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Sample records for eclosion

  1. Mathematical observations on the relation between eclosion periods and the copulation rate of cicadas.

    Science.gov (United States)

    Saisho, Yasumasa

    2010-04-01

    In many species of cicadas the peak of eclosion of males precedes that of females. In this paper, we construct a stochastic model and consider whether this sexual difference of eclosion periods works against mating or not. We also discuss the relation between the peak period of copulations and the development of population number by using this model.

  2. Eclosion rate, development and survivorship of Aedes albopictus (Skuse)(Diptera: Culicidae) under different water temperatures

    International Nuclear Information System (INIS)

    Monteiro, Laura C.C.; Souza, Jose R.B. de; Albuquerque, Cleide M.R. de

    2007-01-01

    In tropical areas, where vector insects populations are particularly numerous, temperature usually range between 25 de C and 35 deg C. Considering the importance of such temperature variation in determining mosquitoes population dynamics, in this work the developmental, eclosion and survival rates of the immature stages of Aedes albopictus (Skuse) were compared under constant 25, 30 and 35 deg C (using acclimatized chambers) and environmental (25 deg C to 29 deg C) temperatures. The hatching rate was considered as total number of larvae recovered after 24h. The development period as well as larval and pupal survival rate were evaluated daily. Eclosion rate was significantly higher under environmental temperature than under the studied constant temperatures, suggesting that temperature variation may be an eclosion-stimulating factor. The mean eclosion time increased with the temperature, ranging from 2.8 h (25 deg C) to 5.2 h (35 deg C). The larval period was greatly variable inside each group, although it did not differ significantly amongst groups (11.0 +- 4.19 days), with individuals showing longer larval stages in water at 35 deg C (12.0 +- 4.95 days) and environmental temperature (13.6 +- 5.98 days). Oppositely, survival was strongly affected by the higher temperature, where only one individual lived through to adult phase. The results suggest that population of Ae. albopictus from Recife may be adapting to increasing of environmental temperatures and that the limiting temperature to larval development is around 35 deg C. (author)

  3. Sexual differences in weight loss upon eclosion are related to life history strategy in Lepidoptera.

    Science.gov (United States)

    Molleman, Freerk; Javoiš, Juhan; Esperk, Toomas; Teder, Tiit; Davis, Robert B; Tammaru, Toomas

    2011-06-01

    Given that immature and adult insects have different life styles, different target body compositions can be expected. For adults, such targets will also differ depending on life history strategy, and thus vary among the sexes, and in females depend on the degree of capital versus income breeding and ovigeny. Since these targets may in part be approximated by loss of substances upon eclosion, comparing sexual differences in such losses upon eclosion among species that differ in life history would provide insights into insect functional ecology. We studied weight loss in eclosing insects using original data on pupal and adult live weights of 38 species of Lepidoptera (mainly Geometridae) and further literature data on 15 species of Lepidoptera and six representatives of other insect orders, and applied the phylogenetic independent contrasts approach. In addition, data on live and dry weights of pupae of four species of Lepidoptera are presented. We documented that Lepidoptera typically lose a large proportion (20-80%) of their pupal weight upon adult eclosion. Sexual differences in weight loss varied between absent and strongly male biased. Most of the weight loss was water loss, and sexual differences in adult water content correlate strongly with differences in weight loss. Using feeding habits (feeds or does not feed as an adult) and female biased sexual size dimorphism as measures of degree of capital breeding, we found that the difference among the sexes in weight loss tends to be more pronounced in capital breeding species. Additionally, females of more pro-ovigenic species (large proportion of eggs mature upon emergence) tend to have higher water contents. Our results suggests that metamorphosis is generally facilitated by a high water content, while adults excrete water upon eclosion to benefit flight unless water has been allocated to eggs, or is treated as a capital resource for adult survival or future allocation to eggs. Copyright © 2011 Elsevier Ltd

  4. The crucial role of cyclic GMP in the eclosion hormone mediated signal transduction in the silkworm metamorphoses.

    Science.gov (United States)

    Shibanaka, Y; Hayashi, H; Okada, N; Fujita, N

    1991-10-31

    The signal transduction of the peptide, eclosion hormone, in the silkworm Bombyx mori appears to be mediated via the second messenger cyclic GMP throughout their life cycle. Injection of 8-bromo-cGMP induced the ecdysis behavior in pharate adults with similar latency to eclosion hormone-induced ecdysis; the moulting occurred 50-70 min after the injection. The potency of 8Br-cGMP was 10(2) fold higher than that of cGMP and the efficacy was increased by the co-injection of the phosphodiesterase inhibitor IBMX. On the other hand, in the silkworm pupal ecdysis the eclosion hormone and also 8Br-cGMP induced the moulting behavior in a dose-dependent manner. The adult development of the ability to respond to 8Br-cGMP took place concomitantly with the response to the eclosion hormone. Both the developmental time courses were shifted by a shift of light and dark cycles. Accordingly, the sensitivities to the peptide and cyclic nucleotide developed correspondently under the light and dark circadian rhythm. Thus throughout the silkworm life cycle, eclosion hormone is effective to trigger the ecdysis behavior and cGMP plays a crucial role as the second messenger in the eclosion hormone-mediated signal transduction.

  5. Post eclosion age predicts the prevalence of midgut trypanosome infections in Glossina.

    Directory of Open Access Journals (Sweden)

    Deirdre P Walshe

    Full Text Available The teneral phenomenon, as observed in Glossina sp., refers to the increased susceptibility of the fly to trypanosome infection when the first bloodmeal taken is trypanosome-infected. In recent years, the term teneral has gradually become synonymous with unfed, and thus fails to consider the age of the newly emerged fly at the time the first bloodmeal is taken. Furthermore, conflicting evidence exists of the effect of the age of the teneral fly post eclosion when it is given the infected first bloodmeal in determining the infection prevalence. This study demonstrates that it is not the feeding history of the fly but rather the age (hours after eclosion of the fly from the puparium of the fly when it takes the first (infective bloodmeal that determines the level of fly susceptibility to trypanosome infection. We examine this phenomenon in male and female flies from two distinct tsetse clades (Glossina morsitans morsitans and Glossina palpalis palpalis infected with two salivarian trypanosome species, Trypanosoma (Trypanozoon brucei brucei and Trypanosoma (Nannomonas congolense using Fisher's exact test to examine differences in infection rates. Teneral tsetse aged less than 24 hours post-eclosion (h.p.e. are twice as susceptible to trypanosome infection as flies aged 48 h.p.e. This trend is conserved across sex, vector clade and parasite species. The life cycle stage of the parasite fed to the fly (mammalian versus insect form trypanosomes does not alter this age-related bias in infection. Reducing the numbers of parasites fed to 48 h.p.e., but not to 24 h.p.e. flies, increases teneral refractoriness. The importance of this phenomenon in disease biology in the field as well as the necessity of employing flies of consistent age in laboratory-based infection studies is discussed.

  6. Post-eclosion odor experience modifies olfactory receptor neuron coding in Drosophila.

    Science.gov (United States)

    Iyengar, Atulya; Chakraborty, Tuhin Subhra; Goswami, Sarit Pati; Wu, Chun-Fang; Siddiqi, Obaid

    2010-05-25

    Olfactory responses of Drosophila undergo pronounced changes after eclosion. The flies develop attraction to odors to which they are exposed and aversion to other odors. Behavioral adaptation is correlated with changes in the firing pattern of olfactory receptor neurons (ORNs). In this article, we present an information-theoretic analysis of the firing pattern of ORNs. Flies reared in a synthetic odorless medium were transferred after eclosion to three different media: (i) a synthetic medium relatively devoid of odor cues, (ii) synthetic medium infused with a single odorant, and (iii) complex cornmeal medium rich in odors. Recordings were made from an identified sensillum (type II), and the Jensen-Shannon divergence (D(JS)) was used to assess quantitatively the differences between ensemble spike responses to different odors. Analysis shows that prolonged exposure to ethyl acetate and several related esters increases sensitivity to these esters but does not improve the ability of the fly to distinguish between them. Flies exposed to cornmeal display varied sensitivity to these odorants and at the same time develop greater capacity to distinguish between odors. Deprivation of odor experience on an odorless synthetic medium leads to a loss of both sensitivity and acuity. Rich olfactory experience thus helps to shape the ORNs response and enhances its discriminative power. The experiments presented here demonstrate an experience-dependent adaptation at the level of the receptor neuron.

  7. WEclMon - A simple and robust camera-based system to monitor Drosophila eclosion under optogenetic manipulation and natural conditions.

    Directory of Open Access Journals (Sweden)

    Franziska Ruf

    Full Text Available Eclosion in flies and other insects is a circadian-gated behaviour under control of a central and a peripheral clock. It is not influenced by the motivational state of an animal, and thus presents an ideal paradigm to study the relation and signalling pathways between central and peripheral clocks, and downstream peptidergic regulatory systems. Little is known, however, about eclosion rhythmicity under natural conditions, and research into this direction is hampered by the physically closed design of current eclosion monitoring systems. We describe a novel open eclosion monitoring system (WEclMon that allows the puparia to come into direct contact with light, temperature and humidity. We demonstrate that the system can be used both in the laboratory and outdoors, and shows a performance similar to commercial closed funnel-type monitors. Data analysis is semi-automated based on a macro toolset for the open imaging software Fiji. Due to its open design, the WEclMon is also well suited for optogenetic experiments. A small screen to identify putative neuroendocrine signals mediating time from the central clock to initiate eclosion showed that optogenetic activation of ETH-, EH and myosuppressin neurons can induce precocious eclosion. Genetic ablation of myosuppressin-expressing neurons did, however, not affect eclosion rhythmicity.

  8. Transgenerational programming of longevity and reproduction by post-eclosion dietary manipulation in Drosophila

    Science.gov (United States)

    Xia, Brian; de Belle, Steven

    2016-01-01

    Accumulating evidence suggests that early-life diet may program one's health status by causing permanent alternations in specific organs, tissues, or metabolic or homeostatic pathways, and such programming effects may propagate across generations through heritable epigenetic modifications. However, it remains uninvestigated whether postnatal dietary changes may program longevity across generations. To address this question of important biological and public health implications, newly-born flies (F0) were collected and subjected to various post-eclosion dietary manipulations (PDMs) with different protein-carbohydrate (i.e., LP, IP or HP for low-, intermediate- or high-protein) contents or a control diet (CD). Longevity and fecundity analyses were performed with these treated F0 flies and their F1, F2 and F3 offspring, while maintained on CD at all times. The LP and HP PDMs shortened longevity, while the IP PDM extended longevity significantly up to the F3 generation. Furthermore, the LP reduced while the IP PDM increased lifetime fecundity across the F0-F2 generations. Our observations establish the first animal model for studying transgenerational inheritance of nutritional programming of longevity, making it possible to investigate the underlying epigenetic mechanisms and identify gene targets for drug discovery in future studies. PMID:27025190

  9. Gamma irradiation of the melon fly: laboratory studies of the sexual competitiveness of flies treated as pupae 2 days before eclosion or as 2-day-old adults

    International Nuclear Information System (INIS)

    Anwar, M.; Chatha, N.; Ohinata, K.; Harris, E.J.

    1975-01-01

    Gamma irradiation (6 krad 2 days before eclosion or 8 krad 2 days after eclosion) induced 98-99% sterility in a laboratory strain of male Dacus cucurbitae Coquillett. Comparable females with 4 krad at the same ages were completely infecund. In trials with 5:1:1 ratios of sterile males-normal males-normal females, sexual competitiveness of males sterilized with 8 krad as 2-day-old adults was similar to that of males treated as pupae with 6 krad. The suppression of the fertility of normal flies by the introduction of sterile females was negligible

  10. dHb9 expressing larval motor neurons persist through metamorphosis to innervate adult-specific muscle targets and function in Drosophila eclosion.

    Science.gov (United States)

    Banerjee, Soumya; Toral, Marcus; Siefert, Matthew; Conway, David; Dorr, Meredith; Fernandes, Joyce

    2016-12-01

    The Drosophila larval nervous system is radically restructured during metamorphosis to produce adult specific neural circuits and behaviors. Genesis of new neurons, death of larval neurons and remodeling of those neurons that persistent collectively act to shape the adult nervous system. Here, we examine the fate of a subset of larval motor neurons during this restructuring process. We used a dHb9 reporter, in combination with the FLP/FRT system to individually identify abdominal motor neurons in the larval to adult transition using a combination of relative cell body location, axonal position, and muscle targets. We found that segment specific cell death of some dHb9 expressing motor neurons occurs throughout the metamorphosis period and continues into the post-eclosion period. Many dHb9 > GFP expressing neurons however persist in the two anterior hemisegments, A1 and A2, which have segment specific muscles required for eclosion while a smaller proportion also persist in A2-A5. Consistent with a functional requirement for these neurons, ablating them during the pupal period produces defects in adult eclosion. In adults, subsequent to the execution of eclosion behaviors, the NMJs of some of these neurons were found to be dismantled and their muscle targets degenerate. Our studies demonstrate a critical continuity of some larval motor neurons into adults and reveal that multiple aspects of motor neuron remodeling and plasticity that are essential for adult motor behaviors. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 76: 1387-1416, 2016. © 2016 Wiley Periodicals, Inc.

