden)

    Ilaria Drago

    2016-09-01

    Full Text Available The uptake of cytoplasmic calcium into mitochondria is critical for a variety of physiological processes, including calcium buffering, metabolism, and cell survival. Here, we demonstrate that inhibiting the mitochondrial calcium uniporter in the Drosophila mushroom body neurons (MBn—a brain region critical for olfactory memory formation—causes memory impairment without altering the capacity to learn. Inhibiting uniporter activity only during pupation impaired adult memory, whereas the same inhibition during adulthood was without effect. The behavioral impairment was associated with structural defects in MBn, including a decrease in synaptic vesicles and an increased length in the axons of the αβ MBn. Our results reveal an in vivo developmental role for the mitochondrial uniporter complex in establishing the necessary structural and functional neuronal substrates for normal memory formation in the adult organism.

  10. Periodic abdominal pumping supports leg development during metamorphosis in tenebrionid beetle Zophobas atratus.

    Science.gov (United States)

    Ichikawa, Toshio

    2008-05-01

    Rhythmic abdominal pumping movements in a pupa of giant mealworm beetle Zophobas atratus caused large hemolymph pressure pulses of approximately 20 mmHg. The abdominal pumping movements were completely blocked by transecting the ventral nerve cord (VNC) between the first and second abdominal ganglia. Transection of the VNC until 2 days after pupation caused a developmental defect of adult legs: morphogenesis of the tibial and tarsal segments was severely retarded, and the segments remained covered with a thick pupal cuticle. The developmental defect was rescued by artificially inducing rhythmic abdominal bending for 3 days after transection of VNC. Blocking of the abdominal pump did not increase the amount of water loss during the pupal period. The transplanted tibial segments lacking active tracheal ventilation could form a thick adult cuticle. The results suggest that abdominal pumping movements during the pupal period support the development of adult legs by facilitating hemolymph circulation.

  11. Screening Commercially Available Entomopathogenic Biocontrol Agents for the Control of Aethina tumida (Coleoptera: Nitidulidae) in the UK.

    Science.gov (United States)

    Cuthbertson, Andrew G S; Mathers, James J; Blackburn, Lisa F; Powell, Michelle E; Marris, Gay; Pietravalle, Stephane; Brown, Mike A; Budge, Giles E

    2012-08-09

    The Small hive beetle, Aethina tumida, is an invasive pest of honey bees. Indigenous to sub-Saharan Africa, it has now become established in North America and Australia. It represents a serious threat to European honey bees. Commercially available entomopathogenic agents were screened for their potential to control beetle larvae. Entomopathogenic fungi investigated had minimal impact. The nematodes Steinernema kraussei and S. carpocapsae provided excellent control with 100% mortality of larvae being obtained. Sequential applications of the nematodes following larvae entering sand to pupate also provided excellent control for up to 3 weeks. The information gained supports the development of contingency plans to deal with A. tumida should it occur in the UK, and is relevant to the management of Small hive beetle where it is already present.

  12. Study on Shortern Forecast of Micromelopha troglodyta%杨小舟蛾短期预测预报研究

    Institute of Scientific and Technical Information of China (English)

    侯丽伟; 王福维; 李晓颖; 高立军; 李贞淑; 陈域横

    1999-01-01

    This paper deals with the bionomics of Micromelopha troglodyta.The pest has 2 generations a year and overwinters in pupa in the fallen leaves.In the food lack condition,the last instar larvae is compelled to pupate in advance,the mass of the pupa is much lighter than that of normal pupa.If the mass of the pupa is below 90 mg,it can not emerge.The mathematical model between the probability of the female and the pupa mass is Yi=-6.22+3.256 logXi.The mathematical model between amount of the female eggs and the pupa mass is Yi'=-1 886.3+1 014.4 logXi.Applying these mathematical models,we can forecast the population dynamics of M.troglodyta.

  13. A Rearing Method for Argynnis (Speyeria diana (Lepidoptera: Nymphalidae That Avoids Larval Diapause

    Directory of Open Access Journals (Sweden)

    Carrie N. Wells

    2011-01-01

    Full Text Available We describe a rearing protocol that allowed us to raise the threatened butterfly, Argynnis diana (Nymphalidae, while bypassing the first instar overwintering diapause. We compared the survival of offspring reared under this protocol from field-collected A. diana females from North Carolina, Georgia, and Tennessee. Larvae were reared in the lab on three phylogenetically distinct species of Southern Appalachian violets (Viola sororia, V. pubescens, and V. pedata. We assessed larval survival in A. diana to the last instar, pupation, and adulthood. Males reared in captivity emerged significantly earlier than females. An ANOVA revealed no evidence of host plant preference by A. diana toward three native violet species. We suggest that restoration of A. diana habitat which promotes a wide array of larval and adult host plants, is urgently needed to conserve this imperiled species into the future.

  14. New method for rearing Spodoptera frugiperda in laboratory shows that larval cannibalism is not obligatory

    Directory of Open Access Journals (Sweden)

    Cherre Sade Bezerra Da Silva

    2013-09-01

    Full Text Available New method for rearing Spodoptera frugiperda in laboratory shows that larval cannibalism is not obligatory. Here we show, for the first time, that larvae of the fall armyworm (FAW, Spodoptera frugiperda (Lepidoptera, Noctuidae, can be successfully reared in a cohort-based manner with virtually no cannibalism. FAW larvae were reared since the second instar to pupation in rectangular plastic containers containing 40 individuals with a surprisingly ca. 90% larval survivorship. Adult females from the cohort-based method showed fecundity similar to that already reported on literature for larvae reared individually, and fertility higher than 99%, with the advantage of combining economy of time, space and material resources. These findings suggest that the factors affecting cannibalism of FAW larvae in laboratory rearings need to be reevaluated, whilst the new technique also show potential to increase the efficiency of both small and mass FAW rearings.

  15. Mosquito mass rearing technology: a cold-water vortex device for continuous unattended separation of Anopheles arabiensis pupae from larvae.

    Science.gov (United States)

    Balestrino, Fabrizio; Gilles, Jérémie R L; Soliban, Sharon M; Nirschl, Anton; Benedict, Quentin E; Benedict, Mark Q

    2011-09-01

    In mass rearing of anopheline mosquitoes, pupae are usually separated from larvae on a daily basis to prevent unwanted adult emergence from trays. Depending on the device and species, 2 physical characteristics have most often been used for separation: buoyant density and size. In this report, we describe a system for continuous separation of Anopheles arabiensis larvae from pupae based on the natural difference in buoyant density and behavior between the 2 stages. We determined that temperatures 4-15 degrees C caused neither mortality nor reduction in likelihood of pupation or emergence. Separation improved as temperatures decreased down to 4 degrees C. We devised and demonstrated a 15 degrees C water vortex separator that we anticipate can process approximately 1 million larvae and pupae per hour with a < 0.3% pupal contamination rate and which operates unattended.

  16. Action of neem oil (Azadirachta indica A. Juss) on cocoon spinning in Ceraeochrysa claveri (Neuroptera: Chrysopidae).

    Science.gov (United States)

    Scudeler, Elton Luiz; Garcia, Ana Silvia Gimenes; Padovani, Carlos Roberto; Santos, Daniela Carvalho

    2013-11-01

    Neem oil is a biopesticide that disturbs the endocrine and neuroendocrine systems of pests and may interfere with molting, metamorphosis and cocoon spinning. The cocoon serves protective functions for the pupa during metamorphosis, and these functions are dependent on cocoon structure. To assess the changes in cocoon spinning caused by neem oil ingestion, Ceraeochrysa claveri larvae, a common polyphagous predator, were fed with neem oil throughout the larval period. When treated with neem oil, changes were observed on the outer and inner surfaces of the C. claveri cocoon, such as decreased wall thickness and impaired ability to attach to a substrate. These negative effects may reduce the effectiveness of the mechanical and protective functions of cocoons during pupation, which makes the specimen more vulnerable to natural enemies and environmental factors. © 2013 Elsevier Inc. All rights reserved.

  17. A new species of Dasineura Rondani (Diptera: Cecidomyiidae) in flower galls of Camassia (Asparagaceae: Agavoideae) in the Pacific Northwest, USA.

    Science.gov (United States)

    Gagné, Raymond J; Barosh, Theresa; Kephart, Susan

    2014-12-22

    A new species, Dasineura camassiae Gagné (Diptera: Cecidomyiidae), is described, illustrated and compared to some of its congeners from related hosts and western North America. The new species causes flower galls on Camassia (Agavoideae; Asparagaceae) in the Pacific Northwest. Its current known distribution is Oregon and Washington, USA. Larvae develop in spring in flowers of Camassia spp., causing the young ovaries to enlarge prematurely and eventually abort, without forming seeds or mature fruit. Full-grown larvae crawl out of the gall in rapid succession and drop to the soil where they pupate; they remain there until spring of the following year when the adults emerge and lay eggs. The galls they induce in camas lily buds represent the first known association of the cosmopolitan genus Dasineura with the group of plants that includes Agave and its relatives.

  18. Attempts to culture the parasitic stage of Dermatobia hominis (L. Jr.) in vitro (Diptera: Cuterebridae).

    Science.gov (United States)

    Zeledón, R; Silva, S

    1987-10-01

    Dermatobia hominis larvae were cultured in a semidefined liquid medium. First-instar larvae (L1) grew well up to 44 days; 29.1% molted in a mean period of 8.62 days. Two larvae reached the third instar but lived only 1 and 18 days, respectively, after the second molt. The increase in size, measured in 4 larvae, was about 10-fold. Second- and third-instar larvae, obtained from the skin of cattle, survived and grew in the medium for up to 2 mo; 39.0% of the L2 molted while 77.3% of the L3 pupated, and some produced flies when transferred to sand after 14.84 +/- 10.08 days in the culture medium. Some maturation factor, obtained from the skin, may be necessary for the larvae to grow satisfactorily and to complete the full parasitic cycle in vitro.

  19. Screening Commercially Available Entomopathogenic Biocontrol Agents for the Control of Aethina tumida (Coleoptera: Nitidulidae in the UK

    Directory of Open Access Journals (Sweden)

    Giles E. Budge

    2012-08-01

    Full Text Available The Small hive beetle, Aethina tumida, is an invasive pest of honey bees. Indigenous to sub-Saharan Africa, it has now become established in North America and Australia. It represents a serious threat to European honey bees. Commercially available entomopathogenic agents were screened for their potential to control beetle larvae. Entomopathogenic fungi investigated had minimal impact. The nematodes Steinernema kraussei and S. carpocapsae provided excellent control with 100% mortality of larvae being obtained. Sequential applications of the nematodes following larvae entering sand to pupate also provided excellent control for up to 3 weeks. The information gained supports the development of contingency plans to deal with A. tumida should it occur in the UK, and is relevant to the management of Small hive beetle where it is already present.

  20. Elevated copper levels during larval development cause altered locomotor behavior in the adult carabid beetle Pterostichus cupreus L. (Coleoptera: Carbidae)

    DEFF Research Database (Denmark)

    Bayley, M; Baatrup, E; Heimbach, U

    1995-01-01

    It is generally believed that copper causes changes in carabid communities indirectly by reducing food availability, because these animals are frequently found to have only slightly elevated metal contents even close to pollution sources. Using computer-centered video tracking, the locomotor...... behavior of adult Pterostichus cupreus carabid beetles was quantified after being raised on copper-contaminated food and soil during larval development. Copper was found to have an acute toxic effect measured in larval mortality, to cause a slight increase in the developmental period of males......, but not to effect the emergence weights of adults of either sex. This toxic effect on the larvae was preserved through pupation to the surviving adults, which were normal in size and appearance, but displayed a dramatically depressed locomotor behavior. Copper analysis of these adults revealed that copper levels...

  1. Toxical effect of Peganum harmala L. leaves on the cotton leaf worm, Spodoptera littoralis Boisd and its parasitoids Microplitis rufiventris Kok.

    Science.gov (United States)

    Shonouda, Mourad; Osman, Salah; Salama, Osama; Ayoub, Amal

    2008-02-15

    The leaf extract and its fractions of Peganum harmala L. have shown pronounced mortal effect, decreased percent pupation and adult emergence of the cotton leaf worm, Spodoptera littoralis Boisd. The third instar larvae fed for two days on treated leaves were more susceptible to plant extract and its ethyl acetate and chloroform fractions. The active lowest concentration (5%) of the leaf fractions of P. harmala showed significant effect on the percentage of emerged adult parasitoids, Microplitis rufiventris Kok. GC/MS analysis showed the major constituent in ethyl acetate fraction was (23S) ethylcholest-5-en-3 beta-ol (28.04%) while those of chloroform fraction were hydroxyfuranocoumarin (Bergaptol) (15.68%), piperidinone (12.08%), thymol (11.82%), phosphoric acid, tributyl ester (9.80%) and trimethyl-nonenol (9.66%). The medicinal plant P. harmala could be carefully applied in integrated pest management due to its strong effect on cotton leaf worm pest.

  2. The complete mitochondrial genome of the codling moth Cydia pomonella (Lepidoptera: Tortricidae).

    Science.gov (United States)

    Shi, Bao-Cai; Liu, Wei; Wei, Shu-Jun

    2013-02-01

    The complete mitochondrial genome of the codling moth Cydia pomonella (Lepidoptera: Tortricidae) was determined. The genome is 15,253 bp long with 37 typical animal mitochondrial genes and an A+T-rich region. All genes are arranged in their conserved positions compared with the pupative ancestral arrangement of insects except for trnM, which was translocated to the upstream of the transfer RNA cluster trnI-trnQ as in all previously reported lepidopteran mitochondiral genomes. Seven portein-coding genes use ATG start codon and five use ATT. However, the cox1 gene uses the CGA start codon as it is found in all previous reported mitochondrial genomes of Lepidoptera. Nine protein-coding genes stop with termination codon TAA. Four protein-coding genes use incomplete stop codons TA or T. The A+T region is located between rrnS and trnM with a length of 331 bp.

  3. Natural History and Comparative Morphology of Immatures of Gamelia anableps (C. Felder & R. Felder) (Lepidoptera: Saturniidae, Hemileucinae).

    Science.gov (United States)

    Moraes, S S; Otero, L S; Freitas, A V L

    2016-12-16

    Egg, larva, and pupa of Gamelia anableps (C. Felder & R. Felder, 1874) are described for the first time and the chaetotaxy of the first instar provided. Eggs and selected structures of larvae and pupae were also investigated by means of scanning electron microscopy. Eggs are laid in clusters, are ellipsoidal and laterally flat. Larvae passed through eight instars in about 78 days. Pupation occurs inside a poorly organized cocoon of yellowish silk. The dark brown pupa is cylindrical in shape with appendages firmly fused together and to the body wall. The chaeotaxy is compared with other Saturniidae species belongining to Hemileucinae, Ceratocampinae, and Saturniinae and the natural history of G. anableps compared with other Saturniidae.

  4. Duration of larval and pupal development stages of Aedes albopictus in natural and artificial containers

    Directory of Open Access Journals (Sweden)

    Gomes Almério de Castro

    1995-01-01

    Full Text Available Aedes albopictus were reared in different containers: a tree hole, a bamboo stump and an auto tire. The total times from egg hatching to adult emergence were of 19.6,27.3 and 37.5 days, respectively, according to the container. The first, second and third-instar larvae presented growth periods with highly similar durations. The fourth-instar larvae was longer than the others stages. The pupation time was longer than the fourth-instar larvae growth period. The temperature of the breeding sites studied, which was of 18degrees C to 22degrees C on average, was also taken into consideration. The mortality of the immature stages was analysed and compared as between the experimental groups; it was lower in the natural containers than in the discarded tire. The average wing length of adult females emerging from tree hole was significantly larger (p < 0.05 than that of those emerging from the tire.

  5. When can ants discriminate the sex of brood? A new aspect of queen-worker conflict.

    Science.gov (United States)

    Nonacs, P; Carlin, N F

    1990-12-15

    The stage in preimaginal ontogeny at which the sexes can first be distinguished has important implications for queen-worker conflict in social insects. If workers are unable to sex larvae at an early instar, their opportunity to control colony reproductive strategies may be limited. In addition, by concealing the sex of her sons for some portion of development, the queen could protect them from the workers' attempts to substitute their own sons or to skew the numerical sex ratio. In a series of choice experiments, workers of the carpenter ant, Camponotus floridanus, failed to discriminate the sex of several stages of larvae but did retrieve female pupae significantly more rapidly than male pupae. Our results suggest that in this species, sex may not become detectable until pupation, which is consistent with sexual deception as an aspect of queen control.

  6. Nesting Biology and Behavior of Euodynerus dantici (Rossi, 1790 (Hymenoptera: Vespidae: Eumeninae in Central Mongolia

    Directory of Open Access Journals (Sweden)

    Batchuluun Buyanjargal

    2015-12-01

    Full Text Available Nesting biology of Euodynerus dantici (Rossi, 1790 was studied in the Khugnu- Khaan Mountains of Khugnu-Tarna National Park, central Mongolia in 2014 using nest traps. Euodynerus dantici is univoltine in the study site, with one generation per growth season. Nest architecture and its structural parts were described in details. The inner cells of the nests were longer and contained a proportionately larger amount of food than the shorter outer cells. Females developed in inner cells and males developed in outer cells. Developmental stages of E. dantici is studied with details of pupation period. All basic behavioral elements of nesting females are described. A nest parasitoid, Chrysis ignita (Linnaeus, 1758 (Hymenoptera, Chrysididae was reared from E. dantici nests for the fi rst time. For provisioning, caterpillars of the family Noctuidae (Lepidoptera were hunted by females. Diversity in nest architecture is possibly a result of nest parasite pressure

  7. Larvicide and oviposition deterrent effects of fruit and leaf extracts from Melia azedarach L. on Aedes aegypti (L.) (Diptera: Culicidae).

    Science.gov (United States)

    Coria, C; Almiron, W; Valladares, G; Carpinella, C; Ludueña, F; Defago, M; Palacios, S

    2008-05-01

    Aedes aegypti (L.) (Diptera: Culicidae), the main urban vector of dengue, has developed resistance to various insecticides, making its control increasingly difficult. We explored the effects of Argentine Melia azedarach L. (Meliaceae) fruit and senescent leaf extracts on Ae. aegypti larval development and survival, by rearing cohorts of first instar mosquitoes in water with different extract concentrations. We also analysed oviposition deterrent activity in choice tests with extract-treated ovitraps. The leaf extract showed a strong larvicide activity, with all larvae dying before pupation, and significantly delayed development time. It strongly inhibited oviposition by Ae. aegypti females. The fruit extract showed much weaker effects. This first report of highly effective larvicidal, growth regulating and oviposition deterrent activity of a senescent leaf extract of M. azedarach against Ae. aegypti, suggests that such extract could represent a promising tool in the management of this mosquito pest.

  8. A Study on the bacterial flora and its significance in the housefly,Musca domestical L. (Diptera : Muscidae

    Directory of Open Access Journals (Sweden)

    Mostafa I. Hassan , Zaineb M. El-Basheer , Eman M. Rashad

    2002-09-01

    Full Text Available The microbial flora associated with the housefly, Musca domestica were isolated and their influence on some biological parameters of the fly was studied. The microbial flora isolation was carried out by using different selective and non-selective media. The examination of the housefly gut revealed a heavy and diverse microbial flora, these were : Enteric bacteria (Eschericia coli, Salmonella sp., Shigella sp., Pseudomonuas sp., Klebsiella sp., Proteus sp., Serratia sp.; Cocci form bacteria (Haemoltic Staphylococci and Streptococci, non-haemolytic Staphylococci and Streptococci and Bacillus sp. Actinomycetec, yeasts and filamentous fungi were isolated only from external surface of the fly. Aposymbiotic (the gut-bacterial free flies were obtained by feeding female flies on norofloxacine antibiotic. Hatchability, larval and pupal mortality, pupation and adult emergence were affected by elimination of bacteria from the fly gut. It was concluded that gut bacteria of the housefly are not pathogenic but their association might be mutual or even symbiotic.

  9. Resistance Analysis of the Binary Insect-resistant Transgenic Soybean to Heliothis viriplaca%双价抗虫转基因大豆抗苜蓿夜蛾分析

    Institute of Scientific and Technical Information of China (English)

    杨向东; 郭东全; 包绍君; 赵桂兰; 康岭生; 钱雪燕; 尹爱萍; 邢国杰

    2008-01-01

    [Objective] The aim of the research was to analyze the resistance of binary insect-resistant transgenic soybean to Heliothis viriplaca.[Method]In this experiment, resistance analysis of the stabilized binary insect-resistant transgenic soybean to Heliothis viriplaca was conducted in lab and in field conditions.[Result] The results indicated that the leaves of insect-resistant transgenic soybeans T5-150 and T5-195 showed lighter damage than those of non-transgenic soybeans. Meanwhile, the Heliothis viriplaca larvae fed on leaves of these two transgenic soybeans were characterized by less leaf consumption, shortening survival day, slower development and less pupation.[Conclusion]It was concluded that insect-resistance of transgenic soybean to Heliothis viriplaca was increased dramatically and the research provided a reference for selecting binary insect-resistant transgenic soybean to Heliothis viriplaca.

  10. Evaluación, en condiciones de laboratorio, de la actividad insecticida de extractos Etanolicos de cinco especies de plantas sobre Tecia solanivora (Lepidoptera: Gelechiidae Laboratory evaluation of the insecticidal activity of five plant species on Tecia solanivora (Lepidoptera: Gelechiidae

    Directory of Open Access Journals (Sweden)

    Castillo Gonzalo

    1998-06-01

    (Lepidoptera: Gelechiidae. The desing was a randomized completely, where the experimental unit were 500 grs of Solanum phureja, the units were sumerged in the plant extracts during five minutes and after evaporating the solvent, 15 1st instar larvae were placed to infested the potatoes. The variables measured were percentage of pupation, days of pupation, emergence of the adults and tubercule damage levels. The activity of the extracts began at 1.000 ppm, the extracts from E. globulus affects the pupation rate; damage was registered on the 1st and 2nd levels (O - 25 and 26 - 50 % respectively. On the units treated with the B sama cana extract, similar pupation rates were present, for the 20 and 25 days after the treatment (ddt; differences in the emergence of the adults were observed no as a result of the treatments.

  11. Significance of the Oviposition Records of Three Western Ghats Endemics, the Malabar Raven, Papilio dravidarum Wood-Mason, Malabar Rose, Atrophaneura pandiyana Moore and Crimson Rose, Atrophaneura hector Linnaeus (Lepidoptera: Papilionidae

    Directory of Open Access Journals (Sweden)

    V.S. Revathy

    2015-01-01

    Full Text Available Observations were made on the biology and bionomics of the three Western Ghats Endemics, the Malabar Raven (Papilio dravidarum Wood-Mason, Malabar Rose (Atrophaneura pandiyana Moore and Crimson Rose (A. hector Linnaeus. The size of the caterpillar (length and breadth, mode of feeding, pupation and emergence were recorded. The biology took 36-40 days for completion in Malabar Raven, 35-37 days in A. pandiyana and A. hector. Butterflies found in different habitats tend to show marked differences in their general appearance and biology as evidenced by the "Ecological races" reported in several species of butterflies. Thorough understanding of the life history and their behavioural patterns of immature stages will help in recognizing geographical and ecological races.

  12. Drosophila melanogaster larvae control amylase secretion according to the hardness of food

    Directory of Open Access Journals (Sweden)

    Honami eSakaguchi

    2013-08-01

    Full Text Available Drosophila melanogaster larvae excrete amylase and perform external digestion of their food. In this study, to investigate whether their external digestion ability varies in response to changes in the external environment, we measured the relative amount of amylase excreted by larvae using a new method: the iodine starch agar method (ISAM. Analysis using this method revealed that the amount of amylase excreted by larvae increased in accordance with the increase in the agar concentration. In addition, we investigated the effect on the larval growth rate of adding amylase to the diet. Pupation occurred 24 h later in food containing 1% amylase than in food containing no amylase. These results suggest that the larvae adjust their amylase excretion in response to changes in the external environment, and that its level has a marked influence on the larval growth rate.

  13. Effects of larval rearing temperature on immature development and West Nile virus vector competence of Culex tarsalis

    Directory of Open Access Journals (Sweden)

    Dodson Brittany L

    2012-09-01

    Full Text Available Abstract Background Temperature is known to induce changes in mosquito physiology, development, ecology, and in some species, vector competence for arboviruses. Since colonized mosquitoes are reared under laboratory conditions that can be significantly different from their field counterparts, laboratory vector competence experiments may not accurately reflect natural vector-virus interactions. Methods We evaluated the effects of larval rearing temperature on immature development parameters and vector competence of two Culex tarsalis strains for West Nile virus (WNV. Results Rearing temperature had a significant effect on mosquito developmental parameters, including shorter time to pupation and emergence and smaller female body size as temperature increased. However, infection, dissemination, and transmission rates for WNV at 5, 7, and 14 days post infectious feeding were not consistently affected. Conclusions These results suggest that varying constant larval rearing temperature does not significantly affect laboratory estimates of vector competence for WNV in Culex tarsalis mosquitoes.

  14. Development and validation of a real-time two-step RT-qPCR TaqMan(®) assay for quantitation of Sacbrood virus (SBV) and its application to a field survey of symptomatic honey bee colonies

    DEFF Research Database (Denmark)

    Blanchard, Philippe; Guillot, Sylvain; Antùnez, Karina

    2014-01-01

    Sacbrood virus (SBV) is the causal agent of a disease of honey bee larvae, resulting in failure to pupate and causing death. The typical clinical symptom of SBV is an accumulation of SBV-rich fluid in swollen sub-cuticular pouches, forming the characteristic fluid-filled sac that gives its name...... bees. A two-step real-time RT-PCR assay, based on TaqMan(®) technology using a fluorescent probe (FAM-TAMRA) was therefore developed to quantify Sacbrood virus in larvae, pupae and adult bees from symptomatic apiaries. This assay was first validated according to the recent XP-U47-600 standard issued...... with individuals without clinical signs. The SBV quantitation revealed that, in symptomatic larvae, the virus load was significantly higher than in samples without clinical signs. Combining quantitation with clinical data, a threshold of SBV viral load related to an overt disease was proposed (10(10) SBV genome...

  15. Effects of herbicides on Behr's metalmark butterfly, a surrogate species for the endangered butterfly, Lange's metalmark.

    Science.gov (United States)

    Stark, John D; Chen, Xue Dong; Johnson, Catherine S

    2012-05-01

    Lange's metalmark butterfly, Apodemia mormo langei Comstock, is in danger of extinction due to loss of habitat caused by invasive exotic plants which are eliminating its food, naked stem buckwheat. Herbicides are being used to remove invasive weeds from the dunes; however, little is known about the potential effects of herbicides on butterflies. To address this concern we evaluated potential toxic effects of three herbicides on Behr's metalmark, a close relative of Lange's metalmark. First instars were exposed to recommended field rates of triclopyr, sethoxydim, and imazapyr. Life history parameters were recorded after exposure. These herbicides reduced the number of adults that emerged from pupation (24-36%). Each herbicide has a different mode of action. Therefore, we speculate that effects are due to inert ingredients or indirect effects on food plant quality. If these herbicides act the same in A. mormo langei, they may contribute to the decline of this species. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Ascarosides coordinate the dispersal of a plant-parasitic nematode with the metamorphosis of its vector beetle

    Science.gov (United States)

    Zhao, Lilin; Zhang, Xinxing; Wei, Yanan; Zhou, Jiao; Zhang, Wei; Qin, Peijun; Chinta, Satya; Kong, Xiangbo; Liu, Yunpeng; Yu, Haiying; Hu, Songnian; Zou, Zhen; Butcher, Rebecca A.; Sun, Jianghua

    2016-01-01

    Insect vectors are required for the transmission of many species of parasitic nematodes, but the mechanisms by which the vectors and nematodes coordinate their life cycles are poorly understood. Here, we report that ascarosides, an evolutionarily conserved family of nematode pheromones, are produced not only by a plant-parasitic nematode, but also by its vector beetle. The pinewood nematode and its vector beetle cause pine wilt disease, which threatens forest ecosystems world-wide. Ascarosides secreted by the dispersal third-stage nematode LIII larvae promote beetle pupation by inducing ecdysone production in the beetle and up-regulating ecdysone-dependent gene expression. Once the beetle develops into the adult stage, it secretes ascarosides that attract the dispersal fourth-stage nematode LIV larvae, potentially facilitating their movement into the beetle trachea for transport to the next pine tree. These results demonstrate that ascarosides play a key role in the survival and spread of pine wilt disease. PMID:27477780

  17. Duration of larval and pupal development stages of Aedes albopictus in natural and artificial containers

    Directory of Open Access Journals (Sweden)

    Almério de Castro Gomes

    1995-02-01

    Full Text Available Aedes albopictus were reared in different containers: a tree hole, a bamboo stump and an auto tire. The total times from egg hatching to adult emergence were of 19.6,27.3 and 37.5 days, respectively, according to the container. The first, second and third-instar larvae presented growth periods with highly similar durations. The fourth-instar larvae was longer than the others stages. The pupation time was longer than the fourth-instar larvae growth period. The temperature of the breeding sites studied, which was of 18° C to 22° C on average, was also taken into consideration. The mortality of the immature stages was analysed and compared as between the experimental groups; it was lower in the natural containers than in the discarded tire. The average wing length of adult females emerging from tree hole was significantly larger (p < 0.05 than that of those emerging from the tire.

  18. The transmission of deformed wing virus between honeybees (Apis mellifera L.) by the ectoparasitic mite varroa jacobsoni Oud

    Science.gov (United States)

    Bowen-Walker; Martin; Gunn

    1999-01-01

    Under field conditions, Varroa jacobsoni were shown to be highly effective vectors of deformed wing virus (DWV) between bees. Adult female mites obtained from honeybee pupae naturally infected with DWV contained virus titers many times in excess of those found in their hosts and, beyond that, which might be expected from a concentration effect. It is therefore possible that DWV may be capable of replicating within V. jacobsoni. Bees which tested positive for DWV exhibited characteristic morphological deformity and/or they died during pupation. Asymptomatic bees had much lower virus titers than those which were deformed or had died during pupation. It is therefore suggested that for DWV to cause pathology it must be present in pupae above a certain concentration. The amount of DWV vectored by V. jacobsoni will depend on the mites' level of infection, which will in turn depend on whether they had fed previously on dead or deformed bees and also on the rate of replication of the virus within the mites. Consequently, developing bees infested with large numbers of mites could suffer a high incidence of deformity if the mites are heavily infected or harbor an especially virulent strain of virus. A positive relationship was found between increasing numbers of mites on individual bees and the incidence of morphological deformity and death. This probably reflected the large number of viral particles transmitted by the mites, which resulted in many multiply infested bees dying before emergence. These results demonstrate the importance of the role of viruses when considering the pathology of V. jacobsoni and that much of the pathology previously associated with the effects of mite feeding could be attributed directly to secondary pathogens vectored by V. jacobsoni. Copyright 1999 Academic Press.

  19. Longevity and reproductive success of Aethina tumida (Coleoptera: Nitidulidae) fed different natural diets.

    Science.gov (United States)

    Ellis, James D; Neumann, Peter; Hepburn, Randall; Elzen, Patti J

    2002-10-01

    The longevity and reproductive success of newly emerged, unfed adult Aethina tumida Murray assigned different diets (control = unfed; honey-pollen; honey; pollen; empty brood comb; bee brood; fresh Kei apples; and rotten Kei apples) were determined. Longevity in honey-fed small hive beetle adults (average maximum: 167 d) was significantly higher than on other diets. Small hive beetles fed empty brood comb lived significantly longer (average maximum: 49.8 d) than unfed beetles (average maximum: 9.6 d). Small hive beetle offspring were produced on honey-pollen, pollen, bee brood, fresh Kei apples, and rotten Kei apples but not on honey alone, empty brood comb, or in control treatments. The highest reproductive success occurred in pollen fed adults (1773.8 +/- 294.4 larvae per three mating pairs of adults). The data also show that A. tumida can reproduce on fruits alone, indicating that they are facultative parasites. The pupation success and sex ratio of small hive beetle offspring were also analyzed. Larvae fed pollen, honey-pollen, or brood had significantly higher pupation success rates of 0.64, 0.73, and 0.65 respectively than on the other diets. Sex ratios of emerging adults fed diets of pollen or brood as larvae were significantly skewed toward females. Because small hive beetle longevity and overall reproductive success was highest on foodstuffs located in honey bee colonies, A. tumida are efficient at causing large-scale damage to colonies of honey bees resulting in economic injury for the beekeeper. Practical considerations for the control of A. tumida are briefly discussed.

  20. Changes of seasonal morph development induced by surgical operations in pupae of the large map butterfly Araschnia burejana Bermer (Lepidoptera: Nymphalidae).

    Science.gov (United States)

    Yamashita, Kae; Kanzaki, Koji; Hinauchi, Mami; Fujishima, Tetsuro; Islam, Abu Taher Md Fayezul; Kitazawa, Chisato; Endo, Katsuhiko; Yamanaka, Akira

    2014-06-01

    The nymphalid butterfly Araschnia burejana and the papilionid butterfly Papilio xuthus exhibit seasonal diphenism comprising spring-morphs that develop from diapause pupae and summer-morphs that develop from non-diapause pupae. The development of seasonal morphs in A. burejana is regulated by the timing of secretion of ecdysteroids for adult development, whereas that in P. xuthus is regulated by the secretion of summer-morph-producing hormone, which is present in the brains and is under control of the photoperiod. We investigated whether a cerebral factor derived from brains plays a significant role in the regulation of seasonal morph development in A. burejana using surgical operations. Pairs of chilled diapause pupae that had been chilled for more than 3 months at 4°C were joined surgically to each other and then developed into spring-morph or spring-like-morph adults. Chilled diapause pupae that were joined with 1-day-old non-diapause pupae developed into summer-morph or summer-like-morph adults. When the brains of non-diapause pupae were removed surgically 6-8 hr after pupation with and without injection of 20-hydroxyecdysone, a large portion of them developed into spring-morph or spring-like-morph adults, respectively. Furthermore, 90% of non-diapause pupae developed into spring-morph or spring-like-morph adults when the neck was ligated within 5 min after pupation. These results indicated that a cerebral factor showing summer-morph-producing hormone activity, which is secreted from the brain in the early pupal stage, in addition to 20-hydroxyecdysone for adult development, play a significant role in the determination of summer-morph development in non-diapause pupae of A. burejana.

  1. Evaluation of heat treatment schedules for emerald ash borer (Coleoptera: Buprestidae).

    Science.gov (United States)

    Myers, Scott W; Fraser, Ivich; Mastro, Victor C

    2009-12-01

    The thermotolerance of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), was evaluated by subjecting larvae and prepupae to a number of time-temperature regimes. Three independent experiments were conducted during 2006 and 2007 by heating emerald ash borer infested firewood in laboratory ovens. Heat treatments were established based on the internal wood temperature. Treatments ranged from 45 to 65 degrees C for 30 and 60 min, and the ability of larvae to pupate and emerge as adults was used to evaluate the success of each treatment. A fourth experiment was conducted to examine heat treatments on exposed prepupae removed from logs and subjected to ambient temperatures of 50, 55, and 60 degrees C for 15, 30, 45, and 60 min. Results from the firewood experiments were consistent in the first experiment. Emergence data showed emerald ash borer larvae were capable of surviving a temperatures-time combination up to 60 degrees C for 30 min in wood. The 65 degrees C for 30 min treatment was, however, effective in preventing emerald ash borer emergence on both dates. Conversely, in the second experiment using saturated steam heat, complete mortality was achieved at 50 and 55 degrees C for both 30 and 60 min. Results from the prepupae experiment showed emerald ash borer survivorship in temperature-time combinations up to 55 degrees C for 30 min, and at 50 degrees C for 60 min; 60 degrees C for 15 min and longer was effective in preventing pupation in exposed prepupae. Overall results suggest that emerald ash borer survival is variable depending on heating conditions, and an internal wood temperature of 60 degrees C for 60 min should be considered the minimum for safe treatment for firewood.

  2. Performance of five food regimes on Anopheles gambiae senso stricto larval rearing to adult emergence in insectary.

    Directory of Open Access Journals (Sweden)

    Happiness S Kivuyo

    Full Text Available BACKGROUND: Rearing of Anopheles gambiae s.s mosquitoes in insectary with quality cheap food sources is of paramount importance for better and healthy colony. This study evaluated larval survival and the development rate of aquatic stages of An.gambiae s.s under five food regimes; tetramin fish food (a standard insectary larval food, maize pollen, Cerelac, green filamentous algae and dry powdered filamentous algae. METHODS: Food materials were obtained from different sources, cerelac was made locally, fresh filamentous algae was taken from water bodies, dry filamentous algae was ground to powder after it was dried under shade, and maize pollen was collected from the flowering maize. Each food source type was used to feed three densities of mosquito larvae 20, 60, and 100 in six replicates each. Larval age structure was monitored daily until pupation and subsequently adult emergence. Tetramin was used and taken as a standard food source for An. gambiae s.s. larvae feeding in Insectary. RESULTS: Larval survivorship using maize pollen and Tetramin fish food was statistically insignificant (P = 0.564. However when compared to other food regime survivorship was significantly different with Tetramin fish food performing better than cerelac (P<0.001, dry algae (P<0.001 and fresh algae (P<0.001. The pupation rates and sex ratio of emerging adults had significant differences among the food regimes. CONCLUSION: The findings of this study have shown that maize pollen had closely similar nutritional value for larval survivorship to tetramin fish food, a standard larvae food in insectary. Further studies are required to assess the effect of food sources on various life traits of the emerged adults.

  3. Effects of Tebufenozide on the Biological Characteristics of Beet Armyworm (Spodoptera exigua Hübner) and Its Resistance Selection

    Institute of Scientific and Technical Information of China (English)

    LIU Wei-wei; MU Wei; ZHU Bing-yu; LIU Feng

    2008-01-01

    In this article, the selection of tebufenozide to beet armyworm (Spodoptera exigua Hubner) was studied by the treatments to alternative generations' 3rd-instar larvae with LC50 dose and to continuous generations' larvae with LC10 dose; the effects of tebufenozide on the biological characteristics of current and subsequent generations were examined by the treatments to 3rd-instar larvae and egg pods in different concentrations. After treatments with LC50 dose till F11, the toxicity of tebufenozide to beet armyworm had no significant change, whereas the pupation rate, pupal weight, and fecundity were reduced markedly. After treatments with LC10 dose till F19, the beet armyworm only developed 3.52-fold resistance, and the main biological characteristics were nearly accordant in each generation. The livability was reduced 72 h later after treatments to 3rd-instar larvae, respectively in 2.5-40 (ig mL-', and larval duration, pupation rate, and pupal weight changed considerably with the increase in concentrations. The fecundity, larval livability, larval weight and pupal weight of subsequent generations were reduced as the dose increased over 10 ug mL-1. The hatching rate of egg pods did not differ with that of the controls obviously after treatment in 10-300 ug mL-1. But the larval livability, larval weight and pupal weight were reduced when eggs were exposed to 50 ug mL-1 dose or more. The results indicated that tebufenozide had low resistance risk to the current and subsequent generations of beet armyworm even if tebufenozide had significant effects on the biological characteristics of this insect.

  4. Relationship between an increase of juvenile hormone titer in early instars and the induction of diapause in fully grown larvae of Sesamia nonagrioides.

    Science.gov (United States)

    Eizaguirre, Matilde; Schafellner, Christa; López, Carmen; Sehnal, Frantisek

    2005-10-01

    The larvae of Sesamia nonagrioides (Lepidoptera: Noctuidae) grown at 25 degrees C and long photoperiod (16:8h light:dark) pupate in the 5th or 6th (mostly) larval instar, while the larvae reared under a short photoperiod (12:12h) enter diapause during which they consume some food and undergo up to 12 (usually 3-4) stationary larval molts. Diapause programming includes an increase of juvenile hormone (JH) titer in the hemolymph from about 20 to 50 nM in the 4th and 5th instar larvae (titer in earlier instars was not measured). JH I, II, and III are present in approximate ratio 1-2:10:1. The JH titer drops to zero before pupation but remains around 20 nM during diapause. Perfect extra larval molts associated with a body weight increase can be induced in the non-diapausing larvae with a JH analogue (JHA). The weight rise is due to accumulation of reserves and not to a general body growth. The timing of extra molts is similar to the molting pattern of the diapausing larvae only when JHA is present since early larval instars. In the diapausing larvae, JHA application affects neither molting periodicity nor the body weight. It is concluded that (1) Increased JH titer in early larval instars is a part of diapause programming; (2) The extension of larval stage in the diapausing larvae, but not the timing pattern of extra molts, is due to continuously high JH titer; (3) The diapause program includes low food intake, maintenance of a certain body weight, and periodic larval molts.

  5. Programmed cell death of larval tissues induced by juvenile hormone in the bamboo borer, Omphisa fuscidentalis.

    Science.gov (United States)

    Manaboon, Manaporn; Yasanga, Tippawan; Sakurai, Sho; Singtripop, Tippawan

    2012-09-01

    Programmed cell death (PCD) plays a critical role during animal development through the destruction of unneeded cells and tissues. In some insects, the prothoracic glands (PGs) and anterior silk glands (ASGs) are larval-specific tissues that are normally eliminated by PCD after pupation. Previous studies report that juvenile hormone analog (JHA) terminates the larval diapause of Omphisa fuscidentalis by increasing the hemolymph ecdysteroids that trigger PCD. Because JHA may indirectly induce the PCD of the PGs and ASGs of Omphisa diapausing larvae, the effects of JHA on the induction of PCD were determined. The application of 1μg JHA induced PCD in the PGs and ASGs of larvae identified as stage G0 (prior to pupation). The injection of 1μg 20E triggered the PCD of the ASGs when the larvae expressed a G0-G1 morphology, whereas PCD occurred in the PGs on day 1 post-injection. Histological studies revealed similar patterns of morphological changes during the PG and ASG PCD in the JHA- and 20E-treated larvae. Furthermore, to confirm that PCD was induced by a high ecdysteroid level that increases after JHA application, the expression profiles of EcR-A and EcR-B1 in the PGs and ASGs from the JHA-treated larvae were examined, and the results showed that the expression levels of EcR-A and EcR-B1 mRNA increased during the G0 stage. These results suggest that JHA may be involved in PCD by increasing the ecdysteroid titer, leading to termination of the larval diapause period in Omphisa fuscidentalis.

  6. Growth and reproductive costs of larval defence in the aposematic lepidopteran Pieris brassicae.

    Science.gov (United States)

    Higginson, Andrew D; Delf, Jon; Ruxton, Graeme D; Speed, Michael P

    2011-03-01

    1. Utilization of plant secondary compounds for antipredator defence is common in immature herbivorous insects. Such defences may incur a cost to the animal, either in terms of survival, growth rate or in the reproductive success. 2. A common defence in lepidopterans is the regurgitation of semi-digested material containing the defensive compounds of the food plant, a defence which has led to gut specialization in this order. Regurgitation is often swift in response to cuticular stimulation and deters predators from consuming or parasitizing the larva. The loss of food and other gut material seems likely to impact on fitness, but evidence is lacking. 3. Here, we raised larvae of the common crop pest Pieris brassicae on commercial cabbage leaves, simulated predator attacks throughout the larval period, and measured life-history responses. 4. We found that the probability of survival to pupation decreased with increasing frequency of attacks, but this was because of regurgitation rather than the stimulation itself. There was a growth cost to the defence such that the more regurgitant that individuals produced over the growth period, the smaller they were at pupation. 5. The number of mature eggs in adult females was positively related to pupal mass, but this relationship was only found when individuals were not subjected to a high frequency of predator simulation. This suggests that there might be cryptic fitness costs to common defensive responses that are paid despite apparent growth rate being maintained. 6. Our results demonstrate a clear life-history cost of an antipredator defence in a model pest species and show that under certain conditions, such as high predation threat, the expected relationship between female body size and potential fecundity can be disrupted.

  7. Effects of nitrogen fertilizer and magnesium manipulation on the Cnaphalocrocis medinalis (Lepidoptera: Pyralidae).

    Science.gov (United States)

    Ge, Lin-Quan; Wan, Don-Ju; Xu, Jie; Jiang, Li-Ben; Wu, Jin-Cai

    2013-02-01

    The rice leaffolder, Cnaphalocrocis medinalis Guenee (Lepidoptera: Pyralidae), is a rice pest that is prone to outbreaks when high levels of nitrogen (N) fertilizer are applied to rice. The larvae feed by scraping the mesophyll cells of leaves, which are mainly composed of chloroplasts containing significant levels of elemental magnesium (Mg). To determine the cause of N fertilizer-induced rice leaffolder outbreaks and the effects of Mg and Mg uptake on the rice leaffolder, the changes in the life history traits and biochemistry of C. medinalis larvae feeding on rice leaves treated with different Mg and N concentrations were investigated in this study. The results showed that foliar treatment using different Mg concentrations under hydroponic culture conditions significantly decreased the developmental duration (days) (DD) of the larvae and pupae but did not influence the pupation rate or adult emergence rate. The number of eggs laid by adult females and the protein content and total sugar content in the larvae and pupae significantly increased with increasing Mg concentrations. Under soil culture conditions, the DD for the larvae and number of eggs laid by adult females significantly increased with increasing nitrogen fertilizer levels, but the applied fertilizer did not influence the DD in the pupae, pupation rate, or adult emergence rate. In contrast, the DD for adults decreased with increased fertilizer levels. In hydroponic culture, Mg in the culture solution and Mg foliar sprays significantly increased the Mg content in rice leaves. In soil cultures, the use of N fertilizer and Mg foliar spray did not significantly increase the leaf Mg content, except at a concentration of 12.5 g/L, indicating that the leaf Mg content may be related to the root uptake of Mg.

  8. Life history, secondary production and trophic basis of two dominant mayflies in a subtropical stream of China

    Institute of Scientific and Technical Information of China (English)

    YAN Yunjun; LI Xiaoyu

    2007-01-01

    Mayflies constitute a major part of macroinvertebrate biomass and production in lotic ecosystems, and play an important role in material cycle and energy flow. There are more than 250 species of mayflies in rivers and streams of China. In order to learn their ecological functions, an investigation on life cycle,production and trophic basis of dominant species of mayflies in a second-order branch_of Hanjiang River basin,Hubei, China was carried out during June 2003 to June 2004. The results showed that the dominant mayfly species Epeorus sp. and Caenis sp. developed two generations per year; in term of Epeorus sp., pupation mainly occurred in spring and then from late summer to early autumn, while Caenis sp. pupated in spring and autumn. The abundance and biomass of the Epeorus sp. population peaked twice (1 226 ind/m2, 3.142 5g/m2)in April and June. Caenis sp. also had two peaks (307ind/m2, 1.590 g/m2), but in February and June. Cohort production and cohort P/B ratio ofEpeorus sp. were 161.009 g/m2 wet weight and 7.7, respectively, and annual production and P/B ratio were 267.46g/m2.a wet weight and 15.4, respectively; cohort production and P/B ratio of Caenis sp. were 26.7995g/m2 wet weight and 4.7, its annual production and P/B ratio were 53.60g/m2.a wet weight and 9.4, respectively. For Epeorus sp., the proportions contributing to secondary production of the main food types were: amorphous detritus, 33.46%; fungi, 10.83%; vascular plant detritus, 1.80%; diatoms, 53.90%; for Caenis sp., the proportions were 70.79%, 6.90%, 3.52% and 18.77%, respectively.

  9. Larvicidal, Biological and Genotoxic Effects, and Temperature-Toxicity Relationship of Some Leaf Extracts of Nerium oleander (Apocynaceae on Culex pipiens (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Shaurub H El-Sayed

    2015-10-01

    Full Text Available  Background: The present study was undertaken to study the larvicidal activity of different extracts of Nerium ole­ander leaves, and post-treatment temperature- toxicity relationship of these extracts against Culex pipiens. Further, the most potent extract was used to evaluate its biological and genotoxic activities. Methods: Crude extracts of N. oleander leaves were prepared using water, chloroform, acetone and diethyl ether as solvents. Extraction was carried out using soxhlet apparatus. Bioassay test was carried out on the larvae, and the LC50 of each extract was determined. Thus, newly hatched first instar larvae were treated, and the mortality count was recorded daily till pupation (accumulated mortality. The LC50 of diethyl ether extract, as the most potent ex­tract, was used for the further biological and genotoxic studies. Results: The results obtained indicated that diethyl ether extract of N. oleander leaves was the most potent extract, with LC50 of 10500 mg/l. The toxicity of the four extracts, using the LC50, at 10 °C was higher than that at 35 °C. The LC50 of diethyl ether extract significantly decreased the larval duration, pupal duration, percentage of pupation, percentage of adult emergence, longevity of females, fecundity, and oviposition activity index, whereas the growth index and the percentage of development per day of larvae and pupae were significantly increased compared to non-treated insects. Moreover, treatment with this extract induced significant dominant lethality in both male and female adults.  Conclusion: It appears that diethyl ether extract of N. oleander leaves is potential control agent to Cx. pipiens. 

  10. Insect growth regulatory effects of some extracts and sterols from Myrtillocactus geometrizans (Cactaceae) against Spodoptera frugiperda and Tenebrio molitor.

    Science.gov (United States)

    Céspedes, Carlos L; Salazar, J Rodrigo; Martínez, Mariano; Aranda, Eduardo

    2005-10-01

    A methanol extract from the roots and aerial parts of Myrtillocactus geometrizans (Cactaceae) yielded peniocerol 1, macdougallin 2, and chichipegenin 3. The natural products 1, 2 their mixtures, MeOH and CH(2)Cl(2) extracts showed insecticidal and insect growth regulatory activity against fall armyworm [Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae)], an important insect pest of corn, and [Tenebrio molitor (Coleoptera)], a pest of stored grains in Mexico. The most active compounds were 1, 2, and a mixture (M(2)) of 1 and 2 (6:4). All these extracts, compounds and the mixture had insect growth regulating (IGR) activity between 5.0 and 50.0 ppm and insecticidal effects between 50 and 300 ppm in diets. The extracts were insecticidal to larvae, with lethal doses between 100 and 200 ppm. These compounds appear to have selective effects on the pre-emergence metabolism of Coleoptera, because in all treatments of the larvae of T. molitor, pupation were shortened and this process show precociousness in relation to controls. In contrast to S. frugiperda larvae, onset of pupation was noticeably delayed. Emergence in both cases was drastically diminished. In both pupae and in the few adults that were able to emerge, many deformations were observed. The results of these assays indicated that the compounds were more active than other known natural insect growth inhibitors such as gedunin and methanol extracts of Cedrela salvadorensis and Yucca periculosa. Peniocerol, macdougallin and chichipegenin, as well as mixtures of these substances, may be useful as natural insecticidal agents.

  11. Modeling the cost-effectiveness of insect rearing on artificial diets: A test with a tephritid fly used in the sterile insect technique

    Science.gov (United States)

    Birke, Andrea; Williams, Trevor; Aluja, Martín

    2017-01-01

    We modeled the cost-effectiveness of rearing Anastrepha ludens, a major fruit fly pest currently mass reared for sterilization and release in pest control programs implementing the sterile insect technique (SIT). An optimization model was generated by combining response surface models of artificial diet cost savings with models of A. ludens pupation, pupal weight, larval development time and adult emergence as a function of mixtures of yeast, a costly ingredient, with corn flour and corncob fractions in the diet. Our model revealed several yeast-reduced mixtures that could be used to prepare diets that were considerably cheaper than a standard diet used for mass rearing. Models predicted a similar production of insects (pupation and adult emergence), with statistically similar pupal weights and larval development times between yeast-reduced diets and the standard mass rearing diet formulation. Annual savings from using the modified diets could be up to 5.9% of the annual cost of yeast, corn flour and corncob fractions used in the standard diet, representing a potential saving of US $27.45 per ton of diet (US $47,496 in the case of the mean annual production of 1,730.29 tons of artificial diet in the Moscafrut mass rearing facility at Metapa, Chiapas, Mexico). Implementation of the yeast-reduced diet on an experimental scale at mass rearing facilities is still required to confirm the suitability of new mixtures of artificial diet for rearing A. ludens for use in SIT. This should include the examination of critical quality control parameters of flies such as adult flight ability, starvation resistance and male sexual competitiveness across various generations. The method used here could be useful for improving the cost-effectiveness of invertebrate or vertebrate mass rearing diets worldwide. PMID:28257496

  12. Primary results on 9MeV X-rays irradiation of Monochamus sutor%云杉小墨天牛幼虫和雌虫辐照处理研究初报

    Institute of Scientific and Technical Information of China (English)

    詹国平; 李柏树; 王跃进; 胡明; 李丽; 覃怀莉

    2011-01-01

    采用9MeV X-射线辐照处理云杉小墨天牛4、5龄幼虫和雌虫,结果表明,辐照能明显影响其发育和繁殖能力,导致幼虫期延长,幼虫不能化蛹或羽化,100%阻止幼虫化蛹和羽化的最低吸收剂量分别为45~60Gy、35~40Gy;阻止田间雌虫繁殖F1代幼虫的不育剂量为140Gy,雌雄两性成虫同时辐照的不育剂量小于60Gy.为此,可分别采用60Gy和140Gy处理原木及木质包装中云杉小墨天牛幼虫和成虫,以防止其扩散和传播.%In laboratory tests, the 4th and 5th instar larvae and adults of pine sawyer beetle, Monochamus sutor Linnaeus, was irradiated by 9MeV X -rays, the result shows that there is significant effect on its development and propagation. The irradiation elongated lifespan of irradiated larvae, and prevented its pupation and eclosion. The minimal absorbed dose for 100% preventing pupation and eclosion is 45 ~ 60Gy and 35 ~40Gy, respectively. The sterile dose for female collected in the field is 140Gy, but it was decreasing to 60Gy as the female and male irradiated together. Thus, in order to prevent the introduction and spreading, the minimum effective dose of 60Gy and 140Gy could be suggested for quarantine treatment of the larvae and newly developed adults of M. sutor in logs and wood packing materials.

  13. Potential of biologically active plant oils to control mosquito larvae (Culex pipiens, Diptera: Culicidae from an egyptian locality Potencial de óleos de plantas biologicamente ativos para o controle da larva do mosquito Culex pipiens (Diptera: Culicidae de localidade egípcia

    Directory of Open Access Journals (Sweden)

    Hanem Fathy Khater

    2008-04-01

    Full Text Available The insecticidal effect of six commercially available plant oils was tested against 4th larval instars of Culex pipiens. Larvae were originally collected from Meit El-Attar, Qalyubia Governorate, Egypt, and then reared in the laboratory until F1 generation. The LC50 values were 32.42, 47.17, 71.37, 83.36, 86.06, and 152.94 ppm for fenugreek (Trigonella foenum-grecum, earth almond (Cyperus esculentus, mustard (Brassica compestris, olibanum (Boswellia serrata, rocket (Eruca sativa, and parsley (Carum ptroselinum, respectively. The tested oils altered some biological aspects of C. pipiens, for instance, developmental periods, pupation rates, and adult emergences. The lowest concentrations of olibanum and fenugreek oils caused remarkable prolongation of larval and pupal durations. Data also showed that the increase of concentrations was directly proportional to reduction in pupation rates and adult emergences. Remarkable decrease in pupation rate was achieved by mustard oil at 1000 ppm. Adult emergence was suppressed by earth almond and fenugreek oils at 25 ppm. In addition, the tested plant oils exhibited various morphological abnormalities on larvae, pupae, and adult stages. Consequently, fenugreek was the most potent oil and the major cause of malformation of both larval and pupal stages. Potency of the applied plant oils provided an excellent potential for controlling C. pipiens.O efeito inseticida de seis óleos de plantas comercialmente disponíveis foi testado contra larvas de 4ºinstar de Culex pipiens. Larvas foram coletadas originalmente de Meit El-Attar, Qalyubia Governorate, Egito e então cultivadas no laboratório até a geração F1. Os valores LC50 foram 32,42, 47,17, 71,37, 83,36, 86,06 e 152,94 ppm para o feno grego (Trigonella foenum-grecum, amêndoa da terra (Cyperus esculentus, mostarda (Brassica compestris, olíbano (Boswellia serrata, rocket (Eruca sativa e salsa (Carum ptroselium, respectivamente. Os óleos testados alteraram

  14. Effects of selenium on the development of Ostrinia furnacalis (Guenée)%硒对亚洲玉米螟生长发育的影响

    Institute of Scientific and Technical Information of China (English)

    韩晓霞; 郑丽霞; 魏洪义; 王广利

    2015-01-01

    Objectives] To investigate the influences of selenium on the growth and development of the Asian corn borer (ACB), Ostrinia furnacalis (Guenée). [Methods] Neonate O. furnacalis larvae were reared on the artificial diet containing selenium at a series of concentrations (0.001, 0.005, 0.010, 0.050, 0.100, 0.500, 1.000 mg/kg) under the laboratory condition. [Results] Low concentrations (0.001-0.100 mg/kg) of selenium enhanced ACB development, i.e., shortened the larval duration, pupal duration and increased male and female pupal weight. At the concentration of 0.100 mg/kg of selenium, O. furnacalis exhibited the optimal growth characteristics, which resulted in the highest male pupal weight, the shortest male and female pupal duration, the longest male and female adult lifespan, the highest pupation rate and emergence rate. High concentrations (0.500-1.000 mg/kg) of selenium inhibited ACB development such as prolonged male and female pupal duration, shortened male adult lifespan, reduced pupation rate and emergence rate. At the concentration of 1.000 mg/kg of selenium, O. furnacalis exhibited the worst growth characteristics, which resulted in the longest larval and pupal duration, the lightest pupal weight, the shortest adult lifespan, the lowest pupation rate and emergence rate. [Conclusion] Low concentrations of selenium had promoting effects on the development of O. furnacalis, while high concentrations exerted inhibited influences on it.%【目的】探讨硒对亚洲玉米螟 Ostrinia furnacalis(Guenée)生长发育的影响。【方法】在实验室条件下以添加不同剂量(0.001、0.005、0.010、0.050、0.100、0.500、1.000 mg/kg)硒的人工饲料饲养亚洲玉米螟初孵幼虫。【结果】低浓度(0.001~0.100 mg/kg)硒对亚洲玉米螟的幼虫历期、蛹重、蛹历期具有促进作用。亚洲玉米螟在0.100 mg/kg 浓度下生长状况最佳,其雄蛹重最大,雌雄蛹历期最短,雌雄成虫寿命最长,化蛹率

  15. Silver nanoparticle toxicity in Drosophila: size does matter

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    Deborah J Gorth

    2011-02-01

    Full Text Available Deborah J Gorth1, David M Rand2, Thomas J Webster11School of Engineering, 2Department of Ecology and Evolutionary Biology, Brown University, Providence, RI, USABackground: Consumer nanotechnology is a growing industry. Silver nanoparticles are the most common nanomaterial added to commercially available products, so understanding the influence that size has on toxicity is integral to the safe use of these new products. This study examined the influence of silver particle size on Drosophila egg development by comparing the toxicity of both nanoscale and conventional-sized silver particles.Methods: The toxicity assays were conducted by exposing Drosophila eggs to particle concentrations ranging from 10 ppm to 100 ppm of silver. Size, chemistry, and agglomeration of the silver particles were evaluated using transmission electron microscopy, X-ray photoelectron spectroscopy, and dynamic light scattering.Results: This analysis confirmed individual silver particle sizes in the ranges of 20–30 nm, 100 nm, and 500–1200 nm, with similar chemistry. Dynamic light scattering and transmission electron microscope data also indicated agglomeration in water, with the transmission electron microscopic images showing individual particles in the correct size range, but the dynamic light scattering z-average sizes of the silver nanoparticles were 782 ± 379 nm for the 20–30 nm silver nanoparticles, 693 ± 114 nm for the 100 nm silver nanoparticles, and 508 ± 32 nm for the 500–1200 nm silver particles. Most importantly, here we show significantly more Drosophila egg toxicity when exposed to larger, nonnanometer silver particles. Upon exposure to silver nanoparticles sized 20–30 nm, Drosophila eggs did not exhibit a statistically significant (P < 0.05 decrease in their likelihood to pupate, but eggs exposed to larger silver particles (500–1200 nm were 91% ± 18% less likely to pupate. Exposure to silver nanoparticles reduced the percentage of pupae able

  16. Larval habitats of Anopheles gambiae s.s. (Diptera: Culicidae influences vector competence to Plasmodium falciparum parasites

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    Gouagna Louis C

    2007-04-01

    Full Text Available Abstract Background The origin of highly competent malaria vectors has been linked to productive larval habitats in the field, but there isn't solid quantitative or qualitative data to support it. To test this, the effect of larval habitat soil substrates on larval development time, pupation rates and vector competence of Anopheles gambiae to Plasmodium falciparum were examined. Methods Soils were collected from active larval habitats with sandy and clay substrates from field sites and their total organic matter estimated. An. gambiae larvae were reared on these soil substrates and the larval development time and pupation rates monitored. The emerging adult mosquitoes were then artificially fed blood with infectious P. falciparum gametocytes from human volunteers and their midguts examined for oocyst infection after seven days. The wing sizes of the mosquitoes were also measured. The effect of autoclaving the soil substrates was also evaluated. Results The total organic matter was significantly different between clay and sandy soils after autoclaving (P = 0.022. A generalized liner model (GLM analysis identified habitat type (clay soil, sandy soil, or lake water and autoclaving (that reduces presence of microbes as significant factors affecting larval development time and oocyst infection intensities in adults. Autoclaving the soils resulted in the production of significantly smaller sized mosquitoes (P = 0.008. Autoclaving clay soils resulted in a significant reduction in Plasmodium falciparum oocyst intensities (P = 0.041 in clay soils (unautoclaved clay soils (4.28 ± 0.18 oocysts/midgut; autoclaved clay soils = 1.17 ± 0.55 oocysts/midgut although no difference (P = 0.480 in infection rates was observed between clay soils (10.4%, sandy soils (5.3% or lake water (7.9%. Conclusion This study suggests an important nutritional role for organic matter and microbial fauna on mosquito fitness and vector competence. It shows that the quality of

  17. Insect Development in Altered Gravitational Environment

    Science.gov (United States)

    Tischler, Marc E.

    1996-01-01

    When tobacco hornworm (Manduca sexta) larvae burrow underground (25-30 cm) to pupate, they reorient themselves to a relatively horizontal position indicating an ability to sense gravity. To evaluate their sensitivity to gravitational environment during metamorphosis, Manduca (pharate adults) were placed in a vertical (head-up) position. Distinct morphological changes, each one reflecting ensuing phases, were used to follow adult development. Five days after pupation, the vertical group showed accelerated (P less than 0.05) development and were nearly 4 phases ahead (P less than 0.0001) after 10 days. Differences in development in the vertical group were characterized further by increased (7-48%) hemolymph concentrations of 13 amino acids, but a decrease in cys and pro and no change in arg, his, met and val (trp, undetectable). Decreased (36%) turnover of injected H-3 - phenylalanine suggested slower utilization of amino acids contributed, at least partly, to the increased concentrations. Vertically-oriented Manduca also exhibited a greater (20 %, P less than 0.001) protein content in their flight muscles near the end of development. Analysis of hemolymph sugar levels showed a redistribution of sugars from the monosaccharide glucose to the disaccharide trehalose. Since injection of 20-hydroxyecdysone decreased (49%) turnover of H-3- phenylalanine in pharate adults and since ecdysteroids are known to increase flight muscle size and control adult development, these results are consistent with our measuring a greater (+80%, P less than 0.05) ecdysteroid titer in the vertically-oriented insects. These results suggest that gravity environment influences ecdysone output by the pharate adult. When we evaluated hemolymph flow in the head-up and control positions, we found that injected C-14-inulin was distributed somewhat more rapidly in the head-up group irrespective of the sight of injection (head or abdomen) likely because in the head-up position flow of the hemolymph is

  18. RNA interference of a putative S-adenosyl-L-homocysteine hydrolase gene affects larval performance in Leptinotarsa decemlineata (Say).

    Science.gov (United States)

    Zhou, Li-Tao; Jia, Shuang; Wan, Pin-Jun; Kong, Ye; Guo, Wen-Chao; Ahmat, Tursun; Li, Guo-Qing

    2013-10-01

    In Leptinotarsa decemlineata, juvenile hormones (JHs) play primary roles in the regulation of metamorphosis, reproduction and diapause. In JH biosynthetic pathway in insect corpora allata, methylation of farnesoic acid or JH acid using S-adenosyl-L-methionine generates a potent feedback inhibitor S-adenosyl-L-homocysteine (AdoHcy). Rapid removal of AdoHcy is hypothesized to be essential for JH synthesis. AdoHcy hydrolase (SAHase) is the only eukaryotic enzyme catalyzing the removal. In the present paper, we firstly cloned a putative LdSAHase gene from L. decemlineata. The cDNA consists of 1806 bp and encodes a 525 amino acid protein. LdSAHase was expressed in all developmental stages. The gene had the highest and the lowest level of transcription respectively in the 3rd- and 4th-instars' heads that contain corpora allata, which was positively correlated with JH titer in the haemolymph and the mRNA level of a JH early-inducible gene, the Krüppel homolog 1 gene (Kr-h1). Secondly, dietary ingestion of bacterially-expressed LdSAHase-dsRNA significantly decreased LdSAHase and LdKr-h1 mRNA levels, reduced JH titer, and caused the death of the larvae, and the failure of pupation and adult emergence. After continuous exposure for 12 days, 42% of the larvae died, 65% of the prepupae failed to pupate and 100% of the pupae failed to emerge. Moreover, RNAi-mediated LdSAHase knockdown also reduced larval developing time, and decreased larval weight. Lastly, application of JH analogue pyriproxyfen to LdSAHase-dsRNA-exposed larvae did not greatly increase LdSAHase expression level and JH content, but up-regulated LdKr-h1 mRNA level. Expectedly, pyriproxyfen application could partially rescue the negative effects on the survival and the development. Thus, our results support the hypothesis that SAHase plays a critical role in JH biosynthesis in insects.

  19. 桑蚕活蛹的最适冷藏期研究%Research on the Best Period of Refrigerated Storage for Alive Silkworm Chrysalis

    Institute of Scientific and Technical Information of China (English)

    陈义安; 王晓芬; 刘俊凤; 刘斌彬; 杜周和

    2011-01-01

    [目的]研究桑蚕活蛹的冷藏技术问题,为利于桑蚕活蛹的食用化利用途径拓展.[方法]将刚化蛹的蚕蛹6h收集1次,分别单独存放,在不同的蛹龄时放入冰箱(2℃)中冷藏60d左右.[结果]蛹龄≤12h的蚕蛹I、Ⅱ区的蛹色均有不同程度的变深;蛹龄<24h的蚕蛹,其存活率很低;蛹龄=48h的蚕蛹,其外观在冷藏前后几乎无变化;蛹龄≥192 h的蚕蛹冷藏后无蚕蛹存活,同时出现了蚕蛹蛋白腐败后特有的蛹臭味.[结论]桑蚕在化蛹48h后用2℃冷藏可达60d以上.%[Objective] The ways for the practical utilization of the freshly living pupa would be expanded through the research on the technique of alive silkworm chrysalis refrigeration. [Method] The silkworm chrysalis, just pupated, was collected at each interval of 6 hours, and, stored separately in the refrigerator( 2 ℃) for about 60 days depending on the different pupae ages. [ Results] The color of the pupa with the age ≤ 12 hours was darker. The survival rate of the pupa with the age <24 hours was very low. The appearance of the pupa with the age = 48 hours was almost no change before and after its cold storage. The survival rate of the pupa with the age < 192 hours was zero and meanwhile the unique bad smell of silkworm pupae protein appeared. [ Conclusion] The silkworm pupa, after 48 hours of its pupation, could be refrigerated at 2 ℃ for 60 days or more.

  20. Sensory cell proliferation within the olfactory epithelium of developing adult Manduca sexta (Lepidoptera.

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    Marie-Dominique Franco

    Full Text Available BACKGROUND: Insects detect a multitude of odors using a broad array of phenotypically distinct olfactory organs referred to as olfactory sensilla. Each sensillum contains one to several sensory neurons and at least three support cells; these cells arise from mitotic activities from one or a small group of defined precursor cells. Sensilla phenotypes are defined by distinct morphologies, and specificities to specific odors; these are the consequence of developmental programs expressed by associated neurons and support cells, and by selection and expression of subpopulations of olfactory genes encoding such proteins as odor receptors, odorant binding proteins, and odor degrading enzymes. METHODOLOGY/PRINCIPAL FINDINGS: We are investigating development of the olfactory epithelium of adult M. sexta, identifying events which might establish sensilla phenotypes. In the present study, antennal tissue was examined during the first three days of an 18 day development, a period when sensory mitotic activity was previously reported to occur. Each antenna develops as a cylinder with an outward facing sensory epithelium divided into approximately 80 repeat units or annuli. Mitotic proliferation of sensory cells initiated about 20-24 hrs after pupation (a.p., in pre-existing zones of high density cells lining the proximal and distal borders of each annulus. These high density zones were observed as early as two hr. a.p., and expanded with mitotic activity to fill the mid-annular regions by about 72 hrs a.p. Mitotic activity initiated at a low rate, increasing dramatically after 40-48 hrs a.p.; this activity was enhanced by ecdysteroids, but did not occur in animals entering pupal diapause (which is also ecdysteroid sensitive. CONCLUSIONS/SIGNIFICANCE: Sensory proliferation initiates in narrow zones along the proximal and distal borders of each annulus; these zones rapidly expand to fill the mid-annular regions. These zones exist prior to any mitotic activity

  1. Study of the combined radial post-feeding dispersion of the blowflies Chrysomya megacephala (Fabricius and C. albiceps (Wiedemann (Diptera, Calliphoridae Estudo da dispersão radial combinada de Chrysomya megacephala (Fabricius e C. albiceps (Wiedemann (Diptera, Calliphoridae

    Directory of Open Access Journals (Sweden)

    Leonardo Gomes

    2005-09-01

    Full Text Available Blowflies use discrete and ephemeral substrates to feed their larvae. After they run out of food, the larvae begin to disperse in order to find adequate places for pupation or additional food sources, a process named post-feeding larval dispersion. Some important aspects of this process were studied in a circular arena allowing the combined radial post-feeding dispersion from the center of the arena of C. albiceps and C. megacephala larvae. To determine the location of each pupa, the arena was divided in 72 identical sections starting from the center. The distance from the center, the depth and weight of each pupa were evaluated. Statistical tests were done to verify the relation between weight, depth and distance for pupation. From the total an average of 976 larvae released (488 for each species were collected considering both experiments 456 C. megacephala pupae and 488 of C. albiceps. This demonstrates that C. albiceps probably preyed on 32 C. megacephala larvae during post-feeding dispersion. The study of this dispersion process can be used to estimate the postmortem interval (PMI of human cadavers in legal medicine.As moscas- varejeiras utilizam-se de substratos discretos e efêmeros para alimentar suas larvas. Após deixarem o substrato alimentar, as larvas começam a dispersar em busca de locais adequados para pupação e fontes adicionais de alimento, um processo denominado dispersão larval pós-alimentar. Alguns aspectos importantes desse processo foram estudados em uma arena permitindo a dispersão radial combinada de larvas de C. megacephala e C. albiceps. Para determinar a localização de cada pupa, a arena foi dividida em 72 setores iguais começando do centro. A distância a partir do centro, a profundidade e o peso de cada pupa foram determinados. Testes estatísticos foram feitos para verificar a relação entre peso, profundidade e distância para pupação. De um total em média de 976 larvas soltas (488 de cada esp

  2. Biology and systematics of the New World Phyllocnistis Zeller leafminers of the avocado genus Persea (Lepidoptera, Gracillariidae).

    Science.gov (United States)

    Davis, Donald R; Wagner, David L

    2011-05-11

    Four New World species of Phyllocnistis Zeller are described from serpentine mines in Persea (Family Lauraceae). Phyllocnistis hyperpersea,new species, mines the upper leaf surfaces of avocado, Persea americana Mill., and red bay, Persea borbonia (L.) Spreng. and ranges over much of the southeastern United States into Central America. Phyllocnistis subpersea,new species, mines the underside and occasionally upper sides of new leaves of Persea borbonia in southeastern United States. Phyllocnistis longipalpa, new species, known only from southern Florida also mines the undersides of new leaves of Persea borbonia. Phyllocnistis perseafolia,new species, mines both leaf surfaces and possibly fruits of Persea americana in Colombia, South America. As in all known species of Phyllocnistis, the early instars are subepidermal sapfeeders in young (not fully hardened) foliage, and the final instar is an extremely specialized, nonfeeding larval form, whose primary function is to spin the silken cocoon, at the mine terminus, prior to pupation. Early stages are illustrated and described for three of the species. The unusual morphology of the pupae, particularly the frontal process of the head, is shown to be one of the most useful morphological sources of diagnostic characters for species identification of Phyllocnistis. COI barcode sequence distances are provided for the four proposed species and a fifth, undescribed species from Costa Rica.

  3. Biology and systematics of the New World Phyllocnistis Zeller leafminers of the avocado genus Persea (Lepidoptera, Gracillariidae

    Directory of Open Access Journals (Sweden)

    Donald Davis

    2011-05-01

    Full Text Available Four New World species of Phyllocnistis Zeller are described from serpentine mines in Persea (Family Lauraceae. Phyllocnistis hyperpersea, new species, mines the upper leaf surfaces of avocado, Persea americana Mill., and red bay, Persea borbonia (L. Spreng. and ranges over much of the southeastern United States into Central America. Phyllocnistis subpersea, new species, mines the underside and occasionally upper sides of new leaves of Persea borbonia in southeastern United States. Phyllocnistis longipalpa, new species, known only from southern Florida also mines the undersides of new leaves of Persea borbonia. Phyllocnistis perseafolia, new species, mines both leaf surfaces and possibly fruits of Persea americana in Colombia, South America. As in all known species of Phyllocnistis, the early instars are subepidermal sapfeeders in young (not fully hardened foliage, and the final instar is an extremely specialized, nonfeeding larval form, whose primary function is to spin the silken cocoon, at the mine terminus, prior to pupation. Early stages are illustrated and described for three of the species. The unusual morphology of the pupae, particularly the frontal process of the head, is shown to be one of the most useful morphological sources of diagnostic characters for species identification of Phyllocnistis. COI barcode sequence distances are provided for the four proposed species and a fifth, undescribed species from Costa Rica.

  4. Transcriptomic Response of Drosophila Melanogaster Pupae Developed in Hypergravity

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    Hosamani, Ravikumar; Hateley, Shannon; Bhardwaj, Shilpa R.; Pachter, Lior; Bhattacharya, Sharmila

    2016-01-01

    The metamorphosis of Drosophila is evolutionarily adapted to Earth's gravity, and is a tightly regulated process. Deviation from 1g to microgravity or hypergravity can influence metamorphosis, and alter associated gene expression. Understanding the relationship between an altered gravity environment and developmental processes is important for NASA's space travel goals. In the present study, 20 female and 20 male synchronized (Canton S, 2 to 3day old) flies were allowed to lay eggs while being maintained in a hypergravity environment (3g). Centrifugation was briefly stopped to discard the parent flies after 24hrs of egg laying, and then immediately continued until the eggs developed into P6-staged pupae (25 - 43 hours after pupation initiation). Post hypergravity exposure, P6-staged pupae were collected, total RNA was extracted using Qiagen RNeasy mini kits. We used RNA-Seq and qRT-PCR techniques to profile global transcriptomic changes in early pupae exposed to chronic hypergravity. During the pupal stage, Drosophila relies upon gravitational cues for proper development. Assessing gene expression changes in the pupa under altered gravity conditions helps highlight gravity dependent genetic pathways. A robust transcriptional response was observed in hypergravity-exposed pupae compared to controls, with 1,513 genes showing a significant (q Drosophila pupae in response to hypergravity.

  5. A new threat to honey bees, the parasitic phorid fly Apocephalus borealis.

    Science.gov (United States)

    Core, Andrew; Runckel, Charles; Ivers, Jonathan; Quock, Christopher; Siapno, Travis; Denault, Seraphina; Brown, Brian; Derisi, Joseph; Smith, Christopher D; Hafernik, John

    2012-01-01

    Honey bee colonies are subject to numerous pathogens and parasites. Interaction among multiple pathogens and parasites is the proposed cause for Colony Collapse Disorder (CCD), a syndrome characterized by worker bees abandoning their hive. Here we provide the first documentation that the phorid fly Apocephalus borealis, previously known to parasitize bumble bees, also infects and eventually kills honey bees and may pose an emerging threat to North American apiculture. Parasitized honey bees show hive abandonment behavior, leaving their hives at night and dying shortly thereafter. On average, seven days later up to 13 phorid larvae emerge from each dead bee and pupate away from the bee. Using DNA barcoding, we confirmed that phorids that emerged from honey bees and bumble bees were the same species. Microarray analyses of honey bees from infected hives revealed that these bees are often infected with deformed wing virus and Nosema ceranae. Larvae and adult phorids also tested positive for these pathogens, implicating the fly as a potential vector or reservoir of these honey bee pathogens. Phorid parasitism may affect hive viability since 77% of sites sampled in the San Francisco Bay Area were infected by the fly and microarray analyses detected phorids in commercial hives in South Dakota and California's Central Valley. Understanding details of phorid infection may shed light on similar hive abandonment behaviors seen in CCD.

  6. Partial co-option of the appendage patterning pathway in the development of abdominal appendages in the sepsid fly Themira biloba.

    Science.gov (United States)

    Bowsher, Julia H; Nijhout, H Frederik

    2009-12-01

    The abdominal appendages on male Themira biloba (Diptera: Sepsidae) are complex novel structures used during mating. These abdominal appendages superficially resemble the serially homologous insect appendages in that they have a joint and a short segment that can be rotated. Non-genital appendages do not occur in adult pterygote insects, so these abdominal appendages are novel structures with no obvious ancestry. We investigated whether the genes that pattern the serially homologous insect appendages have been co-opted to pattern these novel abdominal appendages. Immunohistochemistry was used to determine the expression patterns of the genes extradenticle (exd), Distal-less (Dll), engrailed (en), Notch, and the Bithorax Complex in the appendages of T. biloba during pupation. The expression patterns of Exd, En, and Notch were consistent with the hypothesis that a portion of the patterning pathway that establishes the coxopodite has been co-opted to pattern the developing abdominal appendages. However, Dll was only expressed in the bristles of the developing appendages and not the proximal-distal axis of the appendage itself. The lack of Dll expression indicates the absence of a distal domain of the appendage suggesting that sepsid abdominal appendages only use genes that normally pattern the base of segmental appendages.

  7. Detection of transfluthrin and metofluthrin genotoxicity in the ST cross of the Drosophila Wing Spot Test.

    Science.gov (United States)

    Sarıkaya, Rabia; Memmi, Burcu Koçak

    2013-09-01

    In this study, different concentrations of transfluthrin and metofluthrin have been assayed for genotoxicity by using the Wing Spot Test on Drosophila melanogaster. Standard cross was used in the experiment. Third-instar larvae that were trans-heterozygous for the two genetic markers mwh and flr(3) were treated at different concentrations (0.0103mgmL(-1), 0.103mgmL(-1) for transfluthrin and 6μgmL(-1), 60μgmL(-1) for metofluthrin) of the test compounds. Feeding ended with pupation of the surviving larvae and the genetic changes induced in somatic cells of the wing's imaginal discs lead to the formation of mutant clones on the wing blade. Results indicated that two experimental concentrations of transfluthrin and 60μgmL(-1) metofluthrin showed mutagenic and recombinogenic effects in both the marker-heterozygous (MH) flies and the balancer-heterozygous (BH) flies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Molecular phylogeny reveals high diversity, geographic structure and limited ranges in neotenic net-winged beetles platerodrilus (coleoptera: lycidae).

    Science.gov (United States)

    Masek, Michal; Palata, Vaclav; Bray, Timothy C; Bocak, Ladislav

    2014-01-01

    The neotenic Platerodrilus net-winged beetles have strongly modified development where females do not pupate and retain larval morphology when sexually mature. As a result, dispersal propensity of females is extremely low and the lineage can be used for reconstruction of ancient dispersal and vicariance patterns and identification of centres of diversity. We identified three deep lineages in Platerodrilus occurring predominantly in (1) Borneo and the Philippines, (2) continental Asia, and (3) Sumatra, the Malay Peninsula and Java. We document limited ranges of all species of Platerodrilus and complete species level turnover between the Sunda Islands and even between individual mountain regions in Sumatra. Few dispersal events were recovered among the major geographical regions despite long evolutionary history of occurrence; all of them were dated at the early phase of Platerodrilus diversification up to the end of Miocene and no exchange of island faunas was identified during the Pliocene and Pleistocene despite the frequently exposed Sunda Shelf as sea levels fluctuated with each glacial cycle. We observed high diversity in the regions with persisting humid tropical forests during cool periods. The origins of multiple species were inferred in Sumatra soon after the island emerged and the mountain range uplifted 15 million years ago with the speciation rate lower since then. We suppose that the extremely low dispersal propensity makes Platerodrilus a valuable indicator of uninterrupted persistence of rainforests over a long time span. Additionally, if the diversity of these neotenic lineages is to be protected, a high dense system of protected areas would be necessary.

  9. Larval morphology of Metaphycus flavus and its role in host attachment and larval cannibalism.

    Science.gov (United States)

    Tena, A; Kapranas, A; Walker, G P; Garcia-Marí, F; Luck, R F

    2011-06-01

    Metaphycus flavus (Howard) (Hymenoptera: Encyrtidae) is a facultatively gregarious endoparasitoid of soft scales (Hemiptera: Coccidae). When it develops in superparasitised hosts, the larvae often attack and consume brood mates six or more days post oviposition. Under our laboratory conditions (25±1°C and 14 hours of light followed by 18±1°C and ten hours of darkness in 50-70% R.H.), M. flavus eggs hatched three days after oviposition. Measurements of the mandibles and tentorium indicate there are four larval instars, and M. flavus reaches the fourth instar by day six post oviposition, and pupates on day eight. Thus, cannibalism among M. flavus larvae occurs during the fourth instar. During this instar, M. flavus larvae separate from their attachment to the scale cuticle, to which they were tethered by a respiratory structure during the previous three larval instars. Once detached, they are free to move within the scale, which increases the probability of larval encounters and aggressive behaviours. Moreover, the mandibles of the fourth instar are better adapted for fighting than are those of the first three larval instars, since they are larger and more sclerotized. The cranium and mouthparts of M. flavus have four different types of sensory organs, some of which are almost certainly olfactory, an unexpected function for a larva that presumably is surrounded by an aqueous medium where gustatory sensilla would seem to be more appropriate. The cranium also bears two pairs of what appear to be secretory pores.

  10. Immature stages and natural history of the Andean butterfly Altinote ozomene (Nymphalidae: Heliconiinae: Acraeini

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    Patricia Duque Velez

    2011-10-01

    Full Text Available The immature stages (eggs, larvae and pupae, oviposition and larval behavior of Altinote ozomene (Godart, 1819 are described here for the first time. Larvae were reared from egg clutches collected from the host plants Erato vulcanica (Klatt H.Rob and Munnozia senecionidis Benth (Asteraceae. Eggs were laid in groups on the undersides of leaves. The number of instars varied from five to eight within the same egg clutch, and the corresponding development time from larva to adult varied from 91 to 115 days. Most (72% larvae pupated during the sixth instar. The first four instars fed only on the leaf cuticle, whereas later instars consumed the whole leaf. Larvae were gregarious during all instars but rested together only during the day in later instars, either hidden inside dry leaves, on the stem at the base of the host plants, or in the leaf litter. Larvae showed similar morphology and behavior to those previously described for species of Actinote Hübner, 1819 from southeastern Brazil and the Andes.

  11. Sub-lethal effects of Vip3A toxin on survival, development and fecundity of Heliothis virescens and Plutella xylostella.

    Science.gov (United States)

    Gulzar, Asim; Wright, Denis J

    2015-11-01

    The assessment of sub-lethal effects is important to interpret the overall insecticide efficacy in controlling insect pest populations. In addition to the lethal effect, sub-lethal effects may also occur in exposed insects. Vegetative insecticidal proteins (Vips) have shown a broad spectrum of insecticidal activity against many insect pest species. In this study the sub-lethal effects of the Bacillus thuringiensis vegetative insecticidal toxin Vip3A on the development and reproduction of Heliothis virescens F. and Plutella xylostella L. were evaluated in the laboratory. The results indicated that the sub-lethal concentration of Vip3A increased the duration of the larval and pupal stages as compared with the control treatment for both species. The percent pupation and percent adult emergence were significantly lower for Vip3A-treated insects. The proportion of pairs that produced eggs and the longevity of adults were not significantly different between treatments. H. virescens and P. xylostella treated with Vip3A showed an 11 and 17 % decrease in their intrinsic rate of increase (rm) respectively compared with untreated insects. The results from this study will be helpful to develop the strategy to incorporate Vip 3A containing crops in an integrated pest management programme.

  12. Activity of spores and extracellular proteins from six Cry+ strains and a Cry- strain of Bacillus thuringiensis subsp. kurstaki against the western spruce budworm, Choristoneura occidentalis (Lepidoptera: Tortricidae).

    Science.gov (United States)

    Kalmykova, Galina; Burtseva, Ljudmila; Milne, Ross; van Frankenhuyzen, Kees

    2009-05-01

    We characterized insecticidal activity of previously untested strains of Bacillus thuringiensis kurstaki belonging to two crystal serovars (K-1 and K-73) against the western spruce budworm (Choristoneura occidentalis Freeman 1967). By testing various components, we demonstrated that spores play a critical role in the pathogenesis of each strain. Spore-free crystals caused low mortality and purified spores were generally not toxic. The addition of spores to purified protoxin increased toxicity several hundred-fold, regardless of the parental strain from which the spores or protoxins were derived. The crystal and spore components did not account for full insecticidal activity of whole sporulated cultures owing to the toxicity of soluble proteins that are secreted during cell growth. We observed a marked difference in toxicity of secreted proteins between the K-1 and K-73 type strains, with the K-1 preparations causing much higher mortality, mass reduction, and inhibition of pupation. There was a consistent correlation between relative toxicity of secreted protein preparations and the presence and quantity of the Vip3A protein, suggesting that this protein contributes to the virulence of B. thuringiensis subsp. kurstaki in western spruce budworm larvae. However, other virulence factors have to be invoked to explain the synergizing effect of spores from both K-1 and K-73 strains on Cry protein toxicity.

  13. Impact of Lead Acetate on Quantitative Consumption and Utilization of the Cotton Leaf Worm, Spodoptera littoralis (Boisduval, 1833 (Lepidoptera: Noctuidae

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    Shahenda A. Abu ElEla

    2016-06-01

    Full Text Available The 3rd, 4th, 5th, and 6th instars of the cotton leaf worm Spodoptera littoralis (Boisduval, 1833 were treated with lead acetate, 100 mg lead [Pb (C2H3O24]/kg, using the leaf-dip method, toevaluate the effect of Pb on nutritional indices. The consumption index was significantly increasedat the 3rd and 6th instars. The growth rate significantly increased in 4th instars. The reverse wastrue in 6th instars. The absorptive capacity, in terms of approximate digestibility, wasinsignificantly changed in the entire instars. The food utilization efficiencies, in terms of theconversion of ingested (ECI and digested food (ECD to biomass, were significantly increased in4th instars. However, the ECD was significantly decreased in the 5th and 6th instars. In conclusion,treatment with lead may adversely affect the population biomass of S. littoralis due to the grossreduction in the final weight gain of larvae approaching to pupation. This might lead to reducedlevel of population size.

  14. Simple and effective field extraction of human botfly, Dermatobia hominis, using a venom extractor.

    Science.gov (United States)

    West, Jonathan K

    2013-03-01

    After a trip to Belize, a 25-year-old man noticed an erythematous papule on his upper right chest that enlarged over a 6-week period and formed a central aperture. The patient reported feeling movement and intermittent lancinating pains under the skin. The history and examination were consistent with cutaneous myiasis, likely secondary to the human botfly, Dermatobia hominis. The objective of reporting this case is to present a simple method of extraction of a botfly larva using a commercial venom extractor. The patient's upper chest was prepared, and an occlusive dressing was placed over the lesion for 30 minutes. The Extractor Pump (Sawyer Products, Safety Harbor, FL) was applied and activated, and the larva was rapidly extracted completely intact with no significant discomfort to the patient. The wound fully healed without complication. D hominis is a common etiology of cutaneous myiasis endemic to Belize. The larva burrows under the skin of mammals where it develops for a period of weeks before erupting and falling to the soil to pupate. The diagnosis and treatment of botfly infestation is pertinent to doctors in the United States as Central and South America are common travel destinations for North Americans. In this case, a commercially available venom extractor was demonstrated to be a safe, noninvasive, and painless method for botfly extraction in the field without use of hospital resources. Copyright © 2013 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  15. Effects of High-Quality Aromatic Rice Varieties on the Fitness of the Striped Stem Borer, Chilo suppressalis (Walker) in Central China

    Institute of Scientific and Technical Information of China (English)

    DU Xue-zhu; WANG Yong; CHEN Long-jia; PENG Chuan-hua; MA Wei-hua; LEI Chao-liang

    2013-01-01

    The striped stem borer (SSB), Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), is a major pest of rice in China. Variation in host-plant quality may affect the body size of herbivorous insects, which in turn, can determine their life-history parameters such as survival, fecundity and fitness. In this study, we tested the effects of high-quality aromatic rice varieties on the fitness of SSB in China. Results showed that 1st instar larvae had higher penetrating rates and survival rates on the high-quality aromatic rice varieties (EX-1 and WX-988) than that on the non-aromatic rice varieties (EZ-5 and LYP-9). In addition, shorter developmental periods, greater female pupal weights and higher of other life-history parameters (hatching rate, pupation rate, eclosion rate and increase index) were found on the high-quality aromatic rice varieties, although only female pupal weight showed a significant difference between the two varieties. The highest dead heart rate was found on the aromatic rice variety of EX-1. These results indicate that SSB sustains a lower fitness cost when consuming the high-quality aromatic rice varieties (EX-1 and WX-988) than on the non-aromatic rice varieties (EZ-5 and LYP-9) in Central China.

  16. Life-history responses of the rice stem borer Chilo suppressalis to temperature change: Breaking the temperature-size rule.

    Science.gov (United States)

    Fu, Dao-Meng; He, Hai-Min; Zou, Chao; Xiao, Hai-Jun; Xue, Fang-Sen

    2016-10-01

    Temperature is a key environmental factor for ectotherms and affects a large number of life history traits. In the present study, development time from hatching to pupation and adult eclosion, pupal and adult weights of the rice stem borer, Chilo suppressalis were examined at 22, 25, 28 and 31°C under L18:D 6. Larval and pupal times were significantly decreased with increasing rearing temperature and growth rate was positively correlated with temperature. Larval and pupal developmental times were not significantly different between females and males. The relationship between body weight and rearing temperature in C. suppressalis did not follow the temperature-size rule (TSR), both males and females gained the highest body weight at 31°C. Females were significantly larger than males at all temperatures, showing a female biased sex size dimorphism (SSD). Contrary to Rensch's rule, SSD and body weight in C. suppressalis tended to increase with rising temperature. Male pupae lost significantly more weight at metamorphosis compared to females. We discuss the adaptive significance of the reverse-TSR in the moth's life history.

  17. The biology and ecology of the emerald ash borer, Agrilus planipennis, in China.

    Science.gov (United States)

    Wang, Xiao-Yi; Yang, Zhong-Qi; Gould, Juli R; Zhang, Yi-Nan; Liu, Gui-Jun; Liu, En-shan

    2010-01-01

    The biology, ecology, and life cycle of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), were studied using regular inspection in the forest and observations in the laboratory. Results indicated that A. planipennis are mostly univoltine in Tianjin, China. They overwintered individually as mature larvae in shallow chambers excavated in the outer sapwood. In late July, some full-grown larvae began to build overwintering chambers, and all larvae entered the sapwood for dormancy by early November. A. planipennis pupated in the overwintering chamber from early April to mid May the following year, and the average pupal duration was about 20 days. In late April, some newly eclosed adults could be found in the pupal cells, but they had not yet emerged from the tree. Adults began to emerge in early May, with peak flight occurring in mid May. The average longevity of adults was about 21 days and the adult stage lasted through early July. The adults fed on ash foliage as a source of nutrition. Mating was usually conducted and completed on the leaf or trunk surfaces of ash trees. Oviposition began in mid May and eggs hatched on average in 15.7 days. The first instar larvae appeared in early June. The larval stage lasted about 300 days to complete an entire generation. The emerald ash borer had four larval instars on velvet ash, Fraxinus velutina (Scrophulariales: Oleaceae). The major natural control factors of A. planipennis were also investigated, and preliminary suggestions for its integrated management are proposed.

  18. Identification of FXPRLamide Family Neuropeptides from the Japanese Oak Silkworm, Antheraea yamamai Using Immunocytochemistry Methods

    Institute of Scientific and Technical Information of China (English)

    WEI Zhao-jun; LAI Juan-hong; ZHAO Yuan

    2006-01-01

    In the present study, zooblooting, ELISA, and whole-mount immunocytochemistry methods were used to identify the FXPRLamide family neuropeptides from the Japanese oak silkworm, Antheraea yamamai. The results showed that the genomic DNA from A. yamamai showed positive bands after being hybridized with the fragment of DH-PBAN cDNA from Samia cynthia ricini, which was labeled with [α-32P]-dCTP. The SG showed highest FXPRLamide peptides titer in neural organs. Using an antiserum against Helicoverpa armigera PBAN, PBAN-like immunoreactivity was detected in the SG and TG of A. yamamai by whole-mount immunocytochemistry, and there were three cluster cells in the SG which shows positive PBAN-like immunoreactivity. The titers of FXPRLamide peptides immunoreactivity in the hemolymph were kept at a steady level. During pupation, the titer was increased promptly, but then decreased to a low level after the early pupal stage. The above-mentioned results demonstrate the existence of FXPRLamide family peptides in A. yamamai, but its function needs to be further investigated in the future.

  19. 洪洞县春尺蠖的发生与防治研究%Outbreak and Control Study of Apocheima cinerarius in Hongtong County

    Institute of Scientific and Technical Information of China (English)

    王二虎

    2014-01-01

    The process of adult eclosion , spawning, hatching, larvae harm, mature larvae tunneling and pupation of Apoc-heima cinerarius were monitored.Prevention and treatment of coated pesticide ring , spray, puffing in larvae period and a-dult period were explored .Death rate of Apocheima cinerarius adult was 62.2% and that of larvae was 97.4% in 2013, prevention and treatment effect was obvious that control the danger .Prevention and treatment successful experience of Apoc-heima cinerarius, hidden dangers and biological prevention and treatment development were discussed .%笔者对春尺蠖从成虫羽化、产卵、孵化、幼虫危害、老熟幼虫入土化蛹的整个过程进行了监测,探讨了在成虫期和幼虫期涂药环防治、喷药防治、喷烟防治等防治方法。2013年春尺蠖成虫死亡率达到62.2%,幼虫死亡率达到97.4%,防治效果显著,基本控制了春尺蠖的危害。最后,在此基础上讨论了成功防治春尺蠖的经验和今后防治工作的发展方向。

  20. The Effect of MicroRNA bantam on Baculovirus AcMNPV Infection in Vitro and in Vivo

    Directory of Open Access Journals (Sweden)

    Xiaojie Shi

    2016-05-01

    Full Text Available The role of microRNA bantam, one of the most abundant microRNAs in Sf9 cells, was studied for its role in baculovirus infection in vitro and in vivo. The expression level of bantam was increased after AcMNPV infection in Sf9 cells and in Spodoptera litura larvae. In Sf9 cells, application of bantam inhibitor or mimic altered the expression of many virus genes, the most affected gene being lef8, gp41 and p10, the expression level of which was increased by 8, 10 and 40 times, respectively, in the presence of bantam inhibitor. Virus DNA replication was decreased in the presence of bantam mimic and increased in the presence of bantam inhibitor in a dose dependent manner. However, the production of budded virus did not change significantly. Feeding the larvae of S. litura and Spodoptera exigua with bantam antagomiR, a more stable form of the inhibitor, resulted in an abnormal larval growth and a decreased pupation rate. In S. litura, larvae died 3.5 days sooner than the control when bantam antagomiR was applied, together with AcMNPV. In infected S. exigua, larval mortality increased from 47% without antagomiR to 80% with it. The results suggest that microRNA bantam plays an important role in insect growth, as well as in baculovirus-insect interaction.

  1. Ecological monophagy in Tasmanian Graphium macleayanum moggana with evolutionary reflections of ancient angiosperm hosts

    Institute of Scientific and Technical Information of China (English)

    J.MARK SCRIBER; GEOFF R.ALLEN; PAUL W.WALKER

    2006-01-01

    Local host plant specialization in an insect herbivore may be caused by numerous factors,including host-specific natural enemy pressures or a local lack of suitable host-plant choices that are available elsewhere in its range. Such local specialization or "ecological monophagy",for whatever reason,may reflect reduced ability to behaviourally accept or physiologically utilize other allopatric hosts that are naturally used elsewhere by the species.We tested this feeding specialization hypothesis using the Tasmanian subspecies of Macleay's swallowtail butterfly,Graphium macleayanum moggana (Papilionidae),which uses only a single host-plant species,Antherosperma moschatum (southern sassafras,of the Monimiaceae). Further north,this same butterfly species (G. m. macleayanum) uses at least 13 host-plant species from seven genera and four families (Lauraceae,Rutaceae,Winteraceae,and Monimiaceae). Our larval feeding assays with G. m. moggana from Tasmania showed that certain Magnoliaceae and Lauraceae could support some larval growth to pupation.However,such growth was slower and survival was lower than observed on their normal southern sassafras host (Monimiaceae). We also found that toxicity of particular plant species varied tremendously within plant families (for both the Magnoliceae and the Monimiaceae).

  2. Growth and Reproduction of Artificially Fed Cnaphalocrocis medinalis

    Institute of Scientific and Technical Information of China (English)

    XU Jian; LI Chuan-ming; YANG Ya-jun; QI Jian-hang; ZHENG Xu-song; Hu Rong-li; LU Zhong-xian; LIU Qin

    2012-01-01

    The growth and reproduction of rice leaffolder,Cnaphalocrocis medinalis,fed on an artificial diet were studied.The results showed that the larvae were able to grow and pupate on the artificial diet.The durations of larvae and pupas of C.medinalis on the artificial diet were 28.1 d and 10.1 d,postponed 4.9 d and 1.7 d respectively,compared with those reared with rice leaves.The number of ovipositions was 41.6 per female,26.2% higher than that fed on rice leaves.Survival rate curve of larvae was a descent function of mortality-age,with no significant differences from the curve of larvae fed on rice leaves.The net reproductive rate (Ro),intrinsic rate of increase (rm) and finite rate of increase (λ) of the population fed on diet were 17.6928,0.0884 and 1.0924,respectively,and the mean generation time (T) and double time (td) were prolonged 4.9 d and 1.3 d in comparison with the treatment of rice leaves.Population trend index (Ⅰ) was 3.26,indicating a growing number of the population of C.medinalis fed on artificial diet.

  3. Host manipulation by an ichneumonid spider ectoparasitoid that takes advantage of preprogrammed web-building behaviour for its cocoon protection.

    Science.gov (United States)

    Takasuka, Keizo; Yasui, Tomoki; Ishigami, Toru; Nakata, Kensuke; Matsumoto, Rikio; Ikeda, Kenichi; Maeto, Kaoru

    2015-08-01

    Host manipulation by parasites and parasitoids is a fascinating phenomenon within evolutionary ecology, representing an example of extended phenotypes. To elucidate the mechanism of host manipulation, revealing the origin and function of the invoked actions is essential. Our study focused on the ichneumonid spider ectoparasitoid Reclinervellus nielseni, which turns its host spider (Cyclosa argenteoalba) into a drugged navvy, to modify the web structure into a more persistent cocoon web so that the wasp can pupate safely on this web after the spider's death. We focused on whether the cocoon web originated from the resting web that an unparasitized spider builds before moulting, by comparing web structures, building behaviour and silk spectral/tensile properties. We found that both resting and cocoon webs have reduced numbers of radii decorated by numerous fibrous threads and specific decorating behaviour was identical, suggesting that the cocoon web in this system has roots in the innate resting web and ecdysteroid-related components may be responsible for the manipulation. We also show that these decorations reflect UV light, possibly to prevent damage by flying web-destroyers such as birds or large insects. Furthermore, the tensile test revealed that the spider is induced to repeat certain behavioural steps in addition to resting web construction so that many more threads are laid down for web reinforcement. © 2015. Published by The Company of Biologists Ltd.

  4. La conducta de larvas de Drosophila (Diptera; Drosophilidae: su etología, desarrollo, genética y evolución The behavior of Drosophila larvae: their ethology, development, genetics and evolution

    Directory of Open Access Journals (Sweden)

    RAÚL GODOY-HERRERA

    2001-03-01

    Full Text Available Este trabajo, en honor al Profesor Doctor Danko Brncic Juricic (Q.E.P.D., es una revisión de nuestras contribuciones sobre la etología, desarrollo, genética y evolución de patrones de conducta de larvas de Drosophila. Se discute el desarrollo de conductas larvales de forrajeo y sus bases hereditarias. También se discuten estrategias de investigación dirigidas a entender las relaciones entre genotipo y conducta durante el desarrollo de los organismos. Se relacionan patrones de desarrollo de conductas larvales con la filogenia de las especies del grupo mesophragmatica de Drosophila. Finalmente, se distingue entre evolución de elementos de conducta simple y evolución de conductas complejasThis is a review about our contributions in ethology, development, genetics, and evolution of larval behavioral patterns of Drosophila in honor of the late Professor Doctor Danko Brncic Juricic. The developmental behavioral genetics of larval foraging and pupation of Drosophila are discussed. It is also emphasized the importance of research strategies lead to understand properly the relationships between genotype and behavior during development of the organisms. Finally, a comparison between phylogenetic relationships of six Drosophila species of the mesophragmatica group and their developmental patterns of larval behaviors is provided

  5. Food plants and life histories of sawflies of the families Argidae and Tenthredinidae (Hymenoptera in Costa Rica, a supplement

    Directory of Open Access Journals (Sweden)

    David Smith

    2013-10-01

    Full Text Available Food plants and information on life history are presented for six species of Argidae and four species of Tenthredinidae in Costa Rica. The Argidae include cocoons of Atomacera josefernandezi Smith, sp. n., found on Hampea appendiculata (Donn. Sm. Standl. (Malvaceae and likely feeding on its leaves before pupation, and larvae of Eriglenum tristum Smith feeding on Machaerium seemanii Benth. Ex Seem. (Fabaceae, Ptenos leucopodus (Cameron feeding on Inga oerstediana Benth. and I. vera Willd. (Fabaceae, Ptilia peleterii (Gray feeding on Cnestidium rufescens (Connaraceae, and Scobina lepida (Klug and S. notaticollis (Konow feeding on Sida rhombifolia L. (Malvaceae. The Tenthredinidae include larvae of Dochmioglene crassa (Cameron feeding on the fern Lomariopsis vestita E. Fourn. (Lomariopsidaceeae, Dochmiogleme Smith03 feeding on Blechnum occidentale L. (Blechnaceae, Waldheimia laeta (Cameron feeding on Cissus alata Jacq. (Vitaceae, and Waldheimia lucianocapellii Smith, sp. n., feeding on Davilla nitida (Vahl Kubitzki (Dilleniaceae. Waldheimia lucianocapellii is described from specimens from both Panama and Costa Rica. Selandria crassa Cameron, 1883 is a comb. n. in Dochmioglene.

  6. Tri-trophic effects of seasonally variable induced plant defenses vary across the development of a shelter building moth larva and its parasitoid.

    Science.gov (United States)

    Rose, Noah H; Halitschke, Rayko; Morse, Douglass H

    2015-01-01

    Plant chemical defenses can negatively affect insect herbivore fitness, but they can also decrease herbivore palatability to predators or decrease parasitoid fitness, potentially changing selective pressures on both plant investment in production of chemical defenses and host feeding behavior. Larvae of the fern moth Herpetogramma theseusalis live in and feed upon leaf shelters of their own construction, and their most abundant parasitoid Alabagrus texanus oviposits in early instar larvae, where parasitoid larvae lay dormant for most of host development before rapidly developing and emerging just prior to host pupation. As such, both might be expected to live in a relatively constant chemical environment. Instead, we find that a correlated set of phenolic compounds shows strong seasonal variation both within shelters and in undamaged fern tissue, and the relative level of these compounds in these two different fern tissue types switches across the summer. Using experimental feeding treatments, in which we exposed fern moth larvae to different chemical trajectories across their development, we show that exposure to this set of phenolic compounds reduces the survival of larvae in early development. However, exposure to this set of compounds just before the beginning of explosive parasitoid growth increased parasitoid survival. Exposure during the period of rapid parasitoid growth and feeding decreased parasitoid survival. These results highlight the spatial and temporal complexity of leaf shelter chemistry, and demonstrate the developmental contingency of associated effects on both host and parasitoid, implying the existence of complex selective pressures on plant investment in chemical defenses, host feeding behavior, and parasitoid life history.

  7. Insecticidal Constituents and Activity of Alkaloids from Cynanchum mongolicum.

    Science.gov (United States)

    Ge, Yang; Liu, Pingping; Yang, Rui; Zhang, Liu; Chen, Hongxing; Camara, Ibrahima; Liu, Yiqing; Shi, Wangpeng

    2015-09-21

    Based on MS and NMR data and bioassay-guided tracing, three insecticidal alkaloids I, II and III from Cynanchum mongolicum were identified to be antofine N-oxide, antofine and tylophorine. Alkaloid I was more toxic than alkaloids II and III, but they were less active against Spodoptera litura than total alkaloids. The contact toxicity from these alkaloids against the aphid Lipaphis erysimi was significant, as the 24 h-LC50 values of alkaloids I, II, III and total alkaloids were 292.48, 367.21, 487.791 and 163.52 mg/L, respectively. The development disruption of S. litura larvae was tested, the pupation and emergence rates of S. litura decreased and the acute mortality of S. litura increased significantly by day 3 after being injected in their body cavity with 10-40 mg/L of total alkaloid. The ecdysone titer of treated S. litura larvae and prepupae declined with increasing alkaloid concentration. The alkaloids of Cynanchum mongolicum are potential insect growth inhibitors.

  8. Insecticidal effects of Moroccan plant extracts on development, energy reserves and enzymatic activities of Plodia interpunctella

    Directory of Open Access Journals (Sweden)

    N. Bouayad

    2012-10-01

    Full Text Available The aim of this work was to study the effects of methanol extracts of ten plant species used in traditional medicine in Morocco (Peganum harmala, Ajuga iva, Rosmarinus officinalis, Lavandula stoechas, Lavandula dentata, Cistus ladanifer, Cistus salviaefolius, Cistus monspeliensis, Centaurium erythraea and Launaea arborescens on Plodia interpunctella Hübner (Lepidoptera: Pyralidae larvae. Firstly, we studied the effects of the ingestion of these extracts at 500 ppm on post-embryonic development parameters. Most plant extracts provoked a notable decrease of larval weight 8 days after treatment (up to 33% weight loss with C. erythraea and caused significant alterations on pupation (ranging from 5% to 85% and adult emergence (below 2.5% with R. officinalis, C. erythraea and A. iva. The plant extracts that showed strongest effects on post-embryonic development were selected to test their effects on the following physiological parameters: larval reserve substances (at 500 ppm; and midgut activities of hydrolytic and detoxification enzymes (at 500, 750 and 1000 ppm. All treatments provoked a significant reduction of protein and carbon hydrate larval contents, the inhibition of proteases and α-amylase activities in a dose depended manner, and the induction of glutathione S-transferase and esterase (using MtB as substrate activities, whereas the activity of cytochrome P450 monooxygenases and esterases (using 1-NA as substrate increase or decrease depending on the extract concentration and the plant analyzed.

  9. First report of sacbrood virus in honey bee (Apis mellifera) colonies in Brazil.

    Science.gov (United States)

    Freiberg, M; De Jong, D; Message, D; Cox-Foster, D

    2012-09-13

    Sacbrood disease, an affliction of honey bees (Apis mellifera) characterized by brood that fails to pupate and subsequently dies, is an important threat to honey bee health. The disease is caused by the sacbrood virus (SBV), a positive-, single-stranded RNA virus in the order Picornavirales. Because of the economic importance of honey bees for both pollination and honey production, it is vital to understand and monitor the spread of viruses such as SBV. This virus has been found in many places across the globe, including recently in some South American countries, and it is likely that it will continue to spread. We performed a preliminary study to search for SBV in two apiaries of Africanized honey bees in the State of São Paulo, Brazil, using RT-PCR and Sanger sequencing and found the first evidence of SBV in honey bee colonies in Brazil. The virus was detected in larvae, foraging and nurse bees from two colonies, one of which had symptoms of sacbrood disease, at the beginning of the winter season in June 2011. No SBV was found in samples from nine other nearby colonies.

  10. Irradiation effect of different heavy ions and track section on the silkworm Bombyx mori

    Energy Technology Data Exchange (ETDEWEB)

    Tu Zhenli E-mail: tu514@yahoo.co.jp; Kobayashi, Yasuhiko; Kiguchi, Kenji; Watanabe, Hiroshi

    2003-05-01

    In order to compare the irradiation effects of different ions, wandering larvae were whole-body exposed or locally irradiated with 50-MeV {sup 4}He{sup 2+}, 220-MeV {sup 12}C{sup 5+}, and 350-MeV {sup 20}Ne{sup 8+} ions, respectively. For the whole-body-exposed individuals, the survival rates at the cocooning, pupation, and emergence stages all decreased as dose increased, and a range-dependent difference was clearly observed. For local irradiation of ovaries, irradiation effects depend very strongly on the projectile range. In the case of local irradiation of dermal cells by different track sections of heavy ions, the closer the target was to the high-LET section of the track, the more pronounced were the radiation effects. These results indicated that by selectively using ion species and adjusting the irradiation depth to the target, heavy-ion radiosurgery on particular tissues or organs of small experimental animals can be performed more accurately.

  11. Myiasis with Lund's fly (Cordylobia rodhaini) in travelers.

    Science.gov (United States)

    Tamir, Jeremy; Haik, J; Schwartz, Eli

    2003-01-01

    Myiasis is an infestation of human tissue by the larvae of certain flies. There are many forms of myiasis, including localized furuncular myiasis, creeping dermal myiasis and wound and body cavity myiasis.1 Cordylobia anthropophaga (the Tumbu fly) and Dermatobia hominis (the human botfly) are the most common causes of myiasis in Africa and tropical America respectively. The genus Cordylobia also contains two less common species, C. ruandae and C. rodhaini. The usual hosts of C. rodhaini are various mammals (particularly rodents), and and humans are accidentally infested. Figure 1 shows the life cycle of C. rodhaini, which occurs over 55 to -67 days.3 The female fly deposits her eggs on dry sand polluted with the excrement of animals or on human clothing. In about 3 days, the larva is activated by the warm body of the host, hatches and invades the skin. As the larva matures, it induces a furuncular swelling. In 12 to -15 days, the larva reaches a length of about 23 mm, exits the skin and falls to the ground to pupate. The adult fly emerges in 23 to -26 days, and the life cycle resumes. In humans, the skin lesion starts as a red papule that gradually enlarges and develops into a furuncle. In the center of the lesion an opening forms, through which the larva breaths and discharges its serosanguinous feces. The lesion is associated with increasing pain until the larva exits the skin. The disease is usually uncomplicated and self-limiting.

  12. Combining the sterile insect technique with the incompatible insect technique: I-impact of wolbachia infection on the fitness of triple- and double-infected strains of Aedes albopictus.

    Directory of Open Access Journals (Sweden)

    Dongjing Zhang

    Full Text Available The mosquito species Aedes albopictus is a major vector of the human diseases dengue and chikungunya. Due to the lack of efficient and sustainable methods to control this mosquito species, there is an increasing interest in developing and applying the sterile insect technique (SIT and the incompatible insect technique (IIT, separately or in combination, as population suppression approaches. Ae. albopictus is naturally double-infected with two Wolbachia strains, wAlbA and wAlbB. A new triple Wolbachia-infected strain (i.e., a strain infected with wAlbA, wAlbB, and wPip, known as HC and expressing strong cytoplasmic incompatibility (CI in appropriate matings, was recently developed. In the present study, we compared several fitness traits of three Ae. albopictus strains (triple-infected, double-infected and uninfected, all of which were of the same genetic background ("Guangzhou City, China" and were reared under the same conditions. Investigation of egg-hatching rate, survival of pupae and adults, sex ratio, duration of larval stages (development time from L1 to pupation, time to emergence (development time from L1 to adult emergence, wing length, female fecundity and adult longevity indicated that the presence of Wolbachia had only a minimal effect on host fitness. Based on this evidence, the HC strain is currently under consideration for mass rearing and application in a combined SIT-IIT strategy to control natural populations of Ae. albopictus in mainland China.

  13. Expression of Cry1Aa in cassava improves its insect resistance against Helicoverpa armigera.

    Science.gov (United States)

    Duan, Xiaoguang; Xu, Jia; Ling, Erjun; Zhang, Peng

    2013-09-01

    Lepidopteran insects affect cassava production globally, especially in intercropping system. The expression of Cry toxins in transgenic crops has contributed to an efficient control of insect pests, leading to a significant reduction in chemical insecticide usage. Helicoverpa armigera is a Lepidopteran pest that feeds on a wide range of plants like cotton and cassava. In the present study, transgenic cassava plants over-expressing Cry1Aa, which we named as Bt cassava, were developed and used to evaluate its efficacy against H. armigera as a model. Insect feeding assays were carried out to test the effects of Bt cassava leaves on the development and survival of H. armigera. Significant reduction (P cassava leaves in comparison with those fed with wild-type cassava leaves. The higher expression of Cry1Aa in transgenic cassava caused the lethal effect in larvae, in contrast to the normal growth and development of adults and pupation observed when fed with wild-type leaves. Morphological observation on the larval midguts showed that the consumption of Bt cassava affected the gut integrity of H. armigera. The columnar cells of the midgut epithelium were dramatically damaged and showed loose or disordered structure. Their cytoplasms become highly vacuolated and contained disorganized microvilli. Our study demonstrated that the transgenic cassava expressing the Cry1Aa is effective in controlling H. armigera. Our Bt transgenic cassava plant would provide a long-term beneficial effect on all crops in intercropping system, which in-turn, will be profitable to the farmers.

  14. Evaluation of potential genotoxicity of five food dyes using the somatic mutation and recombination test.

    Science.gov (United States)

    Sarıkaya, Rabia; Selvi, Mahmut; Erkoç, Figen

    2012-08-01

    In this study, different concentrations of five food dyes (amaranth, patent blue, carminic acid, indigotine and erythrosine) have been evaluated for genotoxicity in the Somatic Mutation and Recombination Test (SMART) of Drosophila melanogaster. Standard cross was used in the experiment. Larvae including two linked recessive wing hair mutations were chronically fed at different concentrations of the test compounds in standard Drosophila Instant Medium. Feeding ended with pupation of the surviving larvae. Wings of the emerging adult flies were scored for the presence of spots of mutant cells which can result from either somatic mutation or somatic recombination. For the evaluation of genotoxic effects, the frequencies of spots per wing in the treated series were compared to the control group, which was distilled water. The present study shows that carminic acid and indigotine demonstrated negative results while erythrosine demonstrated inconclusive results. In addition 25 mg mL(-1) concentration of patent blue and 12.5, 25 and 50 mg mL(-1) concentrations of amaranth demonstrated positive results in the SMART.

  15. High sucrose consumption promotes obesity whereas its low consumption induces oxidative stress in Drosophila melanogaster.

    Science.gov (United States)

    Rovenko, Bohdana M; Kubrak, Olga I; Gospodaryov, Dmytro V; Perkhulyn, Natalia V; Yurkevych, Ihor S; Sanz, Alberto; Lushchak, Oleh V; Lushchak, Volodymyr I

    2015-08-01

    The effects of sucrose in varied concentrations (0.25-20%) with constant amount of yeasts in larval diet on development and metabolic parameters of adult fruit fly Drosophila melanogaster were studied. Larvae consumed more food at low sucrose diet, overeating with yeast. On high sucrose diet, larvae ingested more carbohydrates, despite consuming less food and obtaining less protein derived from yeast. High sucrose diet slowed down pupation and increased pupa mortality, enhanced levels of lipids and glycogen, increased dry body mass, decreased water content, i.e. resulted in obese phenotype. Furthermore, it suppressed reactive oxygen species-induced oxidation of lipids and proteins as well as the activity of superoxide dismutase. The activity of catalase was gender-related. In males, at all sucrose concentrations used catalase activity was higher than at its concentration of 0.25%, whereas in females sucrose concentration virtually did not influence the activity. High sucrose diet increased content of protein thiols and the activity of glucose-6-phosphate dehydrogenase. The increase in sucrose concentration also enhanced uric acid level in females, but caused opposite effects in males. Development on high sucrose diets was accompanied by elevated steady-state insulin-like peptide 3 mRNA level. Finally, carbohydrate starvation at yeast overfeeding on low sucrose diets resulted in oxidative stress reflected by higher levels of oxidized lipids and proteins accompanied by increased superoxide dismutase activity. Potential mechanisms involved in regulation of redox processes by carbohydrates are discussed.

  16. Do different casein concentrations increase the adverse effect of rutin on the biology of Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae)?

    Science.gov (United States)

    Salvador, Mariana C; Boiça, Arlindo L; de Oliveira, Maria C N; da Graça, José P; da Silva, Débora M; Hoffmann-Campo, Clara B

    2010-01-01

    The flavonoid rutin is recognized as playing an important role in the protection of plants against lepidopterans. Bioassays with this compound are generally carried out using artificial diets. Proteins of high energy value, such as casein, are important ingredients of insect artificial diets as a source of essential amino acids. However, such proteins can generally increase the allelochemical activity. Our objective was to evaluate the effects of rutin on larvae of the velvetbean caterpillar Anticarsia gemmatalis Hübner by incorporating this allelochemical into diets with different concentrations of casein. Three casein concentrations (0, 7 g, or 14 g) combined with none, 0.65%, or 1.30% of rutin were added to the rearing diet and offered to the larvae from hatching to pupation. Rutin negatively affected larval development, the amount of food consumed, and pupal weight of A. gemmatalis. These negative effects were clearly seen in insects fed on diets with 7 g of casein to which any concentration of rutin was added. The effects of rutin when added to the diets without casein were stronger than in diets containing a suitable amount of casein (14 g). The greater negative effects of rutin in diets containing suboptimal concentrations of casein indicate that casein can increase the effects of rutin only when the diets are nutritionally unsuitable for insect development.

  17. Respiratory changes throughout ontogeny in the tobacco hornworm caterpillar, Manduca sexta.

    Science.gov (United States)

    Greenlee, Kendra J; Harrison, Jon F

    2005-04-01

    The respiratory system of growing caterpillars is challenged in two distinct ways as they develop from hatchlings to fifth instars preparing for pupation. First, across instars, body sizes and tracheal lengths increase substantially. Second, within each instar, animal mass can more than double while major tracheal respiratory system structures, such as spiracles and large tracheae, are fixed in size until molting. To test whether these growth processes result in a decrease in O2 delivery capacity relative to tissue oxygen needs, we exposed feeding Manduca sexta larvae of various ages to decreasing levels of atmospheric O2 and measured their metabolic rate and ability to feed. We found that near the beginning of all instars, M. sexta were able to maintain gas exchange and feed down to approximately 5 kPa O2, indicating that these insects are able to match tracheal O2 delivery to increased metabolic rates across instars. However, gas exchange and feeding of caterpillars nearing the molt were limited at much higher O2 levels (up to 15 kPa O2), suggesting that caterpillars have limited capacities to increase tracheal O2 delivery as O2 consumption rates increase within instars. It seems possible that the safety margin for O2 delivery may disappear completely in the last hours before ecdysis, providing an ultimate if not proximate explanation for the necessity of molting.

  18. An improved quarantine method for mangoes against the Mexican fruit fly based on high-pressure processing combined with heat.

    Science.gov (United States)

    Velazquez, Gonzalo; Candelario, Hugo Ernesto; Ramírez, José A; Montoya, Pablo; Loera-Gallardo, Jesús; Vázquez, Manuel

    2010-05-01

    The Mexican fruit fly Anastrepha ludens Loew (Diptera: Tephritidae) is one of the most important insects infesting mangoes, citrus, and other fruits in Mexico and other Latin-American countries. Quarantine methods approved to destroy this insect decrease the shelf life of commodities. The objective of this study was to determine the effect of high-pressure processing using an initial temperature of 50 degrees C on the survivorship of eggs and larvae of the Mexican fruit fly. Eggs and larvae were pressurized at 25, 50, 75, 100, or 150 MPa for 0, 5, 10, or 20 min. The hatching ability of pressurized eggs of 1, 2, 3, and 4 days old and survivorship of the first, second, and third instars were registered. Further, the ability to pupate was studied in surviving third instars. The results showed that eggs were more resistant than larvae to the high-pressure processing. Treatments at 150 MPa at initial 50 degrees C for 10 min destroyed all eggs and larvae of A. ludens, indicating that this process might be useful as a quarantine method for infested mangoes or other fruits.

  19. RNAi-mediated knockdown of the voltage gated sodium ion channel TcNav causes mortality in Tribolium castaneum

    Science.gov (United States)

    Abd El Halim, Hesham M.; Alshukri, Baida M. H.; Ahmad, Munawar S.; Nakasu, Erich Y. T.; Awwad, Mohammed H.; Salama, Elham M.; Gatehouse, Angharad M. R.; Edwards, Martin G.

    2016-01-01

    The voltage-gated sodium ion channel (VGSC) belongs to the largest superfamily of ion channels. Since VGSCs play key roles in physiological processes they are major targets for effective insecticides. RNA interference (RNAi) is widely used to analyse gene function, but recently, it has shown potential to contribute to novel strategies for selectively controlling agricultural insect pests. The current study evaluates the delivery of dsRNA targeted to the sodium ion channel paralytic A (TcNav) gene in Tribolium castaneum as a viable means of controlling this insect pest. Delivery of TcNav dsRNA caused severe developmental arrest with larval mortalities up to 73% post injection of dsRNA. Injected larvae showed significant (p < 0.05) knockdown in gene expression between 30–60%. Expression was also significantly (p < 0.05) reduced in pupae following injection causing 30% and 42% knockdown for early and late pupal stages, respectively. Oral delivery of dsRNA caused dose-dependant mortalities of between 19 and 51.34%; this was accompanied by significant (p < 0.05) knockdown in gene expression following 3 days of continuous feeding. The majority of larvae injected with, or fed, dsRNA died during the final larval stage prior to pupation. This work provides evidence of a viable RNAi-based strategy for insect control. PMID:27411529

  20. A new species of Stenodiplosis (Diptera: Cecidomyiidae) on Spartina grasses (Poaceae) with notes on its biology and its parasitoid Tetrastichus bromi (Hymenoptera: Eulophidae).

    Science.gov (United States)

    López, J Manuel Perilla; Johnson, Paul J; Gagné, Raymond J; Boe, Arvid

    2015-12-09

    Stenodiplosis spartinae Gagné new species (Diptera: Cecidomyiidae) is described from eastern South Dakota and coastal North Carolina, and compared with other American congeners. The known host plants are Spartina alterniflora and S. pectinata. The larva is a seed predator of the ovule and immature caryopsis of the host plant. Adult activity is from the early emergence of the host inflorescence through anthesis. Oviposition occurs in the floret with eggs laid under the edges of the palea and lemma. The larva apparently overwinters in dehisced spikelets in the soil among rhizomes of S. pectinata, with pupation in late spring. Laboratory emergence and field activity of the adults suggest a potentialsecond or third generation developing on late emerging inflorescences. Larval feeding does not induce external color or shape changes in the spikelet. Apparently all three instars are ectoparasitized by Tetrastichus bromi Kostyukov (Hymenoptera: Eulophidae) that was probably introduced to North America in the late 1800's and is inculcated into parasitoid guilds of several Stenodiplosis species. Resource partitioning appears to occur between the gall midge and early instars of Aethes spartinana Barnes and McDunnough (Lepidoptera: Tortricidae) that feed on maturing caryopses. The feeding of this gall midge and the moth probably account for most of the reduced seed production in both natural and agronomic populations of S. pectinata.

  1. Identification and analysis of host plant resistance in leading maize genotypes against spotted stem borer, Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae).