  11. Roles of NlAKTIP in the Growth and Eclosion of the Rice Brown Planthopper, Nilaparvata lugens Stål, as Revealed by RNA Interference

    Science.gov (United States)

    Hao, Peiying; Lu, Chaofeng; Ma, Yan; Xu, Lingbo; Zhu, Jiajun; Yu, Xiaoping

    2015-01-01

    AKT-interacting protein (AKTIP) interacts with serine/threonine protein kinase B (PKB)/AKT. AKTIP modulates AKT’s activity by enhancing the phosphorylation of the regulatory site and plays a crucial role in multiple biological processes. In this study, the full length cDNA of NlAKTIP, a novel AKTIP gene in the brown planthopper (BPH) Nilaparvata lugens, was cloned. The reverse transcription quantitive PCR (RT-qPCR) results showed that the NlAKTIP gene was strongly expressed in gravid female adults, but was relatively weakly expressed in nymphs and male adult BPH. In female BPH, treatment with dsAKTIP resulted in the efficient silencing of NlAKTIP, leading to a significant reduction of mRNA levels, about 50% of those of the untreated control group at day 7 of the study. BPH fed with dsAKTIP had reduced growth with lower body weights and smaller sizes, and the body weight of BPH treated with dsAKTIP at day 7 decreased to about 30% of that of the untreated control. Treatment of dsAKTIP significantly delayed the eclosion for over 7 days relative to the control group and restricted ovarian development to Grade I (transparent stage), whereas the controls developed to Grade IV (matured stage). These results indicated that NlAKTIP is crucial to the growth and development of female BPH. This study provided a valuable clue of a potential target NlAKTIP for inhibiting the BPH, and also provided a new point of view on the interaction between BPH and resistant rice. PMID:26402675

  12. 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

    Directory of Open Access Journals (Sweden)

    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

  13. Distribution of PER protein, pigment-dispersing hormone, prothoracicotropic hormone, and eclosion hormone in the cephalic nervous system of insects

    Czech Academy of Sciences Publication Activity Database

    Závodská, Radka; Šauman, Ivo; Sehnal, František

    2003-01-01

    Roč. 18, č. 2 (2003), s. 106-122 ISSN 0748-7304 R&D Projects: GA ČR GA204/01/0404; GA AV ČR KSK5052113 Institutional research plan: CEZ:AV0Z5007907 Keywords : insect brain clock * circadian rhythm * PER Subject RIV: ED - Physiology Impact factor: 4.061, year: 2003

  14. Disruption of pupariation and eclosion behavior in the flesh fly, Sarcophaga bullata Parker (Diptera: Sarcophagidae), by venom form the ectoparasitic wasp Nasonia vitripennis (Walker) (Hymenoptera: Pteromalidae)

    Czech Academy of Sciences Publication Activity Database

    Rivers, D. B.; Žďárek, Jan; Denlinger, D. L.

    2004-01-01

    Roč. 57, - (2004), s. 78-91 ISSN 0739-4462 R&D Projects: GA ČR GA522/01/0501 Grant - others:USDA-NRI(US) 98-35302-6659; USDA-NRICGP(US) 2001-1005 Institutional research plan: CEZ:AV0Z4055905 Keywords : ectoparasitoid * ecdysone * fly development Subject RIV: CC - Organic Chemistry Impact factor: 1.173, year: 2004

  15. AFSC/RACE/SAP/Swiney: Primiparous and multiparous Tanner crab egg extrusion, embryo development and hatching

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study compares timing of egg extrusion, embryo development, timing and duration of eclosion, and incubation periods of Kodiak, Alaska primiparous and...

  16. Sterilization of oriental fruit fly by gamma irradiation and its effect on competitiveness

    International Nuclear Information System (INIS)

    Manoto, E.C.; Bautista, R.C.

    1975-01-01

    The Oriental fruit fly, Dacus dorsalis Hendel, was irradiated with 5, 7, or 9 krad of Co-60 gamma rays at one or two days before adult eclosion. It was not clear whether or not male fruit flies were more competitive when irradiated at two days than at one day before adult eclosion. A dose of 5 krad was considered better than the higher doses of 7 or 9 krad because the higher the dosages increased percentage sterility of the male only slightly from 99.8% at 5 krad but considerably reduced male competitiveness from 72% at 5 krad to 52% at 9 krad for flies treated 2 days before emergence. The lowest dose of 5 krad was enough to prevent the female fruit flies from laying any egg. Irradiation at any of the dose levels did not affect the number of adults that emerged and the longevity of the fruit flies up to 38 days after adult eclosion

  17. Thermoperiodism in the cavity nesting alfalfa leafcutting bee, Megachile rotundata

    Science.gov (United States)

    The alfalfa leafcutting bee, Megachile rotundata is the most intensively managed solitary bee, and is the third most used pollinator in the United States. Previous studies have indicated that while the eclosion pattern of this cavity nesting bee is unaffected by photoperiod, a thermoperiod can give...

  18. Out with the garbage: the parasitic strategy of the mantisfly Plega hagenella mass-infesting colonies of the eusocial bee Melipona subnitida in northeastern Brazil

    Science.gov (United States)

    Maia-Silva, Camila; Hrncir, Michael; Koedam, Dirk; Machado, Renato Jose Pires; Imperatriz-Fonseca, Vera Lucia

    2013-01-01

    Between April and June of 2012 mantisflies ( Plega hagenella) were found to be extensively parasitizing the nests of two groups of managed colonzies of eusocial stingless bees ( Melipona subnitida) in the semi-arid region of northeastern Brazil. The mantisfly larvae developed inside closed brood cells of the bee comb, where each mantispid larva fed on the bee larva or pupa present in a single brood cell. Mature mantispid larvae pupated inside silken cocoons spun in place within their hosts' brood cells then emerged as pharate adults inside the bee colony. Pharate adults were never attacked and killed by host colony workers. Instead, colony workers picked up the pharates and removed them from the nest unharmed, treating them similar to the way that the general refuse is removed from the nest. Adult mantispids subsequently eclosed from their pupal exuviae outside the nest. Manipulative experiments showed that post-eclosion adult mantispids placed back within active bee colonies were quickly attacked and killed. These observations demonstrate that pharate and post-eclosion adults of P. hagenella are perceived differently by colony workers and that delayed adult eclosion is an important functional element in the parasitic life strategy of P. hagenella, allowing adults to escape without injury from the bee colonies they parasitize.

  19. Mild heat stress at a young age in Drosophila melanogaster leads to ...

    Indian Academy of Sciences (India)

    Unknown

    effect on stress resistance later in life, and on longevity. ... bouts of mild heat stress (3 h at 34°C) at a young age (days 2, 4 and 6 post-eclosion) or held under .... The mortality during the investigated lifespan .... at least during early senescence.

  20. What have two decades of laboratory life-history evolution studies ...

    Indian Academy of Sciences (India)

    Unknown

    as increased larval and pupal duration, mature larval size, and adult size at eclosion; larger wing size in cold- .... techniques have helped identify genes affecting longevity in D. melanogaster, as well as highlight the numerous ..... 1997), in determining lifespan in D. mela- nogaster, along with the possible role of maternal ...

  1. Influence of plant and residue age on attraction, acceptance and larval survival of the banana weevil Cosmopolites sordidus (Coleoptera: Curculionidae)

    NARCIS (Netherlands)

    Masanza, M.; Gold, C.S.; Huis, van A.; Ragama, P.E.

    2009-01-01

    Laboratory trials were conducted in Uganda at the Kawanda Agricultural Research Institute to determine attraction, eclosion success and larval survivorship of the banana weevil Cosmopolites sordidus (Germar) on crop residues of different ages. In the first experiment, studies focused on different

  2. Ontogeny of flight initiation in the fly Drosophila melanogaster: implications for the giant fibre system.

    Science.gov (United States)

    Hammond, Sarah; O'Shea, Michael

    2007-11-01

    There are two modes of flight initiation in Drosophila melanogaster-escape and voluntary. Although the circuitry underlying escape is accounted for by the Giant fibre (GF) system, the system underlying voluntary flight initiation is unknown. The GF system is functionally complete before the adult fly ecloses, but immature adults initially fail to react to a stimulus known to reliably evoke escape in mature adults. This suggests that escape in early adulthood, approximately 2-h post-eclosion, is not automatically triggered by the hard-wired GF system. Indeed, we reveal that escape behaviour displays a staged emergence during the first hour post-eclosion, suggesting that the GF system is subject to declining levels of suppression. Voluntary flight initiations are not observed at all during the period when the GF system is released from its suppression, nor indeed for some time after. We addressed the question whether voluntary flight initiation requires the GF system by observing take-off in Shak-B ( 2 ) mutant flies, in which the GF system is defunct. While the escape response is severely impaired in these mutants, they displayed normal voluntary flight initiation. Thus, the escape mechanism is subject to developmental modulation following eclosion and the GF system does not underlie voluntary flight.

  3. Experimental evidence for a demographic cline in Panstrongylus megistus populations

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    Barbosa Silvia E

    2001-01-01

    Full Text Available The population biology of three populations of Panstrongylus megistus was compared to determine possible influence on the behaviour and epidemiological importance of this species. The results demonstrated differences in terms of egg eclosion time, nymphal mortality and development rates, and feeding and defaecation rates. These differences appeared to follow a geographical cline, primarily reflecting different degrees of adaptation to domestic habitats.

  4. Development of the teneral adult Anoplophora glabripennis (Coleoptera: Cerambycidae): time to initiate and completely bore out of maple wood

    Science.gov (United States)

    V. Sanchez; M.A. Keena

    2013-01-01

    Anoplophora glabripennis (Motschulsky) is an introduced invasive pest with the potential to devastate hardwood forests in North America. Using artificial pupal chambers, we documented the time required by teneral adults at three temperatures (20, 25, and 30°C), 60-80% RH, and a photoperiod of 16:8 (L:D) h to initiate boring after eclosion...

  5. Activities of natural methyl farnesoids on pupariation and metamorphosis of Drosophila melanogaster

    Science.gov (United States)

    Methyl farnesoate (MF) and juvenile hormone (JH III), which respectively bind to the receptors USP and MET, and bisepoxy JH III (bisJHIII) were assessed for several activities during Drosophila larval development, and during prepupal development to eclosed adults. Dietary MF and JH III were similar...

  6. The Single Kinin Receptor Signals to Separate and Independent Physiological Pathways in Malpighian Tubules of the Yellow Fever Mosquito

    Science.gov (United States)

    2010-06-10

    mortar and pestle . On the day of the experiment a female mosquito, 4-7 days post-eclosion, was cold anesthetized and decapitated. Malpighian tubules...tubules was analyzed with the electron probe as described previously (7, 62), except that we used the JEOL JXA 8900 EPMA Microprobe (Tokyo, Japan

  7. Expression of clock genes /period/ and /timeless /in the central nervous system of the mediterranean flour moth, Ephestia kuehniella

    Czech Academy of Sciences Publication Activity Database

    Kobelková, Alena; Závodská, Radka; Šauman, Ivo; Bazalová, Olga; Doležel, David

    2015-01-01

    Roč. 30, č. 2 (2015), s. 104-116 ISSN 0748-7304 R&D Projects: GA ČR GC14-32654J Institutional support: RVO:60077344 Keywords : circadian clock * activity rhythms * eclosion rhythm Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.824, year: 2015

  8. Collectively Facilitated Behavior of the Neonate Caterpillars of Cactoblastis cactorum (Lepidoptera: Pyralidae

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    Terrence D. Fitzgerald

    2016-10-01

    Full Text Available The behavioral biology of the first instar larva of Cactoblastis cactorum was studied from the time of eclosion until the colony penetrated and initiated excavation of the host plant. Hatching from an egg stick was asynchronous, requiring 20 h for the entire cohort to eclose at 50%–70% RH and significantly longer at a lower range of RHs. On eclosion, neonates aggregated in an arena at the base of their egg stick and did not attempt to excavate the cladode until an average of 25 caterpillars had collected, approximately 15 h after the onset of egg hatch. Typically only a single entrance hole was formed, limiting the active process of excavating to one or a few individuals at-a-time until the host was fully penetrated and enlarged internally. Olfactometer tests showed that the neonates are strongly attracted to volatile chemicals released when caterpillars chewed into the cladode, accounting for the strong fidelity of the whole cohort to the initial site of penetration. In one instance, the caterpillars were observed to deal with an explosive release of mucilage by imbibing the liquid until the flooded zone was drained and the caterpillars could reenter the plant through the original entrance hole. Once inside the cladode, marked individuals adopted a regular cycle of defecating at the surface at a mean interval of approximately 10 min when followed for 35 successive cycles. Blanket spraying cladodes with a mandibular gland extract prior to hatching led to the independent dispersal of neonates and a failure to form an arena. When the cladode was impenetrable at the site of eclosion, the active cohort of unfed neonates set off together in search of a new site, marking and following a persistent trail that allowed late-to-eclose caterpillars to join their departed siblings. The adaptive significance of these observations is discussed in the context of the life history of the caterpillar.