    Science.gov (United States)

    Arabjafari, K H; Jalali, S K

    2007-06-01

    Twenty six popular varieties of maize in Karnataka state (India) were screened for resistance to Chilo partellus (Swinhoe). In field trial, varieties CM132, CM137 and PMZ103 showed the highest level of resistance, respectively. While the varieties GK3014, HY4642 and DK984 had the lowest level of resistance, respectively. In glasshouse trial, the varieties CM137 and HY4642 had the highest and lowest level of resistance. A positive correlation equal to +0.111 (in field) and +0.521 (in glasshouse) was found between the Leaf Injury Score (LIS) and Stem Diameter (SD). Meanwhile, negative correlation equal to -0.432 (in field) and -0.896 (in glasshouse) was found between Leaf Injury Score (LIS) and Internodal Distance (InD). Results of the studies on major nutritional elements on resistant variety CM137 and susceptible variety HY4642 indicated higher percentage of P, K, Fe and Si in stem tissues of the variety CM137, while the variety HY4642 had higher percentage of N and Sugar, highlighting the role of these elements in conferring resistance and susceptibility to C. partellus. Studies on the impact of resistance factors on biological events of C. partellus revealed significant differences between percentage survival of larvae, percentage of pupation, pupal weight and pupal period (females only) on two varieties CM137 and HY4642. But there was no significant difference in the percentage of moth emergence on two varieties.

  2. Assessment of Napier millet (Pennisetum purpureumx P. glaucum) and sorghum (Sorghum bicolor) trap crops for the management of Chilo partellus on maize.

    Science.gov (United States)

    Hari, N S; Jindal, J

    2009-04-01

    Two Napier millet (Pennisetum purpureumxP. glaucum) hybrids, namely PBN 83 and PBN 233 and one sorghum (Sorghum bicolor) variety, SL 44, were assessed for their potential role as a trap crop in the management of the stem borer, Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) on maize. Oviposition preference and larval survival and development were determined for different test plants under laboratory and screen house conditions. Further, field dispersal of C. partellus larvae was assessed between Napier millet and maize crops. Results from no-choice and dual-choice tests indicated that Napier millet hybrids were preferred for oviposition over maize by C. partellus moths. Sorghum was, however, not preferred over maize in this respect. Napier millet hybrids were poor larval hosts, and a rapid decline in larval numbers was noticed within the first five days after hatching and virtually no larvae survived to pupation. Leaf area eaten by the borer larvae was significantly less on these hybrids than on maize or sorghum. Plant damage was more severe in maize and sorghum than Napier millet hybrids. No appreciable larval shift was noticed from Napier millet hybrids to the adjoining maize crop. The evaluated Napier millet hybrids, therefore, had potential for use as trap crop in C. partellus management. Sorghum, however, did not hold promise in this respect.

  3. Diel periodicity of Drosophila suzukii (Diptera: Drosophilidae) under field conditions

    Science.gov (United States)

    Evans, Richard K.; Toews, Michael D.

    2017-01-01

    Drosophila suzukii Matsumura (Diptera: Drosophilidae), an economically important pest of blueberry and other thin-skinned fruits, persists and prolifically reproduces under seemingly lethal climatic conditions in the field. However, behavioral and physiological mechanisms employed by D. suzukii to tolerate such extreme climatic conditions in the field are unknown. The primary objective of this project was to investigate diel periodicity of D. suzukii and their reproductive success under field conditions as related by climatic factors such as temperature and relative humidity. Results show that D. suzukii reproductive success was significantly higher during the night (including dawn and dusk periods) than the day in terms of oviposition, pupation, adult eclosion, and the number of progeny per female. Female D. suzukii reproductive success was not significantly different between specific regions of a blueberry bush in relation to the amount of shade provided by the canopy. Our studies indicate that D. suzukii flight activity is crepuscular and is sensitive to fluctuations in temperature and relative humidity. Results also suggest that the majority of fly activity during peak hours is concentrated in areas around the border and within the center of blueberry orchards with little activity in the surrounding wooded areas. These findings suggest that D. suzukii prefers microclimate with mild temperatures and high humidity, and does not function well when exposed to direct sunlight with extreme heat. The authors propose that D. suzukii management strategies should be implemented during the early morning and immediately before darkness to maximize efficacy. PMID:28187140

  4. Morphology of the Preimaginal Stages of Lasioptera donacis Coutin (Diptera: Cecidomyiidae, a Candidate Biocontrol Agent for Giant Arundo Cane

    Directory of Open Access Journals (Sweden)

    Donald B. Thomas

    2015-01-01

    Full Text Available The larval stages of Lasioptera donacis Coutin consist of three instars which develop within the mesophyll of the leaf sheaths of Arundo donax (L. (Poaceae. The larvae feed aggregatively on mycelia of an ambrosia fungus. The third instars are similar to other members of the genus except for a three-pronged spatula (typically two-pronged and five lateral papillae (typically four and with a nonbristled first instar. A related species, L. arundinis (Schiner which breeds on fungus in Phragmites (Poaceae, also has a three-pronged spatula and five lateral papillae but has a bristled first instar. The third instar of L. donacis has a feeding and a nonfeeding prepupal stage. Papillae associated with the spatula are sensory organs, sensilla chaetica, sensilla trichodea, and sensilla ampullacea, perhaps related to extraoral digestion of the fungal mycelia. Pupation occurs in the host plant within a silken cocoon. Egression of the adult is through an escape hatch excavated by the third instar.

  5. Bioactivity of a water extract of boldus (Peumus boldus Molina against Spodoptera frugiperda (J.E. Smith and Helicoverpa zea Boddie (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    Gonzalo Silva

    2013-06-01

    Full Text Available The insecticidal properties of water-extract of Peumus boldus Molina and its effect on the development cycle and feeding habits of Spodoptera frugiperda J.E. Smith and Helicoverpa zea Boddie were evaluated under laboratory conditions in concentrations of 0.25, 0.5, 1.0, 2.0, 4.0, and 8.0% (w/w. Spodoptera frugiperda was the most susceptible with 75% mortality at 7 d at 8% P. boldus concentration, while H. zea had only 30% mortality. LC50 was 2.31 mL kg-1 for S. frugiperda and 16.05 mL kg¹ for H. zea. When the extract concentration increased in the diet, larval size and weight, percentage of pupation and number of adults decreased, and the time required to reach those states was greater. Neonate larvae fed primarily on the diet with the lower extract concentration and the control was preferred by more than 50% of larvae. Inhibition of feeding, growth, weight gain of 3rd instar larvae as well as new biomass production decreased with concentration of the extract.

  6. Shared Ancestry of Symbionts? Sagrinae and Donaciinae (Coleoptera, Chrysomelidae Harbor Similar Bacteria

    Directory of Open Access Journals (Sweden)

    Dimitra Synefiaridou

    2012-05-01

    Full Text Available When symbioses between insects and bacteria are discussed, the origin of a given association is regularly of interest. We examined the evolution of the symbiosis between reed beetles (Coleoptera, Chrysomelidae, Donaciinae and intracellular symbionts belonging to the Enterobacteriaceae. We analyzed the partial sequence of the 16S rRNA to assess the phylogenetic relationships with bacteria we found in other beetle groups (Cerambycidae, Anobiidae, other Chrysomelidae. We discuss the ecology of each association in the context of the phylogenetic analysis. The bacteria in Sagra femorata (Chrysomelidae, Sagrinae are very closely related to those in the Donaciinae and are located in similar mycetomes. The Sagrinae build a cocoon for pupation like the Donaciinae, in which the bacteria produce the material required for the cocoon. These aspects support the close relationship between Sagrinae and Donaciinae derived in earlier studies and make a common ancestry of the symbioses likely. Using PCR primers specific for fungi, we found Candida sp. in the mycetomes of a cerambycid beetle along with the bacteria.

  7. Cowpea bruchid Callosobruchus maculatus uses a three-component strategy to overcome a plant defensive cysteine protease inhibitor.

    Science.gov (United States)

    Zhu-Salzman, K; Koiwa, H; Salzman, R A; Shade, R E; Ahn, J-E

    2003-04-01

    The soybean cysteine protease inhibitor, soyacystatin N (scN), negatively impacts growth and development of the cowpea bruchid, Callosobruchus maculatus[Koiwa et al. (1998) Plant J 14: 371-379]. However, the developmental delay and feeding inhibition caused by dietary scN occurred only during the early developmental stages (the 1st, 2nd and 3rd instars) of the cowpea bruchid. The 4th instar larvae reared on scN diet (adapted) exhibited rates of feeding and development which were comparable to those feeding on an scN-free diet (unadapted) prior to pupation. Total gut proteolytic capacity at this larval stage significantly increased in the scN-adapted insects. The elevated enzymatic activity was attributed to a differential expression of insect gut cysteine proteases (representing the major digestive enzymes), and of aspartic proteases. scN degradation by the gut extract was observed only in adapted bruchids, and this activity appeared to be a combined effect of scN-induced cysteine and aspartic proteases. Thirty cDNAs encoding cathepsin L-like cysteine proteases were isolated from insect guts, and they were differentially regulated by dietary scN. Our results suggest that the cowpea bruchid adapts to the challenge of scN by qualitative and quantitative remodelling of its digestive protease complement, and by activating scN-degrading protease activity.

  8. Radiation-induced changes in melanization and phenoloxidase in Caribbean fruit fly larvae (diptera:tephritidae) as the basis for a simple test of irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nation, J.L.; Milne, K.; Smittle, B.J. [Univ. of Florida, Gainsville, FL (United States)

    1995-03-01

    First instars of the Caribbean fruit fly, Anastrepha suspensa (Loew), were irradiated with 0, 5, 10, 20, 50, 75, 100, and 150 Gy doses from a Cs-137 source, and observed for whole body melanization as late third instars. Control larvae rapidly melanized, whereas larvae irradiated at {ge}20 Gy failed to show typical melanization after freezing and thawing. Assays of phenoloxidase in control and irradiated larvae showed greatly decreased enzyme activity at {ge}20 Gy and substantial reduction at lower doses. Larvae were also irradiated on the 1st d of each instar, and phenoloxidase activity was determined when they became late third instars. Larvae irradiated on the 1st d of the first instar and on 1st d of the second instar has {approx}90% or greater reduction in phenoloxidase activity as late third instars. Larvae irradiated on the 1st d of the instar had {approx}50% reduction in phenoloxidase activity at the time they became late third instars leaving the food to pupate. A simple spot test for phenoloxidase was developed that produced a red color with a crushed control larvae and no color with a larva irradiated at {ge}25 Gy. The radiation induced changes in melanization and phenoloxidase activity, and a simple spot test may serve as tests for irradiation treatment of Caribbean fruit fly larvae. 10 refs., 2 figs., 2 tabs.

  9. Molecular characterization and functional analysis of BdFoxO gene in the oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae).

    Science.gov (United States)

    Wu, Yi-Bei; Yang, Wen-Jia; Xie, Yi-Fei; Xu, Kang-Kang; Tian, Yi; Yuan, Guo-Rui; Wang, Jin-Jun

    2016-03-10

    The forkhead box O transcription factor (FoxO) is an important downstream transcription factor in the well-conserved insulin signaling pathway, which regulates the body size and development of insects. In this study, the FoxO gene (BdFoxO) was identified from the oriental fruit fly, Bactrocera dorsalis (Hendel). The open reading frame of BdFoxO (2732 bp) encoded a 910 amino acid protein, and the sequence was well conserved with other insect species. The BdFoxO was highly expressed in larvae and pupae among different development stages, and the highest tissue-specific expression level was found in the fat bodies compared to the testis, ovary, head, thorax, midgut, and Malpighian tubules of adults. Interestingly, we found BdFoxO expression was also up-regulated by starvation, but down-regulated when re-fed. Moreover, the injection of BdFoxO double-stranded RNAs into third-instar larvae significantly reduced BdFoxO transcript levels, which in turn down-regulated the expression of other four genes in the insulin signaling pathway. The silencing of BdFoxO resulted in delayed pupation, and the insect body weight increased significantly compared with that of the control. These results suggested that BdFoxO plays an important role in body size and development in B. dorsalis. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Phenoloxidase and its zymogen are required for the larval-pupal transition in Bactrocera dorsalis (Diptera: Tephritidae).

    Science.gov (United States)

    Bai, Ping-Ping; Xie, Yi-Fei; Shen, Guang-Mao; Wei, Dan-Dan; Wang, Jin-Jun

    2014-12-01

    Phenoloxidases (POs) play a key role in melanin production, are involved in invertebrate immune mechanisms, and are considered important enzymes in the insect development process. In the present study, we report the developmental stage and tissue-specific expression patterns of BdPPO1 and PO activity from Bactrocera dorsalis. The results showed that the activity of PO and its zymogen expression were closely related to the development of B. dorsalis during the larval-pupal transition, particularly in the integument. Additionally, biochemical characterization showed that PO from different developmental stages and tissues all had maximum activity at pH 7.5 and 37°C. After feeding a metal ion-containing artificial diet, the activity of PO and expression of BdPPO1 were significantly increased, indicating that PO was a metalloprotein and it could be activated by Zn2+, Mg2+, Ca2+, and Cu2+. The functional analysis showed that the expression of BdPPO1 could be regulated by 20-hydroxyecdysone (20E) after injection. Furthermore, injection of the double-stranded RNA of BdPPO1 into the 3rd instar larvae significantly reduced mRNA levels after 24 h and 48 h, and resulted in a lower pupation rate and abnormal phenotype. These results expand the understanding of the important role of PO and its zymogen in the growth of B. dorsalis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Threat to cedar, Cedrela odorata, plantations in Vietnam by the weevil, Aclees sp.

    Science.gov (United States)

    Thu, Pham Quang; Quang, Dao Ngoc; Dell, Bernard

    2010-01-01

    The recent decline and death of young cedar, Cedrela odorata L. (Sapindales: Meliaceae), plantations in Vietnam is caused by Aclees sp. (Coleoptera: Curculionidae), a wood-boring brown weevil. A field study was undertaken in three-year-old plantations in two districts in Thanh Hoa province in August 2008. Trees were heavily impacted by the weevil, Aclees; the infestation level (P) ranged from 80 to 100% and the average damage index (R) ranged from 1.8 to 2.8. Observations over one year enabled the life history to be determined. Eggs were laid (February to March, September to November) inside the bark from the base of the trunk up to 60 cm in height. Larvae formed extensive feeding tunnels in the inner bark and sap wood. Pupation occurred in feeding tunnels or pupal chambers in the sapwood. Adults emerged twice a year, February to March and August to October. It is concluded that Aclees is a threat to C. odorata plantations in tropical regions of the world, and quarantine measures should be implemented to reduce the risk of spread.

  12. Factors influencing the seasonal abundance of Aedes (Stegomyia) aegypti and the control strategy of dengue and dengue haemorrhagic fever in Thanlyin Township, Yangon City, Myanmar.

    Science.gov (United States)

    Oo, T T; Storch, V; Madon, M B; Becker, N

    2011-08-01

    From June 2006 to May 2007, mosquito surveys were conducted in Thanlyin Township, Yangon City, Myanmar, to determine factors influencing the abundance of Aedes aegypti (Stegomyia aegypti) during the rainy season. Both the biological and environmental factors were included in this study. Increase in the hatchability of egg, larval survival rate, the shortened larval life-span and increased pupation rates supplemented by rainfall (i.e. continuous flooding of the containers, stimulate the continuous hatching of eggs) were observed for correlation with the increase in population density of Ae. aegypti during the rainy season in the study area. Control strategy of Ae. aegypti to analyze the infestation in the community (study area) with larval Ae. aegypti, integrated management measures including health education, attitudes and practices regarding dengue and dengue haemorrhagic fever, transmission of the disease and possible preventive measures, reduction of breeding sites and testing the efficacy of Bacillus thuringiensis israelensis (B.t.i.) with respect to the reduction level of Ae. aegypti larvae in breeding sources, were taken into consideration.

  13. A cathepsin L-like proteinase is involved in moulting and metamorphosis in Helicoverpa armigera.

    Science.gov (United States)

    Wang, L-F; Chai, L-Q; He, H-J; Wang, Q; Wang, J-X; Zhao, X-F

    2010-02-01

    Holometabolous insects undergo larval moulting and metamorphosis within their life cycle. A cDNA encoding the cathepsin L-like proteinase Ha-cathL has been cloned from Helicoverpa armigera. It has a sequence of 1826 bp and encodes a 550-residue protein with a molecular mass of 63 kDa. Northern blot analysis indicated that Ha-cathL is specifically expressed in haemocytes, with increased expression during larval moulting and metamorphosis. In vivo experimentation revealed that Ha-cathL is up-regulated by 20-hydroxyecdysone. Meanwhile, in situ hybridization and immunocytochemistry revealed that Ha-cathL mRNA is mainly expressed in granulocytes and plasmatocytes. Knock down of cathepsin L by RNA interference results in larvae death before pupation or the formation of a chimeric pupa containing a larval head and thorax, abnormal wings and the pupal abdomen. The reason for this is that the affected haemocytes cannot become granulated, and therefore cannot participate in fat body remodelling and wing development. These facts suggest that Ha-cathL is involved in larval moulting and metamorphosis by participating in the functioning of haemocytes.

  14. Correlation of oxygen consumption, cytochrome c oxidase, and cytochrome c oxidase subunit I gene expression in the termination of larval diapause in the bamboo borer, Omphisa fuscidentalis.

    Science.gov (United States)

    Singtripop, Tippawan; Saeangsakda, Manasawan; Tatun, Nujira; Kaneko, Yu; Sakurai, Sho

    2007-09-01

    The moth Omphisa fuscidentalis (Lepidoptera, Pyralidae) is a univoltine insect with a larval diapause period lasting up to 9 months. We studied changes in O(2) consumption in conjunction with cytochrome c oxidase activity and cytochrome c oxidase subunit I (cox1) gene expression. O(2) consumption changed within a day, showing a supradian rhythm with a ca.12-h cycle at 25 degrees C. During the first two-thirds of the diapause period, from October to March, O(2) consumption was constant until January and then increased by March. Topical application of methoprene, a juvenile hormone analog (JHA), to diapausing larvae terminated the diapause and was associated with an increase in O(2) consumption rate at diapause termination. In JHA-treated larvae, cytochrome c oxidase activity in fat bodies was high at the beginning of the prepupal period and highest at pupation. cox1 expression in fat bodies displayed a transient peak 8 days after JHA application and peaked in the prepupal period. Taken together, our results show that the break of diapause by JHA is associated with the activation of cox1, bringing about an increase in cytochrome c oxidase activity, followed by an increase in O(2) consumption rate.

  15. Insecticidal effects of Moroccan plant extracts on development, energy reserves and enzymatic activities of Plodia interpunctella

    Energy Technology Data Exchange (ETDEWEB)

    Bouayard, N.; Rharrabe, K.; Ghailani, N. N.; Jbilou, R.; Castanera, P.; Ortego, F.

    2013-05-01

    The aim of this work was to study the effects of methanol extracts of ten plant species used in traditional medicine in Morocco (Peganum harmala, Ajuga iva, Rosmarinus officinalis, Lavandula stoechas, Lavandula dentata, Cistus ladanifer, Cistus salviaefolius, Cistus monspeliensis, Centaurium erythraea and Launaea arborescens) on Plodia interpunctella Hubner (Lepidoptera: Pyralidae) larvae. Firstly, we studied the effects of the ingestion of these extracts at 500 ppm on post-embryonic development parameters. Most plant extracts provoked a notable decrease of larval weight 8 days after treatment (up to 33% weight loss with C. erythraea) and caused significant alterations on pupation (ranging from 5% to 85%) and adult emergence (below 2.5% with R. officinalis, C. erythraea and A. iva). The plant extracts that showed strongest effects on post-embryonic development were selected to test their effects on the following physiological parameters: larval reserve substances (at 500 ppm); and midgut activities of hydrolytic and detoxification enzymes (at 500, 750 and 1000 ppm). All treatments provoked a significant reduction of protein and carbon hydrate larval contents, the inhibition of proteases and {alpha}-amylase activities in a dose depended manner, and the induction of glutathione S-transferase and esterase (using MtB as substrate) activities, whereas the activity of cytochrome P450 monooxygenases and esterases (using 1-NA as substrate) increase or decrease depending on the extract concentration and the plant analyzed. (Author) 65 refs.

  16. Temporal and spatial variation of Stenoma cathosiota Meyrick (Lepidoptera: Elachistidae) caterpillar abundance in the cerrado of Brasilia, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Morais, Helena C.; Mangabeira, Jacimary A. [Universidade Federal de Brasilia (UnB), DF (Brazil). Inst. de Ciencias Biologicas. Dept. de Ecologia]. E-mail: morais@unb.br; Cabral, Berites C.; Diniz, Ivone R. [Universidade Federal de Brasilia (UnB), DF (Brazil). Inst. de Ciencias Biologicas. Dept. de Zoologia]. E-mail: irdiniz@unb.br

    2007-11-15

    The caterpillars of Stenoma cathosiota Meyrick feed on Roupala montana Aubl. (Proteaceae) in the cerrado of the Distrito Federal, Brazil. They construct shelters by joining leaves of the plant where they feed and pupate. The caterpillars are parasitized by a wasp (Hymenoptera: Brachonidae), which emerges from the pupae. Caterpillar abundance and parasitism frequency were associated in an area of frequently burned cerrado (biennial fire) and in another area that burns sporadically (1987 and 1994). For S. cathosiota, the variation among years in a single area, with sporadic fires, was greater than the variation among areas with different fire regimes. Caterpillar abundance among years was significantly different in the area that burns sporadically (c{sup 2} = 24.06; df. = 1; P = 0.000). However, there were no significant differences on caterpillar abundance between areas for the same period (c{sup 2} 3.45; df. = 1; P = 0.063). Parasitism frequency was high, reaching 29% of the collected caterpillars, and did not differ among areas. The great temporal variation in abundance of lepidopteran caterpillars in the cerrado makes it difficult to determine the effects that fire exerts over this fauna. (author)

  17. Characterization of the complete mitochondrial genome of the black cutworm Agrotis ipsilon (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Wu, Qiu-Ling; Cui, Wen-Xia; Wei, Shu-Jun

    2015-02-01

    The complete mitochondrial genome of the black cutworm Agrotis ipsilon (Lepidoptera: Noctuidae) was determined (GenBank accession No. KF163965). The length of this mitochondrial genome is 15,377 bp with an A + T content of 82.5%. There are 37 typical animal mitochondrial genes, that is, 13 protein-coding, 2 rRNA and 22 tRNA gene and an A + T-rich region. The tRNA gene trnM was rearranged to the upstream of the trnI-trnQ-trnM cluster compared with the pupative ancestral arrangement of insects. All protein-coding genes start with ATN start codon except for the gene cox1, which uses CGA as in other lepidopteran species. Ten protein-coding genes stop with termination codon TAA, whereas three protein-coding gene use incomplete stop codon T. The A + T-region is located between rrnS and trnM with a length of 332 bp and A + T content of 94.88%.

  18. Assessment of electron beam-induced abnormal development and DNA damage in Spodoptera litura (F.) (Lepidoptera: Noctuidae)

    Science.gov (United States)

    Yun, Seung-Hwan; Lee, Seon-Woo; Koo, Hyun-Na; Kim, Gil-Hah

    2014-03-01

    The armyworm, Spodoptera litura (F.) is a polyphagous and important agricultural pest worldwide. In this study, we examined the effect of electron beam irradiation on developmental stages, reproduction, and DNA damage of S. litura. Eggs (0-24 h old), larvae (3rd instar), pupae (3 days old after pupation), and adults (24 h after emergence) were irradiated with electron beam irradiation of six levels between 30 and 250 Gy. When eggs were irradiated with 100 Gy, egg hatching was completely inhibited. When the larvae were irradiated, the larval period was significantly delayed, depending on the doses applied. At 150 Gy, the fecundity of adults that developed from irradiated pupae was entirely inhibited. However, electron beam irradiation did not induce the instantaneous death of S. litura adults. Reciprocal crosses between irradiated and unirradiated moths demonstrated that females were more radiosensitive than males. We also conducted the comet assay immediately after irradiation and over the following 5 days period. Severe DNA fragmentation in S. litura cells was observed just after irradiation and the damage was repaired during the post-irradiation period in a time-dependent manner. However, at more than 100 Gy, DNA damage was not fully recovered.

  19. Monitoring Aethina tumida (Coleoptera: Nitidulidae) with baited bottom board traps: occurrence and seasonal abundance in honey bee colonies in Kenya.

    Science.gov (United States)

    Torto, Baldwyn; Fombong, Ayuka T; Arbogast, Richard T; Teal, Peter E A

    2010-12-01

    The population dynamics of the honey bee pest Aethina tumida Murray (small hive beetle) have been studied in the United States with flight and Langstroth hive bottom board traps baited with pollen dough inoculated with a yeast Kodamaea ohmeri associated with the beetle. However, little is known about the population dynamics of the beetle in its native host range. Similarly baited Langstroth hive bottom board traps were used to monitor the occurrence and seasonal abundance of the beetle in honey bee colonies at two beekeeping locations in Kenya. Trap captures indicated that the beetle was present in honey bee colonies in low numbers all year round, but it was most abundant during the rainy season, with over 80% trapped during this period. The survival of larvae was tested in field releases under dry and wet soil conditions, and predators of larvae were identified. The actvity and survival of the beetle were strongly influenced by a combination of abiotic and biotic factors. Larval survival was higher during wet (28%) than dry (1.1%) conditions, with pupation occurring mostly at 0-15 cm and 11-20 cm, respectively, beneath the surface soil during these periods. The ant Pheidole megacephala was identified as a key predator of larvae at this site, and more active during the dry than wet seasons. These observations imply that intensive trapping during the rainy season could reduce the population of beetles infesting hives in subsequent seasons especially in places where the beetle is a serious pest.

  20. Feast or famine: role of TRPML in preventing cellular amino acid starvation.

    Science.gov (United States)

    Venkatachalam, Kartik; Wong, Ching-On; Montell, Craig

    2013-01-01

    Lysosomal storage diseases are metabolic disorders characterized by the accumulation of acidic vacuoles, and are usually the consequence of the deficiency of an enzyme responsible for the metabolism of vesicular lipids, proteins or carbohydrates. In contrast, mucolipidosis type IV (MLIV), results from the absence of a vesicular Ca ( 2+) release channel called mucolipin 1/transient receptor potential mucolipin 1 (MCOLN1/TRPML1) which is required for the fusion of amphisomes with lysosomes. In Drosophila, ablation of the MCOLN1 homolog (trpml) leads to diminished viability during pupation when the animals rely on autophagy for nutrients. This pupal lethality results from decreased target of rapamycin complex 1 (TORC1) signaling, and is reversed by reactivating TORC1. Our findings indicate that one of the primary causes of toxicity in the absence of TRPML is cellular amino acid starvation, and the resulting decrease in TORC1 activity. Furthermore, our findings raise the intriguing possibility that the neurological dysfunction in MLIV patients may arise from amino acid deprivation in neurons. Therefore, future studies evaluating the levels of amino acids and TORC1 activity in MLIV neurons may aid in the development of novel therapeutic strategies to combat the severe manifestations of MLIV.

  1. Transgenic insect-resistant corn affects the fourth trophic level: effects of Bacillus thuringiensis-corn on the facultative hyperparasitoid Tetrastichus howardi

    Science.gov (United States)

    Prütz, Gernot; Brink, Andreas; Dettner, Konrad

    2004-09-01

    As hyperparasitoids may have a considerable influence on the control of herbivorous arthropods, analyzing the host-mediated impact of Bacillus thuringiensis-plants (“Bt-plants”) on hyperparasitoids is of interest. Laboratory-scale experiments were conducted in order to assess the potential effect of Bt-corn leaf material on the facultative hyperparasitoid Tetrastichus howardi (Olliff) (Hymenoptera: Eulophidae), mediated through the herbivore Chilo partellus Swinhoe (Lepidoptera: Crambidae) and its primary parasitoid Cotesia flavipes (Cameron) (Hymenoptera: Braconidae). In the Bt-group, significantly less C. flavipes larvae per host spun cocoons and pupated than in the control, and the mean fresh weight of a single C. flavipes cocoon was significantly reduced compared to the control. All C. flavipes cocoons of one host formed cocoon clusters. T. howardi females of the Bt-group parasitized significantly less cocoon clusters than in the control. Moreover, significantly fewer C. flavipes cocoons per cocoon cluster were successfully parasitized as compared to the control. As a consequence, T. howardi females of the control had more offspring than in the Bt-group. Adult female T. howardi offspring of the Bt-group weighed significantly less than in the control, but there was no significant weight difference between males of both groups. Our results suggest that transgenic insect-resistant plants could affect hyperparasitoids indirectly. However, it remains to be determined whether facultative hyperparasitoids prefer to develop as primary or secondary parasitoids under field conditions.

  2. Lethal and sublethal effects of an insect growth regulator, pyriproxyfen, on obliquebanded leafroller (Lepidoptera: Tortricidae).

    Science.gov (United States)

    Sial, Ashfaq A; Brunner, Jay F

    2010-04-01

    The obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae), is one of the most destructive pests of tree fruit in Washington. The development of insecticide resistance in C. rosaceana has led us to explore new management tactics. The use of very low doses of insecticides that have strong sublethal effects represents an environmentally friendly option to improve existing integrated pest management (IPM) strategies. We tested the insect growth regulator pyriproxyfen to determine its lethal and sublethal effects on growth and development of C. rosaceana. A leaf-disk bioassay was used to test seven concentrations of pyriproxyfen ranging from 0 to 30 ppm on fifth-instar C. rosaceana. Male and female larvae were assessed separately for mortality as well as other parameters of growth and development. The LC, values for males and females were 2.4 and 4.8 ppm, respectively. The response to pyriproxyfen was concentration-dependent: only 5-6% of the larvae treated with the highest concentration emerged as morphologically normal adults compared with 86% emergence in the controls. The pupation and adult emergence was significantly delayed at concentrations higher than 1 ppm. The weights of C. rosaceana pupae and adults were significantly increased, whereas fecundity and fertility were significantly reduced at a sublethal concentration of 0.3 ppm. We conclude that both lethal and sublethal effects might exhibit significant impacts on the population dynamics of C. rosaceana in tree fruit orchards treated with low concentrations of pyriproxyfen.

  3. Effects of density dependent larval competition on the life history traits of Aedes aegypti and Aedes albopictus (Diptera: Culicidae

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    Sampa Banerjee

    2017-06-01

    Full Text Available Consequences of larval competition at the population level provide explanation for the differences in relative abundance of Aedes aegypti and Aedes albopictus in different geographical regions. The outcome of competition is assessed through the estimates of the life history traits as a response to varying density and resource available for larval development. In the present study, variations in the life history traits due to density-dependent intra- and inter- specific competition involving A. aegypti and A. albopictus were assessed following the minimalist model. The instar-I larvae (0-day old F2 generation of both Aedes species were reared to the adult stages using the initial rearing density of 1, 2, 4 and 6 (individuals/10ml in multiple replicates. The age at pupation, pupal weight, adult weight and adult wing length of the individuals were considered as the response variables and surrogates of estimating the competitive interactions. Density dependent variations in the competitive interactions were evident for both the mosquitoes with reference to the selected life history traits. In A. aegypti, the life history traits varied with the levels of competition, which was not observed for A. albopictus. Although the density levels considered in the present instance were lower than in earlier studies, the observations were similar, with A. albopictus being competitively superior. It appears that irrespective of the density levels, interspecific competition affects A. aegypti and thus may bear population level consequences and overall abundance in the areas where both species are present.

  4. Comparative Growth and Survival of Hylurgus ligniperda (Coleoptera: Scolytinae) and Arhopalus ferus (Coleoptera: Cerambycidae) Reared on Artificial or Natural Diet at 15 or 25°C.

    Science.gov (United States)

    Romo, C M; Bader, M K-F; Pawson, S M

    2016-02-01

    Two saproxylic forest insects, Hylurgus ligniperda (F.) (Coleoptera: Scolytinae) and Arhopalus ferus (Mulsant)(Coleoptera: Cerambycidae), were reared on artificial or natural diet at 15 or 25°C to compare larval growth rates and survival. A significant diet by temperature interaction was observed in the growth of H. ligniperda larvae,which developed faster when reared on natural diet at 15°C, but grew faster and pupated significantly earlier when reared on artificial diet at 25°C. However, H. ligniperda survival by the end of the experiment was low on both diets when reared at 25°C (10.1%, 95% CI: 5.2–15.1%), which suggests that rearing at lower temperatures may be required. A. ferus larvae gained significantly larger body size when reared on artificial diet than on natural diet at both temperatures. Survival of A. ferus reared on artificial diet was significantly lower than larvae reared on natural diet at 25°C. The significant differences between A. ferus larval development rates when reared on artificial and natural diets preclude the use of artificial diet to collect meaningful data to construct temperature development models for ecological comparisons. Artificial diet provided a suitable medium for mass production of individuals for research purposes, e.g., test mortality in response to treatments. However, additional rearing studies are needed to determine whether the larger artificially reared larvae result in adults that are healthier, more productive, and live longer.

  5. E2F function in muscle growth is necessary and sufficient for viability in Drosophila.

    Science.gov (United States)

    Zappia, Maria Paula; Frolov, Maxim V

    2016-01-01

    The E2F transcription factor is a key cell cycle regulator. However, the inactivation of the entire E2F family in Drosophila is permissive throughout most of animal development until pupation when lethality occurs. Here we show that E2F function in the adult skeletal muscle is essential for animal viability since providing E2F function in muscles rescues the lethality of the whole-body E2F-deficient animals. Muscle-specific loss of E2F results in a significant reduction in muscle mass and thinner myofibrils. We demonstrate that E2F is dispensable for proliferation of muscle progenitor cells, but is required during late myogenesis to directly control the expression of a set of muscle-specific genes. Interestingly, E2f1 provides a major contribution to the regulation of myogenic function, while E2f2 appears to be less important. These findings identify a key function of E2F in skeletal muscle required for animal viability, and illustrate how the cell cycle regulator is repurposed in post-mitotic cells.

  6. Insecticidal effects of various concentrations of selected extractions of Cestrum parqui on adult and immature Ceratitis capitata.

    Science.gov (United States)

    Zapata, Nelson; Budia, Flor; Viñuela, Elisa; Medina, Pilar

    2006-04-01

    Aqueous extracts of Cestrum parqui L'Héritier (Solanaceae) were evaluated at different concentrations in several stages of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). For adults, the study was extended to extracts obtained with several solvents of an increasing degree of polarity. Aqueous extracts from C. parqui showed a high toxicity to neonate larvae when ingested through diet, inhibiting pupation at a concentration above 0.6%. Lower concentrations delayed the larval development and reduced the percentages of pupae formed and adult emergence. An LC50 = 0.9% after 3 d of continuous ingestion of C. parqui aqueous extracts could be calculated, whereas extracts obtained with organic compounds were nearly innocuous except with the use of the solvent methanol/water (80:20), the more polar of those tested, that killed 12.5% of adults. Aqueous extracts were also harmful to adults by diminishing the reproductive potential, which implies a significant effect on the offspring. Egg contact with insecticide or dipping third instars did not cause any adverse effect, supporting the hypothesis that only by means of ingestion can the toxic compounds of C. parqui reach the target. Our results showed that C. parqui components causing C. capitata mortality are mostly dissolved in water and not in organic solvents, which point out their polar character.

  7. Molybdate partly mimics insulin-promoted metabolic effects in Drosophila melanogaster.

    Science.gov (United States)

    Rovenko, Bohdana M; Perkhulyn, Natalia V; Lushchak, Oleh V; Storey, Janet M; Storey, Kenneth B; Lushchak, Volodymyr I

    2014-09-01

    Molybdenum-containing salts have been found to attenuate diabetes complications in mammals by affecting processes normally regulated by insulin and thus were believed to mimic insulin activity. In this study, we used a fruit fly model to test sodium molybdate, Na2MoO4, action in relation to insulin-promoted processes and toxicity. We studied how larval food supplementation with sodium molybdate affected levels of body carbohydrates and lipids in two-day old adult Drosophila melanogaster. Molybdate salt, in the concentrations used (0.025, 0.05, 0.5, 5, and 10mM), showed low toxicity to fly larvae and slightly influenced development and the percentage of pupated animals. Additionally, sodium molybdate decreased the level of hemolymph glucose in males by 30%, and increased the level of hemolymph trehalose in flies of both sexes. These changes were accompanied by an increase in whole body trehalose and glycogen of about 30-90%. Although total lipid levels in flies of both sexes were depleted by 25%, an increased amount of triacylglycerides among total lipids was observed. These effects were not related to changes in food intake. Taken together, the present data let us suggest that sodium molybdate may at least partly mimic insulin-related effects in Drosophila.

  8. The mitochondrial genome of the multicolored Asian lady beetle Harmonia axyridis (Pallas) and a phylogenetic analysis of the Polyphaga (Insecta: Coleoptera).

    Science.gov (United States)

    Niu, Fang-Fang; Zhu, Liang; Wang, Su; Wei, Shu-Jun

    2016-07-01

    Here, we report the mitochondrial genome sequence of the multicolored Asian lady beetle Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) (GenBank accession No. KR108208). This is the first species with sequenced mitochondrial genome from the genus Harmonia. The current length with partitial A + T-rich region of this mitochondrial genome is 16,387 bp. All the typical genes were sequenced except the trnI and trnQ. As in most other sequenced mitochondrial genomes of Coleoptera, there is no re-arrangement in the sequenced region compared with the pupative ancestral arrangement of insects. All protein-coding genes start with ATN codons. Five, five and three protein-coding genes stop with termination codon TAA, TA and T, respectively. Phylogenetic analysis using Bayesian method based on the first and second codon positions of the protein-coding genes supported that the Scirtidae is a basal lineage of Polyphaga. The Harmonia and the Coccinella form a sister lineage. The monophyly of Staphyliniformia, Scarabaeiformia and Cucujiformia was supported. The Buprestidae was found to be a sister group to the Bostrichiformia.

  9. Larvicidal effects of a neem (Azadirachta indica oil formulation on the malaria vector Anopheles gambiae

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    Knols Bart GJ

    2007-05-01

    Full Text Available Abstract Background Larviciding is a key strategy used in many vector control programmes around the world. Costs could be reduced if larvicides could be manufactured locally. The potential of natural products as larvicides against the main African malaria vector, Anopheles gambiae s.s was evaluated. Methods To assess the larvicidal efficacy of a neem (Azadirachta indica oil formulation (azadirachtin content of 0.03% w/v on An. gambiae s.s., larvae were exposed as third and fourth instars to a normal diet supplemented with the neem oil formulations in different concentrations. A control group of larvae was exposed to a corn oil formulation in similar concentrations. Results Neem oil had an LC50 value of 11 ppm after 8 days, which was nearly five times more toxic than the corn oil formulation. Adult emergence was inhibited by 50% at a concentration of 6 ppm. Significant reductions on growth indices and pupation, besides prolonged larval periods, were observed at neem oil concentrations above 8 ppm. The corn oil formulation, in contrast, produced no growth disruption within the tested range of concentrations. Conclusion Neem oil has good larvicidal properties for An. gambiae s.s. and suppresses successful adult emergence at very low concentrations. Considering the wide distribution and availability of this tree and its products along the East African coast, this may prove a readily available and cheap alternative to conventional larvicides.

  10. Crystal structure of Bombyx mori arylphorins reveals a 3:3 heterohexamer with multiple papain cleavage sites.

    Science.gov (United States)

    Hou, Yong; Li, Jianwei; Li, Yi; Dong, Zhaoming; Xia, Qingyou; Yuan, Y Adam

    2014-06-01

    In holometabolous insects, the accumulation and utilization of storage proteins (SPs), including arylphorins and methionine-rich proteins, are critical for the insect metamorphosis. SPs function as amino acids reserves, which are synthesized in fat body, secreted into the larval hemolymph and taken up by fat body shortly before pupation. However, the detailed molecular mechanisms of digestion and utilization of SPs during development are largely unknown. Here, we report the crystal structure of Bombyx mori arylphorins at 2.8 Å, which displays a heterohexameric structural arrangement formed by trimerization of dimers comprising two structural similar arylphorins. Our limited proteolysis assay and microarray data strongly suggest that papain-like proteases are the major players for B. mori arylphorins digestion in vitro and in vivo. Consistent with the biochemical data, dozens of papain cleavage sites are mapped on the surface of the heterohexameric structure of B. mori arylphorins. Hence, our results provide the insightful information to understand the metamorphosis of holometabolous insects at molecular level.

  11. Biology and management of the masked chafer Cyclocephala distincta Burmeister (Melolonthidae, Dynastinae, Cyclocephalini

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    Thamyrys B. Souza

    2015-03-01

    Full Text Available Adults of Cyclocephala distincta are flower visitors of Neotropical palms (Arecaceae and commonly found in the Atlantic Forest of Pernambuco, Brazil. Males and females were collected in the wild and subjected to captive rearing and breeding. The egg hatching rate, the life cycle, longevity of immatures and adults, and oviposition parameters in captivity were analyzed. The average duration of the life cycle of C. distincta was 108.2 days (n = 45. The egg stage lasted on average 10.9 days, and the egg-hatching rate was 73.9%. The immature stage lasted on average 93.4 days. The larvae stage exhibited negative phototaxis, and the size of their head capsules increased at a constant rate of 1.6 between instars, following Dyar's rule. The average duration of the first instar was 24.8 days (n = 88, whereas the second and third instars lasted for 17.2 (n = 76 and 40.4 (n = 74 days respectively, and survival rates were 21.6%, 86.4% and 97.4%. The pre-pupal stage was recorded, and pupal chambers were built before pupation. The average number of eggs laid per female was 15.5, the total reproductive period lasted for 3.3 days, and the total fertility was 81.2%. Adults that emerged in captivity exhibited an average longevity of 18.9 days. Adult C. distincta exhibited thanatosis behavior upon manipulation, a strategy observed for the first time in Cyclocephala.

  12. No nutritional benefits of egg cannibalism for Coleomegilla maculata (Coleoptera: Coccinellidae) on a high-quality diet.

    Science.gov (United States)

    Abdelwahab, A H; Michaud, J P; Bayoumy, M H; Awadalla, S S; El-Gendy, M

    2017-09-11

    Egg cannibalism serves various functions in the Coccinellidae. Here we examined the fitness consequences of egg cannibalism by neonates, fourth instar larvae, and prereproductive adults of Coleomegilla maculata DeGeer, with beetles fed a diet of Ephestia kuehniella Zeller eggs. Cannibalism of two eggs by neonates had no effect on development, and cannibalism of five eggs by fourth instars did not benefit any aspect of reproduction, but delayed pupation slightly. Cannibalism of eggs by pre-reproductive adults had no effect on reproductive success in any combination of reciprocal crosses of cannibals and non-cannibals. Females did not recognize, nor avoid consuming, their own clutches, and cannibalism propensity did not change following mating and onset of oviposition in either sex. These results contrast with those for more strictly aphidophagous species in which larvae gain developmental benefits, and females may recognize and avoid filial egg clusters while using cannibalism to interfere with conspecific females, whereas males reduce egg cannibalism after mating because they cannot recognize filial clusters. Egg cannibalism may confer developmental benefits to C. maculata when diet is suboptimal, as previously shown, but no such benefits were evident on the high-quality E. kuehniella egg diet. Female C. maculata do not require aphids to reproduce and distribute their eggs broadly in the environment, given that larvae can develop on pollen and non-aphid prey. Thus, C. maculata is not subject to the intraspecific competition that selects for cannibalism in more aphidophagous species, and also lacks many secondary adaptations associated with the behaviour.

  13. Physical influence on larvicidal and pupicidal activity of the silicone-based monomolecular film.

    Science.gov (United States)

    Ngrenngarmlert, Warunee; Sukkanon, Chutipong; Yaicharoen, Rapeeporn; Chareonviriyaphap, Theeraphap

    2016-10-01

    Although silicone-based monomolecular film (MMF) has been accepted as larvicide in several countries, its mosquito control potential has never been investigated in Thailand. Laboratory assessment in this study was conducted to determine the MMF efficacy against Aedes aegypti. At the recommended dosage (1mL/m(2) of water surface), mortality of pupae (99.17±0.83%) was significantly greater than mortality of old and young larvae (73.33±9.13, 11.67±3.47%; respectively). Pupicidal activity was rapidly exhibited within hours while larvicidal activity took at least one day. Interestingly, among the survived mosquitoes after MMF exposure, larval length (3.6±0.18mm), pupation (0%) and adult emergence (0%) were significantly less than the control group. Gravid females also avoided laying eggs in MMF-treated oviposition cups. There was no influence of physical factors on MMF efficacy and no toxic effects on fish and plants. These results indicated the MMF is promising to provide not only larvicidal and pupicidal activity but also inhibition of larval development as indicated by both larval length and stage transformation.

  14. Purification of Colocasia esculenta lectin and determination of its anti-insect potential towards Bactrocera cucurbitae.

    Science.gov (United States)

    Thakur, Kshema; Kaur, Manpreet; Kaur, Satwinder; Kaur, Amritpal; Kamboj, Sukhdev Singh; Singh, Jatinder

    2013-01-01

    The present study reports the purification of a lectin from Colocasia esculenta (L.) Schott corms and evaluation of its anti-insect potential towards Bactrocera cucurbitae (Coquilett). The lectin was found to be specific towards N-acetyl-D-lactosamine (LacNac), a disaccharide and asialofetuin, a desialylated serum glycoprotein in hemagglutination inhibition assay. Asialofetuin was used as a ligand to purify Colocasia esculenta agglutinin (CEA) by affinity chromatography. The purity of CEA was ascertained by the presence of a single band in reducing SDS-PAGE at pH 8.3. The affinity purified CEA was employed in artificial diet bioassay of second instar larvae (64-72 hr old) of the B. cucurbitae at concentrations ranging between 10-160 microg ml(-1). The lectin significantly (p < 0.01) decreased the percent pupation and emergence with respect to control. Effect on various enzymes was studied by employing LC50 (51.6 microg ml(-1)) CEA in the artificial diet bioassay of second instar larvae. All the enzymes tested namely esterases, phosphatases (acid and alkaline), superoxide dismutases, catalase and glutathione-S-transferase showed a significant (p < 0.01, p < 0.05) increase in their enzyme and specific activities. These results showed that CEA affected normal growth and development and presented stress to the larvae, activating their detoxification and anti-oxidant systems. Thus, the lectin seems to be a useful candidate for the control measures of B. cucurbitae under the integrated pest management (IPM) system.

  15. A review of postfeeding larval dispersal in blowflies: implications for forensic entomology

    Science.gov (United States)

    Gomes, Leonardo; Godoy, Wesley Augusto Conde; von Zuben, Claudio José

    2006-05-01

    Immature and adult stages of blowflies are one of the primary invertebrate consumers of decomposing animal organic matter. When the food supply is consumed or when the larvae complete their development and migrate prior to the total removal of the larval substrate, they disperse to find adequate places for pupation, a process known as postfeeding larval dispersal. Several important ecological and physiological aspects of this process were studied since the work by Green (Ann Appl Biol 38:475, 1951) 50 years ago. An understanding of postfeeding larval dispersal can be useful for determining the postmortem interval (PMI) of human cadavers in legal medicine, particularly because this interval may be underestimated if older dispersing larvae or those that disperse longer, faster, and deeper are not taken into account. In this article, we review the process of postfeeding larval dispersal and its implications for legal medicine, in particular showing that aspects such as burial behavior and competition among species of blowflies can influence this process and consequently, the estimation of PMI.

  16. 致乏库蚊幼虫摄食和消化鱼腥藻的观察%THE OBSERVATION OF FEEDING ABILITY OF CULEX PIPIEN FATIGANS LARVAE ON ANABAENA

    Institute of Scientific and Technical Information of China (English)

    张世萍; 王方雨; 朱艳芳; 但丽; 喻子牛

    2005-01-01

    Under the laboratory condition, the larvae of Culex pipens fatigans may feed mainly on Anabaena sp and complete their life cycle. The retention time of Anabaena sp. in larval intestine is about 6 hours while that of Saccharomyces sp. is about 5hours, meaning that Anabaena sp. is not so digestible for the larvae. From hatching to pupation, the larvae fed with Anabaena sp. lasted 194 hours and those fed with Saccharomyces sp were 142 hours, showing that the duration for completing larval stage of the former is 52 hours, which is longer than those fed on Saccharomyces.%在实验室条件下,致乏库蚊幼虫可大量摄食鱼腥藻,并能消化利用,完成生活史.鱼腥藻在蚊幼虫肠道中滞留时间约6h,酵母约5h,鱼腥藻比酵母稍难消化.蚊幼虫至化蛹时期相比,饲喂鱼腥藻为194h,而饲喂酵母的为142h,饲喂鱼腥藻比饲喂酵母延缓了蚊幼虫期52h.

  17. A new threat to honey bees, the parasitic phorid fly Apocephalus borealis.

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    Andrew Core

    Full Text Available Honey bee colonies are subject to numerous pathogens and parasites. Interaction among multiple pathogens and parasites is the proposed cause for Colony Collapse Disorder (CCD, a syndrome characterized by worker bees abandoning their hive. Here we provide the first documentation that the phorid fly Apocephalus borealis, previously known to parasitize bumble bees, also infects and eventually kills honey bees and may pose an emerging threat to North American apiculture. Parasitized honey bees show hive abandonment behavior, leaving their hives at night and dying shortly thereafter. On average, seven days later up to 13 phorid larvae emerge from each dead bee and pupate away from the bee. Using DNA barcoding, we confirmed that phorids that emerged from honey bees and bumble bees were the same species. Microarray analyses of honey bees from infected hives revealed that these bees are often infected with deformed wing virus and Nosema ceranae. Larvae and adult phorids also tested positive for these pathogens, implicating the fly as a potential vector or reservoir of these honey bee pathogens. Phorid parasitism may affect hive viability since 77% of sites sampled in the San Francisco Bay Area were infected by the fly and microarray analyses detected phorids in commercial hives in South Dakota and California's Central Valley. Understanding details of phorid infection may shed light on similar hive abandonment behaviors seen in CCD.

  18. Ingestion of Bt corn pollen containing Cry1Ab/2Aj or Cry1Ac does not harm Propylea japonica larvae.

    Science.gov (United States)

    Liu, Yanmin; Liu, Qingsong; Wang, Yanan; Chen, Xiuping; Song, Xinyuan; Romeis, Jörg; Li, Yunhe; Peng, Yufa

    2016-03-23

    Propylea japonica (Thunberg) (Coleoptera: Coccinellidae) is a prevalent pollen consumer in corn fields and is therefore exposed to insecticidal proteins contained in the pollen of insect-resistant transgenic corn cultivars expressing Cry proteins derived from Bacillus thuringiensis (Bt). In the present study, the potential effect of Cry1Ab/2Aj- or Cry1Ac-containing transgenic Bt corn pollen on the fitness of P. japonica larvae was evaluated. The results show that the larval developmental time was significantly shorter when P. japonica larvae were fed pollen from Bt corn cultivars rather than control pollen but that pupation rate, eclosion rate, and adult fresh weight were not significantly affected. In the feeding experiments, the stability of the Cry proteins in the food sources was confirmed. When Bt corn pollen passed through the gut of P. japonica, 23% of Cry1Ab/2Aj was digested. The results demonstrate that consumption of Bt corn pollen containing Cry1Ab/2Aj or Cry1Ac has no detrimental effect on P. japonica larvae; the shortened developmental time of larvae that consumed these proteins was likely attributable to unknown differences in the nutritional composition between the Bt-transgenic and control corn pollen.

  19. Aedes aegypti survival in the presence of Toxorhynchites violaceus (Diptera: Culicidae fourth instar larvae

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    Daniel S Albeny

    2011-08-01

    Full Text Available The mosquito Aedes aegypti (Linnaeus, 1762 is the main vector of dengue and yellow fever viruses. Different methods have been used to control A. aegypti, including chemical and biological tools. However, chemical control can lead to a subsequent increase in the mosquitoes' insecticide resistance, and biological control represents an important method as an alternative to insecticide usage. Larvae from the Toxorhynchites genus (Diptera: Culicidae are predators of other mosquitoes and represent a potential natural biocontrol agent of A. aegypti larvae. In the present work, A. aegypti larval survival was studied in the presence of the neotropical Toxorhynchites violaceus (Wiedemann, 1821 fourth instar larvae. Toxorhynchites violaceus consumption of A. aegypti increased during the 192 hours of the experiment and was more marked in the intervals between 96 and 120 hours and between 168 and 192 hours, when the A. aegypti survival reached 0%. During the fourth instar, T. violaceus increased its predation on A. aegypti larvae, possibly in order to increase its nutrient storage prior to pupation. Otherwise, low prey consumption can lead to a nutritional deficit for the larvae, delaying the adult's sexual development and reducing its egg production. Here we show that A. aegypti survival can be reduced by the T. violaceus fourth larvae predation under laboratory conditions

  20. Ontogenetic and interspecific metabolic scaling in insects.

    Science.gov (United States)

    Maino, James L; Kearney, Michael R

    2014-12-01

    Design constraints imposed by increasing size cause metabolic rate in animals to increase more slowly than mass. This ubiquitous biological phenomenon is referred to as metabolic scaling. However, mechanistic explanations for interspecific metabolic scaling do not apply to ontogenetic size changes within a species, implying different mechanisms for scaling phenomena. Here, we show that the dynamic energy budget theory approach of compartmentalizing biomass into reserve and structural components provides a unified framework for understanding ontogenetic and interspecific metabolic scaling. We formulate the theory for insects and show that it can account for ontogenetic metabolic scaling during the embryonic and larval phases, as well as the U-shaped respiration curve during pupation. After correcting for the predicted ontogenetic scaling effects, which we show to follow universal curves, the scaling of respiration between species is approximated by a three-quarters power law, supporting past empirical studies on insect metabolic scaling and our theoretical predictions. The ability to explain ontogenetic and interspecific metabolic scaling effects under one consistent framework suggests that the partitioning of biomass into reserve and structure is a necessary foundation to a general metabolic theory.

  1. VHDL, a larval storage protein from the corn earworm, Helicoverpa zea, is a member of the vitellogenin gene family.

    Science.gov (United States)

    Sum, Herbert; Haunerland, Norbert H

    2007-10-01

    The hemolymph of last instar larvae of the corn earworm, Helicoverpa zea contains a blue very high-density lipoprotein (VHDL) that is selectively taken up into fat body prior to pupation. Its amino-terminal sequence was determined by Edman degradation, and used to design a degenerate primer for PCR amplification. With 5' and 3' RACE techniques, the entire cDNA coding for VHDL was amplified and sequenced. Conceptual translation reveals a 173 kDa protein that contains a 15 amino acid signal sequence immediately before the experimentally determined N-terminus of the mature protein. The protein contains a typical lipoprotein N-terminal domain, and shows high sequence similarity to vitellogenins from Lepidoptera and other insect species. VHDL mRNA was not detectable in adult H. zea, and antibodies raised against VHDL did not react with adult hemolymph or yolk proteins. Therefore VHDL, although a member of the vitellogenin gene family, seems to be distinct from the vitellogenin expressed in adult females.

  2. A new Sigelgaita Heinrich (Lepidoptera, Pyralidae, Phycitinae feeding on cacti in Brazil

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    Ricardo F. Monteiro

    2002-07-01

    Full Text Available Description and biological aspects of a new species of Sigelgaita Heinrich, 1939, the first known to occur east of the Andes, S. cerei Becker, are presented. S. cerei larvae were collected on "restinga" ecosystems feeding on Pilosocereus arrabidae (Lem. Byles & Rowl. (Parque Nacional da Restinga de Jurubatiba-Macaé and Área de Proteção Ambiental de Barra de Marica, Rio de Janeiro and rarely on Cereus obtusus Haw. (PNRJ. Life cycle and behavior of larvae are presented. Larvae are found singly on flower buds, on fruit or more frequently on stem of the plants. They build chambers in the cladodium where they complete their larval development, then droping to the ground in order to pupate. Trichogramma sp. was parasitizing 72% of eggs and a species of braconid was parasitizing half out of ten larvae collected from fruits of Cereus obtusus. S. cerei larvae develop a special role in the colonization and establishment of a diverse fauna associates with the hosts such as insects, spiders and yeasts. Ants, such as Camponotus crassus Mayr, 1862 and C. cingulatus Mayr, 1862 are among the insects which most frequently nest in the chambers abandoned by the larvae of this moth species.

  3. Nickel accumulation and its effects on the survival rate of Spodoptera litura Fabricius under continuous nickel stress

    Institute of Scientific and Technical Information of China (English)

    SUN HongXia; SHU YingHua; TANG WenCheng; WANG Qi; ZHOU Qiang; ZHANG GuRen

    2007-01-01

    The artificial diets mixed with various concentrations of nickel were offered to the larvae of the phytophagous insect Spodoptera litura Fabricius for 3 generations. Nickel accumulations in the 6th instar larvae, pupae and newly emerged adults of the corresponding generations of S. litura were investigated by Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES), and the effects of nickel accumulations on the survival rate of S. litura were also evaluated by individual rearing. The results showed that nickel accumulated in the 6th instar larvae, pupae and adults of S. litura, and the accumulated nickel in all the tested developmental stages within a generation increased with the increase of the nickel doses in the treated diets and showed significant dose-dependent relationship with the nickel doses in the artificial diets. The results also indicated that the nickel accumulations in the 6th instar larvae, pupae, and newly emerged adults from the 3rd generation were higher than those from the 2nd generation, which were also higher than those from the 1st generation. Nickel concentrations in pupae and adults were significantly lower than those in larvae, which indicated that the excessive nickel might be excreted during metamorphosis. Furthermore, larval survival rate, pupation rate and eclosion rate of S. litura in the tested three generations all decreased with the increase of the nickel doses in the treated diets.

  4. Effects of endophyte colonization of Vicia faba (Fabaceae plants on the life-history of leafminer parasitoids Phaedrotoma scabriventris (hymenoptera: braconidae and Diglyphus isaea (hymenoptera: eulophidae.

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    Komivi S Akutse

    Full Text Available Effects of the fungal endophytes Beauveria bassiana (isolates ICIPE 279, G1LU3, S4SU1 and Hypocrea lixii (isolate F3ST1 on the life-history of Phaedrotoma scabriventris and Diglyphus isaea, parasitoids of the pea leafminer Liriomyza huidobrensis, were studied in the laboratory. Parasitoids were allowed to parasitize 2(nd and 3(rd instar L. huidobrensis larvae reared on endophytically-inoculated faba bean, Vicia faba. In the control, parasitoids were reared on non-inoculated host plants. Parasitism, pupation, adult emergence and survival were recorded. No significant difference was observed between the control and the endophyte-inoculated plants in terms of parasitism rates of P. scabriventris (p = 0.68 and D. isaea (p = 0.45 and adult' survival times (p = 0.06. The survival period of the F1 progeny of P. scabriventris was reduced (p<0.0001 in B. bassiana S4SU1 to 28 days as compared to more than 40 days for B. bassiana G1LU3, ICIPE 279 and H. lixii F3ST1. However, no significant difference (p = 0.54 was observed in the survival times of the F1 progeny of D. isaea. This study has demonstrated that together, endophytes and parasitoids have beneficial effects in L. huidobrensis population suppression.

  5. Species composition and population dynamics of thrips (Thysanoptera) in mango orchards of northern peninsular Malaysia.

    Science.gov (United States)

    Aliakbarpour, H; Che Salmah, M R; Dieng, H

    2010-10-01

    Thrips are key pests of mango, Mangifera indica (L.), in Malaysia, including the Northern Peninsular. As Penang has year-round equatorial climate and high of rainfall, the populations of thrips may be subject to variations in composition and size. With a goal of developing an appropriate control strategy, a survey was conducted in Penang to determine species composition and abundance in relation to some environmental factors. Sprayed and unsprayed orchards were sampled on weekly basis through two flowering seasons of 2009 using CO(2) collection technique. Larval population falling into the ground to pupate and adults emerging from the soil were investigated in both orchards. Thrips hawaiiensis (Morgan) and Scirtothrips dorsalis (Hood) were the most prevalent species in the sprayed and the unsprayed orchards, respectively. The abundance of thrips was high during the flowering period of the dry season and decreased during the flowering period of the rainy season. This latter period coincided with decreased temperature and increased relative humidity. Percentage of adult emergence from the soil was lower in the rainy season than recorded in the dry season in both orchards. Taken together, these observations suggest that T. hawaiiensis and S. dorsalis are the main thrips species pests of mango panicles in Penang. Direct control with insecticides focusing on these two species may help to reduce cosmetic injuries and other damages on mango fruits.

  6. Effects of tea saponin on growth and development, nutritional indicators, and hormone titers in diamondback moths feeding on different host plant species.

    Science.gov (United States)

    Cai, Hongjiao; Bai, Yan; Wei, Hui; Lin, Shuo; Chen, Yixin; Tian, Houjun; Gu, Xiaojun; Murugan, Kadarkarai

    2016-07-01

    The diamondback moth (DBM) is an important worldwide pest. This insect has been studied for several decades; however, its control remains problematic. Numerous chemical insecticides have become ineffective and chemical residues constitute an important problem. In the present study, we determined the mortality of 3rd instar DBM larvae feeding on three different host plant species and exposed to various concentrations of tea saponin (TS). In addition, we evaluated growth and development parameters, nutritional indicators, and juvenile hormone (JH) and molting hormone (MH) titers in 2nd instar larvae exposed to LC20 and LC50 doses of TS. We found that treatment of DBM larvae with LC20 and LC50 doses of TS led to lower growth rates, decreased feed consumption, reduced frass production, lower pupal weights, reduced percentage pupation, slower adult emergence percentages, and diminished fecundity, but prolonged durations of the larval and pupal periods. The efficiency of conversion of ingested and digested food increased, but the approximate digestibility did not differ significantly between treatments and controls. JH and MH titers were higher after TS treatment; these increases varied according to the host species and TS concentration. Our results indicate that TS represents a potential new alternative insecticide based on its natural origin, low cost, and minimum environmental impact.

  7. A model of muscle atrophy based on live microscopy of muscle remodelling in Drosophila metamorphosis

    Science.gov (United States)

    Kuleesha, Yadav; Puah, Wee Choo; Wasser, Martin

    2016-01-01

    Genes controlling muscle size and survival play important roles in muscle wasting diseases. In Drosophila melanogaster metamorphosis, larval abdominal muscles undergo two developmental fates. While a doomed population is eliminated by cell death, another persistent group is remodelled and survives into adulthood. To identify and characterize genes involved in the development of remodelled muscles, we devised a workflow consisting of in vivo imaging, targeted gene perturbation and quantitative image analysis. We show that inhibition of TOR signalling and activation of autophagy promote developmental muscle atrophy in early, while TOR and yorkie activation are required for muscle growth in late pupation. We discovered changes in the localization of myonuclei during remodelling that involve anti-polar migration leading to central clustering followed by polar migration resulting in localization along the midline. We demonstrate that the Cathepsin L orthologue Cp1 is required for myonuclear clustering in mid, while autophagy contributes to central positioning of nuclei in late metamorphosis. In conclusion, studying muscle remodelling in metamorphosis can provide new insights into the cell biology of muscle wasting. PMID:26998322

  8. Integument and defence in larva and prepupa of a sawfly living on a semi-aquatic plant

    Science.gov (United States)

    Boevé, Jean-Luc; Voigt, Dagmar; Gorb, Stanislav N.

    2013-01-01

    The larvae of the sawfly Rhadinoceraea micans live and feed on a semi-aquatic plant, Iris pseudacorus, and their integument is strongly hydrophobic. The hydrophobicity is part of a chemical defence strategy, easy bleeding, also known from congeners. The prepupae burrow into the soil where they form a cocoon in which they pupate, thus implying different micro-environmental conditions. The cuticle structure and wetting defensive effectiveness of R. micans were compared between larvae and prepupae. The two stages were similarly well defended against attacking ants by the bleeding of a deterrent hemolymph, whereas they were dissimilar in the cuticle surface that presented sculptures and wax crystals at the larval stage only. The integument of prepupae was less structured, and hydrophilic. Larvae of R. micans exhibit, among sawflies, an exceptional cuticle structuring and we assume that they occupy this particular niche of a semi-aquatic environment to avoid encounters with ground-dwelling predators whereas prepupae may benefit from the chemical defence acquired at larval stage.

  9. Effects of dietary quercetin on performance and cytochrome P450 expression of the cotton bollworm, Helicoverpa armigera.

    Science.gov (United States)

    Liu, D; Yuan, Y; Li, M; Qiu, X

    2015-12-01

    Quercetin is ubiquitous in terrestrial plants. The cotton bollworm Helicoverpa armigera as a highly polyphagous insect has caused severe crop losses. Until now, interactions between this pest and quercetin are poorly understood at the biochemical and molecular levels. In this study, we investigated the in vivo effects of quercetin on performance of cotton bollworm and on cytochrome P450 (P450) expression. Deleterious effects of quercetin on the performance of the cotton bollworm, including growth, survival, pupation and adult emergence were observed after oral administration of 3 and 10 mg g(-1) quercetin to larvae since the third instar, whereas no significant toxic effect was found at 0.1 mg g(-1) quercetin treatment. Piperonyl butoxide treatment enhanced the toxicity of quercetin. In vitro metabolism studies showed that quercetin was rapidly transformed by gut enzymes of fifth instar larvae of the cotton bollworm. qRT-PCR results revealed that the effect of quercetin on P450 expression was tissue- and dose-specific. Quercetin regulated P450 expression in a mild manner, and it could serve as P450 inducer (CYP337B1, CYP6B6) or repressor (CYP337B1, CYP6B7, CYP6B27, CYP9A14, CYP6AE11, and CYP4M7). These findings are important for advancing our understanding of the biochemical and molecular response of insects to plant toxins and have implications for a smart pest control.

  10. [Effectiveness of 2,6-dihalogenbenzoyl urea derivatives as potential inhibitors of chitin biosynthesis regarding the house fly Musca domestica L. and cockroach Blatella germanica L].

    Science.gov (United States)

    Styczyńska, B; Krzemińska, A; Sobótka, W; Balicki, R

    1989-01-01

    The biological activity was determined of 20 compounds from the group of asymmetrically substituted urea derivatives. They were derivatives of 1-(hetero)-aryl-3(2,6-dichlorobenzoyl)urea, compounds in Table 1, (1-12) which represented three groups of compounds: a) monochlorine or trifluoromethyl derivatives of benzene, b) monomethyl-substituted 2-pyridine derivatives, c) a derivative of 5-bromo-3-pyridine, and symmetrical derivates (Table 2 compounds 1-8) 2.2; 3.3; 4.4 groupings: a) N-(2,6-dichlorobenzoyl)urea derivatives, and b) N-(2-chloro-6-fluorobenzoyl)urea derivatives. The experiment was carried out on larvae and adult forms of M. domestica L. and Blatella germanica L. The tested substances were administered in food to the insects. Of the tested compounds complete inhibition of the development of flies was caused by the compound designated with the symbol AG 6. Compounds AG 13, AG 15 and AG 17 given to larvae inhibited the development of the insects by 33 to 100% acting mainly in later phases of the development (pupation). Compound AG 5 was found to be a very strong inhibitor of the development of cockroaches acting on larvae and adult females Of 800 tested larvae exposed to concentrations 0.001 to 1% none reached the adult phase. The exposed adult females formed cocoons but no larvae hatched from them.

  11. Effects of herbicide-treated host plants on the development of Mamestra brassicae L. caterpillars.

    Science.gov (United States)

    Hahn, Melanie; Geisthardt, Martin; Brühl, Carsten A

    2014-11-01

    Herbicides are widely used pesticides that affect plants by changing their chemistry. In doing so, herbicides might also influence the quality of plants as food for herbivores. To study the effects of herbicides on host plant quality, 3 plant species (Plantago lanceolata L., P. major L., and Ranunculus acris L.) were treated with sublethal rates of either a sulfonylurea (Atlantis WG, Bayer CropScience) or a glyphosate (Roundup LB Plus, Monsanto) herbicide, and the development of caterpillars of the cabbage moth Mamestra brassicae L. that fed on these plants was observed. Of the 6 tested plant-herbicide combinations, 1 combination (R. acris + sulfonylurea herbicide) resulted in significantly lower caterpillar weight, increased time to pupation, and increased overall development time compared with larvae that were fed unsprayed plants. These results might be caused by a lower nutritional value of these host plants or increased concentrations of secondary metabolites that are involved in plant defense. The results of the present and other studies suggest potential risks to herbivores that feed on host plants treated with sublethal rates of herbicides. However, as the effects of herbicides on host plant quality appear to be species-specific and as there are numerous plant-herbicide-herbivore relationships in agricultural landscapes, a general reduction in herbicide contamination of nontarget habitats (e.g., field margins) might mitigate the negative effects of herbicides on host plant quality.

  12. Influence of previous experience on the preference, food utilization and performance of Ascia monuste orseis wild larvae (Godart) (Lepidoptera: Pieridae) for three different hosts.

    Science.gov (United States)

    Santana, A F K; Zucoloto, F S

    2011-01-01

    The exhaustion of food resources which occurs during the ontogenetic growth of Ascia monuste orseis (Godart) results in the dispersion of older larvae to nearby plants in order to complete their development, which might expose these animals to the nutritional variation of the hosts found. This study aimed to verify whether the food ingested in the beginning of the development influences the larvae host preference and whether the shift to a new host can affect the digestion and performance of A. monuste orseis, using two natural hosts: kale (Brassica oleracea var. acephala) and rocket (Eruca sativa), or kale and cabbage (B. oleracea var. capitata). Larvae were reared throughout their larval development on a single host or on two different hosts. When a host change was tested, larvae were reared for four instars on a host, and offered the other host plant in the fifth instar. Development time, percentage of pupation and emergence, pupal weight, fecundity and digestive indices were evaluated. The change in feeding preference for kale and for rocket in the fourth instar, when those were the original hosts, respectively, shows that prior experience plays a major role in food preference of immature A. monuste orseis. The shift can be beneficial for larval development, depending on the order of the hosts; in general, larvae fed on kale at the end of the development showed better performance. Our results presented strong evidence of a considerable phenotypic plasticity in A. monuste orseis for host preferences.

  13. Chemical Strategies of the Beetle Metoecus Paradoxus, Social Parasite of the Wasp Vespula Vulgaris.

    Science.gov (United States)

    Van Oystaeyen, Annette; van Zweden, Jelle S; Huyghe, Hilde; Drijfhout, Falko; Bonckaert, Wim; Wenseleers, Tom

    2015-12-01

    The parasitoid beetle Metoecus paradoxus frequently parasitizes colonies of the common wasp, Vespula vulgaris. It penetrates a host colony as a larva that attaches itself onto a foraging wasp's body and, once inside the nest, it feeds on a wasp larva inside a brood cell and then pupates. Avoiding detection by the wasp host is crucial when the beetle emerges. Here, we tested whether adult M. paradoxus beetles avoid detection by mimicking the cuticular hydrocarbon profile of their host. The beetles appear to be chemically adapted to their main host species, the common wasp, because they share more hydrocarbon compounds with it than they do with the related German wasp, V. germanica. In addition, aggression tests showed that adult beetles were attacked less by common wasp workers than by German wasp workers. Our results further indicated that the host-specific compounds were, at least partially, produced through recycling of the prey's hydrocarbons, and were not acquired through contact with the adult host. Moreover, the chemical profile of the beetles shows overproduction of the wasp queen pheromone, nonacosane (n-C29), suggesting that beetles might mimic the queen's pheromonal bouquet.

  14. Characterization and cytotoxic activity of apoptosis-inducing pierisin-5 protein from white cabbage butterfly.

    Science.gov (United States)

    Subbarayan, Sarathbabu; Marimuthu, Satheesh Kumar; Nachimuthu, Senthil Kumar; Zhang, Wenqing; Subramanian, Selvi

    2016-06-01

    In this study, caspase-dependent apoptosis-inducing pierisin-5 gene was identified and characterized from cabbage white butterfly, Pieris canidia. A thousand-fold increase in expression of pierisin-5 gene was observed from second to third instar larvae, gradually decreasing before pupation. Pierisin-5 was purified from the fifth-instar larvae and was found to exhibit cytotoxicity against HeLa and HepG2 human cancer cell lines. Pierisin-5 showed growth inhibition and several morphological changes such as cell shrinkage, chromatin condensation and apoptotic body formation with programmed cell death in HeLa and HepG2 cells. Moreover, DNA fragmentation was observed after gel electrophoresis analysis. Caspase substrate assay showed further cleavage of Ac-DEVD-pNA, suggesting the activation of Caspase-3. Flow cytometry analysis revealed the cell cycle arrest at G1 phase and increased the percentage of apoptotic cells in cancer cell lines treated with pierisin-5. These findings suggest that pierisin-5 could significantly induce apoptosis in cancer cell lines and is mediated by activation of caspase-3 in the mitochondrial pathway. Phylogenetic analysis using pierisin proteins from Pierid butterflies, ADP-ribosylating toxins from bacteria, human, rat, and mouse indicated the possibility of horizontal transfer of pierisin genes from bacteria to butterflies. The single copy of pierisin gene unlike other insect toxin genes also supports lateral transfer. Copyright © 2016. Published by Elsevier B.V.

  15. Oviposition Preference for Young Plants by the Large Cabbage Butterfly (Pieris brassicae ) Does not Strongly Correlate with Caterpillar Performance.

    Science.gov (United States)

    Fei, Minghui; Harvey, Jeffrey A; Yin, Yi; Gols, Rieta

    2017-06-01

    The effects of temporal variation in the quality of short-lived annual plants on oviposition preference and larval performance of insect herbivores has thus far received little attention. This study examines the effects of plant age on female oviposition preference and offspring performance in the large cabbage white butterfly Pieris brassicae. Adult female butterflies lay variable clusters of eggs on the underside of short-lived annual species in the family Brassicaceae, including the short-lived annuals Brassica nigra and Sinapis arvensis, which are important food plants for P. brassicae in The Netherlands. Here, we compared oviposition preference and larval performance of P. brassicae on three age classes (young, mature, and pre-senescing) of B. nigra and S. arvensis plants. Oviposition preference of P. brassicae declined with plant age in both plant species. Whereas larvae performed similarly on all three age classes in B. nigra, preference and performance were weakly correlated in S. arvensis. Analysis of primary (sugars and amino acids) and secondary (glucosinolates) chemistry in the plant shoots revealed that differences in their quality and quantity were more pronounced with respect to tissue type (leaves vs. flowers) than among different developmental stages of both plant species. Butterflies of P. brassicae may prefer younger and smaller plants for oviposition anticipating that future plant growth and size is optimally synchronized with the final larval instar, which contributes >80% of larval growth before pupation.

  16. Response spectrum of pentachlorobenzene and fluoranthene for Chironomus tentans and Hyalella azteca.

    Science.gov (United States)

    Schuler, Lance J; Landrum, Peter F; Lydy, Michael J

    2007-06-01

    The whole-body residues of pentachlorobenzene (PCBz) and fluoranthene (FLU) in Hyalella azteca and Chironomus tentans were determined for a variety of chronic sublethal effects. The endpoints evaluated for H. azteca included 28-d growth and survival and 42-d growth, survival, and reproduction. Adverse effects to C. tentans also were determined at multiple endpoints including 10-d growth, cumulative pupation and emergence, and reproduction. The lowest-observed-effect residue (LOER) based on whole-body residues associated with growth was consistent between compounds and species tested with concentrations ranging from 0.17 to 0.33 micromol/g. For H. azteca, the most sensitive endpoints were growth at 0.23 micromol/g and reproduction at 0.11 micromol/g for PCBz and FLU, respectively. For C. tentans, the most sensitive endpoints were emergence, development and reproduction at 0.02 micromol/g, and development and reproduction at 0.15 micromol/g for PCBz and FLU, respectively. Compared to residues associated with acute lethality, the most sensitive sublethal endpoints were approximately 4 and 60 times lower for PCBz and FLU, respectively. The relative consistency of the sublethal endpoints suggests that body residues can be a valuable tool to evaluate bioaccumulation data as part of a risk assessment to predict adverse effects to biota.

  17. Silicon-mediated resistance in a susceptible rice variety to the rice leaf folder, Cnaphalocrocis medinalis Guenee (Lepidoptera: Pyralidae.

    Directory of Open Access Journals (Sweden)

    Yongqiang Han

    Full Text Available The rice leaf folder, Cnaphalocrocis medinalis (Guenée, is one of the most destructive rice pests in Asian countries. Rice varieties resistant to the rice leaf folder are generally characterized by high silicon content. In this study, silicon amendment, at 0.16 and 0.32 g Si/kg soil, enhanced resistance of a susceptible rice variety to the rice leaf folder. Silicon addition to rice plants at both the low and high rates significantly extended larval development and reduced larval survival rate and pupation rate in the rice leaf folder. When applied at the high rate, silicon amendment reduced third-instars' weight gain and pupal weight. Altogether, intrinsic rate of increase, finite rate of increase and net reproduction rate of the rice leaf folder population were all reduced at both the low and high silicon addition rates. Although the third instars consumed more in silicon-amended treatments, C:N ratio in rice leaves was significantly increased and food conversion efficiencies were reduced due to increased silicon concentration in rice leaves. Our results indicate that reduced food quality and food conversion efficiencies resulted from silicon addition account for the enhanced resistance in the susceptible rice variety to the rice leaf folder.

  18. Biological Strategies of Dermestes maculatus DeGeer (Coleoptera: Dermestidae) at Larval Stages in Different Temperatures.

    Science.gov (United States)

    Zanetti, N I; Visciarelli, E C; Centeno, N D

    2016-12-01

    The intraspecific variation in larval instars is a widely distributed phenomenon amongst holometabolous insects. Several factors can affect the number of instars, such as temperature, humidity, and density. Only a few references could be found in the literature because the invariability in the number of larval instars is considered normal, and the issue has raised little to no interest. Despite this, no study to date has intended to assess or focus on the larval development. Here, we analyzed the effect of different rearing temperature on the larval stage of Dermestes maculatus DeGeer (Coleoptera: Dermestidae). The results indicated that at all temperatures, L5 represented a decisive point for individuals as well as the other later larval instars, because the next step to follow was to pupate or molt to the next larval instar. Furthermore, there were mainly two populations, L5 and L6, although in different proportions according to temperature. We also found that at a greater number of instars, the larval development at all temperatures lasted longer. Moreover, the exponential model was the best adjustment in the developmental time of all populations as well as for the accumulated developmental time of L1-L4. Thus, we conclude that random factors such as genetics could probably cause interspecific variability in D. maculatus larval development.

  19. Effects of steam-distilled shoot extract of Tagetes minuta (Asterales: Asteraceae) and entomopathogenic fungi on larval Tetanops myopaeformis.

    Science.gov (United States)

    Dunkel, Florence V; Jaronski, Stefan T; Sedlak, Christopher W; Meiler, Svenja U; Veo, Kendra D

    2010-06-01

    Interactions of a biopesticidal formulation of steam distilled shoot extract of Mexican marigold, Tagetes minuta, and entomopathogenic fungi were evaluated for management of the sugarbeet root maggot, Tetanops myopaeformis (Röder). Shoot extract plus surfactant (E-Z Mulse) (=T. minuta oil) was used in a 65:35 ratio to test the hypothesis that this fungicidal and nematocidal biopesticide causes dose-dependent mortality and developmental arrest of T. myopaeformis but does not interfere with the action of entomopathogenic fungi when applied together. A soil-petri dish bioassay system was developed to test the hypothesis. For diapausing, nonfeeding but active 12-mo-old third-instar larvae, 0.5% T. minuta oil treatment (=0.325% active ingredient [AI]) was sufficient to prevent pupation without mortality, but 0.75% T. minuta oil treatment (=0.458% AI) was lethal for 93% of the test insects. The effect of T. minuta oil on fungal efficacy under simultaneous use was studied using a model system of two entomopathogenic fungi, Beauveria bassiana (Bals.) Vuillemin. TM28 and Metarhizium anisopliae variety anisopliae (Metsch.) Sorokin MA 1200, in a soil-based bioassay with larval sugarbeet root maggots. No adverse effects of T. minuta oil on action of entomopathogenic fungi and no synergy were found; an additive effect of the T. minuta oil and each fungal isolate separately was found.

  20. The mitochondrial genome of the garden pea leafminer Chromatomyia horticola (Goureau, 1851) (Diptera: Agromyzidae).

    Science.gov (United States)

    Wang, You-Zhu; Jin, Gui-Hua; Zhu, Jia-Ying; Wei, Shu-Jun

    2016-07-01

    Here we report the mitochondrial genome sequence of the garden pea leafminer Chromatomyia horticola (Goureau, 1851) (Diptera: Agromyzidae) (GenBank accession no. KR047789). This is the first species with sequenced mitochondrial genome from the genus Chromatomyia. The current length with partial A  +  T-rich region of this mitochondrial genome is 15,320 bp with an A  +  T content of 77.54%. All the 13 protein-coding, two rRNA, and 22 tRNA genes were sequenced, except for the A  +  T-rich region. As in most other sequenced mitochondrial genomes of Diptera, there is no rearrangement compared with the pupative ancestral arrangement of insects. All protein-coding genes start with the ATN start codon except for the gene cox1, which uses abnormal TTG. The A  +  T-rich region is located between rrnS and trnI with a sequenced length of 503 bp. Phylogenetic analysis using the Bayesian method based on the first and second codon positions of the 13 protein-coding genes recovered the monophyly of Agromyzidae with one species of Chromatomyia and four species of Liriomyza in our study. The superfamily Oestroidea (with Agromyzidae in analysis) is sister to the Opomyzoidea.

  1. Comparative study to determine food consumption of cotton leafworm, Spodoptera littoralis, on some cotton genotypes

    Directory of Open Access Journals (Sweden)

    Khedr Mohamad Ahmad

    2015-07-01

    Full Text Available A study was done on the feeding behaviour, development indices, and biochemical response of 4th instar larvae of Spodoptera littoralis in which seven cotton genotypes were used: Giza86, Giza88, Giza92, 10229 × Giza 86, H10, Suvin, and Karshenseki. Castor bean leaves were used as the control. All the tested cotton genotypes decreased the feeding behavior of S. littoralis larvae in terms of consumption percentages, consumption rate (CR, growth rates (GR, efficiency of conversion of ingested and digested food (ECI and ECD, approximate digestibility (AD, and feeding deterrence (FDI compared to the control. Additionally, all the tested cotton varieties prolonged the time taken for larval and pupal duration and reduced both the pupation percentages and the weight of the resulting pupae, as compared to the control. Giza86 recorded the lowest values of both larval growth index and fitness (7.31 and 1.05, respectively while the genotype Suvin recorded the lowest standardised growth index (0.020 more than other genotypes and the control that gave 10.16, 1.53, and 0.032, respectively. There was a significant inhibition in the level of both total soluble protein and total lipids, and activities of amylase and the trehalase enzymes in all the tested varieties, compared to that found in the control.

  2. Prepupal diapause and instar IV developmental rates of the spruce beetle, Dendroctonus rufipennis (Coleoptera: Curculionidae, Scolytinae).

    Science.gov (United States)

    Hansen, E Matthew; Bentz, Barbara J; Powell, James A; Gray, David R; Vandygriff, James C

    2011-10-01

    The spruce beetle, Dendroctonus rufipennis (Kirby), is an important mortality agent of native spruces throughout North America. The life-cycle duration of this species varies from 1 to 3 years depending temperature. The univoltine cycle (one generation per year) is thought to maximize outbreak risk and accelerate host mortality in established outbreaks. Prepupal diapause is associated with the semivoltine cycle (one generation per 2 years) and we investigated thermal conditions that result in diapause induction. Preliminary experiments used respirometry in an attempt to distinguish the diapause state of experimental insects but the technique was apparently confounded by low respiration before and during pupation, regardless of diapause status. Therefore, diapause induction was deduced using developmental delays. The observed developmental response was not a "switch", with developmental delay either present or absent, but instead varied continuously. We found that temperatures 40 d cumulative exposure was associated with distinct developmental suppression. Intermediate exposure to cool temperatures resulted in minor developmental delays. We used our results to parameterize a maximum likelihood estimation model of temperature-dependent instar IV developmental rates, including the effect of diapause. This model can be included as part of a spruce beetle phenology model for predicting population dynamics. Published by Elsevier Ltd.

  3. Effects of UV-A exposures on longevity and reproduction in Helicoverpa armigera, and on the development of its F1 generation

    Institute of Scientific and Technical Information of China (English)

    Chang-Yu Zhang; Jian-Yu Meng; Xiao-Ping Wang; Fen Zhu; Chao-Liang Lei

    2011-01-01

    Helicoverpa armigera adults display a conspicuous positive phototacdc behavior to light stimuli,and are especially sensitive to ultraviolet (UV) light.The effects of UV-A (longwave) exposures on adult longevity and reproduction in H.armigera were investigated,as well as the development of the F1 generation.Paired adults were exposed to UV-A for various time periods (0,1,5 and 9 h/day),until the end of adult life.The results showed that adult longevity decreased with increasing exposure time for both sexes,and a significant decrease was observed after exposure for 5 and 9 h/day.Fecundity increased when adults were exposed for 1 and 5 h/day,and a significant difference was observed in the 5 h/day group.Oviposition rates of females in all treatments were significantly higher than in the control.Exposure to UV-A for longer periods (5 and 9 h/day) caused a decline in cumulative survival of F1 immature stages,but no significant differences were found in egg hatch,pupation and eclosion.The developmental periods of F1 larvae were significantly prolonged after exposure to UV-A for 5 and 9 h/day.UV-A radiation had no significant effects on F1 pupal period.

  4. Green tea proanthocyanidins cause impairment of hormone-regulated larval development and reproductive fitness via repression of juvenile hormone acid methyltransferase, insulin-like peptide and cytochrome P450 genes in Anopheles gambiae sensu stricto

    Science.gov (United States)

    Nyanjom, Steven G.; Mutunga, James M.; Njeru, Sospeter N.; Bargul, Joel L.

    2017-01-01

    Successful optimization of plant-derived compounds into control of nuisance insects would benefit from scientifically validated targets. However, the close association between the genotypic responses and physiological toxicity effects mediated by these compounds remains underexplored. In this study, we evaluated the sublethal dose effects of proanthocyanidins (PAs) sourced from green tea (Camellia sinensis) on life history traits of Anopheles gambiae (sensu stricto) mosquitoes with an aim to unravel the probable molecular targets. Based on the induced phenotypic effects, genes selected for study targeted juvenile hormone (JH) biosynthesis, signal transduction, oxidative stress response and xenobiotic detoxification in addition to vitellogenesis in females. Our findings suggest that chronic exposure of larval stages (L3/L4) to sublethal dose of 5 ppm dramatically extended larval developmental period for up to 12 days, slowed down pupation rates, induced abnormal larval-pupal intermediates and caused 100% inhibition of adult emergence. Further, females exhibited significant interference of fecundity and egg hatchability relative to controls (p reproductive fitness thus could be potentially used for controlling populations of malaria vectors. PMID:28301607

  5. Silicon-mediated resistance in a susceptible rice variety to the rice leaf folder, Cnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae).

    Science.gov (United States)

    Han, Yongqiang; Lei, Wenbin; Wen, Lizhang; Hou, Maolin

    2015-01-01

    The rice leaf folder, Cnaphalocrocis medinalis (Guenée), is one of the most destructive rice pests in Asian countries. Rice varieties resistant to the rice leaf folder are generally characterized by high silicon content. In this study, silicon amendment, at 0.16 and 0.32 g Si/kg soil, enhanced resistance of a susceptible rice variety to the rice leaf folder. Silicon addition to rice plants at both the low and high rates significantly extended larval development and reduced larval survival rate and pupation rate in the rice leaf folder. When applied at the high rate, silicon amendment reduced third-instars' weight gain and pupal weight. Altogether, intrinsic rate of increase, finite rate of increase and net reproduction rate of the rice leaf folder population were all reduced at both the low and high silicon addition rates. Although the third instars consumed more in silicon-amended treatments, C:N ratio in rice leaves was significantly increased and food conversion efficiencies were reduced due to increased silicon concentration in rice leaves. Our results indicate that reduced food quality and food conversion efficiencies resulted from silicon addition account for the enhanced resistance in the susceptible rice variety to the rice leaf folder.

  6. Female-specific wing degeneration caused by ecdysteroid in the Tussock Moth, Orgyia recens: Hormonal and developmental regulation of sexual dimorphism

    Directory of Open Access Journals (Sweden)

    Saori Lobbia

    2003-04-01

    Full Text Available Females of the tussock moth Orgyia recens have vestigial wings, whereas the males have normal wings. During early pupal development, female wings degenerate drastically compared with those of males. To examine whether ecdysteroid is involved in this sex-specific wing development, we cultured pupal wings just after pupation with ecdysteroid (20-hydroxyecdysone, 20E. In the presence of 20E, the female wings degenerated to about one-fifth their original size. In contrast, the male wings cultured with 20E showed only peripheral degeneration just outside the bordering lacuna, as in other butterflies and moths. TUNEL analysis showed that apoptotic signals were induced by 20E over the entire region of female wings, but only in the peripheral region of male wings. Semi-thin sections of the wings cultured with ecdysteroid showed that phagocytotic hemocytes were observed abundantly throughout the female wings, but in only peripheral regions of male wings. These observations indicate that both apoptotic events and phagocytotic activation are triggered by ecdysteroid, in sex-specific and region-specific manners.

  7. [Effects of fermented cattle dung on the growth and development of Tenebrio molitor larvae].

    Science.gov (United States)

    Zeng, Xiang-Wei; Wang, Xia; Guo, Li-Yue; Zhan, Li-Jie; Bo, Wen-Jing; Li, Zhan; Wu, Guang-Lei; Jiang, Gao-Ming

    2012-07-01

    In order to make use of and industrialize the animal dung from large cattle farms, this paper explored the feasibility of using Tenebrio molitor to digest and utilize cattle dung. Cattle dung was mixed with the conventional feed (65% wheat bran, 30% corn flour, and 5% bean pulp) of T. molitor in definite proportions, and fermented with effective microorganisms (EM). The fermented products containing 60% and 80% of cattle dung (FD1 and FD2, respectively) were selected to feed T. molitor larvae, and the effects of the fermented products on the growth curve, death rate, pupation rate, and antioxidant system of the larvae were compared. Compared with CK (conventional deed), the FD1 made the developmental duration of the larvae prolonged by 10 days and the larvae's death rate upraised somewhat, but made the single larva's total food intake, average body mass, crude fat content, and ratio of unsaturated to saturated fat acids increased by 49%, 28%, 26%, and 32%, respectively (P molitor larvae had weak adaptability to FD2. Our findings suggested that using FD1 to feed the 3rd instar of T. molitor larvae would have good practical prospects in industrializing cattle dung.

  8. Assessing the impact of density dependence in field populations of Aedes aegypti.

    Science.gov (United States)

    Walsh, R K; Facchinelli, L; Ramsey, J M; Bond, J G; Gould, F

    2011-12-01

    Although many laboratory studies of intra-specific competition have been conducted with Ae. aegypti, there have been few studies in natural environments and none that examined density dependence in natural containers at normal field densities. Additionally, current mathematical models that predict Ae. aegypti population dynamics lack empirically-based functions for density-dependence. We performed field experiments in Tapachula, Mexico, where dengue is a significant public health concern. Twenty-one containers with natural food and water that already contained larvae were collected from local houses. Each container was divided in half and the naturally occurring larvae were apportioned in a manner that resulted in one side of the container (high density) having four times the density of the second side (low density). Larvae were counted and pupae were removed daily. Once adults emerged, wing span was measured to estimate body size. Density had a significant impact on larval survival, adult body size, and the time taken to transition from 4(th) instar to pupation. Increased density decreased larval survival by 20% and decreased wing length by an average of 0.19 mm. These results provide a starting point for a better understanding of density dependence in field populations of Ae. aegypti.

  9. E2F function in muscle growth is necessary and sufficient for viability in Drosophila

    Science.gov (United States)

    Zappia, Maria Paula; Frolov, Maxim V.

    2016-01-01

    The E2F transcription factor is a key cell cycle regulator. However, the inactivation of the entire E2F family in Drosophila is permissive throughout most of animal development until pupation when lethality occurs. Here we show that E2F function in the adult skeletal muscle is essential for animal viability since providing E2F function in muscles rescues the lethality of the whole-body E2F-deficient animals. Muscle-specific loss of E2F results in a significant reduction in muscle mass and thinner myofibrils. We demonstrate that E2F is dispensable for proliferation of muscle progenitor cells, but is required during late myogenesis to directly control the expression of a set of muscle-specific genes. Interestingly, E2f1 provides a major contribution to the regulation of myogenic function, while E2f2 appears to be less important. These findings identify a key function of E2F in skeletal muscle required for animal viability, and illustrate how the cell cycle regulator is repurposed in post-mitotic cells. PMID:26823289

  10. Entedoninae wasps (Hymenoptera, Chalcidoidea, Eulophidae) associated with ants (Hymenoptera, Formicidae) in tropical America, with new species and notes on their biology

    Science.gov (United States)

    Hansson, Christer; Lachaud, Jean-Paul; Pérez-Lachaud, Gabriela

    2011-01-01

    Abstract Three new species of Eulophidae associated, or presumed to be associated with ants are described: two species of Horismenus Walker and one species of Microdonophagus Schauff. Information on the biology is also included. The two Horismenus species are from Chiapas, Mexico. Horismenus myrmecophagus sp. n. is known only from females and is a gregarious endoparasitoid in larvae of the weaver ant Camponotus sp. ca. textor. The parasitoids pupate inside the host larva, and an average of 6.7 individuals develops per host. This is the second time a species of genus Horismenus is found parasitizing the brood of a formicine ant of genus Camponotus. Horismenus microdonophagus sp. n. is described from both males and females, and is a gregarious endoparasitoid attacking the larvae of Microdon sp. (Diptera: Syrphidae), a predator on ant brood found in nests of Camponotus sp. ca. textor. The new species of Microdonophagus, Microdonophagus tertius, is from Costa Rica, and known only from the female. Nothing is known about its biology but since another species in same genus, Microdonophagus woodleyi Schauff, is associated with ants through its host, Microdon larva (with same biology as Horismenus microdonophagus), it is possible that also Microdonophagus tertius has this association. A new distributional record for Microdonophagus woodleyi is also reported, extending its distribution from Panama and Colombia to Brazil. PMID:22140342

  11. Detailed Morphology of All Life Stages of the Agave Red Worm, Comadia redtenbacheri (Hammerschmidt) (Lepidoptera: Cossidae).

    Science.gov (United States)

    Castro-Torres, R; Llanderal-Cázares, C

    2016-12-01

    The agave red worm, Comadia redtenbacheri (Hammerschmidt), is an important source of food and income in Mexico. Despite its importance, several aspects of its biology, morphology, and behavior remain poorly studied. In this work, we describe and illustrate the morphology of all the life stages that may aid in understanding certain aspects of its biology. To obtain all life stages, last instar larvae were collected from agave plants and allowed to pupate; after the adults emerged, they were allowed to mate and oviposit. The frenulum is longer in males; epiphysis I is longer in females than in males; the abdomen bears two types of tubercles of unknown function. Eggs present a reticulate chorion; primary rosette cells are highly variable in shape; the micropylar formula is (10-14): (12-13). First instar larvae are white, becoming red as they develop; L3 in the prothorax is subprimary; the SV setal group in A1 is comprised of only SV1 on first instar larvae; last instars have several secondary setae. Pupae are adecticous and obtect; there are rows of spines on the dorsum of the abdomen. The biological significance of some of the findings is discussed.

  12. Allelopathic effects of essential oil from Eucalyptus grandis × E.urophylla on pathogenic fungi and pest insects

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This study on the allelopathic effects and chemical components of the essential oil from Eucalyptus grandis × E.urophylla shows that the leaf oil emulsion of E.grandis × E.urophylla can inhibit the proliferation of pathogenic fungi Fusarium oxysporum,Pyriculerie grisea,Glorosprium musa rum and Phytophthora capsici.Pupation and feeding of the pest insects Spodopteralitura Fabricius and Helicoverpa armigera Hubner are shown to be affected with restraining effects which increase with the increasing levels of oil concentration.A GC/MS analysis of the leaf oil indicated that the main components,with a relative content of≥3%,were alloocimene (43.22%),α-pinene (13.63%),γ-terpinene (5.49%),(E)-3,7-dimethyl-2,6-octadien-1-ol (3.58%),β-fenchyl alcohol (4.58%),and 2-amino-3,5-dicyano-6-(4-methoxyphenoxy)-pyridine (3.67%).Terpenes played an important role in the inhibitory effects of E.grandis × E.urophylla essential oil on pathogenic fungi and pest insects.Poor biodiversity of eucalyptus plantations is a function of allelopathy.

  13. Damage Patterns, Monitoring, and Management of Procontarinia mangiferae (Diptera: Cecidomyiidae) in Pakistan.

    Science.gov (United States)

    Rehman, Hafiz M; Mahmood, Riaz; Razaq, Muhammad; Reddy, Gadi V P

    2016-09-11

    Since 2005, mango has been damaged by a group of new pests, the gall midges, in all mango-growing areas of Pakistan. Little is known about these pests in Pakistan. In this report, we present information on the occurrence, damage patterns, methods for monitoring, and management of Procontarinia mangiferae (Felt), a mango gall midge found in the country. At the study site (Rahim Yar Khan, a district of the province Punjab, Pakistan), the pest was active from January/February to April as eggs, larvae, and adults on mango inflorescence buds, branches (axillaries), and immature fruits. Females of P. mangiferae oviposited in inflorescence tissues, and larvae, after feeding on plant tissues, dropped to the soil under the mango trees for pupation from February to April. Mango trees in commercial orchards were more heavily damaged by P. mangiferae than were isolated trees in farmer fields (66.7%). The adults of P. mangiferae were captured on sticky traps of all tested colors, and were in flight from January to May. Captures per trap were highest on yellow traps, followed by green, blue, and clear traps. Control of mango gall midge was effectively provided by the synthetic insecticide bifenthrin (Talstar 10 EC) and also by application of neem seed kernel extract on the tree canopy if integrated with raking the soil under the mango tree canopy.

  14. SUSCEPTIBILITY OF SPOTTED WING DROSOPHILA (Drosophila suzukii (Matsumura, 1931 PUPAE TO ENTOMOPATHOGENIC FUNGI

    Directory of Open Access Journals (Sweden)

    Jaka Razinger

    2017-01-01

    Full Text Available Spotted wing drosophila (Drosophila suzukii (Matsumura, 1931, Diptera, Drosophilidae management is difficult mainly because of its short generation time, polyphagy and serrated ovipositor, but also because its larvae can pupate in the orchard soil and are thus protected from insecticide applications. We hypothesized that insect-pathogenic soil fungi could successfully infect Drosophila suzukii pupae in soil environment. We tested several entomopathogenic or soil fungi against pupae in a conidia-spiked soil, b via direct applications of conidia, and c by dipping pupae into conidial suspensions. Metarhizium brunneum Petch strain H.J.S. 1154 significantly reduced fly emergence in conidia spiked soil and bioinsecticide Naturalis (based on entomopathogenic fungus Beauveria bassiana (Bals.-Criv. Vuill. in direct exposure tests. Our attempt to determine IC50 of pupal hatching rate by dipping D. suzukii pupae into conidial suspensions was unsuccessful. We conclude that the pupal stage is probably too brief to allow entomopathogens to cause a significant reduction of fly emergence. According to our results and published articles, the fungal biocontrol potential would probably best be evaluated in spray applications against adult flies.

  15. Investigation of Natural Plant Aegle marmelos Essential Oil Bioactivity on Development and Toxicity of Tribolium castaneum (Coleoptera: Tenebrionidae

    Directory of Open Access Journals (Sweden)

    Bhuwan Bhaskar Mishra

    2016-01-01

    Full Text Available Background: The uncontrolled use of synthetic chemicals is a great hazard for the environment and consumers. Methodology: In the present study, essential oil from leaves of Aegle marmelos was isolated by hydro-distillation and tested their insecticidal activity against Tribolium castaneum (Herbst. Results: The results showed that the essential oil of A. marmelos have fumigant toxicity, oviposition and developmental inhibitory activity against T. castaneum. The percentage mortality increased with increasing exposure time and concentration. The median lethal concentration (LC50 of A. marmelos essential oil at 48 h was 14.172 and 17.752 FL against larvae and adults of T. castaneum, respectively. The essential oil significantly reduced oviposition (F3,20 = 304.734 in adults and also reduced pupation (F3,20 = 137.442 and adult emergence (F3,20 = 225.619 in larvae when fumigated with sub-lethal concentration. The percent grains infection was reduced 83.66% at 60% of sub-lethal concentration of 24 h LC50. Fumigation of insect with sub-lethal concentration of A. marmelos essential oil inhibited AChE activity. Reduction in AChE activity was 81.48 and 54.32% of the control, after 24 h of fumigation with sub-lethal concentration. Conclusion: In conclusion, this essential oil probably induces toxicity in insect by inhibiting AChE activity.

  16. Developmental Threshold Temperature and Effective Accumulative Temperature of Pupae and Eggs of Holcocerus hippophaecolus

    Institute of Scientific and Technical Information of China (English)

    Zong Shixiang; Luo Youqing; Wang Tao; Xu Zhichun; Lu Changkuan

    2004-01-01

    In order to understand the occurrence and the developmental regularity of seabuckthorn carpenterworm (Holcocerus hippophaecolus) and predict its population density, the developmental threshold temperature (C) and effective accumulative temperature (K) of the carpenterworm pupae and eggs were analyzed under the conditions of constant and variable temperatures. The results show that the values of C and K of the carpenterworm pupae are (12.1 ± 0.2) °C and (295.2 ± 4.1) day-degrees at constant temperatures, and (15.5 ± 0.4) °C and (202.4 ± 13.1) day-degrees at variable temperatures. However, the values of C and K of the eggs at variable temperatures are (16.7 ± 0.8) °C and (101.5 ± 12.6) day-degrees. The differences of developmental threshold and effective accumulative temperature under the conditions of constant and variable temperatures of the carpenterworm pupae accord with the developmental regularity of most insects in nature. By comparing five different constant temperatures, the conclusion is that the optimum developmental temperature of the pupae is 21 °C when both the pupation of the mature larvae and the eclosion of the pupae are very accordant. Moreover, the percentage of eclosion is over 90%. The average developmental durations of the carpenterworm pupae and eggs are 31 and 16 d at variable temperatures.

  17. On the Biology of the Bark Beetle Scolytus nitidus Schedl (Coleoptera: Scolytidae Attacking Apple Orchards

    Directory of Open Access Journals (Sweden)

    LAKATOS, Ferenc

    2007-01-01

    Full Text Available The biological characters of Scolytus nitidus were investigated both in the field and in thelaboratory as well. This common shot-hole borer overwinters in larval stage on apple trees in Kashmir.After emergence the adults fly to suitable trees and undergo maturation feeding for 4-6 days. Thecopulation takes place at the entrance hole. The maternal gallery is one armed longitudinal, in average4.6 cm long. The female lays 52 eggs on an average. The eggs hatch in 5 to 7 days. The larvae have 5instars and complete their development in 38 to 50 days constructing larval galleries 5-8 cm in length.The larvae pupate for 6-18 days and finally the adults emerge to attack new suitable trees. The adultslive for 45-60 days and the total life-span of this species ranges from 97 to 124 days. The seasonaldistribution of various life stages and the number of generations were also recorded.

  18. Soil application of Beauveria bassiana GHA against apple sawfly, Hoplocampa testudinea (Hymenoptera: Tenthredinidae): Field mortality and fungal persistence.

    Science.gov (United States)

    Świergiel, Weronika; Meyling, Nicolai V; Porcel, Mario; Rämert, Birgitta

    2016-12-01

    Low impact alternatives to synthetic insecticides for the control of apple sawfly (Hoplocampa testudinea Klug) are scarce encumbering pest management in organic apple orchards. We investigated the soil persistence and field efficacy of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (BotaniGard) against apple sawfly under common organic orchard practices. We also assessed the efficacy of B. bassiana GHA and Metarhizium brunneum Petch (indigenous strain) against sawfly in the laboratory. Larvae treated with either fungus in the laboratory died faster than control larvae and displayed 49.4%-68.4% mycosis. In the field, B. bassiana density remained high in the week after application, during larval descent to the soil. Fungal density decreased to 25% at 49 d after application and to 0.4% after 55 weeks. Molecular markers revealed that the majority of fungal isolates recovered comprised the applied B. bassiana strain GHA. Larvae pupating in soil cages in the orchard for 49 d displayed 17% mycosis. The high efficacy under laboratory conditions was not seen in the field. B. bassiana application resulted in densities above the upper natural background level during the growing season, but reversion to background levels occurred within a year. It remains to be investigated whether this has a detrimental effect on nontarget organisms. Additional work is needed to bridge the knowledge gap between laboratory and field efficacy in orchards.

  19. Effects of Bacillus thuringiensis toxin Cry1Ac and Beauveria bassiana on Asiatic corn borer (Lepidoptera: Crambidae).

    Science.gov (United States)

    Ma, Xiao-Mu; Liu, Xiao-Xia; Ning, Xia; Zhang, Bo; Han, Fei; Guan, Xiu-Min; Tan, Yun-Feng; Zhang, Qing-Wen

    2008-10-01

    In this study, interactions between Cry1Ac, a toxic crystal protein produced by Bacillus thuringiensis (Berliner), and Beauveria bassiana on the mortality and survival of Ostrinia furnacalis was evaluated in the laboratory. The results showed that Cry1Ac is toxic to O. furnacalis. Not only were larval growth and development delayed, but pupation, pupal weight and adult emergency also decreased when larvae were fed on artificial diet containing purified Cry1Ac toxin. When third instars O. furnacalis were exposed to combination of B. bassiana (1.8x10(5), 1.8x10(6) or 1.8x10(7) conidia ml(-1)) and Cry1Ac, (0.2 or 0.8 microg g(-1)), the effect on mortality was additive, however, the combinations of sublethal concentrations showed antagonism between Cry1Ac (3.2 or 13 microg g(-1)) and B. bassiana (1.8x10(5) or 1.8x10(6) conidia ml(-1)). When neonates were reared on sublethal concentrations of Cry1AC until the third instar, and survivors exposed B. bassiana conidial suspension, such treatments showed additive effect on mortality of O. furnacalis except for the combination of Cry1Ac (0.2 microg g(-1)) and B. bassiana (1.8x10(6) conidia ml(-1)) that showed antagonism.

  20. Structural Analysis of Hand Drawn Bumblebee Bombus terrestris Silk

    Directory of Open Access Journals (Sweden)

    Andrea L. Woodhead

    2016-07-01

    Full Text Available Bombus terrestris, commonly known as the buff-tailed bumblebee, is native to Europe, parts of Africa and Asia. It is commercially bred for use as a pollinator of greenhouse crops. Larvae pupate within a silken cocoon that they construct from proteins produced in modified salivary glands. The amino acid composition and protein structure of hand drawn B. terrestris, silk fibres was investigated through the use of micro-Raman spectroscopy. Spectra were obtained from single fibres drawn from the larvae salivary gland at a rate of 0.14 cm/s. Raman spectroscopy enabled the identification of poly(alanine, poly(alanine-glycine, phenylalanine, tryptophan, and methionine, which is consistent with the results of amino acid analysis. The dominant protein conformation was found to be coiled coil (73% while the β-sheet content of 10% is, as expected, lower than those reported for hornets and ants. Polarized Raman spectra revealed that the coiled coils were highly aligned along the fibre axis while the β-sheet and random coil components had their peptide carbonyl groups roughly perpendicular to the fibre axis. The protein orientation distribution is compared to those of other natural and recombinant silks. A structural model for the B. terrestris silk fibre is proposed based on these results.

  1. Cannibalistic feeding of larval Trichogramma carverae parasitoids in moth eggs

    Science.gov (United States)

    Heslin, Leeane M.; Merritt, David J.

    2005-09-01

    Wasps of the genus Trichogramma parasitise the eggs of Lepidoptera. They may deposit one or many eggs in each host. Survival is high at low density but reaches a plateau as density increases. To reveal the mechanism by which excess larvae die we chose a lepidopteran host that has flattened, transparent eggs and used video microscopy to record novel feeding behaviours and interactions of larval Trichogramma carverae (Oatman and Pinto) at different densities. Single larvae show a rapid food ingestion phase, followed by a period of extensive saliva release. Ultimately the host egg is completely consumed. The larva then extracts excess moisture from the egg, providing a dry environment for pupation. When multiple larvae are present, the initial scramble for food results in the larvae consuming all of the egg contents early in development. All larvae survive if there is sufficient food for all to reach a threshold developmental stage. If not, physical proximity results in attack and consumption of others, continuing until the surviving larvae reach the threshold stage beyond which attacks seem to be no longer effective. The number of larvae remaining at the end of rapid ingestion dictates how many will survive to emerge as adults.

  2. 二突异翅长蠹的生物学特性及熏蒸技术研究%Biological characteristics and fumigation technology for Heterobostrychus hamatipennis Lesne

    Institute of Scientific and Technical Information of China (English)

    何玉杰; 陈青林; 林华峰; 李茂业; 张玉美; 李世广

    2013-01-01

    Heterobostrychus hamatipennis Lesne causes more and more serious damage on the wicker in warehouse in Anhui province in recent years. In order to control it efficiently, we studied its biological characteristics and fumigation technology. The results of feeding in the laboratory and survey in the warehouse were as follows. It has 2 generations a year in Anhui province and overwinter as matured larvae in the injured wickers. The overwintering larvae begin to harm in late March and pupate in late April. A large number of the adults emerge in the middle of May. The adults start to spawn in late May. The larvae of the first generation hatch in early June. The larvae start to pupate in early August. In the middle of August, the first generation adults emerge. About ten days later, the adults start to spawn. In early September, the second generation larvae hatch. And until November, when the new wickers are harvested, the matured larvae would move into the new wickers and overwinter. The fumigation tests were carried out with aluminium phosphide 56% tablet and dichlorvos 80% emulsion in hermetic bags, and the results showed that the mortality in different stages could achieve 100% at 72 h after fumigation with aluminum phosphide 56% tablet at the dose of 12 g·m-3, and the larvae are more sensitive to phosphine than any other stages. Therefore, fumigation control must focus on the stage of recovery of overwintering generation larvae, which is in late March and early April every year, with aluminium phosphide 56% tablet at 12 g·m-3above 72 h.%近年来二突异翅长蠹对安徽省储藏期柳编原材料——杞柳枝条的危害日趋严重.为了有效防控该虫,对其生物学特性和熏蒸技术进行研究.实验室饲养观测与仓库调查结果表明,该虫在安徽省1年发生2代,以老熟幼虫在被害柳条内部越冬.翌年3月下旬越冬幼虫开始活动为害,4月下旬开始化蛹,5月中旬成虫大量出现,并于5月下旬产卵.第1

  3. Evolution of increased larval competitive ability in Drosophila melanogaster without increased larval feeding rate

    Indian Academy of Sciences (India)

    MANASWINI SARANGI; ARCHANA NAGARAJAN; SNIGDHADIP DEY; JOY BOSE; AMITABH JOSHI

    2016-09-01

    Multiple experimental evolution studies on Drosophila melanogasterin the 1980s and 1990s indicated that enhanced competitive ability evolved primarily through increased larval tolerance to nitrogenous wastes and increased larval feeding and foraging rate, at the cost of efficiency of food conversion to biomass, and this became the widely accepted view of how adaptation to larval crowding evolves in fruitflies. We recently showed that populations of D. ananassaeand D. n. nasuta subjected to extreme larval crowding evolved greater competitive ability without evolving higher feeding rates, primarily through acombination of reduced larval duration, faster attainment of minimum critical size for pupation, greater efficiency of food conversion to biomass, increased pupation height and, perhaps, greater urea/ammonia tolerance. This was a very differentsuite of traits than that seen to evolve under similar selection in D. melanogasterand was closer to the expectations from the theory of K-selection. At that time, we suggested two possible reasons for the differences in the phenotypic correlates ofgreater competitive ability seen in the studies with D. melanogaster and the other two species. First, that D. ananassae and D. n. nasuta had a very different genetic architecture of traits affecting competitive ability compared to the long-term labora-tory populations of D. melanogaster used in the earlier studies, either because the populations of the former two species were relatively recently wild-caught, or by virtue of being different species. Second, that the different evolutionary trajectories in D. ananassae and D. n. nasuta versus D. melanogaster were a reflection of differences in the manner in which larval crowding was imposed in the two sets of selection experiments. The D. melanogaster studies used a higher absolute density of eggs per unit volume of food, and a substantially larger total volume of food, than the studies on D. ananassae and D. n. nasuta. Here, we

  4. Significance of bacteria in oviposition and larval development of the sand fly Lutzomyia longipalpis.

    Science.gov (United States)

    Peterkova-Koci, Kamila; Robles-Murguia, Maricela; Ramalho-Ortigao, Marcelo; Zurek, Ludek

    2012-07-24

    . (76 days, 36.0 %). From the complex natural bacterial community of rabbit feces, R. radiobacter survived pupation and colonized the newly emerged females most successfully (82.6 % of all bacteria cultured); however, only 25 % of females were positive for bacteria in the digestive tract upon emergence. Immunohistochemistry did not reveal any obvious differences in anatomy of the digestive tract between control and axenic larvae. The bacterial community in the sand fly larval habitat affects oviposition and larval development although bacteria are not essential for successful development of L. longipalpis. Different bacteria contribute to larval development to various degrees and some, e.g. Rhizobium radiobacter, survive pupation and colonize the digestive tract of newly emerged females. With the establishment of the axenic rearing system, this study opens new venues to study the effect of bacteria on the gut epithelial immunity and vector competence of sand flies for Leishmania parasites with a goal to develop paratransgenic approaches for Leishmania control.

  5. SCREENING OF MAIZE GENOTYPES AGAINST STEM BORER CHILO PARTELLUS L. IN KHARIF SEASON

    Directory of Open Access Journals (Sweden)

    Rajasekhar Lella

    2013-12-01

    Full Text Available Maize (Zea mays L. being the highest yielding cereal crop in the world is of significant importance for countries like India, where rapidly increasing population already out stripped the available food supplies. Maize crop possesses great genetic diversity. Maize Plant is attacked by 140 species of insects causing varying degree of damage causing an annual loss of over 1 billion in the Semi Arid Tropics (ICRISAT, 1992. Out of these, only 10 species cause serious damage from sowing till storage, of which the stemborer Chilo partellus (Swinhoe is the major one (Hiremath et al., 1988. The larvae of C.partellus after hatching feed on soft surface of the leaves and then enter the stem through whorl of feeding on the pith of the stem. The growth of the plants becomes shunted and resulting in dead hearts when attacked by C.partellus at their initial stages. The larvae transferred from other plants enter the stem through lower nodes by making the holes. Stem borers pupate inside the stem. They make holes before pupation for the emergence of adults. Since host plant resistance is the back bone of Insect Pest Management; hence the present investigation was initiated. Present studies were designed to identify maize genotype resistance against stem borer in order to minimize pesticide use, improve natural balance, and enhance the activity of bio control agents, and to increase crop production. The investigations were carried out on the screening of Maize genotypes against Maize stem borer Chilo partellus in kharif season were conducted on the agricultural farm of the institute of Agricultural Sciences, Banaras Hindu University, Varanasi during kharif season of 2010-2011 to screen the relative resistance /susceptibility of 19 genotypes of maize to the insect pest, maize stem borer (Chilo partellus. In order to screen the relative susceptibility of different maize genotypes to maize stem borer the following genotypes were screened under field conditions. The

  6. Biological Activities of the Extracts of Lantana camara L .against the Ostrinia f urnacalis (Guenée)%马缨丹提取物对亚洲玉米螟的活性研究

    Institute of Scientific and Technical Information of China (English)

    申翠翠; 罗兰; 袁忠林

    2014-01-01

    将阴干粉碎的马缨丹叶片用氯仿、乙酸乙酯、甲醇依次进行提取,3种溶剂的提取物采用点滴法、叶碟法、浸渍法等方法测定了对玉米螟3龄幼虫的触杀、胃毒、拒食作用,对3龄以后各龄期、化蛹、羽化等影响及杀卵活性。结果表明:马缨丹叶片氯仿提取物对亚洲玉米螟3龄幼虫的作用效果比乙酸乙酯和甲醇提取物的效果好。马缨丹叶片氯仿提取物对亚洲玉米螟幼虫有较强的胃毒和触杀活性,在浓度为200mg/mL时,96h其幼虫的死亡率分别为84.31%和64.29%;对玉米螟3龄幼虫的非选择性的拒食作用高于选择性的拒食作用,浓度为200mg/mL时72h对幼虫的非选择性和选择性拒食作用率分别为71.27%和50.66%;对亚洲玉米螟的卵有毒杀作用,并能延迟卵的孵化,能延缓幼虫的发育,降低化蛹率和羽化率。因此马缨丹叶片中含有对玉米螟具有生物活性的物质,但其种类及作用机理有待进一步研究。%Leaves of L .camara were dried in the shade and smashed ,extracted with chloroform ,ethyl ace-tate and methanol in turn .T he stomach poison ,contact poison ,antifeedant ,ovicide and developments of egg hatch and the impact to the larva instars ,pupation and emergence of O .f urnacalis were assayed using the methods of topical application ,stomach poison ,leaf disc ,immersion ,etc ,with the extracts .It shows that the effect of chloroform extract on larva of O . f urnacalis is better than that of the extracts of ethyl acetate and methanol .The mortality of 3rd instars larva are 84.31% and 64.29% respectively using stom-ach and contact poison with chloroform extract at the concentration of 200mg/mL in 96h .The antifeedant effect of no -choice is higher than that of the choice ,and the no -choice and choice anfifeeding rates are 71.27% and 50.66% respectively under the concentration 200mg/mL in 72h .The chloroform extract has ovicidal activity ,can

  7. A New Device Adapted to Observe the Termination of Larval Diapause in Asian Corn Borer,Ostrinia furnacalis%一种适宜亚洲玉米螟幼虫滞育解除的新型装置

    Institute of Scientific and Technical Information of China (English)

    傅淑; 何海敏; 肖海军; 肖亮; 薛芳森

    2015-01-01

    研制了一种适宜亚洲玉米螟幼虫滞育解除的新型装置,装置由托盘、带孔泡沫板、透明圆柱管和脱脂棉4个部件组成。其方法是,将泡沫板置于盛有少量水分的托盘上、将装有亚洲玉米螟滞育幼虫,两端塞有脱脂棉的透明圆柱管插入泡沫板小孔内,然后将整个托盘置于诱导发育的条件下,观察滞育幼虫的化蛹情况。该方法模拟了亚洲玉米螟滞育幼虫解除的外环境,满足了滞育幼虫解除对水分的需求。该方法用于广东惠州(简称HZ)、江西永修(YX)、安微合肥(HF)、山东泰安(TA)、河北廊坊(LF)和辽宁沈阳(SY)6个不同地理种群亚洲玉米螟的滞育解除试验,滞育幼虫在光周期L∶D=18∶6和25℃下及在春季自然条件下化蛹成功率都在85%以上。本方法操作简便,还可直接用于亚洲玉米螟的越冬代幼虫化蛹进度的观察及成虫发生期的预测预报。%The new device is consisted of the plastic pallet,foam board with holes,transparent cylindrical tube and absorbent cotton.The application method is as follows.A foam board is put on a plastic pallet with some water.The diapausing larvae are individually placed in a cylindrical tube and the both ends of the cylin-drical tube are plugged with absorbent cotton.Then, the cylindrical tubes are inserted to the holes of foam board.Finally,the devices are transferred to inducing-development conditions to observe the termination of dia-pause.This device finely simulates the external environment of diapause termination in the field and meets the water needs of the diapausing larvae.Using the new devices,the termination of diapause from six geographical populations originated from Huizhou,Yongxiu,Hefei,Taian,Langfang and Shenyang under L∶D=18∶6 at 25℃and natural conditions was successfully observed.More than 85%diapausing larvae pupated at the two treat-ments.The experimental method is simple and

  8. Evolution of increased larval competitive ability in Drosophila melanogaster without increased larval feeding rate.

    Science.gov (United States)

    Sarangi, Manaswini; Nagarajan, Archana; Dey, Snigdhadip; Bose, Joy; Joshi, Amitabh

    2016-09-01

    Multiple experimental evolution studies on Drosophila melanogaster in the 1980s and 1990s indicated that enhanced competitive ability evolved primarily through increased larval tolerance to nitrogenous wastes and increased larval feeding and foraging rate, at the cost of efficiency of food conversion to biomass, and this became the widely accepted view of how adaptation to larval crowding evolves in fruitflies.We recently showed that populations of D. ananassae and D. n. nasuta subjected to extreme larval crowding evolved greater competitive ability without evolving higher feeding rates, primarily through a combination of reduced larval duration, faster attainment of minimum critical size for pupation, greater efficiency of food conversion to biomass, increased pupation height and, perhaps, greater urea/ammonia tolerance. This was a very different suite of traits than that seen to evolve under similar selection in D. melanogaster and was closer to the expectations from the theory of K-selection. At that time, we suggested two possible reasons for the differences in the phenotypic correlates of greater competitive ability seen in the studies with D. melanogaster and the other two species. First, that D. ananassae and D. n. nasuta had a very different genetic architecture of traits affecting competitive ability compared to the long-term laboratory populations of D. melanogaster used in the earlier studies, either because the populations of the former two species were relatively recently wild-caught, or by virtue of being different species. Second, that the different evolutionary trajectories in D. ananassae and D. n. nasuta versus D. melanogaster were a reflection of differences in the manner in which larval crowding was imposed in the two sets of selection experiments. The D. melanogaster studies used a higher absolute density of eggs per unit volume of food, and a substantially larger total volume of food, than the studies on D. ananassae and D. n. nasuta. Here, we

  9. Studies on the Biology and Control of Acanthoscelides macrophthalmus (Schaeffer) (Coleoptera: Bruchidae)%银合欢豆象生物学特性及其防治

    Institute of Scientific and Technical Information of China (English)

    覃新导; 周祥; 王涛; 陈秀龙; 宋付平; 虞道耿; 陈青

    2011-01-01

    The leucaena bruchid beetle, Acanthoscelides macrophthalmus (Schaeffer, 1907), is an important insect of leucaena seeds and Falcataria moluccana was also used by the larva in China. Among RH75% and 20-35 ℃, The eggs hatch about 4~12 days after they are laid. The young larva comes out from the egg and then enters into and chews the pod. The larva feeds and grows, moults and pupates generally within a single seed. There is usually but not always only one bruchid in each seed. The larva overwinters in the seed. The larva pupates after it conies out from the egg about 18~37 days. And then after 5~11 days, it emerges into the adult. The adults can last about 17~31 days, and the sex ratio of female to male was 1:1. It takes 44~48 days for the bruchid beetle to complete its lifecycle under 26 ℃ and RH 80% . Averagely, A kind of parasitic wasp Pediobius sp. (Hymenoptera: Eulophidae) is found parasitising the immature stages of A. Macrophthalmus. Among RH75%~80% and 25~30℃, all the adults, larva, and pupae died after treated 48~72 hours with aluminium phosphating (56% tablet) at the dose of 7~9 g/m3.%银合欢豆象象[canthoscelides macrophthalmus (Schaeffer,1907)]是银合欢属Leucae植物种子上的重要害虫,除银合欢外,也可蛀食南洋楹(Falcataria moluccana)种子.在75%RH及20~35℃的条件下,卵期为4~12d.幼虫期为18~37 d,蛹期为5~11 d.成虫寿命17~31 d,雌雄性别比约为1∶1.在75%RH及26℃条件下,银合欢豆象完成1个世代需要44~48 d.在野外,银合欢豆象在幼龄阶段常被一种姬小蜂科(Eulophidae)的柄腹姬小蜂属(Pediob ius Walker)寄生.在75%~80% RH及25~30℃条件下,使用56%磷化铝片剂对银合欢豆象进行熏蒸,用药量7~9 g/m3,熏蒸时间48~72h,成虫、幼虫及蛹死亡率100%.