  9. Quality of the oriental fruit fly, bactrocera dorsalis (Hendel) after sifting pupae by mechanical sifter

    International Nuclear Information System (INIS)

    Sutantawong, M.; Uthaisarn, K.

    1996-01-01

    Quality of fruit fly, bactrocera dorsalis (Hendel) in mass production is important for controlling pest populations by means of the sterile insect technique. The experiment was to study the quality of fruit fly after sifting pupae by mechanical sifter. Laboratory-reared pupae, held at 26 ± 1 degree C were sifted at intensity of 18 rpm in a rotary sifting device at 1, 2, 3, 4, 5, 6, 7 and 8 days of age. The quality of fruit flies were determined on adult eclosion and flight capability. The results showed that there were no significantly different (P < 0.05) in adult eclosion between control with sifted pupae at 1 to 8 days of age. However, there were significantly different (P < 0.05) in flight capability between control and sifted pupae at 1, 5, 6, 7, 8 days of age with sifted pupae at 2, 3, 4 days of age

  10. The effects of ionizing radiation on the face fly, Musca autumnalis DeGeer, irradiated in nitrogen

    International Nuclear Information System (INIS)

    Mansour, M.Y.

    1987-01-01

    Six day old face fly pupae, one day before emergence, were irradiated in a nitrogenous atmosphere using gamma radiation from a cobalt 60 source. Six levels of gamma radiation were used: 0, 500, 1000, 1500, 2000 and 2500 rads. The effects of gamma radiation on eclosion, reproduction, and male longevity and competitiveness were determined. Female mating habits under laboratory conditions were also examined. Irradiation under anoxic conditions did not adversely affect adult eclosion, female fecundity or male competitiveness. Sterility in treated males and females increased as radiation dosage increased. A dose of 2500 rads reduced fertility of males to less than 1% and produced similar results in the females. Longevity of treated males was not affected by increasing radiation dose up to 2000 rads. However, males receiving 2500 rads died sooner than unirradiated males. Studies on the mating habit of the female face fly showed that most of the females mated only once; however, a few of them mated a second time

  11. Insecticide-mediated apparent displacement between two invasive species of leafminer fly.

    Directory of Open Access Journals (Sweden)

    Yulin Gao

    Full Text Available BACKGROUND: Closely related invasive species may often displace one another, but it is often difficult to determine mechanisms because of the historical nature of these events. The leafmining flies Liriomyza sativae and Liriomyza trifolii have become serious invasive agricultural pests throughout the world. Where both species have invaded the same region, one predominates over the other. Although L. sativae invaded Hainan Island of China first, it recently has been displaced by the newly invasive L. trifolii. We hypothesized that differential susceptibilities to insecticides could be causing this demographic shift. METHODOLOGY/PRINCIPAL FINDINGS: Avermectin and cyromazine are the most commonly used insecticides to manage leafminers, with laboratory bioassays demonstrating that L. trifolii is significantly less susceptible to these key insecticides than is L. sativae. In trials where similar numbers of larvae of both species infested plants, which subsequently were treated with the insecticides, the eclosing adults were predominately L. trifolii, yet similar numbers of adults of both species eclosed from control plants. The species composition was then surveyed in two regions where L. trifolii has just begun to invade and both species are still common. In field trials, both species occurred in similar proportions before insecticide treatments began. Following applications of avermectin and cyromazine, almost all eclosing adults were L. trifolii in those treatment plots. In control plots, similar numbers of adults of the two species eclosed, lending further credence to the hypothesis that differential insecticide susceptibilities could be driving the ongoing displacement of L. sativae by L. trifolii. CONCLUSIONS/SIGNIFICANCE: Our results show that differential insecticide susceptibility can lead to rapid shifts in the demographics of pest complexes. Thus, successful pest management requires the identification of pest species to understand the

  12. The dynamics of male-male competition in Cardiocondyla obscurior ants

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    Cremer Sylvia

    2012-06-01

    Full Text Available Abstract Background The outcome of male-male competition can be predicted from the relative fighting qualities of the opponents, which often depend on their age. In insects, freshly emerged and still sexually inactive males are morphologically indistinct from older, sexually active males. These young inactive males may thus be easy targets for older males if they cannot conceal themselves from their attacks. The ant Cardiocondyla obscurior is characterised by lethal fighting between wingless (“ergatoid” males. Here, we analyse for how long young males are defenceless after eclosion, and how early adult males can detect the presence of rival males. Results We found that old ergatoid males consistently won fights against ergatoid males younger than two days. Old males did not differentiate between different types of unpigmented pupae several days before emergence, but had more frequent contact to ready-to-eclose pupae of female sexuals and winged males than of workers and ergatoid males. In rare cases, old ergatoid males displayed alleviated biting of pigmented ergatoid male pupae shortly before adult eclosion, as well as copulation attempts to dark pupae of female sexuals and winged males. Ergatoid male behaviour may be promoted by a closer similarity of the chemical profile of ready-to-eclose pupae to the profile of adults than that of young pupae several days prior to emergence. Conclusion Young ergatoid males of C. obscurior would benefit greatly by hiding their identity from older, resident males, as they are highly vulnerable during the first two days of their adult lives. In contrast to the winged males of the same species, which are able to prevent ergatoid male attacks by chemical female mimicry, young ergatoids do not seem to be able to produce a protective chemical profile. Conflicts in male-male competition between ergatoid males of different age thus seem to be resolved in favour of the older males. This might represent selection

  13. Survey of Hatching Spines of Bee Larvae Including Those of Apis mellifera (Hymenoptera: Apoidea).

    Science.gov (United States)

    Rozen, Jerome G; Shepard Smith, Corey; Cane, James H

    2017-07-01

    This article explores the occurrence of hatching spines among bee taxa and how these structures enable a larva on hatching to extricate itself from the egg chorion. These spines, arranged in a linear sequence along the sides of the first instar just dorsal to the spiracles, have been observed and recorded in certain groups of solitary and cleptoparasitic bee taxa. After eclosion, the first instar remains loosely covered by the egg chorion. The fact that this form of eclosion has been detected in five families (Table 1 identifies four of the families. The fifth family is the Andrenidae for which the presence of hatching spines in the Oxaeinae will soon be announced.) of bees invites speculation as to whether it is a fundamental characteristic of bees, or at least of solitary and some cleptoparasitic bees. The wide occurrence of these spines has prompted the authors to explore and discover their presence in the highly eusocial Apis mellifera L. Hatching spines were indeed discovered on first instar A. mellifera. The honey bee hatching process appears to differ in that the spines are displayed somewhat differently though still along the sides of the body, and the chorion, instead of splitting along the sides of the elongate egg, seems to quickly disintegrate from the emerging first instar in association with the nearly simultaneous removal of the serosa that covers and separates the first instar from the chorion. Unexpected observations of spherical bodies of various sizes perhaps containing dissolving enzymes being discharged from spiracular openings during hatching may shed future light on the process of how A. mellifera effects chorion removal during eclosion. Whereas hatching spines occur among many groups of bees, they appear to be entirely absent in the Nomadinae and parasitic Apinae, an indication of a different eclosion process. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  14. Evaluation of the Thorax of Manduca Sexta for Flapping Wing Micro Air Vehicle Applications

    Science.gov (United States)

    2012-12-01

    subject to the effects of low Reynolds number flight. These effects extend from wind gusts to unstable aerodynamic flow and viscous dominated flow (Shyy...operate as a mechanical spring damper at resonance during flapping flight (Bolsman 2010). For wing actuation, the M.sexta has two fairly simple and...freshly eclosed moth a surface to climb up, which is an absolute necessity. The moth must climb off of the ground in order to pump fluids through

  15. Effect of Emamectin Benzoate on Mortality, Proboscis Extension, Gustation and Reproduction of the Corn Earworm, Helicoverpa zea

    OpenAIRE

    López, Juan D.; Latheef, M. A.; Hoffmann, W. C.

    2010-01-01

    Newly emerged corn earworm adults, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) require a carbohydrate source from plant or other exudates and nectars for dispersal and reproduction. Adults actively seek and forage at feeding sites upon eclosion in the habitat of the larval host plant or during dispersal to, or colonization of, a suitable reproductive habitat. This nocturnal behavior of H. zea has potential for exploitation as a pest management strategy for suppression using an adult fee...

  16. Study Regarding the Correlation between Body Mass and Spur Length in Hunting Pheasant (Males, in October

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    Eugenie Grigoroiu

    2011-10-01

    Full Text Available This work presents a study on the correlation between body mass and spur length in October 2009.October is the month when the pheasant hunting begins. The structure per ages of pheasant cocks is not well known, but we may consider that over 80% are pheasants eclosed during the current year, from the first, second or the third mating, so that the body mass and spur length were different according to age.

  17. Edible insects of Northern Angola

    OpenAIRE

    Lautenschläger,Thea; Neinhuis,Christoph; Monizi,Mawunu; Mandombe,José Lau; Förster,Anke; Henle,Thomas; Nuss,Matthias

    2017-01-01

    From 2013–2017, we accompanied and interviewed local people harvesting edible insects in the Northern Angolan province of Uíge. Insect and host plant samples were collected for species identification and nutritive analyses. Additionally, live caterpillars were taken to feed and keep until pupation and eclosion of the imago, necessary for morphological species identification. Altogether, 18 insect species eaten by humans were recorded. Twenty four edible insect species were formerly known from...

  18. The Evolution of Personally Disadvantageous Punishment among Cofoundresses of the Ant Acromyrmex Versicolor

    OpenAIRE

    Cabrales, Antonio; Pollock, Gregory B.; Rissing, Steven W.

    1998-01-01

    Cofoundresses of the desert fungus garden ant Acromyrmex versicolor exhibit a forager specialist who subsumes all foraging risk prior to first worker eclosion (Rissing et al. 1989). In an experiment designed to mimic a "cheater" who refuses foraging assignment when her lot, cofoundresses delayed/failed to replace their forager, often leading to demise of their garden (Rissing et al. 1996). The cheater on task assignment is harmed, but so too is the punisher, as all will die without a healthy ...

  19. Behavior of ergatoid males in the ant, Cardiocondyla nuda

    OpenAIRE

    Heinze, Jürgen; Künholz, S.; Schilder, K.; Hölldobler, B.

    1993-01-01

    Ergatoid males of the ant, Cardiocondyla nuda, attack and frequently kill young males during or shortly after eclosion. Smaller colonies therefore contain typically only one adult male, which may inseminate all alate queens which are reared in the colony over a few weeks. In larger colonies, several males may be present, however, fighting among adult males was not observed. We discuss the significance of male fighting behavior in ants.

  20. Effect of cryopreservation on the pre-hatching behavior in the Mexican fruit fly Anastrepha ludens Loew (Diptera, Tephritidae).

    Science.gov (United States)

    Rajamohan, Arun; Rinehart, Joseph P; Leopold, Roger A

    2018-02-01

    In a sampling of untreated embryos of the economically important fruit pest species, Anastrepha ludens, the cumulative hatch percentage in the lab was noted to be ∼85%. Approximately 70% of the larvae had eclosed through the posterior pole of the egg. This process is effected by the act of Pole Reversal (PR) of the fully developed pre-hatch larva from the wider anterior to the narrower posterior pole of the egg. Investigation of the effects of cryopreservation and various pretreatments prior to cryostorage on the PR behavior was prompted by the observation of significantly lower proportion of cryopreserved embryos exhibiting the PR behavior. Pretreatments (dechorionation and permeabilization) followed by vitrification resulted in delayed hatching, reflecting a slower embryonic development rate of ∼10 h. A smaller proportion of the treated embryos either eclosed from the anterior end of the egg or did not eclose at all despite complete development and prehatch gnawing activity. In the untreated controls, 24.0% of the embryos eclosed from the anterior pole. After permeabilization and cryopreservation, 83% and 55% (adjusted hatch) of the embryos were noted to hatch this way, respectively. An analysis of the hatch count after the treatments shows that factors contributing to the embryos' inability to properly invert polarity is not solely due to cryopreservation but also due to the pretreatment procedures including dechorionation and permeabilization. In fact, the permeabilization pre-treatment contributed the highest to this phenomenon lending support to the view that chemical toxicity rather than physical effects of cryopreservation play a major role in post-cryopreservation effects. Published by Elsevier Inc.