  10. Integrated use of Beauveria bassiana and Bacillus thuringiensis serovar.tenebrionis for microbial biocontrol of colorado potato beetle%球孢白僵菌和苏云金杆菌拟步甲血清亚种联合使用防治马铃薯甲

    Institute of Scientific and Technical Information of China (English)

    斯蒂芬· 瑞特; Mark A Ramos

    2007-01-01

    This paper reviews the potential for using insect pathogens to control the Colorado potato beetle,Leptinotarsa decemlineata,and summarizes results from nearly 10 years of research by USDA-ARS-PPRU scientists aimed at developing methods and strategies for integrated use of Bacillus thuringiensis and Beauveria bassiana for biologically-based management of potato beetles in the northeastern USA.The described studies have resulted in 1) design of a tractor-mounted hydraulic spray system that improved targeting and consequent efficacy of microbial control agents, 2) discovery of synergism between the bacterial pathogen Bacillus thuringiensis (Bt) and the fungal pathogen Beauveria bassiana (Bb),3) findings that substantial mortality of beetle larvae treated with B.bassiana during foliar spray programs did not occur until after they entered the soil to pupate, and 4) observations that spray applications made in the evening (at sunset) were significantly, but not substantially, more effective than applications made during the morning hours.These findings have led to development of a bio-based pest management system based on three spray applications made in the following order at 3-5-day intervals:Bt alone,Bt and Bb mixed,and Bb alone.This spray program,with the applications initiated at 50% egg hatch,is intended to control the actively feeding larval stages (providing protection from defoliation) and reduce survivorship to the adult stage (providing long-term control by reducing populations of overwintering adults). In the initial test of the integrated management system,beetle control and potato yields were statistically equivalent to those in plots in which the beetles were controlled with chemical insecticides.Demonstration of the effectiveness of this program will continue over the next 2-3 field seasons.

  11. Effect of cold storage on larval and adult Anastrepha ludens (Diptera: Tephritidae) viability in commercially ripe, artificially infested Persea americana 'Hass'.

    Science.gov (United States)

    Aluja, M; Díaz-Fleischer, F; Arredondo, J; Valle-Mora, J; Rull, J

    2010-12-01

    Commercially ripe 'Hass' avocados, Persea americana Mill, artificially exposed to wild Anastrepha ludens (Loew) (Diptera: Tephritidae) females 24 h after harvest were placed in a cold storage facility to determine the effect of low temperature on larval survival and adult viability. Fruit were left for 3, 6, 9, and 12 d in a cold room at 5 degrees C followed by a 20-25-d period at ambient temperature to allow for larval development and pupation. Hass avocados and grapefruit, Citrus paradisi Macfadyen, maintained at ambient temperature served as controls. Overall, only 0.23% of the Hass avocados and 19.30% of the grapefruit were infested. The number of infested fruit increased with decreasing exposure time to cold. Puparia from cold-treated Hass avocados were significantly smaller than those stemming from cold-treated grapefruit. Hass avocados exposed for 12 d to 5 degrees C yielded no puparia, and those exposed for 6 and 9 d yielded 22 and two puparia, respectively, but no adults. Although Hass avocados exposed to cold temperature for 3 d yielded adults that reached sexual maturity (N = 16), females laid inviable eggs. Grapefruit exposed to cold for 12 d yielded normal-sized puparia (but no adults), whereas those exposed over 9 d yielded females able to lay viable eggs. We conclude that exposing fruit to cold storage after packing and during transport represents an effective risk-mitigating procedure in the highly improbable event that a gravid A. ludens female might lay eggs in a commercially ripe Hass avocado that had been left unprotected in a packinghouse.

  12. Rasgos morfológicos asociados a la viabilidad de pupas en parasitoides del género Pseudacteon (Diptera: Phoridae Morphological traits associated with pupae viability in Pseudacteon (Diptera: Phoridae parasitoids

    Directory of Open Access Journals (Sweden)

    Patricia J. Folgarait

    2005-12-01

    Full Text Available RESUMEN. Fóridos del género Pseudacteon Coquillett oviponen en forrajeras del género Solenopsis Westwood y empupan en sus cabezas. Se evaluó la relación entre la viabilidad de los parasitoides, la presencia de cuernos respiratorios y el color en los opérculos de los puparios de cuatro especies de Pseudacteon criados sobre Solenopsis invicta Buren y Solenopsis richteri Forel. La presencia de cuernos respiratorios estuvo asociada a la viabilidad de las pupas para las especies consideradas (p 0,09; excepto cuando Pseudacteon cultellatus Borgmeier se desarrolló sobre hormigas de la reserva y niñeras de S. invicta (p ABSTRACT. Pseudacteon Coquillett phorid flies oviposit on Solenopsis Westwood ants and pupate within the ant's head. We have evaluated the relationship between pupae's viability, presence of respiratory horns and the operculum color in four species of Pseudacteon reared on Solenopsis invicta Buren and Solenopsis richteri Forel ants. The presence of respiratory horns was significantly associated with pupae's viability for all species considered (p 0,09, except (p < 0,01 when Pseudacteon cultellatus Borgmeier had developed on S. invicta nanitic and reserve workers. Pupae with light-colored opercula were more frequent in P. cultellatus, whereas brown opercula were more frequent for the other species that attack bigger ants. Mimetism can be invoked to explain the similarity in opercula color with that of the head of the parasitized ant as a way to avoid recognition by members of the colony. We conclude that the presence of respiratory horns is necessary for pupae survival of most of the pupae and we suggest to use the presence of respiratory horns as an indicator of the efficiency of rearing protocols for this group of parasitoids. We also recommend using forager ants because other casts do not seem to be appropriate hosts.

  13. Physiological and morphological aspects of Aedes aegypti developing larvae: effects of the chitin synthesis inhibitor novaluron.

    Science.gov (United States)

    Farnesi, Luana C; Brito, José M; Linss, Jutta G; Pelajo-Machado, Marcelo; Valle, Denise; Rezende, Gustavo L

    2012-01-01

    Population control of the dengue vector mosquito, Aedes aegypti, is difficult due to many reasons, one being the development of resistance to neurotoxic insecticides employed. The biosynthesis of chitin, a major constituent of insect cuticle, is a novel target for population control. Novaluron is a benzoylphenylurea (BPU) that acts as a chitin synthesis inhibitor, already used against mosquitoes. However, information regarding BPU effects on immature mosquito stages and physiological parameters related with mosquito larval development are scarce. A set of physiological parameters were recorded in control developing larvae and novaluron was administered continuously to Ae. aegypti larvae, since early third instar. Larval instar period duration was recorded from third instar until pupation. Chitin content was measured during third and fourth instars. Fourth instars were processed histochemically at the mesothorax region, stained with hematoxylin and eosin (HE) for assessment of internal tissues, and labeled with WGA-FITC to reveal chitinized structures. In control larvae: i) there is a chitin content increase during both third and fourth instars where late third instars contain more chitin than early fourth instars; ii) thoracic organs and a continuous cuticle, closely associated with the underlying epidermis were observed; iii) chitin was continuously present throughout integument cuticle. Novaluron treatment inhibited adult emergence, induced immature mortality, altered adult sex ratio and caused delay in larval development. Moreover, novaluron: i) significantly affected chitin content during larval development; ii) induced a discontinuous and altered cuticle in some regions while epidermis was often thinner or missing; iii) rendered chitin cuticle presence discontinuous and less evident. In both control and novaluron larvae, chitin was present in the peritrophic matrix. This study showed quantitatively and qualitatively evidences of novaluron effects on Ae

  14. Physiological and morphological aspects of Aedes aegypti developing larvae: effects of the chitin synthesis inhibitor novaluron.

    Directory of Open Access Journals (Sweden)

    Luana C Farnesi

    Full Text Available Population control of the dengue vector mosquito, Aedes aegypti, is difficult due to many reasons, one being the development of resistance to neurotoxic insecticides employed. The biosynthesis of chitin, a major constituent of insect cuticle, is a novel target for population control. Novaluron is a benzoylphenylurea (BPU that acts as a chitin synthesis inhibitor, already used against mosquitoes. However, information regarding BPU effects on immature mosquito stages and physiological parameters related with mosquito larval development are scarce. A set of physiological parameters were recorded in control developing larvae and novaluron was administered continuously to Ae. aegypti larvae, since early third instar. Larval instar period duration was recorded from third instar until pupation. Chitin content was measured during third and fourth instars. Fourth instars were processed histochemically at the mesothorax region, stained with hematoxylin and eosin (HE for assessment of internal tissues, and labeled with WGA-FITC to reveal chitinized structures. In control larvae: i there is a chitin content increase during both third and fourth instars where late third instars contain more chitin than early fourth instars; ii thoracic organs and a continuous cuticle, closely associated with the underlying epidermis were observed; iii chitin was continuously present throughout integument cuticle. Novaluron treatment inhibited adult emergence, induced immature mortality, altered adult sex ratio and caused delay in larval development. Moreover, novaluron: i significantly affected chitin content during larval development; ii induced a discontinuous and altered cuticle in some regions while epidermis was often thinner or missing; iii rendered chitin cuticle presence discontinuous and less evident. In both control and novaluron larvae, chitin was present in the peritrophic matrix. This study showed quantitatively and qualitatively evidences of novaluron effects

  15. Live imaging of muscles in Drosophila metamorphosis: Towards high-throughput gene identification and function analysis.

    Science.gov (United States)

    Puah, Wee Choo; Wasser, Martin

    2016-03-01

    Time-lapse microscopy in developmental biology is an emerging tool for functional genomics. Phenotypic effects of gene perturbations can be studied non-invasively at multiple time points in chronological order. During metamorphosis of Drosophila melanogaster, time-lapse microscopy using fluorescent reporters allows visualization of alternative fates of larval muscles, which are a model for the study of genes related to muscle wasting. While doomed muscles enter hormone-induced programmed cell death, a smaller population of persistent muscles survives to adulthood and undergoes morphological remodeling that involves atrophy in early, and hypertrophy in late pupation. We developed a method that combines in vivo imaging, targeted gene perturbation and image analysis to identify and characterize genes involved in muscle development. Macrozoom microscopy helps to screen for interesting muscle phenotypes, while confocal microscopy in multiple locations over 4-5 days produces time-lapse images that are used to quantify changes in cell morphology. Performing a similar investigation using fixed pupal tissues would be too time-consuming and therefore impractical. We describe three applications of our pipeline. First, we show how quantitative microscopy can track and measure morphological changes of muscle throughout metamorphosis and analyze genes involved in atrophy. Second, our assay can help to identify genes that either promote or prevent histolysis of abdominal muscles. Third, we apply our approach to test new fluorescent proteins as live markers for muscle development. We describe mKO2 tagged Cysteine proteinase 1 (Cp1) and Troponin-I (TnI) as examples of proteins showing developmental changes in subcellular localization. Finally, we discuss strategies to improve throughput of our pipeline to permit genome-wide screens in the future.

  16. Effects of Galanthus nivalis agglutinin (GNA) expressed in tomato leaves on larvae of the tomato moth Lacanobia oleracea (Lepidoptera: Noctuidae) and the effect of GNA on the development of the endoparasitoid Meteorus gyrator (Hymenoptera: Braconidae).

    Science.gov (United States)

    Wakefield, M E; Bell, H A; Fitches, E C; Edwards, J P; Gatehouse, A M R

    2006-02-01

    The effect of ingestion of transgenic tomato leaves expressing the plant lectin Galanthus nivalis agglutinin (GNA) on development of larvae of Lacanobia oleracea (Linnaeus) was studied under laboratory conditions. When L. oleracea larvae were fed on tomato line 14.1H, expressing approximately 2.0% GNA, significant increases in the mean larval weight and in the amount of food consumed were found. This resulted in an overall reduction in the mean development time to the pupal stage of approximately 7 days. A significant increase in the percentage survival to the adult moth was also recorded when newly hatched larvae were reared on transgenic tomato leaves (72%) compared to larvae reared on untransformed leaves (40%). The effects of ingestion of GNA by L. oleracea larvae, via artificial diet or the leaves of transgenic tomato or potato plants, on the subsequent development of its solitary endoparasitoid Meteorus gyrator (Thunberg) was also studied. No significant effects on the life cycle parameters of M. gyrator developing in L. oleracea fed on GNA-containing diets were observed. Experiments with transgenic potato plants indicated that the stadium of the host larvae at parasitism had a greater influence on M. gyrator development than the presence of GNA. Potential GNA-binding glycoproteins were detected in the gut and body tissues of larval M. gyrator. Despite detection in host tissues, GNA could not be detected in adult M. gyrator and therefore it is likely that at the time of pupation M. gyrator are able to void the GNA in the meconial pellet.

  17. Involvement of larder beetles (Coleoptera: Dermestidae) on human cadavers: a review of 81 forensic cases.

    Science.gov (United States)

    Charabidze, Damien; Colard, Thomas; Vincent, Benoit; Pasquerault, Thierry; Hedouin, Valery

    2014-11-01

    From 1994 to 2013, French forensic entomology laboratories investigated 1,093 cases. Larder beetles (Coleoptera: Dermestidae) were observed in 81 (7.5%) of these cases. To describe and analyze these 81 cases, eight parameters were used: city, location (indoor or outdoor), decay stage (fresh, decay, or dry), dermestid species and instar (adults and/or larvae), presence of living calliphorid larvae, presence of calliphorid pupae or adults, and presence of other necrophagous species. Eight Dermestidae species were observed: Dermestes frischii (42% of cases), Dermestes undulatus (35.8%), Dermestes peruvianus (12.3%), Dermestes lardarius (9.9%), Dermestes haemorrhoidalis (8.6%), Dermestes maculatus (7.4%), Dermestes bicolor (3.7%), and Dermestes ater (1.2%). Larder beetles primarily developed on human cadavers in outdoor locations in areas with a dry climate and were never reported in oceanic areas (which are characterized by frequent rainfall and high ambient humidity). The number of dermestid species on a single corpse never exceeded three. Typically, one species was found per corpse. Species differed between indoor and outdoor cases, with D. frischii and D. undulatus dominant in outdoor cases, while D. peruvianus dominant in indoor cases. Calliphoridae was found in 88% of the cases, while Hydrotaea and Piophilidae were observed 40% of the time. Regarding Coleoptera, Necrobia spp. (Coleoptera: Cleridae) was observed in 46% of the cases. Lastly, we observed a typical decomposition pattern, with preferential feeding areas on the face, hands, and feet (i.e., the extremities). Pupation chambers on or inside the bones were not observed.

  18. The inheritance of intrasexual dimorphism in female diving beetles (Coleoptera: Dytiscidae).

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    Inoda, Toshio; Härdling, Roger; Kubota, Souichirou

    2012-08-01

    Many species of Dytiscus diving beetles exhibit intrasexual dimorphism, e.g., the elytra is smooth in some females and grooved in others. However, the expression of the grooves and whether they are a product of heredity or the environment remain unknown. One Japanese species, Dytiscus sharpi sharpi Wehncke, 1875 , also shows female dimorphism, with grooved and smooth morphs, while D. sharpi validus Régimbart, 1899, only has a single morph (the grooved type). A hybrid of the two species should therefore provide a means of sorting out how the grooves are inherited. We found two independent wetlands of D. sharpi sharpi in Chiba Prefecture, Japan. One was a place where a high proportion of grooved females lived, and the others had high proportions of smooth females. After five to eight generations of beetles from two populations with different proportions of grooved females were reared under aquarium conditions constituting a common garden design, i.e., water temperature, water depth, and presence of a plant for oviposition, the differences remained. We mated smooth virgin females of D. sharpi sharpi with males of D. sharpi validus to obtain hybrid offspring. The elytral traits of the hybrid females produced only grooved forms. These results suggested that the female dimorphism is determined by genetics, and that the grooved morph was dominant over the smooth one, independent of environmental factors. In addition, the hybrid insects did not differ from the two subspecies insects in larval survivorship, pupation success, or sex ratio. They also showed neither morphological abnormality nor reduced survival.

  19. Egg Cannibalism and its Life History Consequences Vary with Life Stage, Sex, and Reproductive Status in Hippodamia convergens (Coleoptera: Coccinellidae).

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    Bayoumy, Mohamed H; Michaud, J P

    2015-08-01

    Egg cannibalism is common in Coccinellidae, but its biological consequences have not been fully explored. We examined egg cannibalism by neonates, fourth instars, and adults of Hippodamia convergens Guerin-Meneville for effects on development, reproduction, and progeny fitness. We also tested female adults for ability to avoid cannibalizing their own eggs and first-instar larvae, and both sexes for changes in cannibalism propensity following mating, all in the presence of ad libitum food [larvae: eggs of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), adults: Schizaphis graminum (Rondani)]. Cannibalism by neonates reduced developmental time and increased male body size. Cannibalism in the fourth instar accelerated pupation and led to the production of eggs that hatched faster, regardless of which parent cannibalized. However, egg fertility was improved only by maternal cannibalism in the fourth instar. Females recognized their own egg clusters, sometimes added eggs to them, and preferentially cannibalized nonfilial clusters. Most gravid females cannibalized a first-instar larva within 30 min, whether filial or not. Adult egg cannibalism was similar for virgin males and females, but declined after mating in males, and increased in females, although it had no effect on fecundity or fertility. Daughters of cannibal pairs were heavier than those of other mating combinations, but offspring of noncannibal parents had the fastest development. Reproductive females appeared to use egg cannibalism to reduce risk for their own eggs, increasing the number cannibalized with the number laid. Thus, egg cannibalism in coccinellids varies with life stage, sex, and reproductive condition, independent of food availability, and benefits are life stage specific.

  20. Field observations on the overwintering ecology of Culiseta melanura in the northeastern USA.

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    Andreadis, Theodore G; Shepard, John J; Thomas, Michael C

    2012-12-01

    The overwintering ecology of Culiseta melanura was studied in a seasonally flooded evergreen forest swamp in south central Connecticut in an effort to clarify which larval stages successfully overwinter in the northeastern USA, and to determine the degree to which larval development and/or mortality occur during the winter months. A total of 8,626 immature Cs. melanura were collected weekly for analysis from subterranean crypts and cavities located under the roots of trees from December 13, 2011 to May 31, 2012. Despite the formation of ice on the surface water at the entrance holes to the crypts, water temperatures within the cavities remained above freezing (average = 1.8 degrees C) throughout the coldest winter months of January and February. A heterogeneous population of 2nd, 3rd, and 4th instars were recovered throughout the winter and early spring in the same relative proportions (30%, 30%, 40%, respectively), with no significant change in their comparative abundance during this period, providing unequivocal evidence that all 3 instars successfully overwinter in the region. Findings further demonstrate that larvae undergo no development during the winter and do not appear to be impacted by any measurable mortality. The cessation of larval diapause and a resumption of development was observed in mid-April and was coincident with a gradual increase in water temperature within the crypts to 9 degrees C, in agreement with a previously calculated developmental thermal minimum of 8.5 degrees C for Cs. melanura. This resulted in a protracted period of pupation that encompassed a minimum of 5 wk, followed by a staggered emergence of adults and an overlap of the residual overwintering population with larvae of the 1st summer generation.

  1. BIOECOLOGY OF DIORYCTRIA ABIETELLA DENIS AND SCHIFF. A PEST OF CONIFERS IN THE NORTH-WESTERN HIMALAYA

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    T.D. VERMA

    1994-01-01

    Full Text Available Cones and seeds of conifers, such as Pinus roxburghii, P. wallichiana, P. gerardiana, Cedrus deodara, Abies pindrow and Picea smithiana are seriously damaged by Dioryctria abietella Denis and Schiff. (Lepidoptera : Pyralidae in the North-Western Himalayan region of India. Bioecological studies carried out during 1991 - '92 revealed that the females laid whitish, elliptical eggs singly on the depressed surface of the young cones. The average egg size was 1.00 ± 0.11 x 0.60 ±0.08 mm and this stage lasted for 3 - 5 days. The larval stage passed through five instars. All the instars differed in appearance, size and duration and larvae became full-fed in an average of 24.8 ± 1.9 days. The full-fed larva spun a cocoon around itself, sealed it with white papery membrane and pupated inside the cone or any other outside protected place. The prepupal and pupal periods lasted for 7-8 and 10-14 days, respectively. The pupa was dark brown, 13.8 ± 0.07 mm in length. Total period from egg to adult varied from 46 to 59 days (52.7 ±4.8 days. Adults were dirty brown in appearance and were 13.59±0.115 mm long with an average wing expanse of 29.0 ± 1.00 mm. They lived for 4 to 5 days. Under laboratory conditions, the pest completed two generations per year and full-fed larvae of 3rd generation overwintered during September - October. Two larval parasites belonging to order Hymenoptera and Diptera, and a fungal pathogen (Fusarium sp. were found associated with this pest. The detailed biology, nature and extent of damage, along with its distribution have been discussed and methods of control suggested.

  2. Biology, life history, and laboratory rearing of Spathius galinae (Hymenoptera: Braconidae), a larval parasitoid of the invasive emerald ash borer (Coleoptera: Buprestidae).

    Science.gov (United States)

    Duan, Jian J; Watt, Timothy J; Larson, Kristi

    2014-06-01

    Spathius galinae Belokobylskij & Strazanac is a recently described parasitoid of the emerald ash borer, Agrilus planipennis Fairmaire, in the Russian Far East, and is currently being considered for biocontrol introduction in the United States. Using A. planipennis larvae reared with freshly cut ash (Fraxinus spp.) sticks, we investigated the biology, life cycle, and rearing of S. galinae in the laboratory under normal rearing conditions (25 +/- 1 degrees C, 65 +/- 10% relative humidity, and a photoperiod of 16:8 [L:D] h). Our study showed that S. galinae took approximately 1 mo (29 d) to complete a single generation (from egg to adult) under the laboratory rearing conditions. After eclosion from eggs, larvae of S. galinae molted four times to reach the fifth instar, which then spun cocoons for pupation and development to adults. Adult female wasps had a median survival time of 7 wk with fecundity peaking 3 wk after emergence when reared in groups (of five females and five males) and 2 wk in single pairs. Throughout the life span, a single female S. galinae produced a mean (+/- SE) of 31 (+/- 3.0) progeny when reared in groups, and a mean (+/- SE) of 47 (+/- 5.3) progeny when reared in single pairs. Results from our study also showed that S. galinae could be effectively reared with A. planipennis larvae reared in both green (Fraxinus pennsylvanica Marshall) and tropical [Fraxinus uhdei (Wenzig) Lingelsh] ash sticks. However, the abortion (unemergence) rate of S. galinae progeny was much higher (20%) when reared with host larvae in green ash sticks than that (2.1%) in tropical ash sticks.

  3. Thermoregulation in larval aggregations of carrion-feeding blow flies (Diptera: Calliphoridae)

    Science.gov (United States)

    Slone, D.H.; Gruner, Susan V.

    2007-01-01

    The growth and development of carrion-feeding calliphorid (Diptera Calliphoridae) larvae, or maggots, is of great interest to forensic sciences, especially for estimation of a postmortem interval (PMI). The development rate of calliphorid larvae is influenced by the temperature of their immediate environment. Heat generation in larval feeding aggregations (=maggot masses) is a well-known phenomenon, but it has not been quantitatively described. Calculated development rates that do not include internally generated temperatures will result in overestimation of PMI. Over a period of 2.5 yr, 80 pig, Sus scrofa L., carcasses were placed out at study sites in north central Florida and northwestern Indiana. Once larval aggregations started to form, multiple internal and external temperatures, and weather observations were taken daily or every few days between 1400 and 1800 hours until pupation of the larvae. Volume of each aggregation was determined by measuring surface area and average depth. Live and preserved samples of larvae were taken for species identification. The four most common species collected were Lucilia coeruleiviridis (=Phaenicia) (Macquart) (77%), Cochliomyia macellaria (F.) (8.3%), Chrysomya rufifaces (Macquart) (7.7%), and Phormia regina (Meigen) (5.5%). Statistical analyses showed that 1) volume of a larval mass had a strong influence on its temperature, 2) internal temperatures of masses on the ground were influenced by soil temperature and mass volume, 3) internal temperatures of masses smaller than 20 cm3 were influenced by ambient air temperature and mass volume, and 4) masses larger than 20 cm3 on the carcass had strongly regulated internal temperatures determined only by the volume of the mass, with larger volumes associated with higher temperatures. Nonsignificant factors included presence of rain or clouds, shape of the aggregation, weight of the carcass, species composition of the aggregation, time since death, or season.

  4. Mass production of genetically modified Aedes aegypti for field releases in Brazil.

    Science.gov (United States)

    Carvalho, Danilo O; Nimmo, Derric; Naish, Neil; McKemey, Andrew R; Gray, Pam; Wilke, André B B; Marrelli, Mauro T; Virginio, Jair F; Alphey, Luke; Capurro, Margareth L

    2014-01-04

    New techniques and methods are being sought to try to win the battle against mosquitoes. Recent advances in molecular techniques have led to the development of new and innovative methods of mosquito control based around the Sterile Insect Technique (SIT)(1-3). A control method known as RIDL (Release of Insects carrying a Dominant Lethal)(4), is based around SIT, but uses genetic methods to remove the need for radiation-sterilization(5-8). A RIDL strain of Ae. aegypti was successfully tested in the field in Grand Cayman(9,10); further field use is planned or in progress in other countries around the world. Mass rearing of insects has been established in several insect species and to levels of billions a week. However, in mosquitoes, rearing has generally been performed on a much smaller scale, with most large scale rearing being performed in the 1970s and 80s. For a RIDL program it is desirable to release as few females as possible as they bite and transmit disease. In a mass rearing program there are several stages to produce the males to be released: egg production, rearing eggs until pupation, and then sorting males from females before release. These males are then used for a RIDL control program, released as either pupae or adults(11,12). To suppress a mosquito population using RIDL a large number of high quality male adults need to be reared(13,14). The following describes the methods for the mass rearing of OX513A, a RIDL strain of Ae. aegypti (8), for release and covers the techniques required for the production of eggs and mass rearing RIDL males for a control program.

  5. Effects of fluctuating daily temperatures at critical thermal extremes on Aedes aegypti life-history traits.

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    Lauren B Carrington

    Full Text Available BACKGROUND: The effect of temperature on insect biology is well understood under constant temperature conditions, but less so under more natural, fluctuating conditions. A fluctuating temperature profile around a mean of 26°C can alter Aedes aegypti vector competence for dengue viruses as well as numerous life-history traits, however, the effect of fluctuations on mosquitoes at critical thermal limits is unknown. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the effects of large and small daily temperature fluctuations at low (16°C and high (35-37°C mean temperatures, after we identified these temperatures as being thresholds for immature development and/or adult reproduction under constant temperature conditions. We found that temperature effects on larval development time, larval survival and adult reproduction depend on the combination of mean temperature and magnitude of fluctuations. Importantly, observed degree-day estimates for mosquito development under fluctuating temperature profiles depart significantly (around 10-20% from that predicted by constant temperatures of the same mean. At low mean temperatures, fluctuations reduce the thermal energy required to reach pupation relative to constant temperature, whereas at high mean temperatures additional thermal energy is required to complete development. A stage-structured model based on these empirical data predicts that fluctuations can significantly affect the intrinsic growth rate of mosquito populations. CONCLUSIONS/SIGNIFICANCE: Our results indicate that by using constant temperatures, one could under- or over-estimate values for numerous life-history traits compared to more natural field conditions dependent upon the mean temperature. This complexity may in turn reduce the accuracy of population dynamics modeling and downstream applications for mosquito surveillance and disease prevention.

  6. Larval Preference and Performance of Amyelois transitella (Navel Orangeworm, Lepidoptera: Pyralidae) in Relation to the Fungus Aspergillus flavus.

    Science.gov (United States)

    Ampt, Eline A; Bush, Daniel S; Siegel, Joel P; Berenbaum, May R

    2016-02-01

    The navel orangeworm, Amyelois transitella (Walker), is a polyphagous pest of California nut crops and is responsible for extensive losses in the United States. It directly damages crops by feeding and contaminating nuts with frass and webbing and vectors saprophytic fungi that infect crops. The navel orangeworm is commonly associated with Aspergillus species, including the toxigenic Aspergillus flavus, which causes crop loss by producing carcinogens, including aflatoxin B1. This lepidopteran-fungus association is the most economically serious pest complex in Central Valley orchards, and evidence indicates that this relationship is mutualistic. We assessed preference and performance of navel orangeworm larvae associated with A. flavus in behavioral bioassays in which neonates were allowed to orient within arenas to media with or without fungal tissue, and performance bioassays in which larvae were reared with and without A. flavus on potato dextrose agar (PDA) and a semidefined almond PDA diet to evaluate effects on development and pupal weight. Navel orangeworm larvae were attracted to A. flavus and developed faster in its presence, indicating a nutritional benefit to the caterpillars. Larvae reached pupation ∼33% faster on diet containing A. flavus, and pupal weights were ∼18% higher for males and ∼13% higher for females on this diet. Our findings indicate that A. flavus plays an important role in larval orientation and development on infected hosts. The preference-performance relationship between navel orangeworms and Aspergillus flavus is consistent with a facultative mutualism that has broad implications for pest management efforts and basic understanding of Lepidoptera-plant interactions.

  7. Influence of tillage on adult and immature pea leaf weevil (Coleoptera: Curculionidae) densities in pea.

    Science.gov (United States)

    Hanavan, Ryan P; Bosque-Pérez, Nilsa A; Schotzko, Dennis J; Eigenbrode, Sanford D

    2010-06-01

    The pea leaf weevil, Sitona lineatus (L.) (Coleoptera: Curculionidae), has been a major pest of pea, Pisum sativum L., in eastern Washington and northern Idaho since its introduction to the region in the early 1970s. Eggs are deposited in the spring on the soil surface and first instars hatch and move to pea root nodules, where larvae feed before they pupate and adults emerge in mid- to late summer. No-tillage practices are known to reduce pea leaf weevil colonization in pea, but the effects of tillage on larval densities and subsequent adult emergence have not been examined. During 2005, 2006, and 2007, we compared densities of colonizing adult and immature pea leaf weevils on pea plots grown using conventional tillage and no-tillage. In 2005 and 2006, emergence of adult pea leaf weevil was monitored in the same plots. Densities of colonizing adult and immature pea leaf weevil were significantly higher in conventional tillage plots. Larvae in conventional tillage were further along in development than larvae in no-tillage plots during June and July. Densities of emerging adult pea leaf weevil were significantly greater from conventional tillage than no-tillage plots. Based on densities of colonizing and subsequent emerging adults, survival of weevils from egg through adult was greater in conventional tillage plots. Soils under no-tillage are cooler, resulting in later emergence of the pea crop and delayed root nodule development, possibly affecting the ability of first-instar pea leaf weevil to locate host plant roots. Our results indicate no-tillage fields are less suitable for pea leaf weevil colonization and survival than conventional tillage fields.

  8. Increased long-flight activity triggered in beet armyworm by larval feeding on diet containing Cry1Ac protoxin.

    Directory of Open Access Journals (Sweden)

    Xing Fu Jiang

    Full Text Available Evaluating ecological safety and conducting pest risk analysis for transgenic crops are vitally important before their commercial planting. The beet armyworm, Spodoptera exigua, a long-distance migratory insect pest, is not a direct target of transgenic Cry1Ac-expressing cotton in China, but nevertheless it has recently become an important pest. Migrants leaving their natal field arrive in other appropriate habitat far away in a short time, often followed by larval outbreaks. S. exigua has low susceptibility to Cry1Ac. However, our results from laboratory experiments identified (i sublethal effects of Cry1Ac protoxin on larval development rate, larval and pupal weight, and adult lifetime fecundity, and (ii increased long-flight behavior triggered by Cry1Ac which may contribute to larval outbreaks elsewhere. No significant differences in larval mortality, pupation rate, adult emergence rate, longevity, pre-oviposition period, or oviposition period were observed between controls and larvae fed on artificial diet incorporating a low concentration of Cry1Ac protoxin. The negative sublethal effects on some developmental and reproductive traits and lack of effect on others suggest they do not contribute to the observed severity of S. exigua outbreaks after feeding on Cry1Ac cotton. Interestingly, the percentage of long fliers increased significantly when larvae were reared on diet containing either of two low-dose treatments of Cry1Ac, suggesting a possible increased propensity to disperse long distances triggered by Cry1Ac. We hypothesize that negative effects on development and reproduction caused by Cry1Ac in the diet are offset by increased flight propensity triggered by the poor food conditions, thereby improving the chances of escaping adverse local conditions before oviposition. Increased long-flight propensity in turn may amplify the area damaged by outbreak populations. This phenomenon might be common in other migratory insect pests receiving

  9. Tri-trophic effects of seasonally variable induced plant defenses vary across the development of a shelter building moth larva and its parasitoid.

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    Noah H Rose

    Full Text Available Plant chemical defenses can negatively affect insect herbivore fitness, but they can also decrease herbivore palatability to predators or decrease parasitoid fitness, potentially changing selective pressures on both plant investment in production of chemical defenses and host feeding behavior. Larvae of the fern moth Herpetogramma theseusalis live in and feed upon leaf shelters of their own construction, and their most abundant parasitoid Alabagrus texanus oviposits in early instar larvae, where parasitoid larvae lay dormant for most of host development before rapidly developing and emerging just prior to host pupation. As such, both might be expected to live in a relatively constant chemical environment. Instead, we find that a correlated set of phenolic compounds shows strong seasonal variation both within shelters and in undamaged fern tissue, and the relative level of these compounds in these two different fern tissue types switches across the summer. Using experimental feeding treatments, in which we exposed fern moth larvae to different chemical trajectories across their development, we show that exposure to this set of phenolic compounds reduces the survival of larvae in early development. However, exposure to this set of compounds just before the beginning of explosive parasitoid growth increased parasitoid survival. Exposure during the period of rapid parasitoid growth and feeding decreased parasitoid survival. These results highlight the spatial and temporal complexity of leaf shelter chemistry, and demonstrate the developmental contingency of associated effects on both host and parasitoid, implying the existence of complex selective pressures on plant investment in chemical defenses, host feeding behavior, and parasitoid life history.

  10. THE RESPONSE TO SELECTION FOR FAST LARVAL DEVELOPMENT IN DROSOPHILA MELANOGASTER AND ITS EFFECT ON ADULT WEIGHT: AN EXAMPLE OF A FITNESS TRADE-OFF.

    Science.gov (United States)

    Nunney, Leonard

    1996-06-01

    A selection experiment using Drosophila melanogaster revealed a strong trade-off between adult weight and larval development time (LDT), supporting the view that antagonistic pleiotropy for these two fitness traits determines mean adult size. Two experimental lines of flies were selected for a shorter LDT (measured from egg laying to pupation). After 15 generations LDT was reduced by an average of 7.9%. The response appeared to be controlled primarily by autosomal loci. A correlated response to the selection was a reduction in adult dry weight: individuals from the selected populations were on average 15.1% lighter than the controls. The lighter females of the selected lines showed a 35% drop in fecundity, but no change in longevity. Thus, there is no direct relationship between LDT and adult longevity. The genetic correlation between weight and LDT, as measured from their joint response to selection, was 0.86. Although there was weak evidence for dominance in LDT, there was none for weight, making it unlikely that selection acting on this antagonistic pleiotropy could lead to a stable polymorphism. In all lines, sex differences in weight violated expectations based on intrasex genetic correlations: Females, being larger than males, ought to require a longer LDT, whereas there was a slight trend in the opposite direction. Because the sexual dimorphism in size was not significantly altered by selection, it appears that the controlling loci are either invariant or have very limited pleiotropic effect on developmental time. It is suggested that they probably control some intrinsic, energy-intensive developmental process in males. © 1996 The Society for the Study of Evolution.

  11. Tolerance and resistance of invasive and native Eupatorium species to generalist herbivore insects

    Science.gov (United States)

    Wang, Rui-Fang; Feng, Yu-Long

    2016-11-01

    Invasive plants are exotic species that escape control by native specialist enemies. However, exotic plants may still be attacked by locally occurring generalist enemies, which can influence the dynamics of biological invasions. If invasive plants have greater defensive (resistance and tolerance) capabilities than indigenous plants, they may experience less damage from native herbivores. In the present study, we tested this prediction using the invasive plant Eupatorium adenophorum and two native congeners under simulated defoliation and generalist herbivore insect (Helicoverpa armigera and Spodoptera litura) treatments. E. adenophorum was less susceptible and compensated more quickly to damages in biomass production from both treatments compared to its two congeners, exhibiting greater herbivore tolerance. This strong tolerance to damage was associated with greater resource allocation to aboveground structures, leading to a higher leaf area ratio and a lower root: crown mass ratio than those of its native congeners. E. adenophorum also displayed a higher resistance index (which integrates acid detergent fiber, nitrogen content, carbon/nitrogen ratio, leaf mass per area, toughness, and trichome density) than its two congeners. Thus, H. armigera and S. litura performed poorly on E. adenophorum, with less leaf damage, a lengthened insect developmental duration, and decreased pupating: molting ratios compared to those of the native congeners. Strong tolerance and resistance traits may facilitate the successful invasion of E. adenophorum in China and may decrease the efficacy of leaf-feeding biocontrol agents. Our results highlight both the need for further research on defensive traits and their role in the invasiveness and biological control of exotic plants, and suggest that biocontrol of E. adenophorum in China would require damage to the plant far in excess of current levels.

  12. Efficacy of aquatain, a monomolecular film, for the control of malaria vectors in rice paddies.

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    Tullu Bukhari

    Full Text Available BACKGROUND: Rice paddies harbour a large variety of organisms including larvae of malaria mosquitoes. These paddies are challenging for mosquito control because their large size, slurry and vegetation make it difficult to effectively apply a control agent. Aquatain, a monomolecular surface film, can be considered a suitable mosquito control agent for such breeding habitats due to its physical properties. The properties allow Aquatain to self-spread over a water surface and affect multiple stages of the mosquito life cycle. METHODOLOGY/PRINCIPAL FINDINGS: A trial based on a pre-test/post-test control group design evaluated the potential of Aquatain as a mosquito control agent at Ahero rice irrigation scheme in Kenya. After Aquatain application at a dose of 2 ml/m(2 on rice paddies, early stage anopheline larvae were reduced by 36%, and late stage anopheline larvae by 16%. However, even at a lower dose of 1 ml/m(2 there was a 93.2% reduction in emergence of anopheline adults and 69.5% reduction in emergence of culicine adults. No pupation was observed in treated buckets that were part of a field bio-assay carried out parallel to the trial. Aquatain application saved nearly 1.7 L of water in six days from a water surface of 0.2 m(2 under field conditions. Aquatain had no negative effect on rice plants as well as on a variety of non-target organisms, except backswimmers. CONCLUSIONS/SIGNIFICANCE: We demonstrated that Aquatain is an effective agent for the control of anopheline and culicine mosquitoes in irrigated rice paddies. The agent reduced densities of aquatic larval stages and, more importantly, strongly impacted the emergence of adult mosquitoes. Aquatain also reduced water loss due to evaporation. No negative impacts were found on either abundance of non-target organisms, or growth and development of rice plants. Aquatain, therefore, appears a suitable mosquito control tool for use in rice agro-ecosystems.

  13. Cold hardiness and overwintering strategy of the pink maize stalk borer,Sesamia nonagrioides Lef (lepidoptera, noctuidae).

    Science.gov (United States)

    Gillyboeuf, N; Anglade, P; Lavenseau, L; Peypelut, L

    1994-09-01

    The cold-hardening capacity of larvae of the pink maize stalk borer,Sesamia nonagrioides Lef., was examined. Supercooling points (SCPs) of field collected diapausing larvae from south-east and south-west France and non-diapausing and diapausing laboratory-reared larvae did not differ and ranged between -5 and -8°C. Thus, this insect possesses sufficient supercooling ability to avoid freezing over its normal environmental temperature ranges. Despite this, we found thatSesamia presents paradoxical cold reactions. Mortality of cold acclimated diapausing larvae after short-term exposure to temperatures above the SCP is high, supporting the view thatSesamia is cold-sensitive. On the other hand,Sesamia could survive freezing for at least 24 h to temperatures close to the SCP. This ability does not seem to be related to haemolymph trehalose, the sole cold-accumulated compound detected by gas chromatography and mass spectrometry. Despite the mildness of the winter 1990-1991, only 5% of the field population survive and pupate in April. The main part of the population died from November to January, the period during which larvae were mainly located in the part of the corn stem above the ground and experienced air temperatures. After January, all surviving larvae were excuusively located in the root, 10 cm below the soil, where they experienced milder temperatures than air. They exhibited a constant low rate of mortality, possibly independent of the cold. In their current distribution area, survival of overwintering larvae ofS. nonagrioides is only related to the microclimate of the overwintering site and freezing tolerance capacity seems to be irrelevant. This study allows us to propose a non-pollutant pest control method based on the "behavioral strategy" of this insect.

  14. Evaluation of genotoxic and antigenotoxic effects of boron by the somatic mutation and recombination test (SMART) on Drosophila.

    Science.gov (United States)

    Sarıkaya, Rabia; Erciyas, Kamile; Kara, Muhammed Isa; Sezer, Ufuk; Erciyas, Ali Fuat; Ay, Sinan

    2016-10-01

    In this study, different concentrations of boron have been evaluated for genotoxic and antigenotoxic properties by using the somatic mutation and recombination test (SMART) on Drosophila melanogaster. The treatment concentrations were chosen to a pretest. Third-instar larvae trans-heterozygous for two genetic markers, multiple wing hair (mwh) and flare (flr3), were treated at different concentrations (0.1, 5, 10, 20, and 40 mg/mL) of boron. In addition to investigating antigenotoxic effects, the same boron concentrations were co-administered with 0.1 mM Ethyl Methane Sulfonate (EMS). Distilled water was used as a negative control; 0.1 mM of EMS was used as a positive control. For the chronic feeding study, small plastic vials were prepared with 1.5 g of dry Drosophila Instant Medium and 5 mL of the respective test solution. Hundreds of trans-heterozygous larvae were embedded into this medium. Feeding ended with pupation of the surviving larvae. After metamorphosis, all surviving flies were collected and stored in a 70% ethanol solution. Preparation and microscopic analyses of wing were made after the treatment. Then the observed mutations were classified according to size and type of mutation per wing. Results indicated that there is no significant genotoxic effect with all of the boron concentrations. In addition, the antigenotoxic activities of boron against EMS were tested. Results indicated that all boron concentrations (0.1, 5, 10, 20 and 40 mg/mL) were able to abolish the genotoxic effects induced by the EMS. It is suggested that the observed effects can be linked to the antioxidant properties of boron. Moreover, these in vivo results will contribute to the antigenotoxicity database of boron.

  15. Histone deacetylase enzymes as drug targets for the control of the sheep blowfly, Lucilia cuprina

    Directory of Open Access Journals (Sweden)

    Andrew C. Kotze

    2015-12-01

    Full Text Available The Australian sheep blowfly, Lucilia cuprina, is an ecto-parasite that causes significant economic losses in the sheep industry. Emerging resistance to insecticides used to protect sheep from this parasite is driving the search for new drugs that act via different mechanisms. Inhibitors of histone deacetylases (HDACs, enzymes essential for regulating eukaryotic gene transcription, are prospective new insecticides based on their capacity to kill human parasites. The blowfly genome was found here to contain five HDAC genes corresponding to human HDACs 1, 3, 4, 6 and 11. The catalytic domains of blowfly HDACs 1 and 3 have high sequence identity with corresponding human and other Dipteran insect HDACs (Musca domestica and Drosophila melanogaster. On the other hand, HDACs 4, 6 and 11 from the blowfly and the other Dipteran species showed up to 53% difference in catalytic domain amino acids from corresponding human sequences, suggesting the possibility of developing HDAC inhibitors specific for insects as desired for a commercial insecticide. Differences in transcription patterns for different blowfly HDACs through the life cycle, and between the sexes of adult flies, suggest different functions in regulating gene transcription within this organism and possibly different vulnerabilities. Data that supports HDACs as possible new insecticide targets is the finding that trichostatin A and suberoylanilide hydroxamic acid retarded growth of early instar blowfly larvae in vitro, and reduced the pupation rate. Trichostatin A was 8-fold less potent than the commercial insecticide cyromazine in inhibiting larval growth. Our results support further development of inhibitors of blowfly HDACs with selectivity over human and other mammalian HDACs as a new class of prospective insecticides for sheep blowfly.

  16. Use of a pollen-based diet to expose the ladybird beetle Propylea japonica to insecticidal proteins.

    Directory of Open Access Journals (Sweden)

    Xiaojie Zhang

    Full Text Available A rape seed pollen-based diet was developed and found to be suitable for use in a dietary exposure assay for Propylea japonica. Using the diet, we established and validated a dietary exposure assay by using the protease inhibitor E-64 as positive control. Dose-dependent responses were documented for all observed life-table parameters of P. japonica including survival, pupation and eclosion rates, development time and adult weight. Results suggested that the dietary assay can detect the effects of insecticidal compounds on the survival and development of P. japonica. Using the established dietary assay, we subsequently tested the toxicity of Cry1Ab, Cry1Ac and Cry1F proteins that are expressed by transgenic maize, cotton or rice plants to P. japonica larvae. The diet containing E-64 was included as a positive control. Survival and development of P. japonica larvae were not adversely affected when the diet contained purified Cry1Ab, Cry1Ac, or Cry1F at 500 µg/g diet representing a worst-case exposure scenario. In contrast, P. japonica larvae were adversely affected when the diet contained E-64. The bioactivity and stability of the Cry proteins in the diet and Cry protein uptake by the ladybird larvae were confirmed by bioassay with a Cry-sensitive insect species and by ELISA. The current study describes a suitable experimental system for assessing the potential effects of gut-active insecticidal compounds on ladybird beetle larvae. The experiments with the Cry proteins demonstrate that P. japonica larvae are not sensitive to Cry1Ab, Cry1Ac and Cry1F.

  17. Use of a pollen-based diet to expose the ladybird beetle Propylea japonica to insecticidal proteins.

    Science.gov (United States)

    Zhang, Xiaojie; Li, Yunhe; Romeis, Jörg; Yin, Xinming; Wu, Kongming; Peng, Yufa

    2014-01-01

    A rape seed pollen-based diet was developed and found to be suitable for use in a dietary exposure assay for Propylea japonica. Using the diet, we established and validated a dietary exposure assay by using the protease inhibitor E-64 as positive control. Dose-dependent responses were documented for all observed life-table parameters of P. japonica including survival, pupation and eclosion rates, development time and adult weight. Results suggested that the dietary assay can detect the effects of insecticidal compounds on the survival and development of P. japonica. Using the established dietary assay, we subsequently tested the toxicity of Cry1Ab, Cry1Ac and Cry1F proteins that are expressed by transgenic maize, cotton or rice plants to P. japonica larvae. The diet containing E-64 was included as a positive control. Survival and development of P. japonica larvae were not adversely affected when the diet contained purified Cry1Ab, Cry1Ac, or Cry1F at 500 µg/g diet representing a worst-case exposure scenario. In contrast, P. japonica larvae were adversely affected when the diet contained E-64. The bioactivity and stability of the Cry proteins in the diet and Cry protein uptake by the ladybird larvae were confirmed by bioassay with a Cry-sensitive insect species and by ELISA. The current study describes a suitable experimental system for assessing the potential effects of gut-active insecticidal compounds on ladybird beetle larvae. The experiments with the Cry proteins demonstrate that P. japonica larvae are not sensitive to Cry1Ab, Cry1Ac and Cry1F.

  18. Sublethal effects of insecticide seed treatments on two nearctic lady beetles (Coleoptera: Coccinellidae).

    Science.gov (United States)

    Moscardini, Valéria Fonseca; Gontijo, Pablo Costa; Michaud, J P; Carvalho, Geraldo Andrade

    2015-07-01

    Predatory insects often feed on plants or use plant products to supplement their diet, creating a potential route of exposure to systemic insecticides used as seed treatments. This study examined whether chlorantraniliprole or thiamethoxam might negatively impact Coleomegilla maculata and Hippodamia convergens when the beetles consumed the extrafloral nectar of sunflowers grown from treated seed. We reared both species on eggs of Ephestia kuehniella and then switched adult H. convergens to a diet of greenbugs, Schizaphis graminum, in order to induce oviposition in this species. Excised sunflower stems, either treated or control and refreshed every 48 h, were provided throughout larval development, or for the first week of adult life. Exposure of C. maculata larvae to chlorantraniliprole and thiamethoxam applied as seed treatments delayed adult emergence by prolonging the pupal period. When adults were exposed, thiamethoxam reduced the preoviposition period compared to chlorantraniliprole, whereas the latter treatment cause females to produce fewer clutches during the observation period. Larvae of C. maculata did not appear to obtain sufficient hydration from the sunflower stems and their subsequent fecundity and fertility were compromised in comparison to the adult exposure experiment where larvae received supplemental water during development. Exposure of H. convergens larvae to thiamethoxam skewed the sex ratio in favor of females; both materials reduced the egg viability of resulting adults and increased the period required for eclosion. Exposure of H. convergens adults to chlorantraniliprole reduced egg eclosion times compared to thiamethoxam and exposure to both insecticides reduced pupation times in progeny. The results indicate that both insecticides have negative, sublethal impacts on the biology of these predators when they feed on extrafloral nectar of sunflower plants grown from treated seed.

  19. Feeding on Host Plants with Different Concentrations and Structures of Pyrrolizidine Alkaloids Impacts the Chemical-Defense Effectiveness of a Specialist Herbivore.

    Science.gov (United States)

    Martins, Carlos H Z; Cunha, Beatriz P; Solferini, Vera N; Trigo, José R

    2015-01-01

    Sequestration of chemical defenses from host plants is a strategy widely used by herbivorous insects to avoid predation. Larvae of the arctiine moth Utetheisa ornatrix feeding on unripe seeds and leaves of many species of Crotalaria (Leguminosae) sequester N-oxides of pyrrolizidine alkaloids (PAs) from these host plants, and transfer them to adults through the pupal stage. PAs confer protection against predation on all life stages of U. ornatrix. As U. ornatrix also uses other Crotalaria species as host plants, we evaluated whether the PA chemical defense against predation is independent of host plant use. We fed larvae from hatching to pupation with either leaves or seeds of one of eight Crotalaria species (C. incana, C. juncea, C. micans, C. ochroleuca, C. pallida, C. paulina, C. spectabilis, and C. vitellina), and tested if adults were preyed upon or released by the orb-weaving spider Nephila clavipes. We found that the protection against the spider was more effective in adults whose larvae fed on seeds, which had a higher PA concentration than leaves. The exceptions were adults from larvae fed on C. paulina, C. spectabilis and C. vitellina leaves, which showed high PA concentrations. With respect to the PA profile, we describe for the first time insect-PAs in U. ornatrix. These PAs, biosynthesized from the necine base retronecine of plant origin, or monocrotaline- and senecionine-type PAs sequestered from host plants, were equally active in moth chemical defense, in a dose-dependent manner. These results are also partially explained by host plant phylogeny, since PAs of the host plants do have a phylogenetic signal (clades with high and low PA concentrations in leaves) which is reflected in the adult defense.

  20. Spatial distribution of Holcocerus hippophaecolus (Lepidopetera: Cossidae) pupae in a seabuckthorn (Hippophae rhamnoides) stand.

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The seabuckthorn carpenter moth,Holcocerus hippophaecolus,which has a generation time of four years,is recently becoming one of the major pests of the seabuckthorn (Hippophae rhamnoides) in Inner Mongolia,Liaoning,Shanxi,Ningxia and Shaanxi of China (Hua et al.,1990).The larvae of the H.hippophaecolus mainly damage the stems and roots of the seabuckthorn,and the mature larvae pupate in the soil.The spatial distribution of the pupae was analyzed by using biostatistics and geostatistics in order to effectively control the insect and further study the spatial distribution of the population.Results show that most of the pupae (90%) had an eclosion time span from early June to the end of July.The sex ratio of the pupae was nearly 1:1 in the woodland samples.In addition,24.3% of the 971 trees investigated had pupae and it ranged from 0 to 4 per tree within a distance of 1.3 m from the base of the stem.90% of the pupae were aggregated within a distance of 1 m from the base of the stem.The pupae show intense spatial aggregation in the sampled woodland which had an 11.1 m spatial dependence and a 90.7% intensity in the local spatial continuity.Moreover,the population presented an intensive spotted distribution and many aggregated spots were found in the woodlands.As for the relationship between grid size and variogram of the pupae,the variations in the range,the intensity of local spatial continuity and the sill were all very low or non-existent when the grid size was 5 m,6 m or 7 m.Whereas,the value of the decisive coefficient was the biggest when the grid size was 5 m making it the ideal grid size.

  1. The effects of a winter cover crop on Diabrotica virgifera (Coleoptera: Chrysomelidae) populations and beneficial arthropod communities in no-till maize.

    Science.gov (United States)

    Lundgren, Jonathan G; Fergen, Janet K

    2010-12-01

    The effects of an autumn-planted, spring-killed, grass cover crop (Elymus trachycaulus [Link] Gould ex Shinners) on populations of Diabrotica virgifera virgifera LeConte and its predator community were evaluated in South Dakota maize fields over two seasons. Abundance and size of D. virgifera larvae and adults and sex ratio of adults were measured in maize produced under two treatments (i.e., a winter cover crop or bare soil), as were maize root damage and the abundance and diversity of the predator communities collected on the soil surface and in the soil column. First and second instars and adults of D. virgifera were similarly abundant in the two treatments, but third instars were significantly fewer in maize planted after a winter cover crop. Larvae developed at different rates in the two treatments, and second instars were significantly smaller (head capsule width and body length) in the maize planted after a cover crop. First and third instars and adults were of similar size in the two treatments, and adult sex ratios were also similar. Although initially similar, predator populations increased steadily in the cover-cropped maize, which led to a significantly greater predator population by the time D. virgifera pupated. There was significantly less root damage in the cover-cropped maize. Predator communities were similarly diverse in both treatments. Predator abundance per plot was significantly and negatively correlated with the abundance of third instars per plot. Clearly, winter cover crops reduce D. virgifera performance and their damage to the crop, and we suspect that this reduction is caused by both environmental effects of the treatment on D. virgifera size and development, and of increased predation on the third instars of the pest. Additional data on the impact of cover crops on actual predation levels, grain yield and quality, and farmer profitability, and correlations among pest performance, crop characteristics, and predator populations and

  2. Juvenile hormone biosynthesis and secretion by the female Corpora allata of the larval gypsy moth, Lymantria dispar (L. ) utilizing in vitro organ culture

    Energy Technology Data Exchange (ETDEWEB)

    Jones, G.L.

    1986-01-01

    Junvenile hormone synthesis and secretion in the female larval gypsy moth was investigated. In vitro culturing methods were developed including: incubating 2 pair of CC-CA gland complexes in 50 ul of osmotically balanced Grace's insect medium containing 1 uCi /sup 3/H-methyl-methionine for 6 hr. JH homologues were identified and quantified using TLC and HPLC. In vitro methods were employed to investigate trends of JH secretion in 4th and ultimate female larval instar CA. Fourth instar CA produced JH peaks of 0.15 pmole/pr/hr between days 2 and 3, but the rate declined to half by day 4. Ultimate instar larvae began secreting 0.48 pmole/pr/hr, but by day 10, had decreased JH output to negligible levels which continued until pupation. Effects upon in vitro JH secretion produced by precocene II and caffeine were examined. Feulgen staining techniques revealed an equal number of cells (30) in 4th and last instar CA. Last instar Ca were 3 times larger than 4th in volume but their actual in vitro JH secretion at peak levels was only 20% greater. In vitro methods demonstrated that JH secretory trends differ in younger versus mature larval instars. Glandular volume increased in last instars but JH secretion was only 20% greater than in 4th's when compared on the basis of volume. Precocene II elicited a negative response on in vivo JH secretion at levels 10 times less than caffeine. Caffeine was judged not to significantly alter JH secretion.

  3. 活体柞蚕蛹复壮北虫草菌种初探%Rejuvenation Method on Cordyceps militaris Using Antheraea pernyi Guerin-Meneviile Living Body

    Institute of Scientific and Technical Information of China (English)

    张鑫; 唐亮; 徐三妹

    2011-01-01

    目的:对北虫草菌株进行复壮处理以提高菌种活力.方法:用一株人工培育的北虫草菌株P感染刚化蛹的活体柞蚕蛹,蛹体近头部长出子实体后,待子实体近成熟期时采集孢子进行有性繁殖对原菌株进行复壮.结果:复壮后菌株10-2的子实体产量和生物转化率分别是原来菌株P的1.2倍和1.5倍.结论:在表面消毒过的活体柞蚕蛹上接种液体菌株活化复壮菌种的方法是可行的.%This study aimed to increase strain output by using rejuvenation method on Cordyceps militaris strain. Just after pupation, the Antheraea pernyi Guerin-Meneville living body was infected by a manual cultivation for Cordyceps militaris (L.) strain P. After pupal body grew a new sporocarp near the head, the spores were gathered and used for the sexual reproduction on the rejuvenation of strain P at maturity of sporophores. The tracking result of solid medium indicated output and the biological conversion rate of strain were 1.2 times and 1.5 times than strain P, respectively. The conclusion is that using rejuvenation method on Cordyceps militaris strain with Antheraea pernyi Guerin-Meneville living body is practical.

  4. Comparative analysis of proteome maps of silkworm hemolymph during different developmental stages

    Directory of Open Access Journals (Sweden)

    Hou Yong

    2010-09-01

    Full Text Available Abstract Background The silkworm Bombyx mori is a lepidopteran insect with four developmental stages: egg, larva (caterpillar, pupa, and adult. The hemolymph of the silkworm is in an open system that circulates among all organs, and functions in nutrient and hormone transport, injury, and immunity. To understand the intricate developmental mechanisms of metamorphosis, silkworm hemolymph from different developmental stages, including the 3rd day of fifth instar, the 6th day of fifth instar, the 3rd day of pupation, the 8th day of pupal stage and the first day of the moth stage, was investigated by two-dimensional electrophoresis and mass spectrometry. Results Two-dimensional polyacrylamide gel electrophoresis showed that from the larval to moth stages, silkworm hemolymph proteins changed markedly. Not only did major proteins such as SP1, SP2, and the 30 K lipoprotein change, but other proteins varied greatly at different stages. To understand the functions of these proteins in silkworm development, 56 spots were excised from gels for analysis by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS. We identified 34 proteins involved in metamorphosis, programmed cell death, food digestion, metabolism, and nutrient storage and transport. Most proteins showed different expression at different stages, suggesting functions in development and metamorphosis. An abundance of proteins related to immunity were found, including hemolin, prophenoloxidase, serine proteinase-like protein, paralytic peptide-binding protein, and protease inhibitor. Conclusions Proteomics research not only provides the opportunity for direct investigation of protein expression patterns, but also identifies many attractive candidates for further study. Two-dimensional maps of hemolymph proteins expressed during the growth and metamorphosis of the silkworm offer important insights into hemolymph function and insect metamorphosis.

  5. Genetically Engineered Ricin Suppresses Bactrocera dorsalis (Diptera: Tephritidae) based on Demographic Analysis of Group-Reared Life Table.

    Science.gov (United States)

    Chang, Cheng; Huang, Chun-Yen; Dai, Shu-Mei; Atlihan, Remzi; Chi, Hsin

    2016-04-27

    The oriental fruit fly, Bactrocera dorsalis (Hendel), reduces the quantity and quality of many host fruits through the process of oviposition and larval feeding, and this insect has been considered a major insect pest in several Asian countries for decades. Using an earlier-developed, female-specific system that combines the toxicity of the ricin A chain (RTA) and the alternative RNA splicing property of doublesex (Bddsx), we show that transgenic male flies harboring the RTA-Bddsx transgene unevenly repress the pest population through inheritable effects. In age-stage, two-sex life-table analyses, high larval mortality and a delay in pupation were observed after introducing the transgene. The high male to female ratio in DsRed(+) flies demonstrates the lethal effect of ricin on females. The fitness of both the DsRed(+)- and DsRed(-)-transformed females was reduced as shown in the decrease of the net reproductive rate (R0), intrinsic rate (r), and finite rate (λ) values compared with the wild-type populations. The integrity of the RTA-Bddsx transgene remained in more than 80% of DsRed(+) males after ten generations, supporting the stable inheritance of the transgene. All of the data from this study support the proposed RTA-Bddsx SIT approach, which provides a species-specific and environmentally friendly method of suppressing, rather than eradiating, B. dorsalis. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. A cDNA encoding diazepam-binding inhibitor/acyl-CoA-binding protein in Helicoverpa armigera: molecular characterization and expression analysis associated with pupal diapause.

    Science.gov (United States)

    Liu, Ming; Zhang, Tian-Yi; Xu, Wei-Hua

    2005-06-01

    The diazepam binding inhibitor (DBI) or the acyl-CoA-binding protein (ACBP) is a 9-10 kDa highly conserved multifunctional protein that plays important roles in GABA(A) receptor activity regulation, lipid absorption and steroidogenesis in various organisms. To study the functions of DBI/ACBP in insect development or diapause, we cloned the cDNA from Helicoverpa armigera (Har) utilizing rapid amplification of cDNA ends (RACE). By homology search, Har-DBI/ACBP is conserved with the DBI/ACBPs known from other insects. Northern blot analysis showed that DBI/ACBP gene expressed in nonneural and neural tissues. RT-PCR combined Southern blot analysis revealed that DBI/ACBP mRNA in the brain of nondiapause individual was much higher than that in the brain of diapausing insects. At early and middle stages of 6th instar larvae, the level of DBI/ACBP mRNA was higher in the midgut of diapause type than that in nondiapause type and low at late 6th instar larval stage and early pupal stage in both types. In the prothoracic gland (PG), DBI/ACBP expression appeared at a high level at middle and late stages of 6th larval instar in both nondiapause and diapause types, and declined after pupation. In vitro experiments revealed that DBI/ACBP mRNA in PG could be stimulated by synthetic H. armigera diapause hormone (Har-DH), suggesting that Har-DH may stimulate the PG to produce ecdysteroids by the DBI/ACBP signal pathway. By in vitro assay, we also found that FGIN-1-27, which has similar functions to DBI/ACBP in ecdysteroidogenesis, could induce PG ecdysteroidogenesis effectively, suggesting that DBI/ACBP regulates biosynthesis of ecdysteroids in PG. Thus, DBI/ACBP indeed plays a key role in metabolism and development in H. armigera.

  7. The Effect of Ultraviolet-A Radiation Exposure on the Reproductive Ability, Longevity, and Development of the Dialeurodes citri (Homoptera: Aleyrodidae) F1 Generation.

    Science.gov (United States)

    Tariq, Kaleem; Noor, Mah; Saeed, Shafqat; Zhang, Hongyu

    2015-12-01

    Ultraviolet (UV) light has been used worldwide to monitor and trap insect pests. Whitefly adults show conspicuous positive phototactic behavior toward UV light stimuli; however, knowledge of the effect of UV light exposure on various life-history parameters of Dialeurodes citri remains limited. The present research aimed to investigate the effect of ultraviolet radiation (UV-A; long-wave) exposure on the reproduction and longevity of D. citri adults as well as the development of immature (eggs, larvae, and pupae) flies in the F1 generation. Paired D. citri adults were exposed to UV-A radiation for different periods (0, 1, 4, and 7 h/d) until the end of their life. The results of the experiment revealed that fecundity and oviposition rates increased when adults were irradiated for 1 and 4 h/d, but interestingly, both were significantly decreased compared with those of the controls after the longest exposure time (7 h/d). The longevity of adults of both sexes and the cumulative survival of F1 immatures were decreased with increased exposure time. Exposure to UV-A radiation prolonged the developmental time of immature stages, and a positive correlation was observed with exposure time. Exposure to UV light significantly inhibited egg hatching, larval development, pupation, and adult emergence. To the best of our knowledge, this is the first study describing the effect of UV radiation on a homopteran insect pest. This research may provide a foundation for the scientific community to use UV light in the field as an integrated pest management strategy to control this devastating agricultural pest.

  8. Influence of Dual-Bt Protein Corn on Bollworm, Helicoverpa zea (Boddie), Survivorship on Bollgard II Cotton.

    Science.gov (United States)

    Von Kanel, M B; Gore, J; Catchot, A; Cook, D; Musser, F; Caprio, M

    2016-04-01

    Similar Cry proteins are expressed in both Bt corn, Zea mays L., and cotton, Gossypium hirsutum (L.), commercial production systems. At least one generation of corn earworm, Helicoverpa zea (Boddie), completes development on field corn in the Mid-South before dispersing across the landscape into other crop hosts like cotton. A concern is that Bt corn hybrids may result in selection for H. zea populations with a higher probability of causing damage to Bt cotton. The objective of this study was to determine the susceptibility of H. zea offspring from moths that developed on non-Bt and VT Triple Pro (VT3 PRO) field corn to lyophilized Bollgard II cotton tissue expressing Cry1Ac and Cry2Ab. Offspring of individuals reared on VT3 PRO expressing Cry1A.105 and Cry2Ab had a significantly higher LC50 two out of the three years this study was conducted. Excess larvae were placed on artificial diet and allowed to pupate to determine if there were any inheritable fitness costs associated with parental development on VT3 PRO corn. Offspring resulting from males collected from VT3 PRO had significantly lower pupal weight and longer pupal duration compared with offspring of individuals collected from non-Bt corn. However, offspring from females collected from VT3 PRO were not different from non-Bt offspring. Paternal influence on offspring in insects is not commonly observed, but illustrates the side effects of development on a transgenic plant expressing less than a high dose, 25 times the concentration needed to kill susceptible larvae.

  9. Drosophila tribbles antagonizes insulin signaling-mediated growth and metabolism via interactions with Akt kinase.

    Directory of Open Access Journals (Sweden)

    Rahul Das

    Full Text Available Drosophila Tribbles (Trbl is the founding member of the Trib family of kinase-like docking proteins that modulate cell signaling during proliferation, migration and growth. In a wing misexpression screen for Trbl interacting proteins, we identified the Ser/Thr protein kinase Akt1. Given the central role of Akt1 in insulin signaling, we tested the function of Trbl in larval fat body, a tissue where rapid increases in size are exquisitely sensitive to insulin/insulin-like growth factor levels. Consistent with a role in antagonizing insulin-mediated growth, trbl RNAi knockdown in the fat body increased cell size, advanced the timing of pupation and increased levels of circulating triglyceride. Complementarily, overexpression of Trbl reduced fat body cell size, decreased overall larval size, delayed maturation and lowered levels of triglycerides, while circulating glucose levels increased. The conserved Trbl kinase domain is required for function in vivo and for interaction with Akt in a yeast two-hybrid assay. Consistent with direct regulation of Akt, overexpression of Trbl in the fat body decreased levels of activated Akt (pSer505-Akt while misexpression of trbl RNAi increased phospho-Akt levels, and neither treatment affected total Akt levels. Trbl misexpression effectively suppressed Akt-mediated wing and muscle cell size increases and reduced phosphorylation of the Akt target FoxO (pSer256-FoxO. Taken together, these data show that Drosophila Trbl has a conserved role to bind Akt and block Akt-mediated insulin signaling, and implicate Trib proteins as novel sites of signaling pathway integration that link nutrient availability with cell growth and proliferation.

  10. Effects of fluctuating daily temperatures at critical thermal extremes on Aedes aegypti life-history traits.

    Science.gov (United States)

    Carrington, Lauren B; Armijos, M Veronica; Lambrechts, Louis; Barker, Christopher M; Scott, Thomas W

    2013-01-01

    The effect of temperature on insect biology is well understood under constant temperature conditions, but less so under more natural, fluctuating conditions. A fluctuating temperature profile around a mean of 26°C can alter Aedes aegypti vector competence for dengue viruses as well as numerous life-history traits, however, the effect of fluctuations on mosquitoes at critical thermal limits is unknown. We investigated the effects of large and small daily temperature fluctuations at low (16°C) and high (35-37°C) mean temperatures, after we identified these temperatures as being thresholds for immature development and/or adult reproduction under constant temperature conditions. We found that temperature effects on larval development time, larval survival and adult reproduction depend on the combination of mean temperature and magnitude of fluctuations. Importantly, observed degree-day estimates for mosquito development under fluctuating temperature profiles depart significantly (around 10-20%) from that predicted by constant temperatures of the same mean. At low mean temperatures, fluctuations reduce the thermal energy required to reach pupation relative to constant temperature, whereas at high mean temperatures additional thermal energy is required to complete development. A stage-structured model based on these empirical data predicts that fluctuations can significantly affect the intrinsic growth rate of mosquito populations. Our results indicate that by using constant temperatures, one could under- or over-estimate values for numerous life-history traits compared to more natural field conditions dependent upon the mean temperature. This complexity may in turn reduce the accuracy of population dynamics modeling and downstream applications for mosquito surveillance and disease prevention.

  11. Effect of food types on competitive interaction between Aedes aegypti (LINNAEUS, 1762 and Ae. albopictus (SKUSE, 1894 (Diptera, Culicidae: a proximate level appraisal

    Directory of Open Access Journals (Sweden)

    Banerjee Sampa

    2017-06-01

    Full Text Available Competitive interactions between coexisting Aedes aegypti and Ae. albopictus have been implied as a crucial factor shaping life history traits and population characteristics. The overlap in resource requirements and similarities in the life history strategies of the two Aedes mosquitoes form a basis for competitive interactions. In the present study, the role of the food quality of the larval habitats in influencing the outcome of competition between Ae. aegypti and Ae. albopictus is evaluated to highlight food quality as a basis for asymmetric competitive outcomes. Instar I larvae of the two mosquitoes were reared using conspecifics or heterospecifics of constant size and equal ratio with four different food types: boiled rice, boiled pulses, a mixture of boiled rice and pulses, and fish food. Competitive interactions were evaluated using age at pupation (AP, pupal weight (PW, dry adult weight (AW and wing length (WL with respect to intra- and interspecific competition for the two sexes of each mosquito species. The results show that Ae. albopictus developed faster but achieved a smaller size compared to Ae. aegypti under interspecific competition conditions, the extent of the difference varying significantly with the food type. Given the variety of food resources available in the small container larval habitats, the results of the study imply that food quality may act differentially with respect to larval development and adult body size, depending on the conspecifics or heterospecifics and on the sex of the species concerned. The dominance of one species over the other may also be a consequence of the resource utilization pattern that varies in the larval habitats.

  12. Response of last instar Helicoverpa armigera larvae to Bt toxin ingestion: changes in the development and in the CYP6AE14, CYP6B2 and CYP9A12 gene expression.

    Directory of Open Access Journals (Sweden)

    Pilar Muñoz

    Full Text Available Bt crops are able to produce Cry proteins, which were originally present in Bacillus thuringiensis bacteria. Although Bt maize is very efficient against corn borers, Spanish crops are also attacked by the earworm H. armigera, which is less susceptible to Bt maize. Many mechanisms could be involved in this low susceptibility to the toxin, including the insect's metabolic resistance to toxins due to cytochrome P450 monooxygenases. This paper examines the response of last instar H. armigera larvae to feeding on a diet with Bt and non-Bt maize leaves in larval development and in the gene expression of three P450 cytochromes: CYP6AE14, CYP6B2 and CYP9A12. Larvae fed on sublethal amounts of the Bt toxin showed reduced food ingestion and reduced growth and weight, preventing most of them from achieving the critical weight and pupating; additionally, after feeding for one day on the Bt diet the larvae showed a slight increase in juvenile hormone II in the hemolymp. Larvae fed on the non-Bt diet showed the highest CYP6AE14, CYP6B2 and CYP9A12 expression one day after feeding on the non-Bt diet, and just two days later the expression decreased abruptly, a finding probably related to the developmental programme of the last instar. Moreover, although the response of P450 genes to plant allelochemicals and xenobiotics has been related in general to overexpression in the resistant insect, or induction of the genes when feeding takes place, the expression of the three genes studied was suppressed in the larvae feeding on the Bt toxin. The unexpected inhibitory effect of the Cry1Ab toxin in the P450 genes of H. armigera larvae should be thoroughly studied to determine whether this response is somehow related to the low susceptibility of the species to the Bt toxin.

  13. Ecdysis triggering hormone ensures proper timing of juvenile hormone biosynthesis in pharate adult mosquitoes

    Science.gov (United States)

    Areiza, Maria; Nouzova, Marcela; Rivera-Perez, Crisalejandra; Noriega, Fernando G.

    2014-01-01

    Juvenile hormones (JHs) are synthesized by the corpora allata (CA) and play a key role in insect development. A decrease of JH titer in the last instar larvae allows pupation and metamorphosis to proceed. As the anti-metamorphic role of JH comes to an end, the CA of the late pupa (or pharate adult) becomes again “competent” to synthesize JH, which would play an essential role orchestrating reproductive maturation. In the present study, we provide evidence that ecdysis triggering hormone (ETH), a key endocrine factor involved in ecdysis control, acts as an allatotropic regulator of JH biosynthesis, controlling the exact timing of CA activation in the pharate adult mosquito. Analysis of the expression of Aedes aegypti ETH receptors (AeaETHRs) revealed that they are present in the CA and the corpora cardiaca (CC), and their expression peaks 4 h before eclosion. In vitro stimulation of the pupal CA glands with ETH resulted in an increase in JH synthesis. Consistent with this finding, silencing AeaETHRs by RNA interference (RNAi) in pupa resulted in reduced JH synthesis by the CA of one day-old adult females. Stimulation with ETH resulted in increases in the activity of juvenile hormone acid methyltransferase (JHAMT), a key JH biosynthetic enzyme. Furthermore, inhibition of IP3R-operated mobilization of endoplasmic reticulum Ca2+ stores prevented the ETH-dependent increases of JH biosynthesis and JHAMT activity. All together these findings provide compelling evidence that ETH acts as a regulatory peptide that ensures proper developmental timing of JH synthesis in pharate adult mosquitoes. PMID:25257939

  14. Overwintering strategy and mechanisms of cold tolerance in the codling moth (Cydia pomonella.

    Directory of Open Access Journals (Sweden)

    Jan Rozsypal

    Full Text Available BACKGROUND: The codling moth (Cydia pomonella is a major insect pest of apples worldwide. Fully grown last instar larvae overwinter in diapause state. Their overwintering strategies and physiological principles of cold tolerance have been insufficiently studied. No elaborate analysis of overwintering physiology is available for European populations. PRINCIPAL FINDINGS: We observed that codling moth larvae of a Central European population prefer to overwinter in the microhabitat of litter layer near the base of trees. Reliance on extensive supercooling, or freeze-avoidance, appears as their major strategy for survival of the winter cold. The supercooling point decreases from approximately -15.3 °C during summer to -26.3 °C during winter. Seasonal extension of supercooling capacity is assisted by partial dehydration, increasing osmolality of body fluids, and the accumulation of a complex mixture of winter specific metabolites. Glycogen and glutamine reserves are depleted, while fructose, alanine and some other sugars, polyols and free amino acids are accumulated during winter. The concentrations of trehalose and proline remain high and relatively constant throughout the season, and may contribute to the stabilization of proteins and membranes at subzero temperatures. In addition to supercooling, overwintering larvae acquire considerable capacity to survive at subzero temperatures, down to -15 °C, even in partially frozen state. CONCLUSION: Our detailed laboratory analysis of cold tolerance, and whole-winter survival assays in semi-natural conditions, suggest that the average winter cold does not represent a major threat for codling moth populations. More than 83% of larvae survived over winter in the field and pupated in spring irrespective of the overwintering microhabitat (cold-exposed tree trunk or temperature-buffered litter layer.

  15. Cryopreservation of Embryos of the Mediterranean Fruit Fly Ceratitis capitata Vienna 8 Genetic Sexing Strain.

    Science.gov (United States)

    Augustinos, Antonios A; Rajamohan, Arun; Kyritsis, Georgios A; Zacharopoulou, Antigone; Haq, Ihsan Ul; Targovska, Asya; Caceres, Carlos; Bourtzis, Kostas; Abd-Alla, Adly M M

    2016-01-01

    The Mediterranean fruit fly, Ceratitis capitata, is one of the most serious pests of fruit crops world-wide. During the last decades, area-wide pest management (AW-IPM) approaches with a sterile insect technique (SIT) component have been used to control populations of this pest in an effective and environment-friendly manner. The development of genetic sexing strains (GSS), such as the Vienna 8 strain, has been played a major role in increasing the efficacy and reducing the cost of SIT programs. However, mass rearing, extensive inbreeding, possible bottleneck phenomena and hitch-hiking effects might pose major risks for deterioration and loss of important genetic characteristics of domesticated insect. In the present study, we present a modified procedure to cryopreserve the embryos of the medfly Vienna 8 GSS based on vitrification and used this strain as insect model to assess the impact of the cryopreservation process on the genetic structure of the cryopreserved insects. Forty-eight hours old embryos, incubated at 24°C, were found to be the most suitable developmental stage for cryopreservation treatment for high production of acceptable hatch rate (38%). Our data suggest the absence of any negative impact of the cryopreservation process on egg hatch rate, pupation rates, adult emergence rates and stability of the temperature sensitive lethal (tsl) character on two established cryopreserved lines (flies emerged from cryopreserved embryos), named V8-118 and V8-228. Taken together, our study provides an optimized procedure to cryopreserve the medfly Vienna 8 GSS and documents the absence of any negative impact on the genetic structure and quality of the strain. Benefits and sceneries for utilization of this technology to support operational SIT projects are discussed in this paper.

  16. Identifying fly puparia by clearing technique: application to forensic entomology.

    Science.gov (United States)

    Sukontason, Kabkaew L; Ngern-Klun, Radchadawan; Sripakdee, Duanghatai; Sukontason, Kom

    2007-10-01

    In forensic investigations, immature stages of the fly (egg, larva, or puparia) can be used as entomological evidence at death scenes, not only to estimate the postmortem interval (PMI), analyze toxic substances, and to determine the manner of death but also to indicate the movement of a corpse in homicide cases. Of these immature stages, puparia represent the longest developmental time, which makes them of useful. However, in order for forensic entomologists to use puparia effectively, it is crucial that they are able to accurately identify the species of fly found in a corpse. Typically, these puparia are similar in general appearance, being coarctate and light brown to dark brown in color, which makes identification difficult. In this study, we report on the clearing technique used to pale the integument of fly puparia, thereby allowing observation of the anterior end (second to fourth segments) and the profile of the posterior spiracle, which are important clues for identification. We used puparia of the blowfly, Chrysomya megacephala (F.), as the model species in this experiment. With placement in a 20% potassium hydroxide solution daily and mounting on a clearing medium (Permount(R), New Jersey), the profile of the posterior spiracle could be clearly examined under a light microscope beginning on the fifth day after pupation, and the number of papillae in the anterior spiracle could be counted easily starting from the ninth day. Comparison of morphological features of C. megacephala puparia with those of other blowflies (Chrysomya nigripes [Aubertin], Chrysomya rufifacies [Macquart], Chrysomya villeneuvi [Patton], Lucilia cuprina [Wiedemann], and Hemipyrellia ligurriens [Wiedemann]) and a housefly (Musca domestica L.) revealed that the anterior ends and the profiles of the posterior spiracles had markedly distinguishing characteristics. Morphometric analysis of the length and width of puparia, along with the length of the gaps between the posterior spiracles

  17. Effects of pathogen exposure on life history variation in the gypsy moth (Lymantria dispar)

    Science.gov (United States)

    Páez, David J.; Fleming-Davies, Arietta E.; Dwyer, Greg

    2015-01-01

    Investment in host defenses against pathogens may lead to tradeoffs with host fecundity. When such tradeoffs arise from genetic correlations, rates of phenotypic change by natural selection may be affected. However, genetic correlations between host survival and fecundity are rarely quantified. To understand tradeoffs between immune responses to baculovirus exposure and fecundity in the gypsy moth (Lymantria dispar), we estimated genetic correlations between survival probability and traits related to fecundity, such as pupal weight. In addition, we tested whether different virus isolates have different effects on male and female pupal weight. To estimate genetic correlations, we exposed individuals of known relatedness to a single baculovirus isolate. To then evaluate the effect of virus isolate on pupal weight, we exposed a single gypsy moth strain to 16 baculovirus isolates. We found a negative genetic correlation between survival and pupal weight. In addition, virus exposure caused late-pupating females to be identical in weight to males, whereas unexposed females were 2–3 times as large as unexposed males. Finally, we found that female pupal weight is a quadratic function of host mortality across virus isolates, which is likely due to tradeoffs and compensatory growth processes acting at high and low mortality levels, respectively. Overall, our results suggest that fecundity costs may strongly affect the response to selection for disease resistance. In nature, baculoviruses contribute to the regulation of gypsy moth outbreaks, as pathogens often do in forest-defoliating insects. We therefore argue that tradeoffs between host life-history traits may help explain outbreak dynamics. PMID:26201381

  18. Cryopreservation of Embryos of the Mediterranean Fruit Fly Ceratitis capitata Vienna 8 Genetic Sexing Strain

    Science.gov (United States)

    Augustinos, Antonios A.; Rajamohan, Arun; Kyritsis, Georgios A.; Zacharopoulou, Antigone; Haq, Ihsan ul; Targovska, Asya; Caceres, Carlos; Bourtzis, Kostas; Abd-Alla, Adly M. M.

    2016-01-01

    The Mediterranean fruit fly, Ceratitis capitata, is one of the most serious pests of fruit crops world-wide. During the last decades, area-wide pest management (AW-IPM) approaches with a sterile insect technique (SIT) component have been used to control populations of this pest in an effective and environment-friendly manner. The development of genetic sexing strains (GSS), such as the Vienna 8 strain, has been played a major role in increasing the efficacy and reducing the cost of SIT programs. However, mass rearing, extensive inbreeding, possible bottleneck phenomena and hitch-hiking effects might pose major risks for deterioration and loss of important genetic characteristics of domesticated insect. In the present study, we present a modified procedure to cryopreserve the embryos of the medfly Vienna 8 GSS based on vitrification and used this strain as insect model to assess the impact of the cryopreservation process on the genetic structure of the cryopreserved insects. Forty-eight hours old embryos, incubated at 24°C, were found to be the most suitable developmental stage for cryopreservation treatment for high production of acceptable hatch rate (38%). Our data suggest the absence of any negative impact of the cryopreservation process on egg hatch rate, pupation rates, adult emergence rates and stability of the temperature sensitive lethal (tsl) character on two established cryopreserved lines (flies emerged from cryopreserved embryos), named V8-118 and V8-228. Taken together, our study provides an optimized procedure to cryopreserve the medfly Vienna 8 GSS and documents the absence of any negative impact on the genetic structure and quality of the strain. Benefits and sceneries for utilization of this technology to support operational SIT projects are discussed in this paper. PMID:27537351

  19. Immature development of the malaria vector mosquito, Anopheles gambiae S.L. (Diptera: Culicidae), in relation to soil-substrate organic matter content of larval habitats in northcentral Nigeria.

    Science.gov (United States)

    Olayemi, I K; Ojo, V O

    2013-02-01

    This study elucidated the relationships between larval habitat soil-substrate Organic Matter Content (OMC) and immature development of the mosquito Anopheles gambiae S.L. Day-old larvae of the mosquito were reared in media substrated with typical soil samples (i.e., sandy, silt, clayey and loamy soils), from established anopheline breeding sites, to provide a gradient in soil-substrate OMC. The OMC of the soil samples were determined by ignition to a constant weight; while the developing A. gambiae mosquitoes in the culture media were monitored daily for survivorship and duration of immature life stages. The results indicated significant (p OMC of the soil types (range = 11.21 +/- 2.91% in sandy to 29.83 +/- 2.96% in loamy soils). However, though Daily Larval Survival Rates (DLSR) were relatively high (range = 95.21 +/- 2.96 to 96.70 +/- 1.44%), as influenced by OMC, such values were not significantly different (p > 0.05) among the soil-substrate types; results contrary to those of Larval Success Rates (LSR) (i.e., range = 52.07 +/- 13.64 to 74.39 +/- 6.60%). Daily Pupation Rate (DPR) of the mosquitoes varied significantly among the soil-substrates, ranging from 13.87 +/- 2.39% in clayey to 25.00 +/- 4.30% in loamy substrates. Soil-substrate OMC significantly extended the Duration of Immature Life Stages (DILS) of the mosquitoes only in the sandy soil type (range = 12.76 +/- 1.74 to 15.81 +/- 2.40 days). On the whole, DILS was inversely related to soil-substrate OMC. Cross-correlational analysis revealed significant positive association among most of the variables tested. The findings of this study should serve as baseline information for the development of effective environmental management strategies for malaria larval-vector control.

  20. Genetic Evidence for Function of the bHLH-PAS Protein Gce/Met As a Juvenile Hormone Receptor.

    Directory of Open Access Journals (Sweden)

    Marek Jindra

    2015-07-01

    Full Text Available Juvenile hormones (JHs play a major role in controlling development and reproduction in insects and other arthropods. Synthetic JH-mimicking compounds such as methoprene are employed as potent insecticides against significant agricultural, household and disease vector pests. However, a receptor mediating effects of JH and its insecticidal mimics has long been the subject of controversy. The bHLH-PAS protein Methoprene-tolerant (Met, along with its Drosophila melanogaster paralog germ cell-expressed (Gce, has emerged as a prime JH receptor candidate, but critical evidence that this protein must bind JH to fulfill its role in normal insect development has been missing. Here, we show that Gce binds a native D. melanogaster JH, its precursor methyl farnesoate, and some synthetic JH mimics. Conditional on this ligand binding, Gce mediates JH-dependent gene expression and the hormone's vital role during development of the fly. Any one of three different single amino acid mutations in the ligand-binding pocket that prevent binding of JH to the protein block these functions. Only transgenic Gce capable of binding JH can restore sensitivity to JH mimics in D. melanogaster Met-null mutants and rescue viability in flies lacking both Gce and Met that would otherwise die at pupation. Similarly, the absence of Gce and Met can be compensated by expression of wild-type but not mutated transgenic D. melanogaster Met protein. This genetic evidence definitively establishes Gce/Met in a JH receptor role, thus resolving a long-standing question in arthropod biology.

  1. Parasitism-induced effects on host growth and metabolic efficiency in Plutella xylostella larvae parasitized by Cotesia vestalis or Diadegma semiclausum

    Institute of Scientific and Technical Information of China (English)

    Fang Huang; Ting-Ting Cao; Min Shi; Ya-Feng Chen; Xue-xin Chen

    2008-01-01

    The nutritional physiology of the diamondback moth,Plutellaxylostella,larvae was examined after parasitization by the solitary endoparasitoids Cotesia vestalis or Diadegrna semiclausum.Examinations were performed in two phases,one was examined at the time point of 24 h post-parasitization,and the other was done at the end of the 4th instar larvae of host.Rates of growth,food consumption,assimilation,excretion,and respiration were calculated as well as approximate digestibility and the rate ratios ECI (percent efficiency of conversion of ingested food to body substance),and ECD (percent efficiency of conversion of digested food to body substance).Parasitization by C.vestalis resulted in significant decrease in the rates of growth,feeding,excretion,assimilation,and respiration,but the final dry rate of respiration at the end of last larval stadium was elevated.The ECI and ECD were also reduced as the result of parasitization,but digestibility was increased.All these parameters in the larvae parasitized by D.semiclausum at 24 h post-parasitization were also significantly changed compared to the control;however,these differences were quantitatively,but not qualitatively before pupation,similar to those resulted from parasitization by C.vestalis.In spite of the similarities of the parasitism-induced effects caused by these endoparasitoids,the final metabolic rate,that is,the rate of intake of nutrients required to compensate for metabolism,was much lower in the larvae parasitized by C.vestalis than that of the larvae parasitized by D.semiclausum.All of the results discussed here will contribute toward explaining the different ways these two wasps regulate the parasitoid-host relationship.

  2. How Does Garlic Mustard Lure and Kill the West Virginia White Butterfly?

    Science.gov (United States)

    Davis, Samantha L; Frisch, Tina; Bjarnholt, Nanna; Cipollini, Don

    2015-10-01

    As it pertains to insect herbivores, the preference-performance hypothesis posits that females will choose oviposition sites that maximize their offspring's fitness. However, both genetic and environmental cues contribute to oviposition preference, and occasionally "oviposition mistakes" occur, where insects oviposit on hosts unsuitable for larval development. Pieris virginiensis is a pierine butterfly native to North America that regularly oviposits on an invasive plant, Alliaria petiolata, but the caterpillars are unable to survive. Alliaria petiolata has high concentrations of the glucosinolate sinigrin in its tissues, as well as a hydroxynitrile glucoside, alliarinoside. We investigated sinigrin as a possible cause of mistake oviposition, and sinigrin and alliarinoside as possible causes of larval mortality. We found that sinigrin applied to leaves of Cardamine diphylla, a major host of P. virginiensis that does not produce sinigrin, had no effect on oviposition rates. We tested the effect of sinigrin on larval performance using two host plants, one lacking sinigrin (C. diphylla) and one with sinigrin naturally present (Brassica juncea). We found no effect of sinigrin application on survival of caterpillars fed C. diphylla, but sinigrin delayed pupation and decreased pupal weight. On B. juncea, sinigrin decreased survival, consumption, and caterpillar growth. We also tested the response of P. virginiensis caterpillars to alliarinoside, a compound unique to A. petiolata, which was applied to B. oleracea. We found a significant reduction in survival, leaf consumption, and caterpillar size when alliarinoside was consumed. The 'novel weapon' alliarinoside likely is largely responsible for larval failure on the novel host A. petiolata. Sinigrin most likely contributes to the larval mortality observed, however, we did not observe any effect of sinigrin on oviposition by P. virginiensis females. Further research needs to be done on non-glucosinolate contact cues, and

  3. Transgenic Anopheles gambiae expressing an antimalarial peptide suffer no significant fitness cost.

    Science.gov (United States)

    McArthur, Clare C; Meredith, Janet M; Eggleston, Paul

    2014-01-01

    Mosquito-borne diseases present some of the greatest health challenges faced by the world today. In many cases, existing control measures are compromised by insecticide resistance, pathogen tolerance to drugs and the lack of effective vaccines. In light of these difficulties, new genetic tools for disease control programmes, based on the deployment of genetically modified mosquitoes, are seen as having great promise. Transgenic strains may be used to control disease transmission either by suppressing vector populations or by replacing susceptible with refractory genotypes. In practice, the fitness of the transgenic strain relative to natural mosquitoes will be a critical determinant of success. We previously described a transgenic strain of Anopheles gambiae expressing the Vida3 peptide into the female midgut following a blood-meal, which exhibited significant protection against malaria parasites. Here, we investigated the fitness of this strain relative to non-transgenic controls through comparisons of various life history traits. Experiments were designed, as far as possible, to equalize genetic backgrounds and heterogeneity such that fitness comparisons focussed on the presence and expression of the transgene cassette. We also employed reciprocal crosses to identify any fitness disturbance associated with inheritance of the transgene from either the male or female parent. We found no evidence that the presence or expression of the effector transgene or associated fluorescence markers caused any significant fitness cost in relation to larval mortality, pupal sex ratio, fecundity, hatch rate or longevity of blood-fed females. In fact, fecundity was increased in transgenic strains. We did, however, observe some fitness disturbances associated with the route of inheritance of the transgene. Maternal inheritance delayed male pupation whilst paternal inheritance increased adult longevity for both males and unfed females. Overall, in comparison to controls, there was

  4. Transgenic Anopheles gambiae expressing an antimalarial peptide suffer no significant fitness cost.

    Directory of Open Access Journals (Sweden)

    Clare C McArthur

    Full Text Available Mosquito-borne diseases present some of the greatest health challenges faced by the world today. In many cases, existing control measures are compromised by insecticide resistance, pathogen tolerance to drugs and the lack of effective vaccines. In light of these difficulties, new genetic tools for disease control programmes, based on the deployment of genetically modified mosquitoes, are seen as having great promise. Transgenic strains may be used to control disease transmission either by suppressing vector populations or by replacing susceptible with refractory genotypes. In practice, the fitness of the transgenic strain relative to natural mosquitoes will be a critical determinant of success. We previously described a transgenic strain of Anopheles gambiae expressing the Vida3 peptide into the female midgut following a blood-meal, which exhibited significant protection against malaria parasites. Here, we investigated the fitness of this strain relative to non-transgenic controls through comparisons of various life history traits. Experiments were designed, as far as possible, to equalize genetic backgrounds and heterogeneity such that fitness comparisons focussed on the presence and expression of the transgene cassette. We also employed reciprocal crosses to identify any fitness disturbance associated with inheritance of the transgene from either the male or female parent. We found no evidence that the presence or expression of the effector transgene or associated fluorescence markers caused any significant fitness cost in relation to larval mortality, pupal sex ratio, fecundity, hatch rate or longevity of blood-fed females. In fact, fecundity was increased in transgenic strains. We did, however, observe some fitness disturbances associated with the route of inheritance of the transgene. Maternal inheritance delayed male pupation whilst paternal inheritance increased adult longevity for both males and unfed females. Overall, in comparison to

  5. Biology of the blind geobiont scarab beetle genus Chaetonyx Schaum, 1862 (Scarabaeidae: Orphninae with new distribution records of Ch. robustus Schaum, 1862 from Bulgaria

    Directory of Open Access Journals (Sweden)

    DENIS GRADINAROV

    2015-10-01

    Full Text Available Life cycle of the orphnine scarab beetles genus Chaetonyx was recorded for the first time based on the multiyear observations on the populations of its type species, Ch. robustus Schaum, 1862, in riverside habitats at Zemen Gorge region, South-Western Bulgaria. Our observations showed that this geobiont species is common in alluvial soils near Struma River, where it forms large colonies. At the Zemen Gorge, its preferable habitats are sparse riverside forests of Alnus glutinosa L. and Populus nigra L. neighboring grass communities. Larvae, adults and pupae were found up to 50 cm deep with most specimens inhabiting the upper soil layer from 0 to 20 cm deep. The highest recorded density was 89 adults and 581 larvae per 0.25 m2. Oviposition, hatching of the eggs, pupation and emergence of the new adults occur during the summer. Eggs have been found in surface soil layer in July and August, the pupae – mainly in July and August. Larvae of different instars were found in soil during all months of the study period. Adults from the new generation first occur in the beginning of August. In August, September and October adults from different generations can be found together. The main part of the adults seems to die after the reproduction period, and the common lifespan of adults seems to be about a year only. The life cycle of Ch. robustus in investigated habitat seems to be perennial and includes two years as larval stage and one as adult. Tropical Orphninae occupy a number of ecological niches but lack colonial geobiont specialists similar to Chaetonyx.

  6. Exposure of a Dengue Vector to Tea and Its Waste: Survival, Developmental Consequences, and Significance for Pest Management.

    Science.gov (United States)

    Dieng, Hamady; Tan Yusop, Nur Syafiqah Bt; Kamal, Nurafidah Natasyah Bt; Ahmad, Abu Hassan; Ghani, Idris Abd; Abang, Fatimah; Satho, Tomomitsu; Ahmad, Hamdan; Zuharah, Wan Fatma; Majid, Abdul Hafiz Ab; Morales, Ronald E; Morales, Noppawan P; Hipolito, Cirilo N; Noweg, Gabriel Tonga

    2016-05-11

    Dengue mosquitoes are evolving into a broader global public health menace, with relentless outbreaks and the rise in number of Zika virus disease cases as reminders of the continued hazard associated with Aedes vectors. The use of chemical insecticides-the principal strategy against mosquito vectors-has been greatly impeded due to the development of insecticide resistance and the shrinking spectrum of effective agents. Therefore, there is a pressing need for new chemistries for vector control. Tea contains hundreds of chemicals, and its waste, which has become a growing global environmental problem, is almost as rich in toxicants as green leaves. This paper presents the toxic and sublethal effects of different crude extracts of tea on Aedes albopictus. The survival rates of larvae exposed to tea extracts, especially fresh tea extract (FTE), were markedly lower than those in the control treatment group. In addition to this immediate toxicity against different developmental stages, the extracts tested caused a broad range of sublethal effects. The developmental time was clearly longer in containers with tea, especially in those with young larvae (YL) and FTE. Among the survivors, pupation success was reduced in containers with tea, which also produced low adult emergence rates with increasing tea concentration. The production of eggs tended to be reduced in females derived from the tea treatment groups. These indirect effects of tea extracts on Ae. albopictus exhibited different patterns according to the exposed larval stage. Taken together, these findings indicate that tea and its waste affect most key components of Ae. albopictus vectorial capacity and may be useful for dengue control. Reusing tea waste in vector control could also be a practical solution to the problems associated with its pollution.

  7. Incidence of myiasis among humans-a review.

    Science.gov (United States)

    Singh, Amandeep; Singh, Zorawar

    2015-09-01

    Myiasis, the infestation of tissues of live humans and other vertebrate animals with dipteran larvae (maggots), is a phenomenon of widespread occurrence throughout the tropical regions of the world. It is commonly seen in domestic and wild animals but occurs rarely in man also. The tissue invasion in man by maggots is generally a well-recognized complication of neglected wounds. The condition may be asymptomatic but occasionally results in more or less severe problems and even death when larvae invade body cavities or areas that forbid their direct visual examination. Many cases of myiasis, however, usually do not reach the attention of medical practitioners because of the tendency of the mature larvae to migrate out of the lesion for pupation. In the present study, the authors reviewed the past literature describing the cases of human myiasis, causative fly species and predisposing factors for the onset of the same. The aim of the present manuscript is to provide a database for the future reference of medical entomologists, medical practitioners and veterinarians. Review of literature revealed that 37 fly species belonging to ten families were responsible worldwide for the onset of human myiasis. The incidence of myiasis among humans can be correlated to increasing fly populations, poor hygienic conditions and presence of domestic animals in the close vicinity. Other factors responsible for myiasis include neglected open wounds and foul-smelling discharge from natural body openings. Moreover, ignorance plays a key role in its occurrence since people are generally unaware about the actual cause and often correlate the condition to their superstitious beliefs. It is emphasized that the patients should not neglect their wounds and should take proper medical care; otherwise, myiasis may supervene.

  8. An aeroponic culture system for the study of root herbivory on Arabidopsis thaliana

    Science.gov (United States)

    2011-01-01

    Background Plant defense against herbivory has been studied primarily in aerial tissues. However, complex defense mechanisms have evolved in all parts of the plant to combat herbivore attack and these mechanisms are likely to differ in the aerial and subterranean environment. Research investigating defense responses belowground has been hindered by experimental difficulties associated with the accessibility and quality of root tissue and the lack of bioassays using model plants with altered defense profiles. Results We have developed an aeroponic culture system based on a calcined clay substrate that allows insect herbivores to feed on plant roots while providing easy recovery of the root tissue. The culture method was validated by a root-herbivore system developed for Arabidopsis thaliana and the herbivore Bradysia spp. (fungus gnat). Arabidopsis root mass obtained from aeroponically grown plants was comparable to that from other culture systems, and the plants were morphologically normal. Bradysia larvae caused considerable root damage resulting in reduced root biomass and water absorption. After feeding on the aeroponically grown root tissue, the larvae pupated and emerged as adults. Root damage of mature plants cultivated in aeroponic substrate was compared to that of Arabidopsis seedlings grown in potting mix. Seedlings were notably more susceptible to Bradysia feeding than mature plants and showed decreased overall growth and survival rates. Conclusions A root-herbivore system consisting of Arabidopsis thaliana and larvae of the opportunistic herbivore Bradysia spp. has been established that mimics herbivory in the rhizosphere. Bradysia infestation of Arabidopsis grown in this culture system significantly affects plant performance. The culture method will allow simple profiling and in vivo functional analysis of root defenses such as chemical defense metabolites that are released in response to belowground insect attack. PMID:21392399

  9. Identification and Characterization of a Candidate Wolbachia pipientis Type IV Effector That Interacts with the Actin Cytoskeleton

    Directory of Open Access Journals (Sweden)

    Kathy B. Sheehan

    2016-07-01

    Full Text Available Many bacteria live as intracellular symbionts, causing persistent infections within insects. One extraordinarily common infection is that of Wolbachia pipientis, which infects 40% of insect species and induces reproductive effects. The bacteria are passed from generation to generation both vertically (through the oocyte and horizontally (by environmental transmission. Maintenance of the infection within Drosophila melanogaster is sensitive to the regulation of actin, as Wolbachia inefficiently colonizes strains hemizygous for the profilin or villin genes. Therefore, we hypothesized that Wolbachia must depend on the host actin cytoskeleton. In this study, we identify and characterize a Wolbachia protein (WD0830 that is predicted to be secreted by the bacterial parasite. Expression of WD0830 in a model eukaryote (the yeast Saccharomyces cerevisiae induces a growth defect associated with the appearance of aberrant, filamentous structures which colocalize with rhodamine-phalloidin-stained actin. Purified WD0830 bundles actin in vitro and cosediments with actin filaments, suggesting a direct interaction of the two proteins. We characterized the expression of WD0830 throughout Drosophila development and found it to be upregulated in third-instar larvae, peaking in early pupation, during the critical formation of adult tissues, including the reproductive system. In transgenic flies, heterologously expressed WD0830 localizes to the developing oocyte. Additionally, overexpression of WD0830 results in increased Wolbachia titers in whole flies, in stage 9 and 10 oocytes, and in embryos, compared to controls, suggesting that the protein may facilitate Wolbachia’s replication or transmission. Therefore, this candidate secreted effector may play a role in Wolbachia’s infection of and persistence within host niches.

  10. USP2-45 Is a Circadian Clock Output Effector Regulating Calcium Absorption at the Post-Translational Level.

    Directory of Open Access Journals (Sweden)

    Daniel Pouly

    Full Text Available The mammalian circadian clock influences most aspects of physiology and behavior through the transcriptional control of a wide variety of genes, mostly in a tissue-specific manner. About 20 clock-controlled genes (CCGs oscillate in virtually all mammalian tissues and are generally considered as core clock components. One of them is Ubiquitin-Specific Protease 2 (Usp2, whose status remains controversial, as it may be a cogwheel regulating the stability or activity of core cogwheels or an output effector. We report here that Usp2 is a clock output effector related to bodily Ca2+ homeostasis, a feature that is conserved across evolution. Drosophila with a whole-body knockdown of the orthologue of Usp2, CG14619 (dUsp2-kd, predominantly die during pupation but are rescued by dietary Ca2+ supplementation. Usp2-KO mice show hyperabsorption of dietary Ca2+ in small intestine, likely due to strong overexpression of the membrane scaffold protein NHERF4, a regulator of the Ca2+ channel TRPV6 mediating dietary Ca2+ uptake. In this tissue, USP2-45 is found in membrane fractions and negatively regulates NHERF4 protein abundance in a rhythmic manner at the protein level. In clock mutant animals (Cry1/Cry2-dKO, rhythmic USP2-45 expression is lost, as well as the one of NHERF4, confirming the inverse relationship between USP2-45 and NHERF4 protein levels. Finally, USP2-45 interacts in vitro with NHERF4 and endogenous Clathrin Heavy Chain. Taken together these data prompt us to define USP2-45 as the first clock output effector acting at the post-translational level at cell membranes and possibly regulating membrane permeability of Ca2+.

  11. Context- and dose-dependent modulatory effects of naringenin on survival and development of Drosophila melanogaster.

    Science.gov (United States)

    Chattopadhyay, Debarati; Sen, Soumadeep; Chatterjee, Rishita; Roy, Debasish; James, Joel; Thirumurugan, Kavitha

    2016-04-01

    Naringenin, the predominant bioflavonoid found in grapefruit and tomato has diverse bioactive properties that encompass anti-carcinogenic, anti-inflammatory, anti-atherogenic, anti-estrogenic, anti-hyperlipidemic and anti-hyperglycemic characteristics. Naringenin has not been explored for its pro-longevity traits in fruit flies. Therefore, the current study explores its influence on longevity, fecundity, feeding rate, larval development, resistance to starvation stress and body weight in male and female wild-type Drosophila melanogaster Canton-S flies. Flies were fed with normal and high fat diets respectively. The results implied hormetic effects of naringenin on longevity and development in flies. In flies fed with standard and high fat diets, lower concentrations of naringenin (200 and 400 µM) augmented mean lifespan while higher concentrations (600 and 800 µM) were consistently lethal. However, enhanced longevity seen at 400 µM of naringenin was at the expense of reduced fecundity and food intake in flies. Larvae reared on standard diet having 200 µM of naringenin exhibited elevated pupation and emergence as flies. Eclosion time was hastened in larvae reared on standard diet having 200 µM of naringenin. Female flies fed with a standard diet having 200 and 400 µM of naringenin were more resistant to starvation stress. Reduction in body weight was observed in male and female flies fed with a high fat diet supplemented with 200 and 400 µM of naringenin respectively. Collectively, the results elucidated a context- and dose-dependent hormetic efficacy of naringenin that varied with gender, diet and stage of lifecycle in flies.

  12. Oviposition preference and larval performance of Epiphyas postvittana (Lepidoptera: Tortricidae) on Botrytis cinerea (Helotiales: Sclerotiniaceae) infected berries of Vitis vinifera (Vitales: Vitaceae).

    Science.gov (United States)

    Rizvi, Syed Z M; Raman, Anantanarayanan; Wheatley, Warwick M; Cook, Geoffrey

    2016-04-01

    In this paper we tested the behavior of gravid Epiphyas postvittana in selecting the most-appropriate site for oviposition thus benefitting offspring performance. Our hypothesis was built on Jaenike's preference-performance hypothesis (also referred to as the "mother-knows-the-best" hypothesis). To test this, we used the interacting Epiphyas postvittana, its host Vitis vinifera, and the pathogenic microbe Botrytis cinerea system. Populations of E. postvittana and B. cinerea often exist concurrently on V. vinifera in Australasia and their interaction and mutual influence are currently being explored, although the suggestion presently is that the relationship between E. postvittana and B. cinerea is mutualistic. We tested the effect of volatiles from B. cinerea-infected berries and uninfected (control) berries of V. vinifera on the oviposition behavior of E. postvittana. We also characterized the effects of B. cinerea infection on the berries of V. vinifera on the growth and development of E. postvittana. Contrary to the preference-performance hypothesis, oviposition choices made by gravid E. postvittana did not result in the best offspring survival, development, and performance. The preference for oviposition by E. postvittana was strongly influenced by the olfactory and tactile cues. She laid fewer eggs on B. cinerea-infected berries compared to uninfected berries of V. vinifera. The larvae of E. postvittana showed no preference to uninfected berries of V. vinifera. The larvae fed on B. cinerea-infected berries of V. vinifera showing greater survival rate, shorter time to pupation, greater pupal mass, and on becoming adults they laid more numbers of eggs than the larvae that were enabled to feed on uninfected berries. The larvae of E. postvittana transport the conidia of B. cinerea and transmit grey-mould disease to uninfected berries of V. vinifera. © 2014 Institute of Zoology, Chinese Academy of Sciences.

  13. Modeling the effects of developmental variation on insect phenology.

    Science.gov (United States)

    Yurk, Brian P; Powell, James A

    2010-08-01

    Phenology, the timing of developmental events such as oviposition or pupation, is highly dependent on temperature; since insects are ectotherms, the time it takes them to complete a life stage (development time) depends on the temperatures they experience. This dependence varies within and between populations due to variation among individuals that is fixed within a life stage (giving rise to what we call persistent variation) and variation from random effects within a life stage (giving rise to what we call random variation). It is important to understand how both types of variation affect phenology if we are to predict the effects of climate change on insect populations.We present three nested phenology models incorporating increasing levels of variation. First, we derive an advection equation to describe the temperature-dependent development of a population with no variation in development time. This model is extended to incorporate persistent variation by introducing a developmental phenotype that varies within a population, yielding a phenotype-dependent advection equation. This is further extended by including a diffusion term describing random variation in a phenotype-dependent Fokker-Planck development equation. These models are also novel because they are formulated in terms of development time rather than developmental rate; development time can be measured directly in the laboratory, whereas developmental rate is calculated by transforming laboratory data. We fit the phenology models to development time data for mountain pine beetles (MPB) (Dendroctonus ponderosae Hopkins [Coleoptera: Scolytidae]) held at constant temperatures in laboratory experiments. The nested models are parameterized using a maximum likelihood approach. The results of the parameterization show that the phenotype-dependent advection model provides the best fit to laboratory data, suggesting that MPB phenology may be adequately described in terms of persistent variation alone. MPB

  14. Microbial effects on the development of forensically important blow fly species.

    Science.gov (United States)

    Crooks, Esther R; Bulling, Mark T; Barnes, Kate M

    2016-09-01

    Colonisation times and development rates of specific blow fly species are used to estimate the minimum Post Mortem Interval (mPMI). The presence or absence of bacteria on a corpse can potentially affect the development and survival of blow fly larvae. Therefore an understanding of microbial-insect interactions is important for improving the interpretation of mPMI estimations. In this study, the effect of two bacteria (Escherichia coli and Staphylococcus aureus) on the growth rate and survival of three forensically important blow fly species (Lucilia sericata, Calliphora vicina and Calliphora vomitoria) was investigated. Sterile larvae were raised in a controlled environment (16:8h day: night light cycle, 23:21°C day: night temperature cycle and a constant 35% relative humidity) on four artificial diets prepared with 100μl of 10(5) CFU bacterial solutions as follows: (1) E. coli, (2) S. aureus, (3) a 50:50 E. coli:S. aureus mix and (4) a sterile bacteria-free control diet. Daily measurements (length, width and weight) were taken from first instar larvae through to the emergence of adult flies. Survival rates were also determined at pupation and adult emergence. Results indicate that bacteria were not essential for the development of any of the blow fly species. However, larval growth rates were affected by bacterial diet, with effects differing between blow fly species. Peak larval weights also varied according to species-diet combination; C. vomitoria had the largest weight on E. coli and mixed diets, C. vicina had the largest weight on S. aureus diets, and treatment had no significant effect on the peak larval weight of L. sericata. These results indicate the potential for the bacteria that larvae are exposed to during development on a corpse to alter both developmental rates and larval weight in some blow fly species.

  15. Immatures of Lutzia fuscanus (Wiedemann,1820)(Dipter-a:Culicidae)in ricefields:implications for biological con-trol of vector mosquitoes

    Institute of Scientific and Technical Information of China (English)

    Mihir Kumar Pramanik; Gautam Aditya

    2009-01-01

    Objective:Rice fields are dynamic mosquito larval habitats with assemblage of different predator taxa,inclu-ding the larva of the mosquitoes Lutzia.Entomological surveillance in the ricefields is essential to evaluate the potential of these predators as biological resource to regulate vector mosquito population.In view of this,a sur-vey of ricefields for immatures of different mosquito species including Lutzia was conducted.Methods:Survey of selected ricefields was carried out to evaluate the species composition of mosquitoes.Laboratory evaluation of the immatures of Lutzia mosquitoes was carried out to assess its predation potential using mosquitoes and chi-ronomid as preys.Results:The survey revealed the presence of five mosquito species belonging to the genera Anopheles and Culex and the predatory immatures of the mosquito Lutzia fuscana (Wiedemann,1820).The ra-tio of prey and predatory larva ranged between 1.46 and 4.78 during the study period,with a significant corre-lation on the relative abundance of the larval stages of Lt.fuscanus and Anopheles and Culex larvae.Under la-boratory conditions,a single IV instar larvae of Lt.fuscanus was found to consume on an average 5 to 15 equiv-alent instars of Anopheles sp.and Culex sp.larvae per day depending on its age.The prey consumption re-duced with the larval stage approaching pupation.When provided with equal numbers of chironomid and A-nopheles or Culex larvae,larva of Lt.fuscanus consumed mosquito larvae significantly more compared to chi-ronomids.Conclusion:The survey results and the preliminary study on predation are suggestive of the role of Lt.fuscanus in the regulation of vector mosquito populations naturally in the ricefields.Since Lt.fuscanus is common in many Asian countries,further studies on bioecology will be helpful to justify their use in mosquito control programme.

  16. Feeding on Host Plants with Different Concentrations and Structures of Pyrrolizidine Alkaloids Impacts the Chemical-Defense Effectiveness of a Specialist Herbivore

    Science.gov (United States)

    Cunha, Beatriz P.; Solferini, Vera N.

    2015-01-01

    Sequestration of chemical defenses from host plants is a strategy widely used by herbivorous insects to avoid predation. Larvae of the arctiine moth Utetheisa ornatrix feeding on unripe seeds and leaves of many species of Crotalaria (Leguminosae) sequester N-oxides of pyrrolizidine alkaloids (PAs) from these host plants, and transfer them to adults through the pupal stage. PAs confer protection against predation on all life stages of U. ornatrix. As U. ornatrix also uses other Crotalaria species as host plants, we evaluated whether the PA chemical defense against predation is independent of host plant use. We fed larvae from hatching to pupation with either leaves or seeds of one of eight Crotalaria species (C. incana, C. juncea, C. micans, C. ochroleuca, C. pallida, C. paulina, C. spectabilis, and C. vitellina), and tested if adults were preyed upon or released by the orb-weaving spider Nephila clavipes. We found that the protection against the spider was more effective in adults whose larvae fed on seeds, which had a higher PA concentration than leaves. The exceptions were adults from larvae fed on C. paulina, C. spectabilis and C. vitellina leaves, which showed high PA concentrations. With respect to the PA profile, we describe for the first time insect-PAs in U. ornatrix. These PAs, biosynthesized from the necine base retronecine of plant origin, or monocrotaline- and senecionine-type PAs sequestered from host plants, were equally active in moth chemical defense, in a dose-dependent manner. These results are also partially explained by host plant phylogeny, since PAs of the host plants do have a phylogenetic signal (clades with high and low PA concentrations in leaves) which is reflected in the adult defense. PMID:26517873

  17. Feeding on Host Plants with Different Concentrations and Structures of Pyrrolizidine Alkaloids Impacts the Chemical-Defense Effectiveness of a Specialist Herbivore.

    Directory of Open Access Journals (Sweden)

    Carlos H Z Martins

    Full Text Available Sequestration of chemical defenses from host plants is a strategy widely used by herbivorous insects to avoid predation. Larvae of the arctiine moth Utetheisa ornatrix feeding on unripe seeds and leaves of many species of Crotalaria (Leguminosae sequester N-oxides of pyrrolizidine alkaloids (PAs from these host plants, and transfer them to adults through the pupal stage. PAs confer protection against predation on all life stages of U. ornatrix. As U. ornatrix also uses other Crotalaria species as host plants, we evaluated whether the PA chemical defense against predation is independent of host plant use. We fed larvae from hatching to pupation with either leaves or seeds of one of eight Crotalaria species (C. incana, C. juncea, C. micans, C. ochroleuca, C. pallida, C. paulina, C. spectabilis, and C. vitellina, and tested if adults were preyed upon or released by the orb-weaving spider Nephila clavipes. We found that the protection against the spider was more effective in adults whose larvae fed on seeds, which had a higher PA concentration than leaves. The exceptions were adults from larvae fed on C. paulina, C. spectabilis and C. vitellina leaves, which showed high PA concentrations. With respect to the PA profile, we describe for the first time insect-PAs in U. ornatrix. These PAs, biosynthesized from the necine base retronecine of plant origin, or monocrotaline- and senecionine-type PAs sequestered from host plants, were equally active in moth chemical defense, in a dose-dependent manner. These results are also partially explained by host plant phylogeny, since PAs of the host plants do have a phylogenetic signal (clades with high and low PA concentrations in leaves which is reflected in the adult defense.

  18. Larvicidal and Growth-Inhibitory Activity of Entomopathogenic Bacteria Culture Fluids Against Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    da Silva, João Luiz Rosa; Undurraga Schwalm, Fernanda; Eugênio Silva, Carlos; da Costa, Marisa; Heermann, Ralf; Santos da Silva, Onilda

    2017-01-06

    Dengue, Chikungunya, and Zika are important vector-borne diseases, and Aedes aegypti L. is their main transmitter. As the disease management is mainly based on mosquito control strategies, the search for alternative and cost-effective approaches is ongoing. The Gram-negative bacteria Xenorhabdus nematophila and Photorhabdus luminescens are symbiotically associated with entomopathogenic nematodes and are highly pathogenic for insect larvae. After we have recently confirmed the toxicity of these bacteria in Ae. aegypti larvae, we here evaluated the toxic activity of culture fluids on the development of this mosquito species. Larval susceptibility was assessed by exposing larvae to different concentrations of P. luminescens or X. nematophila culture fluids to confirm whether secondary metabolites might cause the mosquitos' death. Xenorhabdus nematophila culture fluid was more effective and stable during the mosquito pathogenicity bioassays compared to that of P. luminescens Larval mortality started a few hours after exposure of the insects to the fluids. Furthermore, the residual effect of larvicidal activity of X. nematophila fluid persisted at full efficiency for 4 d. Particularly, larval mortality was still higher than 50% for up to 8 d. Exposure of larvae to a sublethal dose of X. nematophila fluid delayed pupation as well as emergence of adult mosquitoes and caused cumulative larval mortality higher than 90% by day 14. Here, we describe for the first time the use of stable culture fluids and therefore secondary metabolites of P. luminescens and X. nematophila as a promising basis for the use as biopesticide for control of Ae. aegypti in the future.

  19. Evaluating trap crops for diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae).

    Science.gov (United States)

    Badenes-Perez, Francisco R; Shelton, Anthony M; Nault, Brian A

    2004-08-01

    Potential trap crops for the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), were evaluated through a series of ovipositional preference and larval survival experiments in outdoor screenhouses in 2002 and 2003. Hosts examined as trap crops were glossy and waxy collards, Brassica oleracea L. variety acephala; Indian mustard, Brassica juncea (L.) Czern; and yellow rocket, Barbarea vulgaris (R. Br.) variety arcuata. More eggs were laid on the potential trap crops, with the exception of waxy collards, than on cabbage. When P. xylostella was offered multiple hosts at the same time, numbers of eggs laid on glossy collards, Indian mustard, and yellow rocket were 3, 18, and 12 times greater than on cabbage, respectively. Similarly, when P. xylostella was offered a single trap crop host and cabbage, numbers of eggs laid on glossy collards, Indian mustard, and yellow rocket were 300, 19, and 110 times greater than on cabbage, respectively. Our studies suggest differences in oviposition between the potential trap crops and cabbage were likely due to host volatiles, leaf morphology and color, or a combination of these factors, rather than to total leaf areas, leaf shape, or plant architecture. Two-choice tests with a Y-tube olfactometer indicated that plant volatiles were major factors in P. xylostella host preference. The percentage larval survival from egg to pupation was 22.2% on cabbage, 18.9% on waxy collards, and 24.4% on Indian mustard, whereas survival was significantly lower on glossy collards (6.7%) and yellow rocket (0%). Based on our tests, it seems that yellow rocket may be the best candidate for use as a trap crop for P. xylostella because it is highly attractive for oviposition, but larvae do not survive on it.

  20. Basic helix-loop-helix transcription factor Bmsage is involved in regulation of fibroin H-chain gene via interaction with SGF1 in Bombyx mori.

    Science.gov (United States)

    Zhao, Xiao-Ming; Liu, Chun; Li, Qiong-Yan; Hu, Wen-Bo; Zhou, Meng-Ting; Nie, Hong-Yi; Zhang, Yin-Xia; Peng, Zhang-Chuan; Zhao, Ping; Xia, Qing-You

    2014-01-01

    Silk glands are specialized in the synthesis of several secretory proteins. Expression of genes encoding the silk proteins in Bombyx mori silk glands with strict territorial and developmental specificities is regulated by many transcription factors. In this study, we have characterized B. mori sage, which is closely related to sage in the fruitfly Drosophila melanogaster. It is termed Bmsage; it encodes transcription factor Bmsage, which belongs to the Mesp subfamily, containing a basic helix-loop-helix motif. Bmsage transcripts were detected specifically in the silk glands of B. mori larvae through RT-PCR analysis. Immunoblotting analysis confirmed the Bmsage protein existed exclusively in B. mori middle and posterior silk gland cells. Bmsage has a low level of expression in the 4th instar molting stages, which increases gradually in the 5th instar feeding stages and then declines from the wandering to the pupation stages. Quantitative PCR analysis suggested the expression level of Bmsage in a high silk strain was higher compared to a lower silk strain on day 3 of the larval 5th instar. Furthermore, far western blotting and co-immunoprecipitation assays showed the Bmsage protein interacted with the fork head transcription factor silk gland factor 1 (SGF1). An electrophoretic mobility shift assay showed the complex of Bmsage and SGF1 proteins bound to the A and B elements in the promoter of fibroin H-chain gene(fib-H), respectively. Luciferase reporter gene assays confirmed the complex of Bmsage and SGF1 proteins increased the expression of fib-H. Together, these results suggest Bmsage is involved in the regulation of the expression of fib-H by being together with SGF1 in B. mori PSG cells.

  1. Comparison of the effects of extracts from three Vitex plant species on Anopheles gambiae s.s. (Diptera: Culicidae) larvae.

    Science.gov (United States)

    Nyamoita, Mokua G; Ester, Innocent; Zakaria, Mbwambo H; Wilber, Lwande; Bwire, Ochola J; Ahmed, Hassanali

    2013-09-01

    Acetone and methanol extracts of different parts of three Vitex species (leaves and stem bark of Vitex trifolia, leaves, stem bark and root bark of Vitex schiliebenii and stem and root bark of Vitex payos) were evaluated for their potential to control Anopheles gambiae Giles s.s. larvae (Diptera: Culicidae). The extracts gave different levels and rate of mortality of the larvae. Some (methanol extract of V. trifolia leaves, acetone extracts of stem bark and leaves of V. schiliebenii, acetone extract of root bark of V. payos) caused 100% mortality at 100 ppm in 72 h, with those of V. schiliebenii and V. payos showing faster rate of mortality (LT₅₀=8 h) than that of V. trifolia (LT₅₀=14 h). At lower doses of these extracts (≤50 ppm), most of the larvae failed to transform to normal pupae but gave larval-pupal intermediates between 4 and 14 days of exposure. Some pupated normally but the adults that emerged appeared to be weak and died within 48 h. Extracts of the stem bark of V. payos showed interesting effects on the larvae. Initially, the larvae were relatively hyperactive compared to those in control treatments. Later, the ones that did not transform to larval-pupal intermediates became stretched and inactive and died and floated in clusters on the surface. These observations suggest some interesting growth-disrupting constituents in the plants, with possible application in the practical control of mosquito larvae in aquatic ecosystems. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Exploration of larvicidal and adult emergence inhibition activities of Ricinus communis seed extract against three potential mosquito vectors in Kolkata, India

    Institute of Scientific and Technical Information of China (English)

    Shyamapada Mandal

    2010-01-01

    Objective:To determine the larvicidal and adult emergence inhibition activities of castor (Ricinus communis) seed extract against three potential mosquito vectorsAnopheles stephensi (An. stephensi), Culex quinquefasciatus (Cx. quinquefasciatus) andAedes albopictus (Ae. albopictus) in India.Methods: TheR. communis seed extract was tested, employingWHO procedure, against fourth larval instars of the three mosquito species for 24 h and larval mortalities were recorded at various concentrations (2-64 μg/mL); the 24 hLC50 values of theR. communis seed extract were determined following Probit analysis. The larval killing, antipupation and adult emergence inhibition rates of the test extract, using a single concentration of2μLC50, were studied at different time periods (24-72 h); the extract toxicity was tested against a fish,Oreochromis niloticus (O. niloticus).Results: TheR. communis seed extract exhibited larvicidal effects with 100 % killing activities at concentrations32-64 μg/mL, and withLC50values 7.10, 11.64 and 16.84μg/mL forCx. quinquefasciatus, An. stephensiand Ae. albopictuslarvae, respectively. When the larvae were treated with the extract at a single concentration of2×LC50, significant differences were observed, compared to control groups, in rate of pupation (P<0.001) as well as in adult formation (P<0.001).Conclusions: The present findings suggest that theR. communis seed extract provided an excellent potential for controllingAn. stephensi, Cx. quinquefasciatus andAe. albopictus mosquito vectors.

  3. Fitness costs limit the development of resistance to indoxacarb and deltamethrin in Heliothis virescens (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Sayyed, Ali H; Ahmad, Munir; Crickmore, Neil

    2008-12-01

    Insecticide resistance in Heliothis virescens (F.) (Lepidoptera: Noctuidae) has been documented from all over the world and is often associated with reduced fitness. Fitness costs could delay the development of resistance depending upon the prevailing conditions. We were interested in establishing whether a field-collected population from Washington County, MS, was resistant to spinosad, indoxacarb, and deltamethrin and whether any such resistance was associated with fitness costs. Bioassays results showed that the insecticides were equally toxic to the field population. Upon laboratory selection (generations [G]3 to G8), the resistance ratio increased only 2-, 3-, and 1-fold for spinosad, deltamethrin, and indoxacarb, respectively, compared with the field population. In contrast, the resistance ratios increased 213-, 65-, and 55-fold compared with an unselected population at G9. The estimated realized heritability (h2) after six generations of selection was 0.17, 0.03, and 0.12, respectively, and the number of generations required for 10-fold increase in LC50 of Spino-SEL, Indoxa-SEL, and Delta-SEL was estimated to be 14.3, 50, and 14.3. Comparison of life traits between the selected and unselected populations revealed that the selected populations laid a significantly lower number of eggs and that a lower percentage of eggs hatched. This also was reflected in both the net replacement rate and the intrinsic rate of population increase, which were both lower for the selected populations. It also was observed that the mean relative growth rate of the larvae was lower for the selected populations; not only did the larvae take longer to pupate but the mean weight of the prepupae from the selected populations was lower. Our data suggest that due to fitness costs the development of resistance to the insecticides was limited such that after six generations of selection the larvae were no less susceptible to the insecticides than the field population although were

  4. The FOXO transcription factor controls insect growth and development by regulating juvenile hormone degradation in the silkworm, Bombyx mori.