  1. Residual Toxicity of Abamectin, Chlorpyrifos, Cyromazine, Indoxacarb and Spinosad on Liriomyza trifolii (Burgess (Diptera: Agromyzidae in Greenhouse Conditions

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    Ghasem Askari Saryazdi

    2012-01-01

    Full Text Available Liriomyza trifolii is an important pest of vegetable crops in many parts of the worldincluding Iran. In this study potted bean plants were sprayed with recommended fieldrates of abamectin, chlorpyrifos, cyromazine, indoxacarb and spinosad. To assess the residualactivities of these insecticides, the plants were infested with L. trifolii adults 2 hours; 1, 3,5, 7, 10, 15, 20, 25 and 35 days after insecticidal treatments. The adults were allowed to stayon treated plants for eight hours. The treated plants were kept in a greenhouse. Numberof feeding stipples and larval mines on leaves, as well as pupation and adult eclosion rateswere assessed. Two-way ANOVA procedure of SAS was used for statistical analysis andthe treatment means were separated using Duncan’s multiple range test. Abamectin andspinosad severely affected egg hatching and embryonic development. Eggs oviposited inleaves with residues of chlorpyrifos up to 5 days old, had reduced hatching. Larval developmentwas also, affected by residues of chlorpyrifos up to four weeks old. Indoxacarbreduced larval development and adult eclosion in treatments with up to 20 days old residues.Cyromazine had no effect on the number of larval mines, but, pupation was severelyhampered and adult eclosion was completely ceased even in treatments with five weeksold residues. Determining the residual activity of insecticides used for controlling this pestis useful in avoiding unnecessary treatments.

  2. Influence of Pupation Substrate on Mass Production and Fitness of Adult Anastrepha obliqua Macquart (Diptera: Tephritidae) for Sterile Insect Technique Application.

    Science.gov (United States)

    Aceituno-Medina, Marysol; Rivera-Ciprian, José Pedro; Hernández, Emilio

    2017-12-05

    Tephritid mass-rearing systems require an artificial substrate for pupation. Pupation substrate characteristics influence the quality of insects produced. Coconut fiber, as an alternative to the conventional pupation substrate vermiculite, was evaluated for Anastrepha obliqua Macquart (Diptera: Tephritidae) pupation behavior (pupation patterns, distribution, respiration rate, and pupal weight) and adult fitness (adult eclosion time, flight ability, and male mating competitiveness). Pupation percentage at 24 h, pupal weight, and flight ability were not significantly affected by substrate type. Adult eclosion levels of 50% were reached at 29.7 and 41.6 h for coconut fiber and vermiculite, respectively. Pupae distribution patterns differed between substrates because the larval aggregation level was reduced during the pupation process in coconut fiber. The pupae aggregation was three times greater in vermiculite than in coconut fiber. A higher respiratory rate in the last days of pupation and adult eclosion were recorded in the insects maintained in coconut fiber. Coconut fiber suitability as a pupation substrate for quality mass production of pupae and its implications for sterile insect technique are discussed. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Use of primary cultures of Kenyon cells from bumblebee brains to assess pesticide side effects.

    Science.gov (United States)

    Wilson, Daniel E; Velarde, Rodrigo A; Fahrbach, Susan E; Mommaerts, Veerle; Smagghe, Guy

    2013-09-01

    Bumblebees are important pollinators in natural and agricultural ecosystems. The latter results in the frequent exposure of bumblebees to pesticides. We report here on a new bioassay that uses primary cultures of neurons derived from adult bumblebee workers to evaluate possible side-effects of the neonicotinoid pesticide imidacloprid. Mushroom bodies (MBs) from the brains of bumblebee workers were dissected and dissociated to produce cultures of Kenyon cells (KCs). Cultured KCs typically extend branched, dendrite-like processes called neurites, with substantial growth evident 24-48 h after culture initiation. Exposure of cultured KCs obtained from newly eclosed adult workers to 2.5 parts per billion (ppb) imidacloprid, an environmentally relevant concentration of pesticide, did not have a detectable effect on neurite outgrowth. By contrast, in cultures prepared from newly eclosed adult bumblebees, inhibitory effects of imidacloprid were evident when the medium contained 25 ppb imidacloprid, and no growth was observed at 2,500 ppb. The KCs of older workers (13-day-old nurses and foragers) appeared to be more sensitive to imidacloprid than newly eclosed adults, as strong effects on KCs obtained from older nurses and foragers were also evident at 2.5 ppb imidacloprid. In conclusion, primary cultures using KCs of bumblebee worker brains offer a tool to assess sublethal effects of neurotoxic pesticides in vitro. Such studies also have the potential to contribute to the understanding of mechanisms of plasticity in the adult bumblebee brain. © 2013 Wiley Periodicals, Inc.

  4. The use of statistical procedures for comparison of the production of eggs considering different treatments and lines of quails

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    Robson Marcelo Rossi

    2012-04-01

    Full Text Available To make inferences concerning a population, parametric methods are traditionally used for sample data analysis assuming that these come from ordinary populations, which not always happens. Most of the times such assumption leads to inadequate conclusions and decisions, especially when the data are distributed asymmetrically. It was aimed on this work to adjust some plausible models for this type of data, aiming to compare eggs productions in quails of different lines through frequentist and Bayesian methods. In the analyzed data it could be verified that the parametric and non-parametric frequentist procedures were, in general, equally conclusive. The Bayesian procedure was the only one which detected difference between the yellow and red lines, regarding the preconized energy diet, and between the blue and yellow for the second eclosion group. By the frequentist methods differences between the blue and red lines were not found; however, given a Poisson distribution for the eggs production, through multiple comparisons between the posterior mean under the Bayesian focus, differences were found between all lines. For being more sensitive, besides flexible, such procedure detected differences not observed by the traditional methods between the yellow and red lines, in the higher energy diet; between the blue and the red one in the second eclosion group and in general. It was concluded that quails of the yellow line showed bigger eggs production, regardless of the eclosion group and diet. Such results raise the discussion on the appropriate use of methods and procedures for statistical data analysis.

  5. Impaired Olfactory Associative Behavior of Honeybee Workers Due to Contamination of Imidacloprid in the Larval Stage

    Science.gov (United States)

    Yang, En-Cheng; Chang, Hui-Chun; Wu, Wen-Yen; Chen, Yu-Wen

    2012-01-01

    The residue of imidacloprid in the nectar and pollens of the plants is toxic not only to adult honeybees but also the larvae. Our understanding of the risk of imidacloprid to larvae of the honeybees is still in a very early stage. In this study, the capped-brood, pupation and eclosion rates of the honeybee larvae were recorded after treating them directly in the hive with different dosages of imidacloprid. The brood-capped rates of the larvae decreased significantly when the dosages increased from 24 to 8000 ng/larva. However, there were no significant effects of DMSO or 0.4 ng of imidacloprid per larva on the brood-capped, pupation and eclosion rates. Although the sublethal dosage of imidacloprid had no effect on the eclosion rate, we found that the olfactory associative behavior of the adult bees was impaired if they had been treated with 0.04 ng/larva imidacloprid in the larval stage. These results demonstrate that a sublethal dosage of imidacloprid given to the larvae affects the subsequent associative ability of the adult honeybee workers. Thus, a low dose of imidacloprid may affect the survival condition of the entire colony, even though the larvae survive to adulthood. PMID:23166680

  6. Sigma Virus (DMelSV Incidence in Lines of Drosophila melanogaster Selected for Survival following Infection with Bacillus cereus

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    Meghan L. Bentz

    2017-01-01

    Full Text Available The immune response of Drosophila melanogaster is complex and involves both specific and general responses to parasites. In this study we tested for cross-immunity for bacteria and viruses by scoring the incidence of infection with the vertically transmitted Sigma virus (DMelSV in the progeny of a cross between females transmitting DMelSV at high frequencies and males from lines subjected to three selection regimes related to resistance to Bacillus cereus. There was no significant difference in transmission of DMelSV among selection regimes, though results suggest that the B. cereus selected lines had lower rates of infection by DMelSV. We found a significant difference in viral infection with respect to the sex of the progeny, with males consistently less likely to be infected than females. Given a finite energy budget, flies that have experienced immune system challenge may show alterations in other life history traits. Later eclosing progeny were also less likely to be infected than earlier eclosing progeny, indicating a relationship with development time. Finally, there was a significant interaction between the timing of collection and the sex of the progeny, such that later eclosing males were the most resistant group. Increased development time is sometimes associated with increased energy acquisition; from this perspective, increased development time may be associated with acquiring sufficient resources for effective resistance.

  7. Functional characterization of bursicon receptor and genome-wide analysis for identification of genes affected by bursicon receptor RNAi

    Science.gov (United States)

    Bai, Hua; Palli, Subba R.

    2010-01-01

    Bursicon is an insect neuropeptide hormone that is secreted from the central nervous system into the hemolymph and initiates cuticle tanning. The receptor for bursicon is encoded by the rickets (rk) gene and belongs to the G protein-coupled receptor (GPCR) superfamily. The bursicon and its receptor regulate cuticle tanning as well as wing expansion after adult eclosion. However, the molecular action of bursicon signaling remains unclear. We utilized RNA interference (RNAi) and microarray to study the function of the bursicon receptor (Tcrk) in the model insect, Tribolium castaneum. The data included here showed that in addition to cuticle tanning and wing expansion reported previously, Tcrk is also required for development and expansion of integumentary structures and adult eclosion. Using custom microarrays, we identified 24 genes that are differentially expressed between Tcrk RNAi and control insects. Knockdown in the expression of one of these genes, TC004091, resulted in the arrest of adult eclosion. Identification of genes that are involved in bursicon receptor mediated biological processes will provide tools for future studies on mechanisms of bursicon action. PMID:20457145

  8. 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.

  9. Age-related Decline of Abiotic Stress Tolerance in Young Drosophila melanogaster Adults.

    Science.gov (United States)

    Colinet, Hervé; Chertemps, Thomas; Boulogne, Isabelle; Siaussat, David

    2016-12-01

    Stress tolerance generally declines with age as a result of functional senescence. Age-dependent alteration of stress tolerance can also occur in early adult life. In Drosophila melanogaster, evidence of such a decline in young adults has only been reported for thermotolerance. It is not known whether early adult life entails a general stress tolerance reduction and whether the response is peculiar to thermal traits. The present work was designed to investigate whether newly eclosed D melanogaster adults present a high tolerance to a range of biotic and abiotic insults. We found that tolerance to most of the abiotic stressors tested (desiccation, paraquat, hydrogen peroxide, deltamethrin, and malathion) was high in newly eclosed adults before dramatically declining over the next days of adult life. No clear age-related pattern was found for resistance to biotic stress (septic or fungal infection) and starvation. These results suggest that newly eclosed adults present a culminating level of tolerance to extrinsic stress which is likely unrelated to immune process. We argue that stress tolerance variation at very young age is likely a residual attribute from the previous life stage (ontogenetic carryover) or a feature related to the posteclosion development. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. The seesaw effect of winter temperature change on the recruitment of cotton bollworms Helicoverpa armigera through mismatched phenology.

    Science.gov (United States)

    Reddy, Gadi V P; Shi, Peijian; Hui, Cang; Cheng, Xiaofei; Ouyang, Fang; Ge, Feng

    2015-12-01

    Knowing how climate change affects the population dynamics of insect pests is critical for the future of integrated pest management. Rising winter temperatures from global warming can drive increases in outbreaks of some agricultural pests. In contrast, here we propose an alternative hypothesis that both extremely cold and warm winters can mismatch the timing between the eclosion of overwintering pests and the flowering of key host plants. As host plants normally need higher effective cumulative temperatures for flowering than insects need for eclosion, changes in flowering time will be less dramatic than changes in eclosion time, leading to a mismatch of phenology on either side of the optimal winter temperature. We term this the "seesaw effect." Using a long-term dataset of the Old World cotton bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in northern China, we tested this seesaw hypothesis by running a generalized additive model for the effects of the third generation moth in the preceding year, the winter air temperature, the number of winter days below a critical temperature and cumulative precipitation during winter on the demography of the overwintering moth. Results confirmed the existence of the seesaw effect of winter temperature change on overwintering populations. Pest management should therefore consider the indirect effect of changing crop phenology (whether due to greenhouse cultivation or to climate change) on pest outbreaks. As arthropods from mid- and high latitudes are actually living in a cooler thermal environment than their physiological optimum in contrast to species from lower latitudes, the effects of rising winter temperatures on the population dynamics of arthropods in the different latitudinal zones should be considered separately. The seesaw effect makes it more difficult to predict the average long-term population dynamics of insect pests at high latitudes due to the potential sharp changes in annual growth rates

  11. Sex-specific effect of juvenile diet on adult disease resistance in a field cricket.

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    Clint D Kelly

    Full Text Available Food limitation is expected to reduce an individual's body condition (body mass scaled to body size and cause a trade-off between growth and other fitness-related traits, such as immunity. We tested the condition-dependence of growth and disease resistance in male and female Gryllus texensis field crickets by manipulating diet quality via nutrient content for their entire life and then subjecting individuals to a host resistance test using the live bacterium Serratia marcescens. As predicted, crickets on a high-quality diet eclosed more quickly, and at a larger body size and mass. Crickets on a high-quality diet were not in better condition at the time of eclosion, but they were in better condition 7-11 days after eclosion, with females also being in better condition than males. Despite being in better condition, however, females provided with a high-quality diet had significantly poorer disease resistance than females on a low-quality diet and in poor condition. Similarly, males on low- and high-quality diets did not differ in their disease resistance, despite differing in their body condition. A sex difference in disease resistance under diet-restriction suggests that females might allocate resources toward immunity during development if they expect harsh environmental conditions as an adult or it might suggest that females allocate resources toward other life history activities (i.e. reproduction when food availability increases. We do not know what immune effectors were altered under diet-restriction to increase disease resistance, but our findings suggest that increased immune function might provide an explanation for the sexually-dimorphic increase in longevity generally observed in diet-restricted animals.