    Science.gov (United States)

    Zeng, Baosheng; Huang, Yuping; Xu, Jun; Shiotsuki, Takahiro; Bai, Hua; Palli, Subba Reddy; Huang, Yongping; Tan, Anjiang

    2017-07-14

    Forkhead box O (FOXO) functions as the terminal transcription factor of the insulin signaling pathway and regulates multiple physiological processes in many organisms, including lifespan in insects. However, how FOXO interacts with hormone signaling to modulate insect growth and development is largely unknown. Here, using the transgene-based CRISPR/Cas9 system, we generated and characterized mutants of the silkworm Bombyx mori FOXO (BmFOXO) to elucidate its physiological functions during development of this lepidopteran insect. The BmFOXO mutant (FOXO-M) exhibited growth delays from the first larval stage and showed precocious metamorphosis, pupating at the end of the fourth instar (trimolter) rather than at the end of the fifth instar as in the wild-type (WT) animals. However, different from previous reports on precocious metamorphosis caused by juvenile hormone (JH) deficiency in silkworm mutants, the total developmental time of the larval period in the FOXO-M was comparable with that of the WT. Exogenous application of 20-hydroxyecdysone (20E) or of the JH analog rescued the trimolter phenotype. RNA-seq and gene expression analyses indicated that genes involved in JH degradation but not in JH biosynthesis were up-regulated in the FOXO-M compared with the WT animals. Moreover, we identified several FOXO-binding sites in the promoter of genes coding for JH-degradation enzymes. These results suggest that FOXO regulates JH degradation rather than its biosynthesis, which further modulates hormone homeostasis to control growth and development in B. mori In conclusion, we have uncovered a pivotal role for FOXO in regulating JH signaling to control insect development. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Response of the gypsy moth, Lymantria dispar to transgenic poplar, Populus simonii x P. nigra, expressing fusion protein gene of the spider insecticidal peptide and Bt-toxin C-peptide.

    Science.gov (United States)

    Cao, Chuan-Wang; Liu, Gui-Feng; Wang, Zhi-Ying; Yan, Shan-Chun; Ma, Ling; Yang, Chuan-Ping

    2010-01-01

    The response of the Asian gypsy moth Lymantria dispar (L.) (Lepidoptera: Lymantriidae) to a fusion gene consisting of the spider, Atrax robustus Simon (Araneae: Hexanthelidae) ω-ACTX-Ar1 sequence coding for an ω-atracotoxin and a sequence coding for the Bt-toxin C-peptide, expressed in transgenic poplar Populus simonii x P. nigra L. (Malphigiales: Salicaceae) was investigated. Individual performance, feeding selection, midgut proteinase activity and nutrition utilization were monitored. The growth and development of L. dispar were significantly affected by continually feeding on the transgenic poplar, with the larval instars displaying significantly shorter developmental times than those fed on nontransgenic poplar, but pupation was delayed. Mortality was higher in populations fed transgenic poplar leaves, than for larvae fed nontransgenic poplar leaves. The cumulative mortality during all stages of larvae fed transgenic leaves was 92% compared to 16.7% of larvae on nontransgenic leaves. The highest mortality observed was 71.7% in the last larval instar stage. A two-choice test showed that fifth-instar larvae preferred to feed on nontransgenic leaves at a ratio of 1:1.4. Feeding on transgenic leaves had highly significant negative effects on relative growth of larvae, and the efficiency of conversion of ingested and digested food. Activity of major midgut proteinases was measured using substrates TAME and BTEE showed significant increases in tryptase and chymotrypsinlike activity (9.2- and 9.0-fold, respectively) in fifth-instar larvae fed on transgenic leaves over control. These results suggest transgenic poplar is resistant to L. dispar, and the mature L. dispar may be weakened by the transgenic plants due to Bt protoxins activated by elevated major midgut proteinase activity. The new transgenic poplar expressing fusion protein genes of Bt and a new spider insecticidal peptide are good candidates for managing gypsy moth.

  6. Biopotency of serine protease inhibitors from cowpea (Vigna unguiculata) seeds on digestive proteases and the development of Spodoptera littoralis (Boisduval).

    Science.gov (United States)

    Abd El-latif, Ashraf Oukasha

    2015-05-01

    Serine protease inhibitors (PIs) have been described in many plant species and are universal throughout the plant kingdom, where trypsin inhibitors is the most common type. In the present study, trypsin and chymotrypsin inhibitory activity was detected in the seed flour extracts of 13 selected cultivars/accessions of cowpea. Two cowpea cultivars, Cream7 and Buff, were found to have higher trypsin and chymotrypsin inhibitory potential compared to other tested cultivars for which they have been selected for further purification studies using ammonium sulfate fractionation and DEAE-Sephadex A-25 column. Cream7-purified proteins showed two bands on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) corresponding to molecular mass of 17.10 and 14.90 kDa, while the purified protein from Buff cultivar showed a single band corresponding mass of 16.50 kDa. The purified inhibitors were stable at temperature below 60°C and were active at wide range of pH from 2 to 12. The kinetic analysis revealed noncompetitive type of inhibition for both inhibitors against both enzymes. The inhibitor constant (Ki ) values suggested high affinity between inhibitors and enzymes. Purified inhibitors were found to have deep and negative effects on the mean larval weight, larval mortality, pupation, and mean pupal weight of Spodoptera littoralis, where Buff PI was more effective than Cream7 PI. It may be concluded that cowpea PI gene(s) could be potential insect control protein for future studies in developing insect-resistant transgenic plants.

  7. Almost there: transmission routes of bacterial symbionts between trophic levels.

    Directory of Open Access Journals (Sweden)

    Elad Chiel

    Full Text Available Many intracellular microbial symbionts of arthropods are strictly vertically transmitted and manipulate their host's reproduction in ways that enhance their own transmission. Rare horizontal transmission events are nonetheless necessary for symbiont spread to novel host lineages. Horizontal transmission has been mostly inferred from phylogenetic studies but the mechanisms of spread are still largely a mystery. Here, we investigated transmission of two distantly related bacterial symbionts--Rickettsia and Hamiltonella--from their host, the sweet potato whitefly, Bemisia tabaci, to three species of whitefly parasitoids: Eretmocerus emiratus, Eretmocerus eremicus and Encarsia pergandiella. We also examined the potential for vertical transmission of these whitefly symbionts between parasitoid generations. Using florescence in situ hybridization (FISH and transmission electron microscopy we found that Rickettsia invades Eretmocerus larvae during development in a Rickettsia-infected host, persists in adults and in females, reaches the ovaries. However, Rickettsia does not appear to penetrate the oocytes, but instead is localized in the follicular epithelial cells only. Consequently, Rickettsia is not vertically transmitted in Eretmocerus wasps, a result supported by diagnostic polymerase chain reaction (PCR. In contrast, Rickettsia proved to be merely transient in the digestive tract of Encarsia and was excreted with the meconia before wasp pupation. Adults of all three parasitoid species frequently acquired Rickettsia via contact with infected whiteflies, most likely by feeding on the host hemolymph (host feeding, but the rate of infection declined sharply within a few days of wasps being removed from infected whiteflies. In contrast with Rickettsia, Hamiltonella did not establish in any of the parasitoids tested, and none of the parasitoids acquired Hamiltonella by host feeding. This study demonstrates potential routes and barriers to horizontal

  8. Temperature cycle amplitude alters the adult eclosion time and expression pattern of the circadian clock gene period in the onion fly.

    Science.gov (United States)

    Miyazaki, Yosuke; Watari, Yasuhiko; Tanaka, Kazuhiro; Goto, Shin G

    2016-03-01

    Soil temperature cycles are considered to play an important role in the entrainment of circadian clocks of underground insects. However, because of the low conductivity of soil, temperature cycles are gradually dampened and the phase of the temperature cycle is delayed with increasing soil depth. The onion fly, Delia antiqua, pupates at various soil depths, and its eclosion is timed by a circadian clock. This fly is able to compensate for the depth-dependent phase delay of temperature change by advancing the eclosion time with decreasing amplitude of the temperature cycle. Therefore, pupae can eclose at the appropriate time irrespective of their location at any depth. However, the mechanism that regulates eclosion time in response to temperature amplitude is still unknown. To understand whether this mechanism involves the circadian clock or further downstream physiological processes, we examined the expression patterns of period (per), a circadian clock gene, of D. antiqua under temperature cycles that were square wave cycles of 12-h warm phase (W) and 12-h cool phase (C) with the temperature difference of 8 °C (WC 29:21 °C) and 1 °C (WC 25.5:24.5 °C). The phase of oscillation in per expression was found to commence 3.5h earlier under WC 25.5:24.5 °C as compared to WC 29:21 °C. This difference was in close agreement with the eclosion time difference between the two temperature cycles, suggesting that the mechanism that responds to the temperature amplitude involves the circadian clock.

  9. Evaluation of Impact of Pollen Grains from Bt, Bt/CpTI Transgenic Cotton and Bt Corn Plants on the Growth and Development of the Mulberry Silkworm, Bombyx mori Linnaeus (Lepidoptera: Bombycidae)

    Institute of Scientific and Technical Information of China (English)

    LI Wen-dong; YE Gong-yin; WU Kong-ming; WANG Xiao-qi; GUO Yu-yuan

    2002-01-01

    The δ-endotoxin genes of Bacillus thuringiensis (Bt) and proteinase inhibitor (PI) genes aretwo kinds of genes popularly used for developing transgenic plants resistant to insect pests. To clarify whetherthere is any risk concerning the effects of pollens from these transgenic crops on non-target insects with eco-nomic importance, such as the effects on the growth and development as well as cocoon quality of the silk-worm, Bombyx mori Linnaeus, a series of feeding experiments were conducted, using pollens from transgeniccotton or corn containing crylAc, cry1A+-CpTI or crylAb genes, compared with pollens from non-transgenicnormal cotton and corn as well as the non-pollen treatment. In contrast to the latter ones, pollens from trans-genic plants showed no significant adverse effects on larval mortality, cocoon weight, pupa weight, cocoonshell weight, pupation rate, emergence rate and fecundity of the silkworm after neonates were fed with thepollens for 72 h. In addition, no dosage effects of pollens were found. Though the duration of 1st instar larvaewas prolonged in the case of feeding with transgenic pollens as compared with those of the non-pollen treat-ment, but they were not significantly different from those fed with pollens from non-transgenic cotton or corn.Meanwhile, the body weight of the 3rd instar molters fed with transgenic pollens was obviously different fromthose for non-pollen treatment, and was all significantly heavier than that of the controls. Consequently, it isconsidered that the adverse effect of pollens from transgenic insect-resistant cotton and corn on the growth anddevelopment of the silkworm is negligible.

  10. Transcriptional profiling of midgut immunity response and degeneration in the wandering silkworm, Bombyx mori.

    Directory of Open Access Journals (Sweden)

    Qiuyun Xu

    Full Text Available BACKGROUND: Lepidoptera insects have a novel development process comprising several metamorphic stages during their life cycle compared with vertebrate animals. Unlike most Lepidoptera insects that live on nectar during the adult stage, the Bombyx mori silkworm adults do not eat anything and die after egg-laying. In addition, the midguts of Lepidoptera insects produce antimicrobial proteins during the wandering stage when the larval tissues undergo numerous changes. The exact mechanisms responsible for these phenomena remain unclear. PRINCIPAL FINDINGS: We used the silkworm as a model and performed genome-wide transcriptional profiling of the midgut between the feeding stage and the wandering stage. Many genes concerned with metabolism, digestion, and ion and small molecule transportation were down-regulated during the wandering stage, indicating that the wandering stage midgut loses its normal functions. Microarray profiling, qRT-PCR and western blot proved the production of antimicrobial proteins (peptides in the midgut during the wandering stage. Different genes of the immune deficiency (Imd pathway were up-regulated during the wandering stage. However, some key genes belonging to the Toll pathway showed no change in their transcription levels. Unlike butterfly (Pachliopta aristolochiae, the midgut of silkworm moth has a layer of cells, indicating that the development of midgut since the wandering stage is not usual. Cell division in the midgut was observed only for a short time during the wandering stage. However, there was extensive cell apoptosis before pupation. The imbalance of cell division and apoptosis probably drives the continuous degeneration of the midgut in the silkworm since the wandering stage. CONCLUSIONS: This study provided an insight into the mechanism of the degeneration of the silkworm midgut and the production of innate immunity-related proteins during the wandering stage. The imbalance of cell division and apoptosis

  11. Insecticidal and Feeding Deterrent Effects of Fraxinellone from Dictamnus dasycarpus against Four Major Pests

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    Huixia Liu

    2013-03-01

    Full Text Available Fraxinellone, a well-known and significant naturally occurring compound isolated from Meliaceae and Rutaceae spp. has been widely used as a drug for the treatment of tumors. On the other hand, fraxinellone exhibited a variety of insecticidal activities including feeding-deterrent activity, inhibition of growth, and larvicidal activity. The present study focused on the antifeedant and larvicidal activities of fraxinellone against the larvae of Lepidoptera, including Mythimna separata, Agrotis ypsilon, Plutella xylostella, and one kind of sanitary pest, Culux pipiens pallens. Meanwhile, the ovicidal activities and the effects of fraxinellone on the larval development of M. separata were also observed. The LC50 values of fraxinellone against 3rd instar larvae of M. separata, 2nd instar larvae of P. xylostella and 4th instar larvae of C. pipiens pallens were 15.95/6.43/3.60 × 10−2 mg mL−1, and its AFC50 values against 5th instar larvae of M. separata, 2nd instar larvae of P. xylostella and 2nd instar larvae of A. ypsilon were 10.73/7.93/12.58 mg mL−1, respectively. Compared with the control group, fraxinellone obviously inhibited the pupation rate and the growth of M. separata. Once M. separata was treated with fraxinellone at concentrations of 5.0, 10.0, and 20.0 mg mL−1, respectively, the stages from the larvae to adulthood and the egg hatching duration were prolonged to 1/2/3, and 4/3/4 days, respectively. Additionally, fraxinellone strongly inhibited the development rate and the egg hatch proportion of M. separata.

  12. LBD1 of Vitellogenin Receptor Specifically Binds to the Female-Specific Storage Protein SP1 via LBR1 and LBR3

    Science.gov (United States)

    Liu, Lina; Wang, Yejing; Li, Yu; Lin, Ying; Hou, Yong; Zhang, Yan; Wei, Shuguang; Zhao, Peng; Zhao, Ping; He, Huawei

    2016-01-01

    Storage proteins are the major protein synthesized in the fat body, released into hemolymph and re-sequestered into the fat body before pupation in most insect species. Storage proteins are important amino acid and nutrition resources during the non-feeding pupal period and play essential roles for the metamorphosis and oogenesis of insects. The sequestration of storage protein is a selective, specific receptor-mediated process. However, to date, the potential receptor mediating the sequestration of storage protein has not been determined in Bombyx mori. In this study, we expressed and purified the first ligand binding domain of Bombyx mori vitellogenin receptor (BmVgR), LBD1, and found LBD1 could bind with an unknown protein from the hemolymph of the ultimate silkworm larval instar via pull-down assay. This unknown protein was subsequently identified to be the female-specific storage protein SP1 by mass spectrometry. Furthermore, far western blotting assay, immunoprecipitation and isothermal titration calorimetry analysis demonstrated LBD1 specifically bound with the female-specific SP1, rather than another unisex storage protein SP2. The specific binding of LBD1 with SP1 was dependent on the presence of Ca2+ as it was essential for the proper conformation of LBD1. Deletion mutagenesis and ITC analysis revealed the first and third ligand binding repeats LBR1 and LBR3 were indispensable for the binding of LBD1 with SP1, and LBR2 and LBR4 also had a certain contribution to the specific binding. Our results implied BmVgR may mediate the sequestration of SP1 from hemolymph into the fat body during the larval-pupal transformation of Bombyx mori. PMID:27637099

  13. Down-regulation of a chitin synthase a gene by RNA interference enhances pathogenicity of Beauveria bassiana ANU1 against Spodoptera exigua (HÜBNER).

    Science.gov (United States)

    Lee, Jung-Bok; Kim, Hyun Soo; Park, Youngjin

    2017-02-01

    Chitin synthase (CHS) is an important enzymatic component, which is required for chitin formation in the cuticles and cuticular linings of other tissues in insects. CHSs have been divided into two classes, classes A and B, based on their amino acid sequence similarities and functions. Class A CHS (CHS-A) is specifically expressed in the epidermis and related ectodermal cells such as tracheal cells, while class B CHS (CHS-B) is expressed in gut epithelial cells that produce peritrophic matrices. In this study, we cloned the CHS-A gene from the beet armyworm, Spodoptera exigua (SeCHS-A). The SeCHS-A contains an open reading frame of 4,698 nucleotides, encoding a protein of 1,565 amino acids with a predicted molecular mass of approximately 177.8 kDa. The SeCHS-A mRNA was expressed in all developmental stages and specifically in the epidermis and tracheae tissue by quantitative real-time-PCR analysis. Expression of SeCHS-A gene was suppressed by feeding double-stranded RNA (dsCHS-A, 400 ng/larva) in the third instar larvae of S. exigua. Suppression of the SeCHS-A gene expression significantly increased 35% of mortality on pupation of S. exigua. Also, the third instar larvae fed with dsCHS-A significantly increased susceptibility to entomopathogenic fungi, Beauveria bassiana ANU1 at 3 days after treatment. These results suggest that the SeCHS-A gene plays an important role in development of S. exigua and RNA interference may apply to effective pest control with B. bassiana.

  14. Costs of Three Wolbachia Infections on the Survival of Aedes aegypti Larvae under Starvation Conditions.

    Science.gov (United States)

    Ross, Perran A; Endersby, Nancy M; Hoffmann, Ary A

    2016-01-01

    The mosquito Aedes aegypti, the principal vector of dengue virus, has recently been infected experimentally with Wolbachia: intracellular bacteria that possess potential as dengue biological control agents. Wolbachia depend on their hosts for nutrients they are unable to synthesize themselves. Consequently, competition between Wolbachia and their host for resources could reduce host fitness under the competitive conditions commonly experienced by larvae of Ae. aegypti in the field, hampering the invasion of Wolbachia into natural mosquito populations. We assess the survival and development of Ae. aegypti larvae under starvation conditions when infected with each of three experimentally-generated Wolbachia strains: wMel, wMelPop and wAlbB, and compare their fitness to wild-type uninfected larvae. We find that all three Wolbachia infections reduce the survival of larvae relative to those that are uninfected, and the severity of the effect is concordant with previously characterized fitness costs to other life stages. We also investigate the ability of larvae to recover from extended food deprivation and find no effect of Wolbachia on this trait. Aedes aegypti larvae of all infection types were able to resume their development after one month of no food, pupate rapidly, emerge at a large size, and exhibit complete cytoplasmic incompatibility and maternal transmission. A lowered ability of Wolbachia-infected larvae to survive under starvation conditions will increase the threshold infection frequency required for Wolbachia to establish in highly competitive natural Ae. aegypti populations and will also reduce the speed of invasion. This study also provides insights into survival strategies of larvae when developing in stressful environments.

  15. Influence of media type and moisture on adult development and pupal mortality in Rhagoletis indifferens (Diptera: Tephritidae).

    Science.gov (United States)

    Yee, Wee L

    2013-06-01

    The influence of media type and moisture on adult development and pupal mortality in western cherry fruit fly, Rhagoletis indifferens Curran (Diptera:Tephritidae), was assessed using the pupal-adult and the larval-pupal stage. Inside containers, a higher percent of flies that emerged from dry loam was deformed (44.2%, 1-cm-depth loam; 84.4%, 5-cm-depth loam) than flies from 16% moist loam and dry and 16% moist lab soil (peat moss-sand mix) (0-14.9%). Percent of flies deformed from dry sand (22.1%, 1-cm depth; 49.5%, 5-cm depth) was greater than from 16% moist sand and dry and 16% moist peat moss (0-10.5%). Percents of flies deformed from 8% moist loam, lab soil, sand, and peat moss (0-5.8%) did not differ. Pupae suffered higher mortality at 7 and 14 d after larvae were dropped onto dry loam and dry sand (68.2-94.0%) than dry lab soil and dry peat moss (3.0-53.0%); respective mortalities at 21 and 28 d were similar (81.3-96.0 versus 64.7-97.9%). Pupal mortality in moist media was lower (0.5-40.3%) than in dry media. In outdoor tests, pupal mortality was also higher in dry loam than other dry media. In nature, 60.9% of pupae in dry sandy loams in late summer were dead. Results suggest R. indifferens has not yet evolved to fully cope with dry soils and that pupation in media with traits similar to those of peat moss or a peat moss-sand mix could reduce negative effects of dry environments on fly survival.

  16. 基于均匀设计与支持向量回归的棉铃虫幼虫全纯人工饲料配方优化%Optimization of chemically defined diet for larvae of the cotton bollworm (Helicoverpa armigera)based on uniform design and support vector regression

    Institute of Scientific and Technical Information of China (English)

    周世豪; 李俊; 姚润贤; 张星; 袁哲明

    2012-01-01

    昆虫全纯人工饲料配方是精细研究昆虫营养生理的前提.本研究以棉铃虫Helicoverpa armigera幼虫为供试对象,以本研究室前期发展的多因素多水平配方优化实验设计与分析方法UD-SVR为指导,以略加修改的苹浅褐卷蛾Epiphyas postvittana幼虫全纯人工饲料为初始配方,先优化20种天然氨基酸,再优化蔗糖等其他8种非氨基酸营养组分,经4轮97个处理组合,获得一个棉铃虫幼虫全纯人工饲料满意配方,平均蛹重、化蛹率分别由初始配方的0.160 g和10.4%高效增至满意配方的0.255 g和97.9%.该全纯人工饲料满意配方的获得,不但再次证实了 UD-SVR方法的有效性,同时为进一步深入研究棉铃虫营养需求与营养代谢奠定了基础.%In order to get a satisfying formula of the chemically artificial diet for larvae of the cotton bollworm, Helicoverpa armigera, we used UD-SVR, an experimental design and analysis method reported by our preliminary studies, for formula optimization. Based on the benchmark diet of a chemically artificial diet for the larvae of the light brown apple moth, Epiphyas postvittana, the contents of 20 natural amino acids were optimized first, and the contents of 8 non-amino acid nutrients including sucrose were optimized then. After 4 rounds of optimization with total 97 schemes, an optimal formula of the chemically artificial diet for the cotton bollworm larvae was obtained. When the H. Armigera larvae fed on this diet, their mean pupal weight and the pupation rate were 0. 255 g and 97. 9% , respectively; when the larvae fed on the benchmark diet, however, the above two indices were only 0. 160 g and 10. 4% ,respectively. The results reconfirmed the effectiveness of UD-SVR in the complex prescription optimization. More importantly, the optimized chemically artificial diet for the cotton bollworm provides the basis for further research on the requirement and metabolism of nutrition compounds in the moth.

  17. Uracil-containing DNA in Drosophila: stability, stage-specific accumulation, and developmental involvement.

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    Villő Muha

    Full Text Available Base-excision repair and control of nucleotide pools safe-guard against permanent uracil accumulation in DNA relying on two key enzymes: uracil-DNA glycosylase and dUTPase. Lack of the major uracil-DNA glycosylase UNG gene from the fruit fly genome and dUTPase from fruit fly larvae prompted the hypotheses that i uracil may accumulate in Drosophila genomic DNA where it may be well tolerated, and ii this accumulation may affect development. Here we show that i Drosophila melanogaster tolerates high levels of uracil in DNA; ii such DNA is correctly interpreted in cell culture and embryo; and iii under physiological spatio-temporal control, DNA from fruit fly larvae, pupae, and imago contain greatly elevated levels of uracil (200-2,000 uracil/million bases, quantified using a novel real-time PCR-based assay. Uracil is accumulated in genomic DNA of larval tissues during larval development, whereas DNA from imaginal tissues contains much less uracil. Upon pupation and metamorphosis, uracil content in DNA is significantly decreased. We propose that the observed developmental pattern of uracil-DNA is due to the lack of the key repair enzyme UNG from the Drosophila genome together with down-regulation of dUTPase in larval tissues. In agreement, we show that dUTPase silencing increases the uracil content in DNA of imaginal tissues and induces strong lethality at the early pupal stages, indicating that tolerance of highly uracil-substituted DNA is also stage-specific. Silencing of dUTPase perturbs the physiological pattern of uracil-DNA accumulation in Drosophila and leads to a strongly lethal phenotype in early pupal stages. These findings suggest a novel role of uracil-containing DNA in Drosophila development and metamorphosis and present a novel example for developmental effects of dUTPase silencing in multicellular eukaryotes. Importantly, we also show lack of the UNG gene in all available genomes of other Holometabola insects, indicating a potentially

  18. Effects of nuclear polyhedrosis virus on cannibalism in Helicoverpa armigera%核型多角体病毒感染对棉铃虫幼虫同类相残行为的影响

    Institute of Scientific and Technical Information of China (English)

    李静雯; 褚艳娜; 王琼; 刘小侠; 张青文

    2012-01-01

    The effects of nuclear polyhedrosis virus infection on cannibalism in Helicoverpa armigera ( H(u)bner) was evaluated under laborratory conditions. The number of infected larvae preyed on by healthy larvae increased with the progress of the disease. There was no significant difference in the percentage of dead infected larvae, frozen infected larvae and frozen healthy larvae that were preyed on by healthy larvae. This suggests that infected larvae and dead infected larvae are more likely to be cannibalized simply because they become less vigorous and less capable of defending themselves than healthy larvae. There was no significant difference in the frequency of cannibalism of frozen infected larvae by healthy larvae and infected larvae. This suggests that the tendency towards cannibalism is not altered by infection. Cannibalism is potentially costly. The pupation and eclosion rate of healthy larvae that ate infected larvae was lower than that of those that had not cannibalized infected larvae.%在室内研究核型多角体病毒(HaSNPV)感染对棉铃虫Helicoverpa armigera(Hübner)幼虫同类相残行为的影响.结果显示:感病棉铃虫随感病程度的加重,越容易被健康棉铃虫残食,而自然死亡的感病棉铃虫、冻死的感病棉铃虫和冻死的健康棉铃虫三者被健康棉铃虫残食的百分率无显著差异.表明感病棉铃虫和病虫尸体更易于被健康棉铃虫残食,是由于棉铃虫体力减弱而失去反击能力,不是由于病毒本身的影响.以健康棉铃虫、感病棉铃虫为残食者,冻死的病虫为被残食者,相残率无显著差异,表明病毒并未改变棉铃虫残食同类的天性.残食病虫的健康棉铃虫的化蛹率和羽化率均低于正常的健康棉铃虫,残食者为相残行为付出了很高的代价.

  19. Helicopter thermal imaging for detecting insect infested cadavers.

    Science.gov (United States)

    Amendt, Jens; Rodner, Sandra; Schuch, Claus-Peter; Sprenger, Heinz; Weidlich, Lars; Reckel, Frank

    2017-09-01

    One of the most common techniques applied for searching living and even dead persons is the FLIR (Forward Looking Infrared) system fixed on an aircraft like e.g. a helicopter, visualizing the thermal patterns emitted from objects in the long-infrared spectrum. However, as body temperature cools down to ambient values within approximately 24h after death, it is common sense that searching for deceased persons can be just applied the first day post-mortem. We postulated that the insect larval masses on a decomposing body generate a heat which can be considerably higher than ambient temperatures for a period of several weeks and that such heat signatures might be used for locating insect infested human remains. We examined the thermal history of two 70 and 90kg heavy pig cadavers for 21days in May and June 2014 in Germany. Adult and immature insects on the carcasses were sampled daily. Temperatures were measured on and inside the cadavers, in selected maggot masses and at the surroundings. Thermal imaging from a helicopter using the FLIR system was performed at three different altitudes up to 1500ft. during seven day-flights and one night-flight. Insect colonization was dominated by blow flies (Diptera: Calliphoridae) which occurred almost immediately after placement of the cadavers. Larvae were noted first on day 2 and infestation of both cadavers was enormous with several thousand larvae each. After day 14 a first wave of post-feeding larvae left the carcasses for pupation. Body temperature of both cadavers ranged between 15°C and 35°C during the first two weeks of the experiment, while body surface temperatures peaked at about 45°C. Maggot masses temperatures reached values up to almost 25°C above ambient temperature. Detection of both cadavers by thermal imaging was possible on seven of the eight helicopter flights until day 21. Copyright © 2017 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.

  20. Immune system responses and fitness costs associated with consumption of bacteria in larvae of Trichoplusia ni

    Directory of Open Access Journals (Sweden)

    Heckel David G

    2007-12-01

    Full Text Available Abstract Background Insects helped pioneer, and persist as model organisms for, the study of specific aspects of immunity. Although they lack an adaptive immune system, insects possess an innate immune system that recognizes and destroys intruding microorganisms. Its operation under natural conditions has not been well studied, as most studies have introduced microbes to laboratory-reared insects via artificial mechanical wounding. One of the most common routes of natural exposure and infection, however, is via food; thus, the role of dietary microbial communities in herbivorous insect immune system evolution invites study. Here, we examine the immune system response and consequences of exposing a lepidopteran agricultural pest to non-infectious microorganisms via simple oral consumption. Results Immune system response was compared between Trichoplusia ni larvae reared on diets with or without non-pathogenic bacteria (Escherichia coli and Micrococcus luteus. Two major immune response-related enzymatic activities responded to diets differently – phenoloxidase activity was inhibited in the bacteria-fed larvae, whereas general antibacterial activity was enhanced. Eight proteins were highly expressed in the hemolymph of the bacteria fed larvae, among them immune response related proteins arylphorin, apolipophorin III and gloverin. Expression response among 25 putative immune response-related genes were assayed via RT-qPCR. Seven showed more than fivefold up regulation in the presence of bacterial diet, with 22 in total being differentially expressed, among them apolipophorin III, cecropin, gallerimycin, gloverin, lysozyme, and phenoloxidase inhibiting enzyme. Finally, potential life-history trade-offs were studied, with pupation time and pupal mass being negatively affected in bacteria fed larvae. Conclusion The presence of bacteria in food, even if non-pathogenic, can trigger an immune response cascade with life history tradeoffs. Trichoplusia ni

  1. Characterization and expression patterns of let-7 microRNA in the silkworm (Bombyx mori

    Directory of Open Access Journals (Sweden)

    Hong Kaili

    2007-07-01

    Full Text Available Abstract Background lin-4 and let-7, the two founding members of heterochronic microRNA genes, are firstly confirmed in Caenorhabditis elegans to control the proper timing of developmental programs in a heterochronic pathway. let-7 has been thought to trigger the onset of adulthood across animal phyla. Ecdysone and Broad-Complex are required for the temporal expression of let-7 in Drosophila melanogaster. For a better understanding of the conservation and functions of let-7, we seek to explore how it is expressed in the silkworm (Bombyx mori. Results One member of let-7 family has been identified in silkworm computationally and experimentally. All known members of this family share the same nucleotides at ten positions within the mature sequences. Sequence logo and phylogenetic tree show that they are not only conserved but diversify to some extent among some species. The bmo-let-7 was very lowly expressed in ova harvested from newborn unmated female adult and in individuals from the first molt to the early third instar, highly expressed after the third molt, and the most abundant expression was observed after mounting, particularly after pupation. The expression levels were higher at the end of each instar and at the beginning of each molt than at other periods, coinciding with the pulse of ecdysone and BR-C as a whole. Using cultured ovary cell line, BmN-SWU1, we examined the effect of altered ecdysone levels on bmo-let-7 expression. The expression was also detected in various tissues of day 3 of the fifth instar and of from day 7 of the fifth to pupa, suggesting a wide distributing pattern with various signal intensities. Conclusion bmo-let-7 is stage- and tissue-specifically expressed in the silkworm. Although no signals were detected during embryonic development and first larval instar stages, the expression of bmo-let-7 was observed from the first molt, suggesting that it might also function at early larval stage of the silkworm. The

  2. Biolarvacidal activity of methanol extract of Kipahit leaves (Tithonia diversifolia against larvae of Chrysomya bezziana fly

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    Wardhana AH

    2014-03-01

    Full Text Available Myiasis or “belatungan” is the infestation of live human and vertebrate animal tissue with dipterous larvae, Chrysomya bezziana. In general, synthetic insecticides were applied to control the disease. However, it causes negative impact on animal product, so that it is required to find an alternative treatment using herbal medicine. The aim of this study was to access activity of methanol extract of Kipahit leaves (Tithonia diversifolia against various stages of C. bezziana larvae (L1, L2 and L3. Five treatments were applied with five replications, i.e. control/water (P0, 0,5%, 1%, 2% of the extract for PI, PII and PIII, respectively. Another treatment was 0,05% Asuntol for positive control (PIV. Each treatment was added with1% DMSO and twenty larvae were examined for each replication. Bioassay of L1 and L2 was addressed to investigate effect of intestinal toxicity by mixing the extract with Meat-Blood Mixture (MBM and Larval Rearing Media (LRM for L1 and L2, respectively. Bioassay of L3 was to investigate effect of contact toxicity through soaking the larvae into the extract solution for 10 seconds followed by incubating in vermiculite at 36oC. All living larvae after being treated by various concentration of the extract were reared to pupae and allowed to emerge as imago. Number of living larvae and pupae, pupae weight and number of imago were observed. All data were analysed using ANOVA followed by Dunnett test at 95% confidential limit. For L2, larval mortality were counted and probit analysed using POLO-PC software, therefore the lethal concentration (LC50 and LC95 and lethal time (LT50 and LT95 were defined. Results demonstrated that 1% of the extract was the most effective concentration which was able to kill the larvae and decrease the pupae weight. It also caused to fail pupation and imago emergence. The further study might be pursued to investigate in vivo assay of the extract in infested livestock.

  3. Biological potential study of metal complexes of sulphonylurea glibenclamide on the house fly, Musca domestica (Diptera—Muscidae): Preparation, spectroscopic and thermal characterization

    Science.gov (United States)

    Mohamed, Gehad G.; Abdallah, S. M.; Zayed, M. A.; Nassar, M. M. I.

    2009-10-01

    The ligatation behaviour of sulphonylurea glibenclamide drug is studied in order to give an idea about its potentiality towards some transition metals in vitro systems. Metal complexes of glibenclamide (GCA; H 3L) drug are prepared and characterized based on elemental analyses, IR, diffused reflectance, magnetic moment, molar conductance and thermal analysis (TG and DTG) techniques. From the elemental analyses data, the complexes are proposed to have the general formulae [M(H 3L)Cl n(H 2O) m]· yH 2O (where M = Cr(III) ( n = 3, m = 1, y = 3); Mn(II) ( n = 2, m = 0, y = 1); Fe(III) ( n = 3, m = 1, y = 0), Co(II) ( n = 2, m = 2, y = 0); Ni(II) ( n = 2, m = 2, y = 3); Cu(II) ( n = 2, m = 2, y = 2) and Zn(II) ( n = 2, m = 0, y = 0). The molar conductance data reveal that all the metal chelates are non-electrolytes. IR spectra show that GCA is coordinated to the metal ions in a neutral bidentate manner with OO donor sites of the amide- O and sulphone -O. From the magnetic and solid reflectance spectra, it is found that the geometrical structures of these complexes are octahedral except Mn(II) and Zn(II) complexes which have tetrahedral structure. The thermal behaviour of these chelates is studied using thermogravimetric analysis (TG and DTG) technique. The activation thermodynamic parameters are calculated using Coats-Redfern method. The GCA drug, in comparison to its metal complexes also is screened for its biological activity against house fly, Musca domestica (Diptera—Muscidae). Dose of 5 μg/insect of GCA is topically applied against 3 days old larval instar of M. domestica. Survival of pupal and adult stages has been affected by the complexes of GCA more than larval instars. Morphogenic abnormalities of larvae, pupae and adults are studied. On the other hand pupation and adult emergence program is deteriorated by the effect of different chemicals.

  4. Identification of 20-hydroxyecdysone late-response genes in the chitin biosynthesis pathway.

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    Qiong Yao

    Full Text Available BACKGROUND: 20-hydroxyecdysone (20E and its receptor complex ecdysone receptor (EcR and ultraspiracle (USP play a crucial role in controlling development, metamorphosis, reproduction and diapause. The ligand-receptor complex 20E-EcR/USP directly activates a small set of early-response genes and a much larger set of late-response genes. However, ecdysone-responsive genes have not been previously characterized in the context of insect chitin biosynthesis. PRINCIPAL FINDINGS: Here, we show that injection-based RNA interference (RNAi directed towards a common region of the two isoforms of SeEcR in a lepidopteron insect Spodoptera exigua was effective, with phenotypes including a high mortality prior to pupation and developmental defects. After gene specific RNAi, chitin contents in the cuticle of an abnormal larva significantly decreased. The expression levels of five genes in the chitin biosynthesis pathway, SeTre-1, SeG6PI, SeUAP, SeCHSA and SeCHSB, were significantly reduced, while there was no difference in the expression of SeTre-2 prior to 72 hr after injection of EcR dsRNA. Meanwhile, injection of 20E in vivo induced the expression of the five genes mentioned above. Moreover, the SeTre-1, SeG6PI, SeUAP and SeCHSB genes showed late responses to the hormone and the induction of SeTre-1, SeG6PI, SeUAP and SeCHSB genes by 20E were able to be inhibited by the protein synthesis inhibitor cycloheximide in vitro indicating these genes are 20E late-response genes. CONCLUSIONS: We conclude that SeTre-1, SeG6PI, SeUAP and SeCHSB in the chitin biosynthesis pathway are 20E late-response genes and 20E and its specific receptors plays a key role in the regulation of chitin biosynthesis via inducing their expression.

  5. Insecticidal Efficacy of Azadirachta indica, Nucleopolyhedrovirus and Chlorantraniliprole Singly or Combined against Field Populations fo Helicoverpa armigera Hübner (Lepidoptera: Noctuidae Eficacia Insecticida de Azadirachta indica, Nucleopolihedrovirus y Clorantraniliprol solo y sus Aplicaciones Integradas contra Poblaciones de Campo de Helicoverpa armigera Hübner (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    Waqas Wakil

    2012-03-01

    Full Text Available The development of resistance in cosmopolitan insect Helicoverpa armigera Hubner (Lepidoptera: Noctuidae forced the researchers for alternative control measures. In the present study, insecticidal efficacy of formulations of Azadirachta indica, a Nucleopolyhedrovirus (NPV, and new anthranilic diamide insecticide (chlorantraniliprole formulations was determined against 2nd, through 5th larval instars of H. armigera collected from diverse geographical locations in the Punjab province, Pakistan. Azadirachta indica was applied at 5 μL L-1; NPV at 2.1 x 10(5 polyhedral occlusion bodies (POB mL4 and chlorantraniliprole at 0.01 μL L-1, either alone or in combinations with each other. The bioassays were conducted at 27 ± 1 °C and 65 ± 5% relative humidity. The mortality varied greatly among treatments, larval instars, and locations. The combinations of NPV with A. indica and chlorantraniliprole caused higher mortality, pupation and produced an additive effect compared to their application singly in all the tested populations. The population from Rawalpindi was always susceptible while the Gujranwala was the resistant. The results herein suggest that the effectiveness of NPV and A. indica can be improved by the presence of chlorantraniliprole against the larvae of H. armigera.Se determinó la eficacia insecticida de formulaciones de Azadirachta indica, Nucleopolihedrovirus (VPN y el nuevo insecticida diamida antranílico (clorantraniliprol en contra de segundo, tercero, cuarto y quinto estadios larvales de Helicoverpa armigera Hubner (Lepidoptera: Noctuidae recogidos de diversas ubicaciones geográficas de la provincia de Punjab, Pakistán. Azadirachta indica se aplicó en dosis de 5 μL L-1; VPN en dosis 2.1 x 10(5 POB mL-1 y clorantraniliprol fue 0,01 μL L-1 ya sea solos o en combinaciones. Los bioensayos se realizaron a 27 ± 1 °C y 65 ± 5% de humedad relativa. La mortalidad fue notablemente variada entre los tratamientos, estadios larvales y

  6. Elevated CO{sub 2} levels and herbivore damage alter host plant preferences

    Energy Technology Data Exchange (ETDEWEB)

    Agrell, J. [Lund Univ., Dept. of Animal Ecology, Lund (Sweden); Anderson, Peter, Swedish Univ. of Agricultural Sciences, Dept. of Crop Sciences, Alnarp (SE)); Oleszek, W.; Stochmal, Anna [Inst. of Soil Science and Plant Cultivation, Dept. of Biochemistry, Pulawy (Poland); Agrell, Cecilia [Lund Univ., Dept. of Chemical Ecology and Ecotoxicology, Lund (Sweden)

    2006-01-01

    Interactions between the moth Spodoptera littoralis and two of its host plants, alfalfa (Medicago sativa) and cotton (Gossypium hirsutum) were examined, using plants grown under ambient (350 ppm) and elevated (700 ppm) CO{sub 2} conditions. To determine strength and effects of herbivore-induced responses assays were performed with both undamaged (control) and herbivore damaged plants. CO{sub 2} and damage effects on larval host plant preferences were determined through dual-choice bioassays. In addition, larvae were reared from hatching to pupation on experimental foliage to examine effects on larval growth and development. When undamaged plants were used S. littoralis larvae in consumed more cotton than alfalfa, and CO{sub 2} enrichment caused a reduction in the preference for cotton. With damaged plants larvae consumed equal amounts of the two plant species (ambient CO{sub 2} conditions), but CO{sub 2} enrichment strongly shifted preferences towards cotton, which was then consumed three times more than alfalfa. Complementary assays showed that elevated CO{sub 2} levels had no effect on the herbivore-induced responses of cotton, whereas those of alfalfa were significantly increased. Larval growth was highest for larvae fed undamaged cotton irrespectively of CO{sub 2} level, and lowest for larvae on damaged alfalfa from the high CO{sub 2} treatment. Development time increased on damaged cotton irrespectively of CO{sub 2} treatment, and on damaged alfalfa in the elevated CO{sub 2} treatment. (au) These results demonstrate that elevated CO2 levels can cause insect herbivores to alter host plant preferences, and that effects on herbivore-induced responses may be a key mechanism behind these processes. Furthermore, since the insects were shown to avoid foliage that reduced their physiological performance, our data suggest that behavioural host plant shifts result in partial escape from negative consequences of feeding on high CO2 foliage. Thus, CO2 enrichment can alter

  7. Diet and density dependent competition affect larval performance and oviposition site selection in the mosquito species Aedes albopictus (Diptera: Culicidae

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    Yoshioka Miho

    2012-10-01

    Full Text Available Abstract Background Oviposition-site choice is an essential component of the life history of all mosquito species. According to the oviposition-preference offspring-performance (P-P hypothesis, if optimizing offspring performance and fitness ensures high overall reproductive fitness for a given species, the female should accurately assess details of the heterogeneous environment and lay her eggs preferentially in sites with conditions more suitable to offspring. Methods We empirically tested the P-P hypothesis using the mosquito species Aedes albopictus by artificially manipulating two habitat conditions: diet (measured as mg of food added to a container and conspecific density (CD; number of pre-existing larvae of the same species. Immature development (larval mortality, development time to pupation and time to emergence and fitness (measured as wing length were monitored from first instar through adult emergence using a factorial experimental design over two ascending gradients of diet (2.0, 3.6, 7.2 and 20 mg food/300 ml water and CD (0, 20, 40 and 80 larvae/300 ml water. Treatments that exerted the most contrasting values of larval performance were recreated in a second experiment consisting of single-female oviposition site selection assay. Results Development time decreased as food concentration increased, except from 7.2 mg to 20.0 mg (Two-Way CR ANOVA Post-Hoc test, P > 0.1. Development time decreased also as conspecific density increased from zero to 80 larvae (Two-Way CR ANOVA Post-Hoc test, P . Combined, these results support the role of density-dependent competition for resources as a limiting factor for mosquito larval performance. Oviposition assays indicated that female mosquitoes select for larval habitats with conspecifics and that larval density was more important than diet in driving selection for oviposition sites. Conclusions This study supports predictions of the P-P hypothesis and provides a mechanistic understanding

  8. Efficacy of eco-smart insecticides against certain biological stages of jasmine moth, Palpita unionalis Hb.(Lepidoptera: Pyralidae

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    Mahmoud Farag Mahmoud

    2014-03-01

    Full Text Available The efficacy of six eco-smart insecticides, Dipel 2x 6.4% WP (Bacillus thuringensis AI, Biofly 100% WP (Beauvaria bessiana AI, Radiant 12% SC (Saccharopolyspora spinosa AI, Mectin 1.8% EC (Streptomyces avermitilis AI, Nimbecidine 0.03% EC (Azadirachtin AI and Bio-Power 50% EC (Beauvaria bessiana AI, were tested against eggs, larvae and pupae of the jasmine moth, Palpita unionalis Hb. and its parasitoid Apanteles syleptae under laboratory conditions. Data indicated that all tested insecticides had ovicidal activity against P. unionalis. Mectin was the most toxic among the tested insecticides against the egg stage, followed by Radiant or Dipel 2x, and their respective values of LC50 were 0.005 cm/l, 0.006 cm/l and 0.055 g/l. Dipel 2x was the most toxic insecticide to the 1st instar larvae of P. unionalis, whereas Mectin was the most toxic to both the 3rd and 5th instar larvae. Also, the results revealed that Mectin was the most effective against the pupal stage, followed descendingly by Radiant and Dipel 2x. The toxicity index values showed a superior efficiency of Mectin at LC50 (100% against eggs, 3rd and 5th instar larvae, and pupal stage, whereas Dipel 2x showed such superior efficiency at LC50 (100% only against 1st instar larvae. The results showed that the percents of pupation and emergence of moths were significantly different in all treatments compared to control, while deformed pupae and malformed adults were insignificantly different when fifth instar larvae were treated with the tested insecticides. Moreover, the rate of P. unionalis adult emergence from treated pupae was concentration-dependent and significant differences were found between insecticide treatments and control. Generally, Mectin, Radiant and Dipel 2x caused the highest impacts on adult emergence and malformed adults percentages. Regarding the toxicity of insecticides to the endoparasitoid A. syleptae, the treated cocoons developed to adult stages with no significant

  9. Development of Metarhizium anisopliae and Beauveria bassiana formulations for control of malaria mosquito larvae

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    Takken Willem

    2011-02-01

    Full Text Available Abstract Background The entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana have demonstrated effectiveness against anopheline larvae in the laboratory. However, utilising these fungi for the control of anopheline larvae under field conditions, relies on development of effective means of application as well as reducing their sensitivity to UV radiation, high temperatures and the inevitable contact with water. This study was conducted to develop formulations that facilitate the application of Metarhizium anisopliae and Beauveria bassiana spores for the control of anopheline larvae, and also improve their persistence under field conditions. Methods Laboratory bioassays were conducted to test the ability of aqueous (0.1% Tween 80, dry (organic and inorganic and oil (mineral and synthetic formulations to facilitate the spread of fungal spores over the water surface and improve the efficacy of formulated spores against anopheline larvae as well as improve spore survival after application. Field bioassays were then carried out to test the efficacy of the most promising formulation under field conditions in western Kenya. Results When formulated in a synthetic oil (ShellSol T, fungal spores of both Metarhizium anisopliae and Beauveria bassiana were easy to mix and apply to the water surface. This formulation was more effective against anopheline larvae than 0.1% Tween 80, dry powders or mineral oil formulations. ShellSol T also improved the persistence of fungal spores after application to the water. Under field conditions in Kenya, the percentage pupation of An. gambiae was significantly reduced by 39 - 50% by the ShellSol T-formulated Metarhizium anisopliae and Beauveria bassiana spores as compared to the effects of the application of unformulated spores. Conclusions ShellSol T is an effective carrier for fungal spores when targeting anopheline larvae under both laboratory and field conditions. Entomopathogenic fungi formulated with

  10. A Simple Rearing Method for Bradysia odoriphaga%韭菜迟眼蕈蚊的简易人工饲养方法

    Institute of Scientific and Technical Information of China (English)

    许静杨; 谷希树; 徐维红; 白义川; 陈俊荣; 胡霞

    2014-01-01

    本研究通过自制的饲养器具,建立了饲养韭菜迟眼蕈蚊的简易方法。将野外采集的幼虫饲养在自制装置中,(25±1)℃、相对湿度70%、光暗周期L∶D=16∶8的条件下,用滤纸收集蛹,用葱白片收集卵。采用此法饲养的韭菜迟眼蕈蚊可顺利完成生活史,其孵化率为91.0%~94.2%,幼虫的存活率为86.4%~92.0%,化蛹率为82.0%~87.6%。本方法节省人工和饲养空间,可有效实现韭菜迟眼蕈蚊的人工批量繁殖。本方法能广泛应用于其它根蛆类昆虫的饲养。%A convenient method for rearing Bradysia odoriphaga ( Diptera: Sciaridae ) was conducted . The larvae collected from the field were reared in modified culture dishes .The experiment was performed in an artificial climate chamber with the air temperature of (25 ±1)℃, humidity of 70%and the light-dark cycle of 16∶8 .The pupae were collected with pieces of filter paper .The eggs were collected with welsh onion stalks .Under these conditions , Bradysia odoriphaga could complete life cycle successfully .The hatching rate of eggs was 91.0%~94.2%, the survival rate of larvae was 86.4%~92.0% and the pupation rate was 82 .0%~87 .6%.This method could save labour and rearing space and effectively achieve mass propagation of Bradysia odoriphaga.It also could be used for rearing other root maggots .

  11. Postmortem Attraction of Sarcosaprophagous Diptera to Tramadol-Treated Rats and Morphometric Aspects of the Developed Larvae.

    Science.gov (United States)

    AbouZied, E M

    2016-06-01

    The presence of some specific drugs in animal tissues may affect the time of minimal postmortem intervals estimated during forensic entomological investigations. To test the effects of a specific drug on decomposition, a field study was conducted at Fayoum University campus, Egypt, from March to May 2013, using tramadol, a synthetic analgesic opioid used to treat moderate to severe pain in humans. Albino rats were used as the animal model during this study. The duration of the fresh stage of tramadol treated rat (Ttr) carcasses was significantly shorter (2.4 ± 0.27 days) compared to tramadol free rat (Tfr) carcasses (6.4 ± 0.49 days). The dry carcass stage of Ttr lasted longer (10.3 ± 0.99 days) as compared to (7.4 ± 0.18 days) the Tfr carcass. The decomposition process of the (Ttr) carcass was not significantly faster (24.9 ± 1.58 days) as compared to (Tfr) carcasses (29.5 ± 1.69). Lucilia cuprina (Wiedemann), Chrysomya albiceps (Wiedemann), and Musca domestica L. were less attracted to Ttr carcass-baited traps than traps with Tfr carcasses. However, females of Sarcophaga spp. showed a greater attraction to Ttr carcasses. Females of another sarcophagid fly, Wohlfahrtia spp. exhibited similar attraction tendencies to both types of trap baits. Larvae of S. argyrostoma (Robineau-Desvoidy) collected from Ttr carcasses developed to a significantly longer total body length (10.4 ± 0.04 mm) as compared to the average length of the larvae collected from Tfr carcasses (8.9 ± 0.34 mm). During days 9-13 after rat death, the relative lengths of larvae from Ttr carcasses were not significantly different from Tfr carcasses. Larvae fed on Ttr carcasses pupated 2 days later than the control larvae.

  12. Incidence of fruit flies on coffee and citrus and quarantine treatment of citrus fruits by gamma radiation; Incidencia de moscas-das-frutas em cafe e citros e tratamento quarentenario de frutos citricos com radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Raga, Adalton

    1996-12-31

    The objective of this study was to evaluate the fruit fly infestation on coffee and citrus, and also to determine gamma radiation doses for immature stages of Ceratitis capitata and Anastrepha fraterculus, in order to satisfy quarantine regulations. Coffee arabica varieties Icatu Vermelho, Catuai Amarelo, Mundo Novo and Sarchimor showed the highest infestation indices (pupa/berry): 0.53; 0,41; 0.33 and 0.36. respectively Icatu Vermelho and Catuai Vermelho showed the highest values of pupa/berry weight (0.49 and 0.39, respectively), and Robusta (Coffea canephora) presented the lowest index (0.01). The following fruit flies were found in coffee berries: C. capitata (76.6%) Anastrepha spp. (7.4%) and Lonchaeidae (17.0%). In area near coffee plantation, fruit fly infestation indices in sweet oranges were of 4.77 larvae/kg and 0.55 larva/fruit. The infestation indices for sweet orange, collected from five regions of the State of Sao Paulo ranged from 0.73 to 7.60 pupa/kg and 0.12 to 1.27 pupa/fruit. The same species of fruit flies were found in oranges. In the case of C. capitata eggs with 24-48 hours old, 20 Gy prevented completely adult emergence (artificial diet and orange). No emergence of adult occurred when C. capitata larvae of third instar were irradiated at 20 Gy in their rearing medium. But at 25 Gy, the number of adults was reduced by 54% and 97% from larval infestation in oranges and grapefruit, respectively. A dose of 30 Gy was required to prevent medfly emergence from third instar larvae in grapefruit. A dose of 15 Gy was required for third instar, to prevent adult emergence of A. fraterculus. No adult emerged from C third instar, to prevent adult emergence of A. fraterculus. No adult emerged from C capitata pre-pupa irradiated at 30 Gy. One medfly adult emerged from pupa (3-4 days after pupating) irradiated at 120 Gy. At the same dose, sixteen A. fraterculus adults emergency from irradiated pupa with 5-6 days old. (author) 85 refs., 2 figs., 13 tabs.

  13. Transcriptome analysis of the painted lady butterfly, Vanessa cardui during wing color pattern development.

    Science.gov (United States)

    Connahs, Heidi; Rhen, Turk; Simmons, Rebecca B

    2016-03-31

    Butterfly wing color patterns are an important model system for understanding the evolution and development of morphological diversity and animal pigmentation. Wing color patterns develop from a complex network composed of highly conserved patterning genes and pigmentation pathways. Patterning genes are involved in regulating pigment synthesis however the temporal expression dynamics of these interacting networks is poorly understood. Here, we employ next generation sequencing to examine expression patterns of the gene network underlying wing development in the nymphalid butterfly, Vanessa cardui. We identified 9, 376 differentially expressed transcripts during wing color pattern development, including genes involved in patterning, pigmentation and gene regulation. Differential expression of these genes was highest at the pre-ommochrome stage compared to early pupal and late melanin stages. Overall, an increasing number of genes were down-regulated during the progression of wing development. We observed dynamic expression patterns of a large number of pigment genes from the ommochrome, melanin and also pteridine pathways, including contrasting patterns of expression for paralogs of the yellow gene family. Surprisingly, many patterning genes previously associated with butterfly pattern elements were not significantly up-regulated at any time during pupation, although many other transcription factors were differentially expressed. Several genes involved in Notch signaling were significantly up-regulated during the pre-ommochrome stage including slow border cells, bunched and pebbles; the function of these genes in the development of butterfly wings is currently unknown. Many genes involved in ecdysone signaling were also significantly up-regulated during early pupal and late melanin stages and exhibited opposing patterns of expression relative to the ecdysone receptor. Finally, a comparison across four butterfly transcriptomes revealed 28 transcripts common to all

  14. Control Effectiveness of Insect Growth Regulators on Tribolium castaneum%两种昆虫生长调节剂对赤拟谷盗的控制效果

    Institute of Scientific and Technical Information of China (English)

    陈雅群; 谢令德; 张建珍; 贺艳萍; 何君; 陈春武

    2012-01-01

    选取氟啶脲( Chlorfluazuron)和灭幼宝(Pyriproxyfen)两种昆虫生长调节剂对储藏物害虫赤拟谷盗进行了控制效果的研究.结果表明,在40、20、10 mg/kg剂量下,氟啶脲对赤拟谷盗幼虫有较高的校正死亡率,依次为94.44%、88.89%、83.33%,幼虫均不能化蛹,表明该药剂可能作用于几丁质合成酶,抑制了几丁质合成酶的活性.在相同浓度下,灭幼宝对赤拟谷盗幼虫没有明显的致死效果,但其能延长赤拟谷盗幼虫的发育历期,使其不能正常化蛹,最终导致畸形死亡,表明灭幼宝有类似保幼激素的作用.%The paper study the control effectiveness of two IGRs, Chlorfluazuron and Pyriproxyfen to Tribolium castaneum, a main insect pest occurring in stored product. The result showed that Chlorfluazuron had a high mortality rate on Tribolium castaneum larva, which is 94.44% ,,88. 89% ,,83. 33% corresponding to the concentration of 40,20, 10 mg/kg. ,and make them pupate hardly,so Chlorfluazuron had significant death effect on Tribolium castaneum larva , and it acted on chitin synthase, inhibiting the activity of chitin synthase. Pyriproxyfen didn't have obvious death effect on Tribolium castaneum at the same concentration as Chlorfluazuron, but Pyriproxyfen can delay the development of Tribolium castaneum larva, affect their normal pupa, and eventually cause their deformity death. The result preliminary shows that Pyriproxyfen has similar function as juvenile hormones.

  15. Effects of dietary cadmium in larval stage on fecundity and gonad development of Boettcherisca peregrine ( Diptera: Sarcophagidae)%幼虫期染镉对棕尾别麻蝇繁殖力及生殖腺发育的影响

    Institute of Scientific and Technical Information of China (English)

    高熹; 朱家颖; 吴国星; 杨彦伟; 李强

    2011-01-01

    For evaluating the effects of dietary cadmium (Cd) on fecundity and gonad development of Boettcherisca peregrine, newly oviposited larvae of the fly were exposed to various administered concentrations in the artificial diet until pupation under laboratory conditions, and some parameters were observed and analyzed. The results indicated that the lifespan and survival rate of adults decreased obviously when they exposed to various concentrations (100, 200, 400 and 800 μ/g ) in their larval stage, but mating rate had no distinct influence. Quantity of eggs containing correlated to the concentration of female adult contacted. If they contacted higher concentration in larval stage, the lower eggs in their ovaries we would found. Moreover, with increasing of dietary Cd concentration, the genital organs coefficient became lighter, the length and width of testis and ovary became shorter.%通过在饲料中添加重金属镉(Cd)饲喂棕尾别麻蝇Boettcherisca peregrine的幼虫,研究镉对其成虫繁殖能力和生殖腺发育的影响.结果表明,棕尾别麻蝇幼虫在取食含100 μg/g、200 μg/g、400 μg/g和800 μg/g Cd2的人工饲料后,成虫的羽化率和寿命都明显下降;但镉处理对成虫的交配率无显著影响,雌成虫的卵巢含卵量与雌虫是否在幼虫期取食镉有关,雌虫在幼虫阶段接触到的镉浓度越高,含卵量越低.成虫生殖腺的发育也与幼虫期接触到的镉浓度相关,镉浓度越高,精巢和卵巢的长度就越短,生殖器系数也越小.

  16. Study on Biological Characteristics of Papilio machaon Linnaeus*%金凤蝶生物学特性研究

    Institute of Scientific and Technical Information of China (English)

    张建化; 戴仁怀

    2011-01-01

    通过不同恒温条件下饲养金凤蝶Papilio machaon Lirnaeus以研究其生长发育.结果表明,金凤蝶卵、幼虫和蛹的发育历期均与温度呈直线关系,发育起点温度分别为8.32℃、9.11℃和8.95℃,有效积温分别为79.39d·℃、297.99 d·℃和182.47d·℃;16℃条件下蛹滞育.9月份起室内常温条件下金凤蝶卵、幼虫和蛹的发育历期分别为(2.98±1.04)d、(21.84±2.67)d和(22.52±12.52)d;孵化率、化蛹率和羽化率分别为66.13%、55.28%和95.59%;绿色蛹占91.18%,明显高于褐色蛹;蛹质量(1.05±0.16)g,成虫性比(♀/♂)为0.97.%Development of P. machaon Linnaeus under different temperatures was investigated in the current work. The results indicated that the relationship between the development periods of egg, larva, pupa and temperatures was in linear form, the threshold temperatures and the effective accumulative temperature for egg, larva, pupa were 8.32℃, 9.11 ℃, 8.95 ℃ and 79.39, 297.99, 182.47 degree days, respectively.Pupae began to diapause under 16℃. From September, developmental periods of egg, Larva and pupa were (2.98 ± 1.04), (21.84 ± 2.67 ) and (22.52 ± 12.52 ) days, respectively, and the rates of hatchability,pupation and emergence were 66.13% , 55.28% and 95.59% respectively. The percentage of green pupae was 91.18% , and obviously higher than that of brown pupae. The pupal weight was ( 1.05 ±0.16) g, and the sex ratio ( ♀/♂ ) was 0.97.