  12. Gamma irradiation effects on the larval stage of the mediterranean flour moth Ephestia Kuehniella (Zell.)

    International Nuclear Information System (INIS)

    Salem, Y.S.; Ahmed, M.Y.Y.; El-Banby, M.A.; Abdel-Baky, S.M.

    1985-01-01

    Larvae of Ephestia Kuehniella Z. were irradiated with different doses of gamma radiation to study the effect of irradiation on immature stages, pupation, emergence, malformation and sex ratio of the produced insects. Mortality percent of irradiated larvae was increased progressively with increasing the dose. Sublethal doses retarded the duration of the immature stages. There was a gradual decrease in adult eclosion and adult longevity with increasing the dose. Fecundity and fertility of the resulting adults were gradually reduced with the increase of the dose. No complete sterility occurred after larval irradiation. Malformed adults of both sexes increased as the dose was increased

  13. Effects of gamma irradiation on larvae development of Monochamns altevnatus hope in packing wood

    International Nuclear Information System (INIS)

    Chen Wentuan; Zhong Guohua; Hu Meiying; Chen Xiaofan; Luo Zijuan; Pan Guoqi

    2006-01-01

    Effects of gamma irradiation on Monochamns altevnatus Hope larvae were studied. The results showed that mortality of Monchamns altevnatus Hope on the 21 st day reached over 90% by a dose of 500 Gy treatment. The pupating rate decreased below 10% with the dose higher than 400 Gy, while the abnormal pupae began to appear at this dose, and there are no eclosion at 450 Gy. The relationship between death rate and absorbed dose could be described by dose-response curve for tested pest. (authors)

  14. Impact of moisture on survival of Aedes aegypti eggs and ovicidal activity of Metarhizium anisopliae under laboratory conditions

    Directory of Open Access Journals (Sweden)

    C Luz

    2008-03-01

    Full Text Available The effect of relative humidity (43%, 75%, 86% and > 98% on Aedes aegypti eggs treated with Metarhizium anisopliae or water only was tested for up to a six months exposure at 25ºC. Survival of larvae inside eggs was clearly affected by the lowest humidity (43% tested, and eclosion diminished at all humidities after increasing periods of exposure. M. anisopliae showed to have a strong ovicidal activity only at humidity close to saturation. No difference of activity was found between conidia and hyphal bodies tested. This fungus affected larvae inside eggs and has potential as a control agent of this important vector in breeding sites with high moisture.

  15. Pupal development and pigmentation process of a polka-dotted fruit fly, Drosophila guttifera (Insecta, Diptera).

    Science.gov (United States)

    Fukutomi, Yuichi; Matsumoto, Keiji; Agata, Kiyokazu; Funayama, Noriko; Koshikawa, Shigeyuki

    2017-06-01

    Various organisms have color patterns on their body surfaces, and these color patterns are thought to contribute to physiological regulation, communication with conspecifics, and signaling with the environment. An adult fly of Drosophila guttifera (Insecta: Diptera: Drosophilidae) has melanin pigmentation patterns on its body and wings. Though D. guttifera has been used for research into color pattern formation, how its pupal development proceeds and when the pigmentation starts have not been well studied. In this study, we defined the pupal stages of D. guttifera and measured the pigment content of wing spots from the pupal period to the period after eclosion. Using a transgenic line which carries eGFP connected with an enhancer of yellow, a gene necessary for melanin synthesis, we analyzed the timing at which the yellow enhancer starts to drive eGFP. We also analyzed the distribution of Yellow-producing cells, as indicated by the expression of eGFP during pupal and young adult periods. The results suggested that Yellow-producing cells were removed from wings within 3 h after eclosion, and wing pigmentation continued without epithelial cells. Furthermore, the results of vein cutting experiments showed that the transport of melanin precursors through veins was necessary for wing pigmentation. These results showed the importance of melanin precursors transported through veins and of extracellular factors which were secreted from epithelial cells and left in the cuticle.

  16. Big maggots dig deeper: size-dependent larval dispersal in flies.

    Science.gov (United States)

    Davis, Jeremy M; Coogan, Laura E; Papaj, Daniel R

    2015-09-01

    The ability of individual animals to select habitats optimal for development and survival can be constrained by the costs of moving through the environment. Animals that seek overwintering sites underground, for example, may be constrained by the energy required to burrow into the soil. We conducted field and laboratory studies to determine the relationship between individual size and overwintering site selection in the tephritid flies, Rhagoletis juglandis and Rhagoletis suavis. We also explored the effect of site selection on pupal mortality, parasitism, and the ability to emerge from overwintering sites after eclosion. In both species, and in both lab and field tests, larger pupae were found at deeper soil depths. In addition, marginally non-significant trends indicated pupae in deeper sites were 48% more likely to survive the overwintering period. Finally, larger individuals were more likely to eclose and emerge from the soil at a given depth, but flies in deep overwintering sites were less likely to emerge from those sites than flies in shallow sites. Our data indicate that overwintering site selection represents a trade-off between avoiding predators and parasites that occur at shallow sites, and the energetic and mortality costs of burrowing to, overwintering in, and emerging from, deeper sites. The size-dependent overwintering site selection demonstrated here has implications for population dynamics and pest control strategies. Some fly control measures, such as the introduction of parasites or predators, will be mitigated when the deepest and least accessible overwintering pupae represent a disproportionately large amount of the population's reproductive capacity.

  17. INCUBATION YIELD AS A FUNCTION OF BROILER BREEDER AGE / RENDIMENTO DE INCUBAÇÃO EM FUNÇÃO DA IDADE DA MATRIZ

    Directory of Open Access Journals (Sweden)

    G. F. da Silva

    2017-09-01

    Full Text Available The factors involved in poultry egg incubation include breeder hen age, which may influence both the external and internal quality of eggs. In this context, this study sought to determine incubation yield among eggs from breeder hens at three ages. A total of 1,728 eggs were obtained from Cobb broiler breeders at three ages (26 weeks, 32 weeks, and 53 weeks and incubated. At the end of the incubation process, eclosion, hatchability, the percentage of infertile eggs, the time of embryo mortality, and chick weight were all analyzed according to breeder hen age. Analysis of variance was applied to the results, and egg fertility was found to be associated with breeder age, since lower rates of eclosion were found in eggs from younger broiler breeders. Chick weight was also found to be influenced by breeder age, since eggs from older broiler breeders hatched into heavier chicks. However, neither mortality nor hatchability were found to be affected by breeder hen age.

  18. Sex-specific life history responses to nymphal diet quality and immune status in a field cricket.

    Science.gov (United States)

    Kelly, C D; Neyer, A A; Gress, B E

    2014-02-01

    Individual fitness is expected to benefit from earlier maturation at a larger body size and higher body condition. However, poor nutritional quality or high prevalence of disease make this difficult because individuals either cannot acquire sufficient resources or must divert resources to other fitness-related traits such as immunity. Under such conditions, individuals are expected to mature later at a smaller body size and in poorer body condition. Moreover, the juvenile environment can also produce longer-term effects on adult fitness by causing shifts in resource allocation strategies that could alter investment in immune function and affect adult lifespan. We manipulated diet quality and immune status of juvenile Texas field crickets, Gryllus texensis, to investigate how poor developmental conditions affect sex-specific investment in fitness-related traits. As predicted, a poor juvenile diet was related to smaller mass and body size at eclosion in both sexes. However, our results also reveal sexually dimorphic responses to different facets of the rearing environment: female life history decisions are affected more by diet quality, whereas males are affected more by immune status. We suggest that females respond to decreased nutritional income because this threatens their ability to achieve a large adult body size, whereas male fitness is more dependent on reaching adulthood and so they invest in immunity and survival to eclosion. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  19. Effects of gamma-radiation on eggs of Pomacea Haustrum (Reeve, 1843) from the Pampulha Lake, Belo Horizonte, M. G. (prosobranchia, Pilidae)

    Energy Technology Data Exchange (ETDEWEB)

    Dos Santos Carvalho, O; Milward De Andrade, R; Ricardo C Adriano, A; Mansur Neto, E

    1974-01-01

    Pomacea haustrum eggs, with less than 24 hours after oviposition in the field, were exposed, in groups, to 500, 1,000, 1,500, 2,000, 2,500, 3,000, 3,500, and 4,000 rad, respectively. As regards the irradiated eggs, only 23.9 percent (1,460) achieved eclosion, whose percentage varied according to the gamma-ray dosage used: 41.6 percent for 500 rad; 35.5 percent for 1,000; 21.1 percent for 1,500; 7.9 percent for 2,000; 4.9 percent for 3,000 and, finally, 0.3 percent for 3,500 rad. The 6 egg-masses (1,500 eggs) irradiated with 2,500 rad as well as the 4 (1,401 eggs) exposed to 4,000 rad did not hatch up to 30 days after exposure to gamma-rays. Hatching, among the irradiated eggs, started 11 to 16 days later, their maximum incubation period having ranged from 14 to 16 days. It has also been observed that both the period of incubation and that of recovery of the eggs not irreversibly damaged by the gamma-rays are proportional to the intensity of radiation. Field and laboratory investigations have shown that the eggs in a same mass do not hatch simultaneously, a period of two or more days having already elapsed between the first and last eclosion.

  20. Poor sequestration of toxic host plant cardenolides and their rapid loss in the milkweed butterfly Danaus chrysippus (Lepidoptera: Nymphalidae: Danainae: Danaini).

    Science.gov (United States)

    Mebs, Dietrich; Wunder, Cora; Toennes, Stefan W

    2017-06-01

    Butterflies of the genus Danaus are known to sequester toxic cardenolides from milkweed host plants (Apocynaceae). In particular, Danaus plexippus efficiently sequesters and stores these compounds, whereas D. chrysippus, is considered to poorly sequester cardenolides. To estimate its sequestration capability compared with that of D. plexippus, larvae of both species were jointly reared on Asclepias curassavica and the major cardenolides of the host plant, calotropin and calactin, were analyzed in adults sampled at different time intervals after eclosion. Both cardenolides were detected in body and wings of D. plexippus. Whereas the calotropin-concentration remained constant over a period of 24 days, that of calactin steadily decreased. In the body, but not in the wings of D. chrysippus, calactin only was detected in low amounts, which was then almost completely lost during the following 8 days after eclosion, suggesting that in contrast to D. plexippus, cardenolides seem to be less important for that butterfly's defence against predators. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Developmental Times of Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) at Constant Temperatures and Applications in Forensic Entomology.

    Science.gov (United States)

    Yang, Yong-Qiang; Li, Xue-Bo; Shao, Ru-Yue; Lyu, Zhou; Li, Hong-Wei; Li, Gen-Ping; Xu, Lyu-Zi; Wan, Li-Hua

    2016-09-01

    The characteristic life stages of infesting blowflies (Calliphoridae) such as Chrysomya megacephala (Fabricius) are powerful evidence for estimating the death time of a corpse, but an established reference of developmental times for local blowfly species is required. We determined the developmental rates of C. megacephala from southwest China at seven constant temperatures (16-34°C). Isomegalen and isomorphen diagrams were constructed based on the larval length and time for each developmental event (first ecdysis, second ecdysis, wandering, pupariation, and eclosion), at each temperature. A thermal summation model was constructed by estimating the developmental threshold temperature D0 and the thermal summation constant K. The thermal summation model indicated that, for complete development from egg hatching to eclosion, D0 = 9.07 ± 0.54°C and K = 3991.07 ± 187.26 h °C. This reference can increase the accuracy of estimations of postmortem intervals in China by predicting the growth of C. megacephala. © 2016 American Academy of Forensic Sciences.

  2. DNA degradation and genetic analysis of empty puparia: genetic identification limits in forensic entomology.

    Science.gov (United States)

    Mazzanti, Morena; Alessandrini, Federica; Tagliabracci, Adriano; Wells, Jeffrey D; Campobasso, Carlo P

    2010-02-25

    Puparial cases are common remnants of necrophagous flies in crime investigations. They usually represent the longest developmental time and, therefore, they can be very useful for the estimation of the post-mortem interval (PMI). However, before any PMI estimate, it is crucial to identify the species of fly eclosed from each puparium associated with the corpse. Morphological characteristics of the puparium are often distinctive enough to permit a species identification. But, even an accurate morphological analysis of empty puparia cannot discriminate among different species of closely related flies. Furthermore, morphological identification may be impossible if the fly puparia are poorly preserved or in fragments. This study explores the applicability of biomolecular techniques on empty puparia and their fragments for identification purposes. A total of 63 empty puparia of necrophagous Diptera resulting from forensic casework were examined. Samples were divided into three groups according to size, type and time of eclosion in order to verify whether the physical characteristics and puparia weathering can influence the amount of DNA extraction. The results suggest that a reliable genetic identification of forensically important flies may also be performed from empty puparia and/or their fragments. However, DNA degradation can deeply compromise the genetic analysis since the older the fly puparia, the smaller are the amplified fragments. 2009 Elsevier Ireland Ltd. All rights reserved.

  3. Effect of Cymbopogon citratus (lemongrass) and Syzygium aromaticum (clove) oils on the morphology and mortality of Aedes aegypti and Anopheles dirus larvae.

    Science.gov (United States)

    Soonwera, Mayura; Phasomkusolsil, Siriporn

    2016-04-01

    Cymbopogon citratus (lemongrass) and Syzygium aromaticum (clove) oils were evaluated to determine mortality rates, morphological aberrations, and persistence when used against third and fourth larval instars of Aedes aegypti and Anopheles dirus. The oils were evaluated at 1, 5, and 10 % concentrations in mixtures with soybean oil. Persistence of higher concentrations was measured over a period of 10 days. For Ae. aegypti, both plant oils caused various morphological aberrations to include deformed larvae, incomplete eclosion, white pupae, deformed pupae, dead normal pupae, and incomplete pupal eclosion. All of these aberrations led to larval mortality. In Ae. aegypti larvae, there were no significant differences in mortality at days 1, 5, and 10 or between third and fourth larval instar exposure. In An. dirus, morphological aberrations were rare and S. aromaticum oil was more effective in causing mortality among all larval stages. Both oils were equally effective at producing mortality on days 1, 5, and 10. Both oils had slightly increased LT50 rates from day 1 to day 10. In conclusion, both lemongrass and clove oils have significant effects on the immature stages of Ae. aegypti and An. dirus and could potentially be developed for use as larvicides.

  4. Effect of Gamma Radiation on Sterility , Sexual Competitiveness and Mating Ability of Carob Moth Ephestia calidella (Guen.) Irradiated as Pupae

    International Nuclear Information System (INIS)

    Ahmad, T.R.; Hamad, B.S.; Barkhi, G.S.

    2007-01-01

    When mature pupae (2 days before eclosion) of Ephestia calidella (Guen.) were irradiated with the doses of 0, 100, 200, 300 and 400 Gy, the males had a high level of sterility which was 92% at 300 Gy, but it was not significantly different from those treated with 200 and 400 Gy respectively.Furthermore,a high level of sterility (100%) was obtained for female pupae treated with 400 Gy.Meanwhile, when both males and females irradiated as pupae (2 days before eclosion) with 200, 300 and 400 Gy showed a high level of sterility which was 94.4, 98.2 and 99.6%, respectively.It is evident that females were less radio-resistant than males.When males from irradiated pupae at different doses added to untreated adult at ratio of (3:1:1) irradiated males :unirradiated males: unirradiated females the percentage og egg hatch decreased from 76.4% in the control to 36.3% at the dose of 400 Gy.However, sexual competitiveness value and inseminate female irradiated as pupae reduced with increasing doses

  5. Effect of gamma radiation on the metamorphic stages of Dermestes maculatus DeGeer (Coleoptera: Dermestidae)

    International Nuclear Information System (INIS)

    Seal, D.R.; Tilton, E.W.

    1986-01-01

    The effects of γ-radiation on all stages of the hide beetle Dermestes maculatus, DeGeer were studied. Eggs of D. maculatus were more susceptible to γ radiation than other stages. Egg radiosensitivity decreased with increasing embryonic development. An absorbed dose of 200 Gy killed the 1st, 6th and 7th instar larvae, but the 4th and 5th instar larvae were more resistant. The developmental period increased in treated larvae. Pupae (24 h) treated with 150 Gy failed to eclose, but eclosion was not affected in older pupae. Adults from female pupae irradiated at 72 h with 150 Gy were infertile, but male pupae required more than 200 Gy for sterilization. The average number of eggs per female decreased with increasing doses when either the male or female of the pair was irradiated as pupae or adults. Adult males were sterile after irradiation 300 Gy and adult females treated with the same dose failed to lay eggs. Newly emerged irradiated adults or female adults from irradiated 72-h-old pupae recovered some fertility after treatment with doses as high as 150 Gy. Adult males from irradiated 72-h-old pupae were treated at doses of 50 and 100 Gy showed a higher reproductive capacity at 60 days than at 15 days post-treatment. A dose between 200 and 300 Gy was necessary to provide complete sterility of 24-h-old adults. (author)

  6. Storage hexamer utilization in two lepidopterans: differences correlated with the timing of egg formation

    Directory of Open Access Journals (Sweden)

    M.L. Pan

    2001-04-01

    Full Text Available Most insects produce two or more storage hexamers whose constituents and developmental profiles are sufficiently different to suggest specialization in the ways that they support metamorphosis and reproduction. Hexamerin specializations are compared here in the Cecropia moth (Hyalophora cecropia, which produces eggs during the pupal-adult molt, and the Monarch butterfly (Danaus plexippus, which produces eggs under long-day conditions after adult eclosion. In both sexes of both species, reserves of arylphorin (ArH were exhausted by the end of metamorphosis. In Cecropia, the same was true for the high-methionine hexamerins, V-MtH and M-MtH. But in short day Monarch females 20-30% of the pupal reserves of V-MtH and M-MtH survived metamorphosis, persisting until long-day conditions were imposed to stimulate egg formation. Differences in storage sites have been documented in other lepidopterans, with MtH reserves being found primarily in fat body protein granules and the ArH reserve being found primarily in the hemolymph. Similar differences could explain how a fraction of the MtH's, but not of ArH, escapes utilization during metamorphosis in a species with post-eclosion egg formation. No differences in utilization schedules were detected between V- and M-MtH, despite divergent compositions and antigenic reactivity.

  7. Multidendritic sensory neurons in the adult Drosophila abdomen: origins, dendritic morphology, and segment- and age-dependent programmed cell death

    Directory of Open Access Journals (Sweden)

    Sugimura Kaoru

    2009-10-01

    Full Text Available Abstract Background For the establishment of functional neural circuits that support a wide range of animal behaviors, initial circuits formed in early development have to be reorganized. One way to achieve this is local remodeling of the circuitry hardwiring. To genetically investigate the underlying mechanisms of this remodeling, one model system employs a major group of Drosophila multidendritic sensory neurons - the dendritic arborization (da neurons - which exhibit dramatic dendritic pruning and subsequent growth during metamorphosis. The 15 da neurons are identified in each larval abdominal hemisegment and are classified into four categories - classes I to IV - in order of increasing size of their receptive fields and/or arbor complexity at the mature larval stage. Our knowledge regarding the anatomy and developmental basis of adult da neurons is still fragmentary. Results We identified multidendritic neurons in the adult Drosophila abdomen, visualized the dendritic arbors of the individual neurons, and traced the origins of those cells back to the larval stage. There were six da neurons in abdominal hemisegment 3 or 4 (A3/4 of the pharate adult and the adult just after eclosion, five of which were persistent larval da neurons. We quantitatively analyzed dendritic arbors of three of the six adult neurons and examined expression in the pharate adult of key transcription factors that result in the larval class-selective dendritic morphologies. The 'baseline design' of A3/4 in the adult was further modified in a segment-dependent and age-dependent manner. One of our notable findings is that a larval class I neuron, ddaE, completed dendritic remodeling in A2 to A4 and then underwent caspase-dependent cell death within 1 week after eclosion, while homologous neurons in A5 and in more posterior segments degenerated at pupal stages. Another finding is that the dendritic arbor of a class IV neuron, v'ada, was immediately reshaped during post-eclosion

  8. The effects of constant and alternating temperatures on the reproductive potential, life span, and life expectancy of Anastrepha fraterculus (Wiedemann (Dipteria: Tephritidae

    Directory of Open Access Journals (Sweden)

    V. V. CARDOSO

    Full Text Available Ovarian development, oviposition, larval eclosion, ornithine decarboxylase (ODC activity, ovarian, testis and ejaculatory apodeme measurements (length, width, and area, and the number of spermatozoa of Anastrepha fraterculus (Wiedemann were analyzed at alternating (20º/6ºC and 20º/13°C and constant (6°C; 25°C temperatures. Life span and life expectancy were also analyzed for both genders. All the results suggest that temperature, especially alternating temperatures, increase not only male and female reproductive potential but also their life span and life expectancy. These changes can be a powerful strategy triggered by A. fraterculus as a means to survive the stressful temperature conditions found in winter in the apple production region in Brazil, enabling this species to increase its population density and cause apple damage when spring begins.

  9. The effects of constant and alternating temperatures on the reproductive potential, life span, and life expectancy of Anastrepha fraterculus (Wiedemann (Dipteria: Tephritidae

    Directory of Open Access Journals (Sweden)

    CARDOSO V. V.

    2002-01-01

    Full Text Available Ovarian development, oviposition, larval eclosion, ornithine decarboxylase (ODC activity, ovarian, testis and ejaculatory apodeme measurements (length, width, and area, and the number of spermatozoa of Anastrepha fraterculus (Wiedemann were analyzed at alternating (20masculine/6masculineC and 20masculine/13degreesC and constant (6degreesC; 25degreesC temperatures. Life span and life expectancy were also analyzed for both genders. All the results suggest that temperature, especially alternating temperatures, increase not only male and female reproductive potential but also their life span and life expectancy. These changes can be a powerful strategy triggered by A. fraterculus as a means to survive the stressful temperature conditions found in winter in the apple production region in Brazil, enabling this species to increase its population density and cause apple damage when spring begins.

  10. Translocation-based genetic sexing system to enhance the sterile insect technique against the melon fly (Diptera: Tephritidae)

    International Nuclear Information System (INIS)

    McCombs, S.D.; Lee, S.G.; Saul, S.H.

    1993-01-01

    The autosomal recessive bubble wing (bw) mutant was used to construct a translocation-based genetic sex sorting system in the melon fly, Bactrocera cucurbitae (Coquillett). The translocation stock has females with the bubble wing phenotype that are unable to fly, but the males are wild-type and fly normally. The bubble wing translocation strain has lower egg hatch, larval viability, and eclosion rates than the wild-type strain. Expression of the bubble wing trait is temperature-dependent, with high expression of the trait in 92% of adults at 23°C but in only 15% of adults at 28°C. This translocation-based sex sorting system is the only method available for automatic separation of male and female melon flies in sterile insect release programs

  11. Control of egg hatch ability and adult emergence of three fruit fly species in papayas by gamma irradiation

    International Nuclear Information System (INIS)

    Resilva, S.S.; Pasion, W.B.; Moy, J.H.

    1991-01-01

    The effects of gamma radiation on the oriental fruit fly, Bactrocera Dorsalis (Hendel), melon fly, Bactrocera Cucurbitae (Coquilett), and Mediterranean fruit fly, Ceratitis Capitata (Weidemann) were studied. Melon fly was determined to be the most susceptible of the three species. A dosage of 550 Gy rendered the eggs 100% sterile when irradiated in papayas at 4-6 hours before hatching. Oriental and mediterranean fruit flies were found to be more resistant, requiring doses of 750 and 850 Gy, respectively. A dose of only 100 Gy was needed to inhibit adult eclosion when the three species were treated at third instar larvae. Warm water treatment at 49 0 C for 20 minutes was found sufficient in preventing the hatching of any egg in the infested papaya fruits. However, since eggs may hatch before the warm-water treatment can be applied, a combination of irradiation treatment using 100 Gy is recommended for disinfestation of papaya fruits. (author). 17 refs.; 3 tabs

  12. Reações da espécie invasora Achatina fulica (Mollusca: Achatinidae à fatores abióticos: perspectivas para o manejo Reactions of the invasive alien species Achatina fulica to abiotic factors: perspectives for the management

    Directory of Open Access Journals (Sweden)

    Marta Luciane Fischer

    2009-09-01

    Full Text Available Achatina fulica Bowdich, 1822 is an african snail that is invasive in different parts of the world, being characterized mainly by its high adaptability. Our objective was to evaluate the influence of abiotic factors, such as temperature and substrate, on the egg eclosion, adult and juvenile reaction to different abiotics factors, and the resistance of A. fulica to popular methods of control. Three studies were made, including 19 laboratory experiments and observations of free animals in the municipal district of Guaraqueçaba, southern Brazil. Eggs were characterized as the most fragile phase, whereas the juveniles and adults were resistant to the immersion in fresh and salt water and little resistant to temperature variation and salt, using burying, aestivation, and muscular force as defense strategies. Those strategies should be considered in management actions and in orientating popular methods of control.