  17. The capacity of a Myrmica ant nest to support a predacious species of Maculinea butterfly.

    Science.gov (United States)

    Thomas, J A; Wardlaw, J C

    1992-08-01

    Caterpillars of Maculinea arion are obligate predators of the brood of Myrmica sabuleti ants. In the aboratory, caterpillars eat the largest available ant larvae, although eggs, small larvae and prepupae are also palatable. This is an efficient way to predate. It ensures that newly-adopted caterpillars consume the final part of the first cohort of ant brood in a nest, before this pupates in early autumn and becomes unavailable as prey. At the same time, the fixed number of larvae in the second cohort is left to grow larger before being killed in late autumn and spring. Caterpillars also improve their feeding efficiency by hibernating for longer than ants in spring, losing just 6% of their weight while the biomass of ant larvae increases by 27%. Final instar caterpillars acquire more than 99% of their ultimate biomass in Myrmica nests, growing from 1.3 mg to an estimated 173 mg. A close correlation was found between the weights of caterpillars throughout autumn and the number of large ant larvae they had eaten. This was used to calculate the number of larvae eaten in spring, allowing both for the loss of caterpillar weight during winter and the increase in the size of their prey in spring. It is estimated that 230 of the largest available larvae, and a minimum nest size of 354 M. sabuleti workers, is needed to support one butterfly. Few wild M. sabuleti nests are this large: on one site, it was estimated that 85% of nests were too small to produce a butterfly, and only 5% could support two or more. This prediction was confirmed by the mortalities of 376 caterpillars in 151 wild M. sabuleti nests there. Mortalities were particularly high in nests that adopted more than two caterpillars, apparently due to scramble competition and starvation in autumn. Survival was higher than predicted in wild nests that adopted one caterpillar. These caterpillars seldom exhaust their food before spring, when there is intense competition among Myrmica for nest sites. Ants often desert

  18. Influence of photoperiod on body weight and depth of burrowing in larvae of Chrysomya megacephala (Fabricius (Diptera, Calliphoridae and implications for forensic entomology A influência do fotoperíodo no peso corpóreo e na profundidade de enterramento em larvas de Chrysomya megacephala (Fabricius (Diptera, Calliphoridae e as implicações para entomologia forense

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    Leonardo Gomes

    2006-03-01

    Full Text Available Blowflies use discrete, ephemeral breeding sites for larval nutrition. After exhaustion of the food supply, the larvae disperse in search of sites to pupate or to seek other sources of food in a process known as post-feeding larval dispersal. In this study, some of the most important aspects of this process were investigated in larvae of the blowflies Chrysomya megacephala exposed to a variety of light: dark (LD cycles (0:0 h, 12:12 h and 24:0 h and incubated in tubes covered with vermiculite. For each pupa, the body weight and depth of burrowing were determined. Statistical tests were used to examine the relationship of depth of burrowing and body weight to photoperiod at which burrowing occurred. The study of burial behavior in post-feeding larval dispersing can be useful for estimating the postmortem interval (PMI of human corpses in forensic medicine.Moscas-varejeiras usam substratos discretos e efêmeros para nutrição larval. Após a exaustão do suprimento de comida, as larvas dispersam na procura por locais para pupação na outros recursos de alimento em um processo conhecido como dispersão larval pós- alimentar. Nesse estudo, alguns dos aspectos mais importantes desse processo foram investigados em larvas de moscas-varejeiras Chrysomya megacephala expostas a uma variação de ciclos luz: escuro (LD (0:24h, 12:12h e 24:0h e incubadas em tubos cobertos com vermiculita. Para cada pupa, o peso corpóreo e a profundidade de enterramento foram determinados. Testes estatísticos foram usados para examinar a relação entre profundidade de enterramento e o peso corpóreo e o fotoperíodo a que esse enterramento ocorreu. O estudo do comportamento de enterramento na dispersão larval pós-alimentar pode ser útil para estimar o intervalo pós-morte (IPM em cadáveres humanos em medicina forense.

  19. Comparison of the developmental and morphological characteristics of non-, winter- and summer-diapausing pupae of the onion maggot, Delia antiqua ( Diptera : Anthomyiidae)%葱蝇非滞育、冬滞育和夏滞育蛹发育和形态特征比较

    Institute of Scientific and Technical Information of China (English)

    黎万顺; 陈斌; 何正波

    2012-01-01

    maggot Delia antiqua as the model species through anatomic and photographed observation and measurement, with emphasis on the head evagination- and diapause-related characteristics. The study aims to understand the differences of developmental and morphological characteristics of ND, WD and SD pupae, and lays a morphological base for the distinguishment of diapause developmental stage and study of diapause molecular mechanism. The developmental durations of pre-diapause, diapause and post-diapause of WD pupae were 4, 85 and 27 d, respectively, while those for SD pupae were 2, 8 and 22 d, respectively. The pre-diapause begins at the pupation stage, and ends when the free fat body appears in the central area of eyes, which happens 10 h after the completion of head evagination. The completion of head evagination is the premise of diapause occurrence, the head evagination of ND, SD and WD pupae happened at 48, 36 and 83 h after pupation, and there was no morphological difference observed in the developmental process of head evagination between these three kinds of pupae. During the process of head evagination, firstly, the head capsule and thoracic appendages turned out from thorax capsule, and the head got to the location and shape of matured pupae; then, the abdominal muscles continued contraction to push the haemolymph and fat body into the head capsule and thoracic appendages. The pupae entered SD and WD when approximate 15% total effective accumulated temperature was obtained at the pupal stage. In the duration of diapause, the pupal morphology remained in the form of the appearance of free fat body in the central area of eyes, and no difference was observed between these two kinds of diapausing pupae in morphology in the diapause stage. The WD pupae had the largest body length, width and weight, followed by SD pupae and then ND pupae. At the post-diapause stage, malpighian tubules of ND pupae were green and clearly visible during the existence of the yellow body

  20. Influence of Incubation Temperature on Expression of Diapause Hormone Receptor Genes in Bivoltine Bombyx mori Variety and Structural Features of the Gene%催青温度对家蚕二化性品种滞育激素受体基因表达的影响及基因的结构特征

    Institute of Scientific and Technical Information of China (English)

    王力刚; 宋海韬; 黄勇; 汪生鹏; 唐顺明; 赵巧玲; 沈兴家

    2011-01-01

    Diapause of bivoltine silkworm ( Bombyx mori) eggs is influenced by the living environment of their parenta generation. When bivoltine silkworm eggs (parental generation) are incubated at 25 ℃ in lightness, the moths will lay diapause eggs. In contrast, when the eggs are incubated at 15 ℃ in darkness, the moths will lay non-diapause eggs.For probing into the molecular mechanism of how incubation temperature regulates diapause in bivoltine silkworm,bioinformatic analysis was carried out on the 5 cDNAs of diapause hormone receptor gene, namely Bmdhr cDNA-1 to Bmdhr cDNA-5, which were cloned from the ovary of B.mori. The results showed that these 5 cDNAs of Bmdhr gene were from the same mRNA transcript through different splicing patterns. Among them, Bmdhr cDNA-1 and Bmdhr cDNA-2 encoded the same amino acid sequence. Amino acid sequence encoded by Bmdhr cDNA-4 had 99.2%identity with that of BmDHR-1. Eggs of bivoltine silkworm strain Qiufeng were divided into two groups with the half-egg batch method. One group was incubated at 15℃ in darkness and the other at 25℃ in lightness, respectively. By using real-time fluorescent quantitative PCR, the influences of incubation temperature on the transcription of Bmdhr mRNA were analyzed in different developmental stages and in various tissues. The results showed that; Bmdhr mRNA-1 was expressed mainly in ovaries of pupae and its mRNA level quickly reached the peak level at day 4 after pupation during which the pupae were most sensitive to diapause hormone, and the peak mRNA level of the group incubated at 25 ℃ was significantly higher than that incubated at 15 ℃. Bmdhr mRNA-4 was expressed mainly in hemolymph of silkworm at various developmental stages. Especially, its expression level from incubation at 25 ℃ in lightness was 7. 7 times to that at 15 ℃ in darkness, implying that BmDHR-4 might be a key factor determining whether the next generation eggs fall into diapause. Expression level of Bmdhr mRNA-5 was

  1. Análisis del Voltinismo y la Diapausa en Poblaciones de Apagomerella versicolor (Coleoptera: Cerambycidae en el Gradiente Latitudinal de su Distribución en la Argentina Voltinism and Diapause in Populations of Apagomerella versicolor (Coleoptera: Cerambycidae in the Distribution of its Latitudinal Gradient

    Directory of Open Access Journals (Sweden)

    Guillermo Logarzo

    2005-12-01

    between 25 and 39 o S. Studies conducted in Buenos Aires (35 o S indicated that A. versicolor is univoltine and has a winter diapause, and also indicate that diapuse larvae exposed to low temperatures broke the diapuse. However, some observations suggested that populations from northern Argentina could be bi or multivoltine and did not diapause. The voltinism and the diapause of A. versicolor were studied along its latitudinal distribution, between 25 and 32 o S. We conducted an experiment to identify diapause presence; larvae collected at different latitudes were separate in two groups, one of them were exposed to low temperatures to break the diapause, the other one was control. Those diapausing larvae that received cold treatment should pupate in a shorter time than those that did not receive it. In addition, ten collecting trips were made in January, March, July, August, October and December in different years in the study area to observe the immature stages present in its main hosts, Pluchea sagittalis Cabr. and Xanthium cavanillesii Schouw, at different latitudes. It was found evidence that A. versicolor is at least bivoltine between 25 º and 27 o S, and it does diapause at latitudes over 31 o S. The influence of the biology of the host plants on voltinism and diapause is discussed here.

  2. Effects of Transgenic crylAh Corn Pollen on Growth and Development and Adult Mobility in Propyleajaponica (Thunberg) (Coleoptera: Coccinellidae)%转crylAh基因玉米花粉对龟纹瓢虫生长发育和成虫移动能力的影响

    Institute of Scientific and Technical Information of China (English)

    崔蕾; 王振营; 何康来; 白树雄

    2011-01-01

    本文利用花粉饲喂法研究了转crylAh基因玉米花粉对龟纹瓢虫Propyleajaponica生长发育及成虫移动能力的影响。结果显示,与混有适量蚜虫的非转基因亲本对照玉米花粉(花粉与蚜虫重量比为2:1)相比,龟纹瓢虫幼虫取食混有适量蚜虫的转crylAh基因玉米花粉(花粉与蚜虫重量比为2:1)后,幼虫总发育历期、蛹期和成虫寿命均无显著差异,但l、3和4龄幼虫的发育历期显著高于对照,2龄幼虫的发育历期显著低于对照;2龄和4龄幼虫的存活率与对照无显著差异,但3龄幼虫的存活率显著增加;幼虫取食Bt花粉对该虫的蛹重、羽化率和雌雄比与对照无显著差异。幼虫期取食Bt玉米花粉而成虫期取食蚜虫对成虫的日产卵量无不利影响,与对照无显著差异。幼虫取食Bt玉米花粉羽化后雄虫和雌虫的步速和翻跃时间与对照均无显著差异。%Laboratory feeding experiments were carried out to study effects of Bt corn pollen expressing crylAh toxin on the growth and development and adult mobility of Propyleajaponica. Larvae of P.japonica were fed with transgenic crylAh corn pollen mixed with a certain proportion of the grain aphid Sitobion avenae, and non Bt corn pollen with a certain proportion orS. avenae, respectively. Parameters of growth, reproduction and adult mobility of P. japonica were assessed under laboratory condition. Results showed that developmental time of the 1st, 3rd and 4th instar larvae fed on Bt com pollen with aphid was significantly longer, and that of the 2nd instar larvae was significantly shorter than that of the control. However, there were no significant differences in the developmental time of total duration of larval development, pupation and longevity of the adults between Bt and non-Bt corn pollen treatments. The survival rate of the 3rd instar larvae fed on Bt corn pollen with aphid was significantly higher than that of the control

  3. História natural da mariposa Chlamydastis smodicopa (Meyrick (Lepidoptera, Elachistidae, Stenomatinae Natural history of the moth Chlamydastis smodicopa (Meyrick (Lepidoptera, Elachistidae, Stenomatinae

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    Helena C. Morais

    2005-09-01

    and found 38 species of lepidopteran larvae on 26% of the examined plants. Despite the fact that C. smodicopa is the most common species found on the host, it occurred only on 7% of the inspected plants. In the last instars they present a dark chestnut head, a brownish prothoracic shield with a yellow stripe in the anterior margin, a body integument that is grayish with brownish transverse stripes, brownish-yellow dorsolateral stripes, and they can attain up to 30 mm in length. Larvae are solitary and build an ovoid shelter by attaching two leaves together with silk, but leave both extremities open: one is used for feeding, and the other one for frass deposition. New shelters are built as they grow or when the leaves become senescent. Larvae in the last instar build a cocoon inside the shelter, where the pupal stage occurs, and under laboratory conditions the mean pupation time was 18 days. Their larvae had the highest frequency of occurrence from August to September, the final months of the dry season in the cerrado.

  4. Biology of Bazaria dulanensis and toxicity of four pesticides in the laboratory%都兰钝额斑螟的生物学特性及四种杀虫剂的室内毒力测定

    Institute of Scientific and Technical Information of China (English)

    严林; 邓晓青; 张永军; 杜艳丽

    2011-01-01

    Bazaria dulanensis Du et Yan is an important pest of the shrub Nitrada tangutorum Bohr. in the southern Tsaidam Basin. Field and laboratory experiments were carried out to investigate the biology of B. dulanensis, and toxicity tests were run to determine the potential of four pesticides; alpha-cypermethrin, Neichanjian, avermectins and Caoduer to control this pest. The results show that this moth is univoltine in the Tsaidam Basin with five larval instars. The pupae overwinter in soil and adults emerge the following May. Mating and copulation were often observed during the first third of June, whereas the hatching of eggs occurred in late June. The larval stage occurred from mid-June to late-August, and larvae pupated from mid to late August. Mid to late July is the critical time for control of early-stage larvae. The relative ingested toxicity of the 4 insecticides with respect to 4th instar larvae was, in descending order, alpha-cypermethrin >avermectias > Pseudomonas pseudoalcaligenes > Gynaephora ruoergensis Nuchear polyHedrosis rims, and, for 5th instar larvae; alpha-cypermethrin > Pseudomonas pseudoalcaligenes > avermectins > Gynaephora ruoergensis Nuchear polyHedrosis rirus. The relative contact toxicity to 4th instar larvae was avermectins > Pseudomonas pseudoalcaligenes >alpha-cypermethrin > Gynaephora ruoergensis Nuchear polyHedrosis rirus, and for 5th instar larvae; Pseudomonas pseudoalcaligenes > avermectins > alpha-cypermethrin > Gynaephora ruoergensis Nuchear polyHedrosis rirus.%都兰钝额斑螟Bazaria dulanensis Du et Yan是柴达木盆地南部地区唐古特白刺(Nitrada tangutorum Bobr.)灌丛的主要害虫之一.为有效控治该害虫对唐古特白刺的危害,本研究采用室内饲养和田间定点观察,对其生物学特性进行观察,结果表明:都兰钝额斑螟在柴达木盆地一年发生1代,幼虫共5龄,以滞育蛹越冬,翌年5月下旬越冬成虫开始羽化,6月上旬为交配、产卵盛期,6

  5. Performance of Anastrepha obliqua (Diptera, Tephritidae larvae fed on artificial diets Desempenho das larvas de Anastrepha obliqua (Diptera, Tephritidae alimentadas com dietas artificiais

    Directory of Open Access Journals (Sweden)

    Tânia M. L. Fontellas-Brandalha

    2010-06-01

    was to determine the effect on the Anastrepha obliqua (Macquart, 1835 larvae performance of different kinds and amounts of carbohydrates in the diet. Larvae were individually reared until pupation in test tubes containing one of the artificial diets to be tested. The basic composition of the diets to be tested included 2.5 g agar, 3.25 g brewer's yeast and several different amounts of flour and sucrose. The suitability of the artificial diet for A. obliqua was tested evaluating the larvae and pupae survival (% and the larvae, pupae and larvae-adults periods of development. The diet containing flour (2 g and sucrose (2 g and the diet containing only sucrose (5.5 g have shown the best results regarding larval performance. All tested diets presented similar or superior results as compared to diets used in other studies. The importance of flour and its nutritional value for the larvae was discussed.

  6. Atividade inseticida in vitro do óleo de sementes de nim sobre Lutzomyia longipalpis (Diptera: Psychodidae In vitro insecticidal activity of seed neem oil on Lutzomyia longipalpis (Diptera: Psychodidae

    Directory of Open Access Journals (Sweden)

    Michelline V. Maciel

    2010-03-01

    Full Text Available Lutzomyia longipalpis é o principal vetor da Leishmaniose visceral no Brasil. O objetivo deste trabalho foi avaliar o efeito do óleo de sementes de nim (Azadirachta indica sobre ovos, larvas e adultos do vetor. Os insetos foram capturados no campo e mantidos no laboratório a ± 27 °C e 80% de umidade relativa. Cinco tratamentos com diferentes concentrações foram realizados, usando-se dois controles negativos, um com água destilada e outro com Tween 80 (3% e um controle positivo com cipermetrina. Os ovos foram borrifados com o óleo em diferentes concentrações e avaliou-se o número de larvas eclodidas por 10 dias consecutivos. A mortalidade das larvas foi observada até a pupação, e a mortalidade dos adultos foi observada após 24, 48, e 72 horas. A análise estatística foi feita pelo teste de Tukey a 5% de probabilidade. No teste com ovos, a maior concentração obteve 65,16 ± 3,24% de eficácia. O teste com larvas apresentou 67,75 ± 2,21% de eficácia na concentração de 100 mg.mL-1. Com adultos, a eficácia na concentração de 100 mg.mL-1 foi de 96,64 ± 4,11%, após 24 horas. A análise fitoquímica revelou a presença de triterpenos. Esses resultados demonstram o potencial uso desse óleo no controle deste vetor.Lutzomyia longipalpis is the main vector of visceral leishmaniasis in Brazil. The objective was to evaluate the effect of oil from (Azadirachta indica neem seeds on eggs, larvae and adults of the vector. The insects were captured in the field and kept in the laboratory at ± 27 °C and 80% relative humidity. Five treatments with different concentrations were performed using two negative controls (distilled water and Tween 80 and a positive control. The eggs were sprayed with the oil at different concentrations and the number of hatched larvae evaluated for 10 days. Mortality of larvae was observed to pupation and adult mortality was observed after 24, 48, and 72 hours. Statistical analysis was performed by Tukey test

  7. Eclosion time and larval behavior of the tomato fruit borer, Neoleucinodes elegantalis (Guenée (Lepidoptera: Crambidae Tempo de eclosão e comportamento de larvas da broca-pequena-do-tomateiro, Neoleucinodes elegantalis (Guenée (Lepidoptera: Crambidae

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    Alvaro E. Eiras

    2003-02-01

    Full Text Available In several regions of Brazil, Neoleucinodes elegantalis (Guenée is one of the most serious tomato pests. The moth lays eggs on the calyx or developing fruit, and shortly after eclosion larvae penetrate into the fruit, where they remain until pupation. Once larvae have entered the fruits, insecticides and biological control agents are relatively ineffective. Because N. elegantalis is most susceptible to conventional treatments when the larvae are outside the host tissues (or fruit, it would be advantageous to know the time required for egg development and the length of time that the larvae spend on the surface of the fruit. To answer these questions detailed behavioral studies were untaken. Eggs were collected from the field and maintained in an environmental chamber at 20°C, 75 ± 5% R.H., and a 12L:12D photoperiod. The time of egg eclosion was recorded with a video camera, whereas larval behavior and time required to enter the fruit were determined by direct observations. The majority of eggs (93% hatched within the first two hours after the beginning of photophase. Larvae spent 51.1 ± 31.1 (mean ± SEM min on the surface of the fruits. Once a suitable site was identified, larvae required an additional 23.8 ± 19.4 min to completely enter the fruit. Eighty-six percent of the larvae were successful in penetrating the fruit. Of the larvae that bored into the fruit, 42% selected the upper portion, 18% selected the middle portion, and 40% selected the lower portion.Neoleucinodes elegantalis (Guenée é uma das pragas mais sérias do tomate em várias regiões do Brasil. A fêmea deposita seus ovos no cálice ou nos frutos em desenvolvimento, e logo após a eclosão a larva penetra no fruto, onde permanece até a pupação. Depois que a larva entra no fruto, inseticidas e agentes de controle biológico são relativamente ineficazes. Como N. elegantalis é mais suscetível a métodos de controle quando a larva encontra-se no exterior do hospedeiro

  8. 枣实蝇产卵选择习性研究%Oviposition preference of ber fruit fly

    Institute of Scientific and Technical Information of China (English)

    胡陇生; 朱银飞; 齐长江; 任玲; 田呈明

    2012-01-01

    通过枣实蝇产卵选择习性研究,发现枣实蝇喜欢产卵于枣果的背阴面及底部,其产卵孔周围呈现凹陷或瘤状凸起症状,且对不同品种枣果的产卵选择性不同,‘鸡心枣’、‘骏枣’对枣实蝇的抗性大于‘梨枣’、‘灰枣’和‘相枣’;枣果受伤害程度越重,产卵量就越少;不同大小的枣果均受到危害,且以中型果受害最为严重;随枣果成熟度的增加其产卵量逐渐减少,且不产卵于完全红的枣果上.同时枣实蝇对枣、海棠果、青杏、番茄、葡萄等不同寄主的产卵选择性均存在显著性差异,但更喜欢产卵于枣果.胁迫性寄主试验中不同寄主果实的产卵量存在显著差异,但枣果与杏之间的产卵量差异不明显,而且枣实蝇可以在杏果中化蛹并羽化.%The ber fruit fly Carpomya vesuviana Costa preferred to oviposit on the shades and bottom of jujube based on our study on oviposition preference. The oviposition aperture showed hollow and lump-like shapes. It was showed that the ber fruit fly had different ovipositional selection to different varieties of jujube. The 'Jix-inzao' jujube and ' Junzao' jujube were less severely damaged than ' pear jujube', ' grey jujube' and ' Xiang jujube' . It ovipositional selection decreased as the extent of damage increased. The ber fruit fly's harms to the jujube differed depending on jujube size. The medium-sized jujube was more hurtful than others. Its ovipositional selection decreased as the maturing stage of the jujube increased. The ber fruit fly showed no ovipositional selection at full maturity. The jujube was more hurtful than others and had significant difference in oviposition preference for jujube, Beijing flowering crab, apricot, tomato and grape. No significant difference existed between jujube and apricot, but significant difference existed in oviposition preference between different species of hosts. The ber fruit fly could pupate and eclose on the

  9. The Return of the Blue Butterfly

    Science.gov (United States)

    Santos, Anabela

    2014-05-01

    laying eggs. Each female lays an average of 60 eggs. Larva must grow in a plant near an anthill of Myrmica aloba species. This is important because butterfly larvae are myrmecophilous, living with ants that feed the butterfly larvae for 11 months, because the ants think the butterfly larvae are ant larvae. In early summer the larvae pupate in the nest of ants. Before expanding their wings, they have to leave quickly to avoid being killed by ants when the ants discover have been deceived. My students became aware of this research; we studied and prepared in order to carry out fieldwork. Thus students learn the content and curricular in a scientifically fun way, first with group work in the classroom with my guidance and in a second stage carry knowledge to the field under the guidance of Dra Paula Seixas Arnaldo. We know where we started ... where we arrives is success!

  10. Evaluation of insecticidal potentialities of extracts from Calotropis procera Ait. against Henosepilachna elaterii Rossi%牛角瓜(Calotropis procera Ait.)提取物对非洲瓜瓢虫(Henosepilachna elaterii Rossi)的杀虫潜能评价

    Institute of Scientific and Technical Information of China (English)

    Umsalama A.M.AHMED; Nabil H.H.BASHIER; 施祖华

    2006-01-01

    The extractive methods and bioactivity of the extracts from different parts of Calotropis procera was evaluated against African melon ladybird beetle, Henosepilachna elaterii in laboratory.Soxhlet method yielded more extracts than electric shaker method. Leaf produced more extracts than flower and root. Leaf extracts showed stronger bioactivity than those from flowers and roots. The extracts gave complete feeding repellency to the newly hatched larvae. All larvae in fourth instar forced to feed on extract-treated pumpkin leaf died without pupation. Topical application of the extracts from leaves and flowers to the fourth instar larvae increased larval and subsequent pupal mortality of the pest and produced more abnormal adults compared to the control. However, if larvae were forced to feed on extract-treated pumpkin leaf for 2 days only, and then provided with untreated leaf, they were still able to complete their life cycle; their fecundity and life span for the adults resulted from the treatment were not reduced compared to those from the control.%室内评价了牛角瓜(Calotropis procera Ait.)提取物对非洲瓜瓢虫(Henosepilachna elaterii Rossi)的生物活性及提取方法.结果表明,浸泡提取法的提取效率显著比电动振荡提取法高;植物的不同部分提取效率存在显著差异,以叶最高,花次之,根最低;叶提取物的生物活性高于花和根;初孵的幼虫不取食牛角瓜叶、花和根提取物处理过的南瓜叶;用提取物处理过的南瓜叶饲养4龄幼虫,幼虫不能化蛹就死亡;4龄幼虫前胸背板点滴牛角瓜叶或花提取物试验表明,点滴处理后幼虫的死亡率、随后的蛹死亡率和羽化的畸形成虫比例增加.但4龄幼虫先用牛角瓜叶、花和根提取物处理过的南瓜叶饲养2天,随后用未经提取物处理的南瓜叶饲养,则这些幼虫仍能完成幼虫和蛹的发育,而且育出的成虫寿命和生殖力不受影响.

  11. 100-N Area Strontium-90 Treatability Demonstration Project: Food Chain Transfer Studies for Phytoremediation Along the 100-N Columbia River Riparian Zone

    Energy Technology Data Exchange (ETDEWEB)

    Fellows, Robert J.; Fruchter, Jonathan S.; Driver, Crystal J.

    2009-04-01

    the plant over a 17-day exposure period. The 90Sr in the exuded honeydew during this period amounted to 1.17 ± 0.28% of this total label. The honeydew would eventually be deposited into the soil at the base of the plant, but the activity would be so dispersed as to be undetectable. Moth larvae will consume 90Sr contaminated leaves but retain very little of the label (~0.02%) and only that contained in their digestive tracts. As the moths pupated and became adults, they contained no detectable amounts of 90Sr. Over the 10-day exposure period, ~4% of the phytoextracted 90Sr was lost from the plant as moth feces. However, like the honeydew, feces dispersed into the soil were undetectable. As the plant diminishes the content of 90Sr in the soil, the activity of the label in the leaves and new stems would also diminish. The results of these studies indicate that the risk for detectable transfer of 90Sr from willow trees growing in the contaminated soil along the 100-N shoreline through the food chain of herbivorous insects would be very slight to non-existent

  12. 人工模拟"庇护所"和"非庇护所"条件下棉铃虫对 Bt 棉的抗性演变%Studies on Resistance Evolution of Cotton Bollworm to Bt Transgenic Cotton in Artificial Simulating "Refuges" and "Non-refuges" Conditions

    Institute of Scientific and Technical Information of China (English)

    肖留斌; 孙厚俊; 柏立新

    2011-01-01

    In order to rind out the resistance evolution of Helicoverpa armigera(Hubner) to Bt cotton, "refuges" and "non-refuges"conditions were simulated. Laboratory screening was conducted for obtaining the resistant strains of inbred and hybrid line feeding on the artificial diet which contained cotton seeds powder from Bt hybrid CCRI 29. The results showed that: screening for 11 generations, the mortality rates of inbred strain and hybrid strain of H. armigera larva decreased, larval weight and larval length increased, the larval duration shortened, pupation rate and emergence rate increased. Contrast with the hybrid strain, the inbred strain adapted faster to Bt transgenic cotton. Screening for 1 1 generations, using different resistant strains of cotton bollworm for transgenic insect-resistance assessment, results indicated that the resistance grade of phase-sensitive strains determination of four insect-resistant transgenic cotton cultivars did not change, and resistance grade of three transgenic varieties to self-bred lines from CCRI 29, Nankang-3, and Kemian-1 decreased by one. The resistance ratio of self-strain and hybrid strain to Bt preparations was 9.3876 and 2.5215, respectively. According to the preliminary results of this study, the policy of "refuges" to delay the resistance of cotton bollworm to Bt transgenic cotton is feasible.%人工饲料中添加转Bt基因杂交棉品种中棉所29棉仁粉,建立杂交和自交品系分别模拟"庇护所"和"非庇护所"条件,连续多代进行棉铃虫对Bt棉的抗性筛选.结果表明:经11代筛选,棉铃虫自交品系和杂交品系的幼虫死亡率下降,体重和体长增加,幼虫历期缩短,化蛹率和羽化率增加.依据幼虫死亡率、体重、体长、幼虫历期以及化蛹率、羽化率等生命参数的演变,相较杂交品系,自交品系对Bt棉能更快地产生适应性.11代筛选后,利用不同抗性品系棉铃虫进行转基因棉抗虫性评估,结果表明:相比

  13. Producción masiva y simultánea de machos de Ceratitis capitata (Diptera: Tephritidae y parasitoides Dichasmimorpha longicaudata (Hymenoptera: Braconidae Massive and simultaneous production of Ceratitis capitata (Diptera: Tephritidae males and Diachasmimorpha longicaudata (Hymenoptera: Braconidae parasitoids

    Directory of Open Access Journals (Sweden)

    Silvia N. López

    2006-12-01

    objective of the present work was to do this two thing simultaneously and at a larger scale than previously. Besides, in an attempt to improve malefemale separation under this conditions, a pulse of 15ºC was applied to first stage larva during 1 or 2 days; these larvae were later held either at 20ºC or, at 25ºC until pupation, both groups of pupae being then kept at 25ºC . The best separation between male and female, achieved rearing larvae at 20ºC without any pulse of 15ºC , was then used to evaluate the quality of the parasitoids Diachasmimorpha longicaudata reared on the larvae remaining after male separation. These larvae were exposed to the parasitoid under standard conditions. The rate of parasitism obtained was similar to the one found when parasitoids are exposed to wild strain, and the F1 sex rate was even more biased toward females. The potential use at larger scale of the Cast191 strain of C. capitata for producing sterile males and D. longicaudata parasitoids is discussed.

  14. Implementing the Spirit of Literature and Art Symposium to Integrate Military Literature Creation Strength:Review on Seminar of “Special Issue on Military Literature”, the 8th Issue of The People’s Literature in 2014%贯彻文艺工作座谈会精神整合军事文学创作力量--《人民文学》2014年第8期“军事文学专号”作品研讨会综述

    Institute of Scientific and Technical Information of China (English)

    蔡静平

    2015-01-01

    literature, and generally believed thatThe People’s Literature’s timely publication of “special issue on military literature” is of great significance. In addition, they also had an extensive and in-depth discussion on the rise and innovation of new authors group in the army, as well as the challenges and opportunities faced by the contemporary military literature. They sincerely looked forward to the prospect that the new prominent square can step out of the maze and pupate into a butterfly to create a new and shining future of the Chinese military literature.

  15. Analysis on Insecticidal Activity of Bt Transgenic Populus deltoides × P.euramericana cv‘ Nanlin895’ and Its Effects on Soil Microorganism%转Bt基因南林895杨抗虫性及对土壤微生物影响分析

    Institute of Scientific and Technical Information of China (English)

    张雁; 郭同斌; 潘惠新; 黄敏仁; 王明庥; 诸葛强

    2012-01-01

    During the growing season of 2011, the leaves of four Bt transgenic clones Bl, B4, B17 and B21 of Populus deltoides x P. euramericana cv. ' Nanlin895' were exposed to the target pest larvae of Micromelalopha troglr odyla to assess the insecticidal activity of Bt transgenic P. deltoides × P. euramericana cv. ' Nanlin895' under laboratory and field conditions. It was showed that all the clones had certain insecticidal activity against target pests. The corrected mortality of the target pest feeding on clone B21 was as high as 95.3%. The corrected mortalities in August and September were 35.0% -88.8% and 40.5% -95.3% respectively under field conditions. The pupation ratio was 83.3% -96.0% in CK, while in transgenic poplar that was 8.0% -76.7% , showing a significant difference between them. The development of target larvae was inhibited by Bt transgenic P. deltoides x P. euramericana cv. ' Nanlin895'. After 8 days' feeding, the intake and growth rate of target larvae were significantly lower than that of the CK. The effect of Bl transgenic poplars on microorganisms in rhizosphere soil was also studied and no significant difference was found in the quantities of bacteria, fungi, and actinomycete between the transgenic and non-transgenic poplars, suggesting no negative influence on the soil microorganism system.%以转Bt基因南林895杨株系B1、B4、B17、B21扦插苗为试验材料,分析其在室内和野外自然条件下对靶标害虫杨小舟蛾幼虫的抗虫性.结果表明:转Bt基因杨树4个株系均有一定的杀虫活性,其中株系B21对杨小舟蛾1龄幼虫12d校正死亡率高达95.3%;虫试表明转Bt基因杨树各株系扦植苗在野外自然条件下的12 d幼虫校正死亡率8月份为35.0%~88.8%,9月份为40.5%~95.3%.用转Bt基因杨树叶片饲养杨小舟蛾,对照植株杨小舟蛾幼虫化蛹率为83.3%~96.0%,而转Bt基因株系幼虫化蛹率为8.0%~76.7%,二者有显著差异.转Bt基因杨树对杨

  16. 不同地区转Bt基因抗虫水稻稻谷对赤拟谷盗生长发育的影响%Influence of transgenic Bt rice on the growth and development of Tribolium castaneum (Coleoptera : Tenebrionidae)

    Institute of Scientific and Technical Information of China (English)

    姚英娟; 徐雪亮; 严寒; 蔡万伦; 林拥军; 华红霞

    2012-01-01

    The effect of the transgenic Bt rice Shanyou 63 with crylAb/crylAc, cry2A and crylC (TT51, T2A-1 and T1C-19) on the growth and development of Tribolium castaneum Herbst was investigated using rice from three different areas (Wuxue, Xiaogan and Suizhou in Hubei Province). The results show that the duration of the egg, larval, pupal and preoviposition stages were 3 to 4 days, 22 to 27 days, 6 to 7 days and 5 to 7 days, respectively. Hatchability, pupation rate and emergence rate were 85% to 100% , 85% to 97% and 82% to 97% , respectively. The weight of 100 pupae was 0. 25 to 0. 31 g and the sex ratio was 0. 8 to 1. 4. No significant differences were found among the different rice varieties. All three Bt proteins could be detected in T. castaneum larvae, but the accumulated amount was very small. There was no significant accumulative effect despite larvae being reared on these strains.%为了明确来自湖北武穴、孝感、随州3个不同地区的转cry1Ab/cry1Ac、cry2A、cry1C基因明恢63(分别命名为TT51、T2A-1和T1C-19)对赤拟谷盗Tribolium castaneum Herbst生长发育的影响,在室内以不同的转Bt基因稻谷继代饲养赤拟谷盗6代,结果表明:各处理赤拟谷盗的卵期3~4d,卵孵化率85% ~ 100%,幼虫期22 ~ 27 d,化蛹率85%~97%,蛹期6~7d,百蛹重0.25~0.31 g,性比0.8~1.4,羽化率82%~97%,产卵前期5~7d.不同抗虫转基因水稻对赤拟谷盗各发育历期及生命表参数没有显著的影响,同一转基因事件,没有因为种植地区的不同造成对赤拟谷盗生长发育的差异.3种Bt蛋白在继代饲养的赤拟谷盗幼虫体内检测均呈阳性反应,但积累量很小,继代饲养后,没有发现在赤拟谷盗体内明显的累积.

  17. Detrimental effect of rutin on Anticarsia gemmatalis Efeito prejudicial de rutina em Anticarsia gemmatalis

    Directory of Open Access Journals (Sweden)

    Clara Beatriz Hoffmann-Campo

    2006-10-01

    Full Text Available Behavioral and nutritional effect of rutin (quercetin 3-O-rutinosídeo on Anticarsia gemmatalis Hübner (Lep.: Noctuidae, a major soybean defoliator in Brazil, was evaluated from the third instar to pupation. Rutin is one of the flavonol glycosides identified in the leaves of the wild soybean PI 227687. Larval weight and amount of ingested food decreased as rutin concentration in the diet increase. An interactive effect between feeding time and diet (treatment was observed on insect growth; when larvae fed on pure-diet, feeding time elongation resulted in heavier pupae. Differently, the weight of larvae fed on rutin-diet remained almost stable, in spite of eating for longer. A. gemmatalis growth was negatively influenced by rutin-diet not only by feeding deterrence but also by post-ingestive effect on insect growth, since after adjustment of pupal weight by the amount of ingested food (covariate, the effect of diet remained significant. Rutin negatively influenced A. gemmatalis growth as result of pre-ingestive effect, indicated by reduction in food consumption, and post-ingestive effect, indicated by lower conversion of ingested food into body mass and food assimilation.O efeito de dieta contendo rutina (quercetina 3-O-rutinosídeo no comportamento e na nutrição do principal desfolhador da soja, Anticarsia gemmatalis Hübner (Lep.: Noctuidae foi avaliado do terceiro ínstar até a formação da pupa. Rutina é um dos flavonóis glicosídicos identificados em folhas da soja selvagem PI 227687. O peso das lagartas e o consumo decresceram com o aumento na concentração de rutina na dieta. Houve interação entre o tempo de alimentação e a dieta no crescimento do inseto; lagartas alimentadas com dieta pura, cujo tempo de alimentação prolongou-se, originaram pupas mais pesadas. O peso das pupas alimentadas com dieta contendo rutina permaneceu estável, apesar do maior tempo de alimentação. Rutina afetou negativamente o crescimento do inseto

  18. Nasal bots...a fascinating world!

    Science.gov (United States)

    Angulo-Valadez, Carlos E; Scholl, Philip J; Cepeda-Palacios, Ramón; Jacquiet, Philippe; Dorchies, Philippe

    2010-11-24

    Larvae causing obligatory myiasis are numerous and they may affect cutaneous and subcutaneous tissues, wounds, nasopharyngeal cavities (nasal bots), internal organs and the digestive tract (bots) of domestic and wild animals and humans as well. Nasal bots belong to the Family Oestridae, Subfamily Oestrinae, which includes several important genera: Oestrus, Kirkioestrus, and Gedoelstia infecting Artiodactyla (except Cervidae) in Africa and Eurasia, Cephenemyia and Pharyngomyia infecting Cervidae, Rhinoestrus infecting horses, Cephalopina infecting camels, Pharyngobolus infecting African elephants, and Tracheomyia infecting Australian kangaroos. Nasal bots are widespread in Mediterranean and tropical areas and in affected animals they induce sneezing and nasal discharge which may become caked with dust making breathing very difficult. The aforementioned species of larvae are host-specific but sometimes the may be deposited in human eyes inducing a painful opthalmomyiasis of short duration. The first fascinating trait of these parasites is the very efficient morphological and biological adaptations to parasitism they show either as larvae or as adults, in order to facilitate their survival and search for a suitable host. Nasal bots have reached different degrees of complexity in their life cycles. Indeed, while for some species (e.g., Oestrus ovis, Rhinoestrus usbekistanicus) larvae are injected by flies directly into nostrils and develop in the sinuses before being ejected for external pupation, some other species migrate from eyes to blood before returning to nasal cavities either through the ethmoid bone (Gedoelstia hässleri) or via lungs and bronchi (Gedoelstia cristata). Moreover, larvae are very well-adapted to their environment being able to undergo through hypobiosis either inside or outside the host, according to the climatic environmental conditions and seasonality. The second fascinating trait of nasal bots is related to host behavioural and immune

  19. EVALUATION OF NATURAL ENEMIES IN CONTROLLING OF THE BANANA WEEVIL BORER Cosmopolites sordidus Germar IN WEST SUMATRA

    Directory of Open Access Journals (Sweden)

    Ahsol Hasyim

    2016-10-01

    Full Text Available The banana weevil, Cosmopolites sordidus Germar, is an important pest of highland banana and plantain in Africa, but it exists in low densities in presumed area of origin in Southeast Asia such as in Indonesia. This suggests a possible existence of effective co-evolved natural enemies in the origin area of Indonesia, especially West Sumatra. The objectives of this study were: (1 to evaluate banana weevil pest status at selected sites in West Sumatra, (2 to survey parasitoids and predators, and (3 to determine the control potential of the most important natural enemies. Surveys were undertaken in March 2002-August 2003 in five locations in West Sumatra, i.e., Bukittinggi, Sitiung, Pariaman, Pasaman, and Batusangkar. Five farms per site were selected randomly among all farms that contained banana stands of > 0.5 ha. Sampling for banana weevil adults and damage, and for predators was done throughout small banana stands and within a 20 m x 40 m (0.08 ha subplot on larger farms. Field-collected larvae were taken to the laboratory and reared on corm pieces (3 cm x 3 cm x 3 cm until pupation. Larvae were collected from pseudostem as well as corm residues. To estimate the abundance of non-social predators, i.e., those other than ants, 10 residues each on each farm were examined from plants that had been harvested 1-4 weeks, 5-8 weeks or 9 or more weeks before our visit to the site. Samples of the different morphospecies were saved in alcohol for later identification. The result showed that the banana weevil incidence was found to be low,  0.6-1.7 adults per trap. Plant damage indices were below 2.2%. We collected and reared 24,360 eggs and 3118 larvae, but no parasitism was detected. Phorids (Megaselia sp. and drosophilids were recovered from larval rearings, but most likely were scavengers. A complex of predators was detected, the most important of which was the histerid beetles,  Plaesius javanus Erichson. In laboratory tests, adults and larvae

  20. Myiopardalis pardalina in Afghanistan

    Energy Technology Data Exchange (ETDEWEB)

    Stonehouse, J. [Imperial College, London (United Kingdom); Sadeed, S.M.; Harvey, A.; Haiderzada, G.S. [Food and Agriculture Organisation of the United Nations, Mazar-i-Sharif (Afghanistan)

    2006-07-01

    The Baluchistan melon fly, Myiopardalis pardalina (Bigot), is a serious and worsening problem in Central Asia. As it survives snowy and subzero temperatures as an over wintering pupa, it constitutes a quarantine risk to temperate countries where melons are grown, including in North America and Southern Europe. It is spreading rapidly in Turkmenistan and Uzbekistan as well as Afghanistan, and present from Turkey to India. Losses without control mount as high as 80%. In spite of this, the control of the fly has been little studied, and published recommendations are largely for cover applications of chemicals. It responds to no known lures, and reports of bait responses, though mixed, indicate poor responsivity. This study addressed these problems with a crash program of research in the melon season of 2006, in Mazar-i-Sharif, Afghanistan, with the following findings. (1) Although absence of proof of response is not proof of absence of response, adult flies responded to none of a wide suite of food baits in the field or laboratory. (2) Females laid viable eggs, with offspring completing their life cycle, having received no food as adults, adding suggestive support to a conclusion that adults may not be attracted to food baits. (3) When leaves were coated with sugar, however, flies which were on them were stimulated to remain, indicating that the addition of sugar to cover sprays (as opposed to spot sprays which might have attracted flies from a distance) may enhance their effectiveness and persistence. (4) Pupae experimentally buried to different depths led to teneral adult emergence from 50cm of soil, and thus fruit disposal by burial may need to be deeper than this. (5) Pupae in soil fully flooded for 48 hours suffered no reduction in survival, and thus field flooding for control may need to be longer than this. (6) A study of pupation found that: up to ten prepupal larvae may leave a melon through the same hole; unlike those of Bactrocera, larvae do not jump about

  1. Aspectos biológicos de Dione juno juno (Cramer (Lepidoptera: Nymphalidae em genótipos de maracujazeiro Biological aspects of Dione juno juno (Cramer (Lepidoptera: Nymphalidae on passion fruit genotypes

    Directory of Open Access Journals (Sweden)

    Arlindo Leal Boiça Júnior

    2008-03-01

    . edulis f. flavicarpa Deg. ('Sul Brasil', P. edulis f. flavicarpa, P. edulis f. flavicarpa ('Maguary FB-100' and P. foetida L. Fifty larvae from eggs collected in the field were used per genotype. Larvae were kept on passion fruits branches inside PVC tubes until pupation. Daily observations were performed and branches were replaced whenever necessary. The following parameters were evaluated: duration and viability of larval and pupal phases, larval and pupal weight and adult longevity. The experiment was arranged in randomized blocks design with seven treatments and ten replications. Data were subjected to an ANOVA and means were compared by Tukey test at 5% of probability. The least adequate genotypes for D. juno juno development were P. alata , P. serrato-digitata and P. foetida, showing a high level of antibiosis, while P. edulis, P. edulis f. flavicarpa, 'Maguary FB-100' and 'Sul Brasil' were the most suitable.

  2. 意大利蜜蜂工蜂幼虫饲料中适宜色氨酸水平%Appropriate Level of Tryptophan for Apis mellifera Worker Bee Larvae Feed

    Institute of Scientific and Technical Information of China (English)

    赵凤奎; 胥保华; 王红芳

    2015-01-01

    %[Objective] The objective of this research is to study the appropriate levels of tryptophan in Apis mellifera worker bee larvae feed, and to provide a theoretical basis for the nutritional needs of tryptophan. [Method] A total of 1 008 one-day-old larvae were randomly divided into seven groups of three replicates of 48 larvae, and were fed different diets with tryptophan at the levels of 7.84, 8.84, 9.84, 10.84, 11.84, 12.84 and 13.84 mg·g-1, respectively. The 5-day-old worker bee larvae were used for measuring TPH (tryptophan hydroxylase) gene and 5-HTR (5-hydroxytryptamine receptors) 1, 2α, 2β, 7 gene expression. The 6-day-old worker bee larvae as samples for determining total protein content, MDA (malondialdehyde), T-AOC (total antioxidant capacity), and the 6-day-old larval hemolymph was taken to be used for measuring the level of free tryptophan. The pupation rate was calculated at 7-day-old. Deposition amount of tryptophan was analyzed using 9-day-old pupa, and the worker bee eclosion rate was calculated at 21-day-old.[Result]Pupation rate and larvae total protein content at 6-day-old, tryptophan deposition at 9-day-old pupa and worker bee eclosion rate at 21-day-old were the highest when the tryptophan level was 10.84 mg·g-1. The expressions of TPH, 5-HT receptors 1, 2α and 2β genes of larvae at 5-day-old and hemolymph free tryptophan content of larvae at 6-day-old were elevated significantly by 10.84-11.84 mg·g-1 tryptophan (P<0.05). However, 5-HT receptor 7 gene expression of 5-day-old worker bee larvae and MDA level of 6-day-old worker bee larvae fed 12.84-13.84 mg·g-1 tryptophan were higher than worker bee larvae fed 7.84-11.84 mg·g-1 tryptophan (P<0.05). Dietary supplied with 10.84-13.84 mg·g-1 tryptophan improved significantly 6-day-old worker bee larvae T-AOC compared with dietary with 7.84-9.84 mg·g-1 tryptophan (P<0.05). [Conclusion] The appropriate level of tryptophan for A. mellifera worker bee larvae is 10.84-11.84 mg·g-1.

  3. 橘小实蝇、瓜实蝇和南亚果实蝇人工饲料的优化%Optimization of artificial diets for mass rearing of Bactrocera dorsalis,Bactrocera cucurbitae and Bactrocera tau

    Institute of Scientific and Technical Information of China (English)

    林明光; 汪兴鉴; 张艳; 孙蕊芬; 曾玲

    2013-01-01

    per female,egg-laying stage and hatching rate were 424.16-445.75 individuals,30.90-31.87 days and 74.60%-75.40%,respectively.The effects of rearing larvae of B.dorsalis,B.cucurbitae and B.tau (Walker) on 18 different artificial diet formulae were compared.Corn and wheat bran mixtures were found to be better than oatmeal and wheat bran.The optimal formula for an artificial diet for rearing B.dorsalis larvae was 125 g corn,25 g wheat bran,25 g sucrose,25 g beer yeast,0.9 g methyl p-hydroxybenzoate,4 mL 1 mol/L hydrochloric acid,4 g paper towel and 300 mL tap water.Biological parameters measured in individuals of this species reared on the larval diet were hatching rate of the next generation,pupation rate,emergence rate and average pupa weight.These were 81.17% ± 0.05%,96.41% ± 0.02%,94.85% ± 0.01% and 19.40 ± 0.08 mg,respectively.By comparison,the optimal artificial diet formula for rearing larvae of B.cucurbitae and B.tau was 100 g corn,50 g wheat bran,30 g sucrose,25 g beer yeast,with the same amounts of the other ingredients as for B.dorsalis larvae.Biological parameters measured in individuals of the two species reared on the larval diet were hatching rate of the next generation,pupation rate,emergence rate and average pupa weight.These were 78.50% ±0.04% and 76.96% ±0.12%,95.73% ±0.03% and 94.69% ±0.02%,94.57% ±0.02% and 95.82% ±0.03%,18.62 ±0.23 mg and 22.83 ± 1.38 mg,respectively.It was found that all three pest species raised on their respective optimal larval artificial diets could be reared successfully for successive generations.The diets are practical for maintaining populations of these three Bactrocera species because they are effective,simple to prepare and the ingredients required are widely available and inexpensive.

  4. 新烟碱类等杀虫剂对葱蝇的毒力及其对生长发育和繁殖的影响%Toxicity and effects on the growth,development and reproduction of neonicotinoid insecticides to Delia antique(Meigen)

    Institute of Scientific and Technical Information of China (English)

    张庆臣; 薛明; 王征; 张云霞; 李贤贤

    2011-01-01

    采用定量滴加法和浸渍法测定了8种药剂对葱蝇1龄和3龄幼虫的毒力,用噻虫胺和噻虫嗪等新烟碱类杀虫剂的亚致死浓度分别处理葱绳1龄和3龄幼虫,观察其对葱蝇生长发育和繁殖的影响,并进行了田间药效试验.结果表明,噻虫胺和噻虫嗪对3龄幼虫48h的LC50分别为14.7839mg/L和13.3055mg/L,毒力为毒死蟀的0.41倍和0.50倍.但LC30-40剂量处理葱蝇3龄幼虫后,第6天存活幼虫体重分别较对照降低35.47%和36.34%a,幼虫发育历期延长3.68天和3.98天,化蛹率降低71.91%和78.65%,雌蛹重降低13.36%和14.72%,雄蛹重降低15.97%和18.32%,羽化率降低12.50%和17.86%,单雌产卵量降低47.71%和51.68%.噻虫胺和噻虫嗪处理1龄幼虫,对其生长发育也有显著不利影响.田间药效试验结果显示,1200g/hm2噻虫胺和噻虫嗪处理后7天防效分别达98.16%和92.46%,表明这两种药剂对葱绳防治效果高、推广应用价值大.%The toxicity of 8 kinds of insecticides to 1 st and 3rd instars of Delia antiqua larvae was detected using the dripping ration liquid and dipping methods. Effects to development and adult fecundity of D. antique were studied by treating the 1st and 3rd larvae of onion maggot with LC30-40 concentration of clothianidin, thiamethoxam and other insecticides. The field experiments were also treated. The results showed that LC50 of clothianidin and thiamethoxam to the 3rd instar larvae was 14.7839 mg/L and 13. 3055 mg/L, it is only 0.41 and 0.50 times those of chlorpyrifos, respectively. When the 3rd instars were treated by LC30-40 concentration, compared to control, surviving larvae weight reduced by 35.47%and 36.34% at six days treated, larval developmental period prolonged 3.68 and 3.98 days, pupation rate reduced by 71.91% and 78.65%, female pupae weight decreased by 13.36% and 14.72%, male pupae weight decreased by 15.97% and 18.32%, emergence rate reduced by 12.50% and 17.86%,eggs laid per female

  5. 沙蒿木蠹蛾生物学特性研究%Bionomics of the sand sagebrush carpenterworm, Holcocerus artemisiae (Lepidoptera: Cossidae)

    Institute of Scientific and Technical Information of China (English)

    王建伟; 骆有庆; 宗世祥

    2011-01-01

    沙蒿木蠹蛾Holcocerus artemisiae Chou et Hua是危害油蒿Artemisia ordosica Krasch和籽蒿A.sphaerocephala Krasch的重要钻蛀性害虫,以幼虫蛀食根部,导致寄主植物长势衰弱甚至死亡.为有效控制其危害,我们对该虫形态和生物学特征结合野外调查和室内饲养观察进行了研究.结果表明:在宁夏,该虫2年发生1代,以幼虫在被害油蒿根部越冬;老熟幼虫于5月中旬从受害根部钻出,在周围的沙土里结茧化蛹,蛹期平均19.5±3.5 d;成虫始见于6月初,终见于8月末,期间经历3次羽化高峰,分别为6,7,8月的上旬.成虫羽化主要在14:00-17:00,整个过程持续30~45 min;羽化当日即可交配,交配时间为20:00-21:00,高峰期为20:30左右;雄虫有2次交尾现象.雄虫寿命2~3 d,雌虫寿命1~3 d,极少4 d.雌雄性比约为1∶2.16.卵初见于6月中旬,初孵幼虫初见于6月下旬.幼虫常单独危害,且具有转移危害的习性,蛀食坑道不规则.5-9月,油蒿受害率为11%~44%,平均24%,株虫口密度为0.13头/株.幼虫对油蒿的树龄和地径有较明显的选择性,主要危害1~4年生、地径16~34mm的油蒿.沙蒿木蠹蛾生物学特征的系统研究为其控制措施的制定提供了科学依据.%The sand sagebrush carpenterworm, Holcocerus artemisiae Chou et Hua, is a severe pest of Artemisia ordosica and A.sphaerocephala, with the larval stages boring into the roots of the host plants.Morphological and biological characteristics of H.artemisiae in Ningxia were studied through field survey and laboratory breeding and observation.The results showed that a generation takes two years in fields of Ningxia.Larvae of all instars were found to overwinter in the host plant roots.Mature larvae begin to pupate in mid May in the soil around the base of plant stems, with the average pupal stage lasting 19.5 ±3.5 d.Moths emerge from the beginning of June to the end of August, with three peaks of eclosion observed in the early June

  6. CO2浓度升高对稻纵卷叶螟生长发育、繁殖和食物利用效率的影响%Effects of Elevated CO2 Concentration on Development, Reproduction and Food Utilization of the Cnaphalocrocis medinalis Guenée (Lepidoptera:Pyralidae)

    Institute of Scientific and Technical Information of China (English)

    李保平; 郭庆; 孟玲

    2013-01-01

    reproductive performances were examined, and food consumption and nutritional utilization indices were measured for the 4th instar larva. [Result]The doubling CO 2 treatment significantly influenced body weight of larvae till 5th instar, pupal time and body weight, but did not influence larval time and pupation rate. The body weight of the final instar (5th) larva decreased by 16.1%, pupal duration by 28.7%, and pupal weight by 9.9%, under the elevated CO2 as opposed to the ambient CO2. The CO2 elevation did not affect sex ratio and fecundity, but significantly influenced the larva-to-adult emergence survival and egg hatching. The larva-to-adult emergence survival rate decreased by 44.0%and the egg hatching rate reduced by 26.8%under the elevated CO2 as compared to the ambient CO2. The trial of the 4th instar larva showed significant effects of elevated CO 2 on food consumption and utilization. The food consumption increased but the relative consumption rate was not changed by the elevated CO2. The relative growth rate increased by 21.2%and the approximate digestibility increased by 15.7%, but the efficiency of conversion of ingested food to body substance decreased by 24.8%and the efficiency of conversion of digested food to body substance decreased by 37.1%.[Conclusion]The CO2 enrichment may have negative effects on life history traits of C. medinalis, but the population dynamics of insect is complex and other effect such as temperature should be considered.

  7. Structure and function of sterol carrier proteins in insects%昆虫固醇转运蛋白的结构与功能

    Institute of Scientific and Technical Information of China (English)

    张丽丽; 郭兴荣; 冯启理; 郑思春

    2011-01-01

    , cholesterol derivatives, fatty acids,acyl-coenzyme A and phospholipids. Over-expression of SlSCP-x and SlSCP-2 genes can increase the uptake of cholesterol into cells and RNAi inhibits the expression of SlSCP-x and SlSCP-2 genes in S. litura larvae,resulting in a decrease in cholesterol level in the hemolymph and a delay in larval growth and pupation.%在昆虫中,胆固醇不仅是细胞膜的重要成分之一,也是昆虫蜕皮激素生物合成的前体.由于昆虫体内缺少两种合成胆固醇所必需的关键性酶,所以昆虫不能自主地从简单的前体化合物从头合成胆同醇,而必须通过吸收食物中的甾醇转化为胆固醇来满足生长、发育和繁殖的需要.胆固醇在组织和细胞内的运输主要由固醇转运蛋白(sterol carrier proteins,SCPs)执行.因此,对同醇转运蛋白结构与功能的研究对于阐明昆虫中固醇运输具有重要的意义.本文对同醇转运蛋白的基因和蛋白结构、细胞内表达和定位、翻译后修饰、蛋白三维结构、底物特异性和可能的运输途径等方面的研究进展进行了综述,并对其作为害虫防治分子靶标的可能性进行了初步的讨论.研究发现,不同物种的SCP蛋白的基因编码形式和蛋白剪切形式不同;双翅目昆虫埃及伊蚊Aedes aegypti和黑腹果蝇Drosophila melanogaster除了SCP-x基因可编码SCP-x和SCP-2蛋白外,还有另外的SCP-2和类SCP-2(SCP-2L)基因编码SCP-2和类SCP-2蛋白;而鳞翅目昆虫棉贪夜蛾Spodoptera littoralis、斜纹夜蛾Spodoptera litura和家蚕Bombyx mori中SCP-x 基因的表达和转录方式与脊椎动物的SCP-x基因类似,通过转录和翻译后剪切形成SCP-2蛋白.SCP-x和SCP-2蛋白定位于过氧化物酶体.SCP-2蛋白由5个α-螺旋和5个β-折叠组成,其中α5-螺旋可影响蛋白与底物的结合.SCP-2蛋白以不同的亲和力与固醇、胆同醇衍生物、脂肪酸、脂酰辅酶A和磷脂等化合物结合.超表达斜纹夜蛾SlSCP-x和SlSCP-2

  8. 黑果蝇dlts品系的温度敏感时期及dlts基因多效影响的自主性研究%Temperature-sensitive periods and autonomy of pleiotropic effects of dlts, a conditional discless lethal mutation in Drosophila virilis

    Institute of Scientific and Technical Information of China (English)

    Vladimir G. MITROFANOV; 薛东; 杨长举; 姚英娟; 蔡万伦

    2005-01-01

    -sensitive period (TSP) is determined by the analysis of both shift-up and shift-down experiments. Discrete TSPs for lethality are localized on the first, the second and the third larval instar for a 10 hr period after pupation with an interval of a few hours between TSP and the lethal phase (LP). TSPs for adult morphology defects are localized on the second, the third larval instars and the early pupal period. Animals during TSPs are subjected to 12-hr-pulse, 24-hr-pulse, and 48-hr-pulse treatments respectively, and have produced a large number of defects. The defects include: eye scar, clumping pigment eye, small and lozenge-shaped eye, missing facets, small wing, thick wing vein, shortened tarsal segments, fused leg segments, extra macrochaetae or bristles, missing antennal segments, and duplicating palpus and/or lacinia, with distinct patterns of eye, wing, bristle and leg defects observed within the third larval instar. Homoeotic mutants also occur in this period. Each defect has its own specific time-dependent pattern. The patterns of damage are observed in imaginal tissue and all the defects are categorized into three classes: repeat, deletion and repeat and deletion happened at the same time. There is evidence from genetic somatics that there are some specific time patterns for dlts to produce the pleiotropic effects.

  9. Asociación Thysanoptera (Insecta-Vicia faba (Fabaceae en la Prepuna y Puna de Jujuy, Argentina Thysanoptera (Insecta-Vicia faba (Fabaceae association in Prepuna and Puna in Jujuy, Argentina

    Directory of Open Access Journals (Sweden)

    María Inés Zamar

    2012-03-01

    . occidentalis utilizan la planta en forma temporal y oportunista en Prepuna, mientras que la presencia de F. gemina en Puna es esporádica. Se amplía el número de especies de tisanópteros asociadas al cultivo de haba en ArgentinaThysanoptera (Insecta-Vicia faba (Fabaceae association in Prepuna and Puna in Jujuy, Argentina. The different phenological stages of Vicia faba provide food resources and substrates for the development of a significant diversity of insects. This study aimed to identify the complex of anthophyllous thrips, analyze the species population fluctuations, to obtain some bioecological aspects and the role they play in this association. The study and sampling was conducted during the flowering-fruiting bean crop stages in two phytogeographical regions of Jujuy: Prepuna (2 479m asl on a weekly basis, from October-December 1995-1996 and Puna (3 367m asl every two weeks, from December 2007-March 2008. Each sample consisted of 25 flowers taken at random; only at Prepuna a complementary sampling of three hits per plant (n=10 plants was conducted. Observations were made on oviposition sites, admission to the flower, pupation sites, feeding behavior and injuries caused. In Prepuna, the Thysanoptera complex consisted of Frankliniella australis, F. occidentalis, F. gemina, F. schultzei and Thrips tabaci; in Puna, the specific diversity was restricted to F. australis and F. gemina. Although the planting-harvest period in both areas did not match, the fluctuations in populations showed the same pattern: as flowering progressed, the number of thrips coincided with the availability of food resources. In both areas, F. australis was the dominant species and maintained successive populations; it layed eggs in flower buds, and larvae hatched when flowers opened; feeding larvae and adults brought about silvery stains with black spots. In Prepuna, F. australis went through the mobile immature stages on flowers, while quiescent stages were on the ground; in the Puna, all

  10. 维生素C对中华蜜蜂幼虫发育及工蜂生存能力的影响%Effects of Vitamin C on Development of Larvae and Viability of Worker Bees for Apis cerana cerana

    Institute of Scientific and Technical Information of China (English)

    韩旭; 田柳青; 王子龙; 颜伟玉; 曾志将; 吴小波

    2014-01-01

    The objective of this experiment was to explore the effects of vitamin C on the development of lar-vae and the viability of worker bees for Apis cerana cerana.The experiment contained 2 parts: larvae and worker bees’ feeding trails.Larvae bees’ feeding trail:eight hundred larvae for Apis cerana cerana were ran-domly distributed into 5 groups with 8 replicates in each group and 20 larvae in each replicate.The larvae in control group ( group Ⅰ) were fed a basal diet containing 1.6 mg/kg vitamin C, and those in 4 experimental groups were fed experiment diets supplemented with 10 ( group Ⅱ) , 20 ( group Ⅲ) , 30 ( group Ⅳ) and 40 mg/kg ( group Ⅴ) vitamin C, respectively.Worker bees’ feeding trail:one-day-old worker bees for Apis cerana cerana were distributed into 4 groups with 6 replicates in each group and 24 g ( about 300 bees) in each replicate.The worker bees in control group ( groupⅥ) were fed a 1∶1 sweet water, and those in 3 experimen-tal groups were fed 1∶1 sweet water supplemented with 50 ( group Ⅶ) , 500 ( group Ⅷ) and 2 500 mg/kg ( group Ⅸ) vitamin C, respectively.The results showed as follows: during the development stage of larvae, the body weight of 6-day-old larvae, 3-day-old pupae and new-emerged bees was increased firstly and then de-clined with the increase of vitamin C content, and that in groupsⅡandⅢwas significantly higher than that in control group ( P<0.05) .The pupation rate and eclosion rate of larvae showed trends similar with body weight. Moreover, the relative expression level of Cu/Zn superoxide dismutase ( Cu/Zn-SOD) gene was also increased firstly and then declined with the increase of vitamin C content, and the relative expression level of Cu/Zn-SOD gene of 6-day-old larvae and 3-day-old pupae in experimental groups was significantly higher than that in con-trol group ( P<0.05) .In the aspect of viability of worker bees, the average lifespan of worker bees was in-creased firstly and then decreased with the