  13. A simple method for preparing artificial larval diet of the West Indian sweetpotato weevil, Euscepes postfasciatus (Fairmaire) (Coleoptera: Curculionidae)

    International Nuclear Information System (INIS)

    Uesato, T.; Kohama, T.

    2008-01-01

    The method for preparing ordinary larval artificial diet for Euscepes postfasciatus (old diet) was complicated and time consuming. Some ingredients (casein, saccharose, salt mixture, etc.) of the diet were added to boiled agar solution, others (vitamin mixture, sweetpotato powder, etc.) were added after the solution was cooled to 55degC. To simplify the diet preparation, we combined all ingredients before mixing with water, and then boiled the solution (new diet). There were no significant differences of survival rate (from egg hatching to adult eclosion) and right elytron length between the weevils reared on the old and new diets, but the development period (from egg to adult) of the weevils fed the new diet was significantly (1.3 days) longer than that of those fed the old diet. Preparation time of the new diet was half that of the old diet. These results suggest that simplified diet preparation can be introduced into the mass-rearing of E. postfasciatus

  14. Male fighting and ``territoriality'' within colonies of the ant Cardiocondyla venustula

    Science.gov (United States)

    Frohschammer, Sabine; Heinze, Jürgen

    2009-01-01

    The ant genus Cardiocondyla is characterized by a bizarre male polymorphism with wingless fighter males and winged disperser males. Winged males have been lost convergently in several clades, and in at least one of them, wingless males have evolved mutual tolerance. To better understand the evolutionary pathways of reproductive tactics, we investigated Cardiocondyla venustula, a species, which in a phylogenetic analysis clusters with species with fighting and species with mutually tolerant, wingless males. Wingless males of C. venustula use their strong mandibles to kill freshly eclosed rival males and also engage in short fights with other adult males, but in addition show a novel behavior hitherto not reported from social insect males: they spread out in the natal nest and defend “territories” against other males. Ant males therefore show a much larger variety of reproductive tactics than previously assumed.

  15. Male fighting and "territoriality" within colonies of the ant Cardiocondyla venustula.

    Science.gov (United States)

    Frohschammer, Sabine; Heinze, Jürgen

    2009-01-01

    The ant genus Cardiocondyla is characterized by a bizarre male polymorphism with wingless fighter males and winged disperser males. Winged males have been lost convergently in several clades, and in at least one of them, wingless males have evolved mutual tolerance. To better understand the evolutionary pathways of reproductive tactics, we investigated Cardiocondyla venustula, a species, which in a phylogenetic analysis clusters with species with fighting and species with mutually tolerant, wingless males. Wingless males of C. venustula use their strong mandibles to kill freshly eclosed rival males and also engage in short fights with other adult males, but in addition show a novel behavior hitherto not reported from social insect males: they spread out in the natal nest and defend "territories" against other males. Ant males therefore show a much larger variety of reproductive tactics than previously assumed.

  16. Patogenisitas Beberapa Isolat Cendawan Entomopatogen Metarhizium spp. terhadap Telur Spodoptera litura Fabricius (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    Trizelia Trizelia

    2015-09-01

    Full Text Available Metarhizium spp. is one of the entomopathogenic fungus that can be used to control Spodoptera litura. The purpose of this research was to study the pathogenicity of Metarhizium spp. to Spodoptera litura eggs. The isolates were collected from rhizosphere of different crops i.e., cabbage, onion, leek and chili. The results showed that there was effect of all isolates on egg mortality. Mortality of S. litura eggs depend on the fungal isolates, ranged between 19.79%-75.70%. First instar larvae was also died 3 days after eclosion. The maximum mortality of first instar larvae was 58.65%. At a concentration of 108 conidia/ml, isolate Mt-kb had the highest virulence which caused higher mortality of eggs and first instar larvae.

  17. Inherited partial sterility and chromosomal rearrangements in succeeding generations after irradiation of Adoxophyes orana (Lepidoptera, Tortricidae) with substerilizing doses of X-rays and fast neutrons

    International Nuclear Information System (INIS)

    Snieder, D.; Velde, H.J. ter

    1975-01-01

    Male and female adult Adoxophyes orana F.v.R. were irradiated within 24 h of eclosion with doses of X-rays between 2.5 and 22.5 krad and with 3 krad fast neutrons. The treated moths were single pair mated with untreated moths and egg hatchability was assessed. The surviving F1 progeny and also succeeding generations were tested in a similar manner. Mortality of larval and pupal stages and sex ratios were also determined. Differences observed between the fertility of the F1 from irradiated males and from irradiated females led to the hypothesis that the time of meiosis with respect to the time of irradiation is of crucial importance in the expression and inheritance of the induced rearrangements. Consequences for differences in radiosensitivity between sexes and for the application of sub-sterile insects for practical control purposes are discussed

  18. Gamma radiation effect on the pupal stage of Ephestia kuehniella Z

    International Nuclear Information System (INIS)

    Ahmed, M.Y.Y.; Abdel-Baky, S.M.; El-Bamby, M.A.; Salem, Y.S.

    1985-01-01

    The effects of gamma radiation on the pupal stage of Ephestia kuehniella (Zell.) was studied. Percent mortality of irradiated pupae increased gradually with increasing the dose. The dose 10 krad delivered to 1-2 day old pupae prevented adult emergence, while the dose 60 krad gave rise to 100% mortality of the full grown pupae. There was a gradual decrease in the percent of adult eclosion as a result of pupal irradiation at both ages. Life span of adults of both sexes, irradiated in the pupal stages, was shortened as the dose increased. The doses 25 and 45 krad induced complete sterility for females and males, respectively. Male pupae were more radioresistant than females. The fecundity and fertility were decreased by increasing the dose. The greater reduction in fecundity and fertility was obtained when both sexes were treated and mated together rather than when one sex only was treated. (author)

  19. How age influences phonotaxis in virgin female Jamaican field crickets (Gryllus assimilis

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    Karen Pacheco

    2013-08-01

    Full Text Available Female mating preference can be a dominant force shaping the evolution of sexual signals. However, females rarely have consistent mating preferences throughout their lives. Preference flexibility results from complex interactions of predation risk, social and sexual experience, and age. Because residual reproductive value should theoretically decline with age, older females should not be as choosy as younger females. We explored how age influences phonotaxis towards a standard mate attraction signal using a spherical treadmill (trackball and a no-choice experimental protocol. Female Jamaican field crickets, Gryllus assimilis, were highly variable in their phonotaxis; age explained up to 64% of this variation. Females 10 days post imaginal eclosion and older oriented toward the mate attraction signal, with 10- and 13-day females exhibiting the greatest movement in the direction of the signal. Our study suggests 10- and 13-day old females would be most responsive when quantifying the preference landscape for G. assimilis sexual signals.

  20. Alterations in premating behavior and pheromone biology of gamma-irradiated Trichoplusia ni (Lepidoptera:Noctuidae)

    International Nuclear Information System (INIS)

    Szentesi, A.; McLaughlin, J.R.; Coffelt, J.A.

    1977-01-01

    Exposure of female cabbage looper pupae, Trichoplusia ni, to gamma irradiation at 0 to 72 hr before eclosion resulted in significantly reduced moving and calling activity of the adults. The effects were dose-related from 10 to 40 kR. Generally, irradiation in a nitrogen atmosphere slightly reduced deleterious effects, but fractionation of the radiation dose did not. Four-day-old irradiated females contained significantly more sex pheromone than untreated females, indicating that loss of pheromone is positively correlated to the amount of calling activity. Males exposed to 20 kR or 40 kR in nitrogen were not affected in their flight response in an olfactometer to a level of synthetic pheromone ca. equal to that released by a calling female or to 0.1 x this level. The response of males exposed to 40 kR in air, however, was significantly decreased at the lower pheromone concentration

  1. Remodeling of peripheral nerve ensheathment during the larval-to-adult transition in Drosophila.

    Science.gov (United States)

    Subramanian, Aswati; Siefert, Matthew; Banerjee, Soumya; Vishal, Kumar; Bergmann, Kayla A; Curts, Clay C M; Dorr, Meredith; Molina, Camillo; Fernandes, Joyce

    2017-10-01

    Over the course of a 4-day period of metamorphosis, the Drosophila larval nervous system is remodeled to prepare for adult-specific behaviors. One example is the reorganization of peripheral nerves in the abdomen, where five pairs of abdominal nerves (A4-A8) fuse to form the terminal nerve trunk. This reorganization is associated with selective remodeling of four layers that ensheath each peripheral nerve. The neural lamella (NL), is the first to dismantle; its breakdown is initiated by 6 hours after puparium formation, and is completely removed by the end of the first day. This layer begins to re-appear on the third day of metamorphosis. Perineurial glial (PG) cells situated just underneath the NL, undergo significant proliferation on the first day of metamorphosis, and at that stage contribute to 95% of the glial cell population. Cells of the two inner layers, Sub-Perineurial Glia (SPG) and Wrapping Glia (WG) increase in number on the second half of metamorphosis. Induction of cell death in perineurial glia via the cell death gene reaper and the Diptheria toxin (DT-1) gene, results in abnormal bundling of the peripheral nerves, suggesting that perineurial glial cells play a role in the process. A significant number of animals fail to eclose in both reaper and DT-1 targeted animals, suggesting that disruption of PG also impacts eclosion behavior. The studies will help to establish the groundwork for further work on cellular and molecular processes that underlie the co-ordinated remodeling of glia and the peripheral nerves they ensheath. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1144-1160, 2017. © 2017 Wiley Periodicals, Inc.

  2. Rearing larvae of the oriental fruit fly, Dacus Dorsalis Hendel on media containing banana or rice bran

    International Nuclear Information System (INIS)

    Poramarcom, R.; Mitchell, S.

    1983-12-01

    Materials available in Thailand were substituted for some of those in the standard medium currently used in rearing larvae of Dacus dorsalis Hendel at the Tropical Fruit and Vegetable Research Laboratory, Honolulu, Hawaii. The purpose of this study is to decrease rearing costs through medium modification in Thailand. Larvae were reared in different media: three media containing banana and the other three containing rice bran, as the main ingredient. Wheat germ flakes and torula yeast were added to at: (1) 7.2 and 3.6% (2) 7.2 and 7.2% and (3) 10.8 and 7.2% by weight respectively. The standard medium comprised the seventh medium. The results showed that higher mean pupal recovery, higher mean pupal weight, and higher mean percentage of adult eclosion were obtained from media containing banana compared to media without banana. Media containing banana, (3) and (1), resulted in a significantly (P=0.05) higher mean pupal recovery, 57.49 and 56.88% respectively. Media containing banana, (2) and (3), resulted in the highest mean pupal weight, 12 and 11.68 mg. respectively. Media containing banana produced pupae with highest percentage of adult eclosion. No significant difference was observed in fecundity and fertility of flies reared in all media. Torula yeast and/or wheat germ flakes did not increase the number or weight of pupae. This study showed that media containing banana was the most suitable media for rearing D. dorsalis larvae. All three media containing rice bran were unsuitable for rearing this insect

  3. Host status of grapefruit and Valencia oranges for Anastrepha serpentina and Anastrepha ludens (Diptera: Tephritidae).

    Science.gov (United States)

    Mangan, Robert L; Thomas, Donald B; Moreno, Aleena M Tarshis

    2011-04-01

    Anastrepha serpentina (Wiedemann) (Diptera: Tephritidae) is sporadically captured in the Rio Grande Valley of Texas. Although its preferred hosts are in the Sapotaceae family, several varieties of Citrus, including grapefruit and oranges are listed as alternate hosts. Although Mexican fruit fly, Anastrepha ludens (Loew), is known to be a major pest of Citrus, doubt exists as to the status of Citrus as a breeding host for A. serpentina. To evaluate the host status of commercial Citrus for A. serpentina we compared oviposition and development with that of A. ludens under laboratory conditions with 'Rio Red' grapefruit (Citrus paradisi MacFayden) and 'Valencia' oranges [Citrus sinensis (L.) Osbeck] in different stages of maturity. Both fly species oviposited in early season fruit in which the eggs and larvae died in the fruit albedo. Survival of either species to the adult stage occurred in later season grapefruit. In oranges, no A. serpentina larvae survived compared with 150 A. ludens surviving to adults. Survival on both Citrus species was much lower for A. serpentina, only approximately 5% of eggs eclosed into larvae in grapefruit compared with approximatley 50% for A. ludens. In oranges approximately 16% of A. serpentina eggs eclosed compared with approximately 76% for A. ludens. In grapefruit, only one fourth as many A. serpentina larvae survived to the adult stage compared with A. ludens. Additional experiments were performed in a greenhouse on small, caged trees of la coma (Sideroxylon celastrinum H.B.K.), a Texas species of Sapotaceae. The A. serpentina females readily oviposited into these berries and normal adults emerged. The present low incidence of the adults, coupled with the high mortality during development of the larvae, suggests that Texas citrus is unlikely to support a breeding population of A. serpentina.

  4. Effect of microwave exposure on the ovarian development of Drosophila melanogaster.

    Science.gov (United States)

    Panagopoulos, Dimitris J

    2012-06-01

    In the present experiments the effect of GSM radiation on ovarian development of virgin Drosophila melanogaster female insects was studied. Newly emerged adult female flies were collected and divided into separate identical groups. After the a lapse of certain number of hours-different for each group-the insects (exposed and sham-exposed) were dissected and their intact ovaries were collected and photographed under an optical microscope with the same magnification. The size of the ovaries was compared between exposed and sham-exposed virgin female insects, during the time needed for the completion of oogenesis and maturation of the first eggs in the ovarioles. Immediately after the intact ovaries were photographed, they were further dissected into individual ovarioles and treated for TUNEL and acridine-orange assays to determine the degree of DNA damage in the egg chamber cells. The study showed that the ovarian size of the exposed insects is significantly smaller than that of the corresponding sham-exposed insects, due to destruction of egg chambers by the GSM radiation, after DNA damage and consequent cell death induction in the egg chamber cells of the virgin females as shown in previous experiments on inseminated females. The difference in ovarian size between sham-exposed and exposed virgin female flies becomes most evident 39-45 h after eclosion when the first eggs within the ovaries are at the late vitellogenic and post-vitellogenic stages (mid-late oogenesis). More than 45 h after eclosion, the difference in ovarian size decreases, as the first mature eggs of the sham-exposed insects are leaving the ovaries and are laid.

  5. Chronic low-dose γ-irradiation of Drosophila melanogaster larvae induces gene expression changes and enhances locomotive behavior

    International Nuclear Information System (INIS)

    Kim, Cha Soon; Lee, Byung Sub; Lee, In Kyung; Yang, Kwang Hee; Kim, Ji-Young; Nam, Seon Young; Seong, Ki Moon

    2015-01-01

    Although radiation effects have been extensively studied, the biological effects of low-dose radiation (LDR) are controversial. This study investigates LDR-induced alterations in locomotive behavior and gene expression profiles of Drosophila melanogaster. We measured locomotive behavior using larval pupation height and the rapid iterative negative geotaxis (RING) assay after exposure to 0.1 Gy γ-radiation (dose rate of 16.7 mGy/h). We also observed chronic LDR effects on development (pupation and eclosion rates) and longevity (life span). To identify chronic LDR effects on gene expression, we performed whole-genome expression analysis using gene-expression microarrays, and confirmed the results using quantitative real-time PCR. The pupation height of the LDR-treated group at the first larval instar was significantly higher (∼2-fold increase in PHI value, P < 0.05). The locomotive behavior of LDR-treated male flies (∼3 − 5 weeks of age) was significantly increased by 7.7%, 29% and 138%, respectively (P < 0.01), but pupation and eclosion rates and life spans were not significantly altered. Genome-wide expression analysis identified 344 genes that were differentially expressed in irradiated larvae compared with in control larvae. We identified several genes belonging to larval behavior functional groups such as locomotion (1.1%), oxidation reduction (8.0%), and genes involved in conventional functional groups modulated by irradiation such as defense response (4.9%), and sensory and perception (2.5%). Four candidate genes were confirmed as differentially expressed genes in irradiated larvae using qRT-PCR (>2-fold change). These data suggest that LDR stimulates locomotion-related genes, and these genes can be used as potential markers for LDR. (author)

  6. Identification of lipases involved in PBAN stimulated pheromone production in Bombyx mori using the DGE and RNAi approaches.

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    Mengfang Du

    Full Text Available BACKGROUND: Pheromone biosynthesis activating neuropeptide (PBAN is a neurohormone that regulates sex pheromone synthesis in female moths. Bombyx mori is a model organism that has been used to explore the signal transduction pattern of PBAN, which is mediated by a G-protein coupled receptor (GPCR. Although significant progress has been made in elucidating PBAN-regulated lipolysis that releases the precursor of the sex pheromone, little is known about the molecular components involved in this step. To better elucidate the molecular mechanisms of PBAN-stimulated lipolysis of cytoplasmic lipid droplets (LDs, the associated lipase genes involved in PBAN- regulated sex pheromone biosynthesis were identified using digital gene expression (DGE and subsequent RNA interference (RNAi. RESULTS: Three DGE libraries were constructed from pheromone glands (PGs at different developed stages, namely, 72 hours before eclosion (-72 h, new emergence (0 h and 72 h after eclosion (72 h, to investigate the gene expression profiles during PG development. The DGE evaluated over 5.6 million clean tags in each PG sample and revealed numerous genes that were differentially expressed at these stages. Most importantly, seven lipases were found to be richly expressed during the key stage of sex pheromone synthesis and release (new emergence. RNAi-mediated knockdown confirmed for the first time that four of these seven lipases play important roles in sex pheromone synthesis. CONCLUSION: This study has identified four lipases directly involved in PBAN-stimulated sex pheromone biosynthesis, which improve our understanding of the lipases involved in releasing bombykol precursors from triacylglycerols (TAGs within the cytoplasmic LDs.

  7. Vertebrate-like CRYPTOCHROME 2 from monarch regulates circadian transcription via independent repression of CLOCK and BMAL1 activity.

    Science.gov (United States)

    Zhang, Ying; Markert, Matthew J; Groves, Shayna C; Hardin, Paul E; Merlin, Christine

    2017-09-05

    Circadian repression of CLOCK-BMAL1 by PERIOD and CRYPTOCHROME (CRY) in mammals lies at the core of the circadian timekeeping mechanism. CRY repression of CLOCK-BMAL1 and regulation of circadian period are proposed to rely primarily on competition for binding with coactivators on an α-helix located within the transactivation domain (TAD) of the BMAL1 C terminus. This model has, however, not been tested in vivo. Here, we applied CRISPR/Cas9-mediated mutagenesis in the monarch butterfly ( Danaus plexippus ), which possesses a vertebrate-like CRY (dpCRY2) and an ortholog of BMAL1, to show that insect CRY2 regulates circadian repression through TAD α-helix-dependent and -independent mechanisms. Monarch mutants lacking the BMAL1 C terminus including the TAD exhibited arrhythmic eclosion behavior. In contrast, mutants lacking the TAD α-helix but retaining the most distal C-terminal residues exhibited robust rhythms during the first day of constant darkness (DD1), albeit with a delayed peak of eclosion. Phase delay in this mutant on DD1 was exacerbated in the presence of a single functional allele of dpCry2 , and rhythmicity was abolished in the absence of dpCRY2. Reporter assays in Drosophila S2 cells further revealed that dpCRY2 represses through two distinct mechanisms: a TAD-dependent mechanism that involves the dpBMAL1 TAD α-helix and dpCLK W328 and a TAD-independent mechanism involving dpCLK E333. Together, our results provide evidence for independent mechanisms of vertebrate-like CRY circadian regulation on the BMAL1 C terminus and the CLK PAS-B domain and demonstrate the importance of a BMAL1 TAD-independent mechanism for generating circadian rhythms in vivo.

  8. Uso da uréia como suplemento protéico na dieta de doadoras e receptoras de embriões bovinos Urea as a protein supplementation in the diet of bovine embryo donors and recipients

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    Amílcar Gasperin Barreto

    2003-02-01

    Full Text Available Doze doadoras de embriões Bos indicus da raça Nelore foram confinadas recebendo 25 kg de silagem de milho e 2,5 kg de três diferentes suplementos concentrados ao dia. O ingrediente protéico ofertado foi SOJA (S, SOJA+URÉIA (S+U e URÉIA (U. Após período de 20 dias, as doadoras foram superovuladas e seus embriões colhidos e cultivados in vitro até eclosão. Não se observou diferença entre tratamentos com relação ao número total de estruturas colhidas (4,17; 8,42 e 7,00, número de embriões viáveis (2,25; 3,50 e 4,33, de ovócitos (1,42; 3,92 e 1,08 ou de estruturas degeneradas (0,5; 1,0 e 1,83, bem como na taxa de eclosão in vitro (81,48%; 78,57% e 84,62% nos grupos S, S+U e U, respectivamente. As 66 receptoras de embriões foram mantidas em pasto de Braquiaria decumbens com 1,25 kg de suplemento concentrado dividido em três tratamentos semelhantes aos recebidos pelas doadoras. Após 37 dias, embriões foram descongelados e transferidos em grupos S, S+U e U. Não se observaram diferenças na taxa de gestação aos 30 dias (25; 28 e 28,57% e aos 60 dias (16,67; 28 e 25%, nos grupos S, S+U e U, respectivamente. Tendo em vista que não foi observado efeito deletério na qualidade dos embriões, taxa de eclosão e fertilidade das receptoras, pode-se concluir que a uréia se mostrou como uma opção na substituição do farelo de soja em concentrados na suplementação de doadoras e receptoras de embriões.Twelve Bos indicus (Nellore embryo donors were confined receiving 25 kg maize silage and 2.5 kg concentrate supplement per day. The proteic supplements used were SOYA (S, SOYA+UREA (S+U and UREA (U. After 20 day, embryo donors were superovulated and their embryos collected and cultivated in vitro until eclosion. There was no significant statistical difference between the three groups in total number of structures collected (4.17, 8.42 and 7.00, number of viable embryos (2.25, 3.50 and 4.33, oocytes (1.42, 3.92 and 1.08 or

  9. Functional characterization of three MicroRNAs of the Asian Tiger Mosquito, Aedes albopictus

    Science.gov (United States)

    2013-01-01

    Background Temporal and stage specific expression of microRNAs (miRNAs) in embryos, larvae, pupae and adults of Aedes albopictus showed differential expression levels across the four developmental stages, indicating their potential regulatory roles in mosquito development. The functional characterization of these miRNAs was not known. Accordingly our study evaluated the functional characterization of three miRNAs, which are temporally up-regulated in the various developmental stages of Ae. albopictus mosquitoes. Methods miRNA mimics, inhibitors and negative controls were designed and their knock-in and knock-down efficiency were analyzed by qRT-PCR after transfecting the mosquito cell lines C6/36, and also by injecting in their specific developmental stages. The functional role of each individual miRNA was analyzed with various parameters of development such as, hatching rate and hatching time in embryos, eclosion rate in larvae, longevity and fecundity in the adult mosquitoes. Results The knock-in with the specifically designed miRNA mimics showed increased levels of expression of miRNA compared with their normal controls. We confirmed these findings using qRT-PCR, both by in vitro expression in C6/36 mosquito cell lines after transfection as well as in in vivo expression in developmental stages of mosquitoes by microinjection. The knock-down of expression with the corresponding inhibitors showed a considerable decrease in the expression levels of these miRNAs and obvious functional effects in Ae. albopictus development, detected by a decrease in the hatching rate of embryos and eclosion rate in larvae and a marked reduction in longevity and fecundity in adults. Conclusion This study carried out by knock-in and knock-down of specifically and temporally expressed miRNAs in Ae. albopictus by microinjection is a novel study to delineate the importance of the miRNA expression in regulating mosquito development. The knock-down and loss of function of endogenously

  10. Gene Expression Associated with Early and Late Chronotypes in Drosophila melanogaster

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    Mirko ePegoraro

    2015-05-01

    Full Text Available The circadian clock provides the temporal framework for rhythmic behavioural and metabolic functions. In the modern era of industrialization, work and social pressures, the clock function is often jeopardized, resulting in adverse and chronic effects on health. Understanding circadian clock function, particularly individual variation in diurnal phase preference (chronotype, and the molecular mechanisms underlying such chronotypes may lead to interventions that could abrogate clock dysfunction and improve human (and animal health and welfare. Our preliminary studies suggested that fruitflies, like humans, can be classified as early rising ‘larks’ or late rising ‘owls’, providing a convenient model system for these types of studies. We have identified strains of flies showing increased preference for morning emergence (Early or E from the pupal case, or more pronounced preference for evening emergence (Late or L. We have sampled pupae the day before eclosion (4th day after pupariation at 4 h intervals in the E and L strains, and examined differences in gene expression by RNAseq. We have identified differentially expressed transcripts between the E and L strains which provide candidate genes for studies of Drosophila chronotypes and their human orthologues.

  11. Loss of Centrobin Enables Daughter Centrioles to Form Sensory Cilia in Drosophila.

    Science.gov (United States)

    Gottardo, Marco; Pollarolo, Giulia; Llamazares, Salud; Reina, Jose; Riparbelli, Maria G; Callaini, Giuliano; Gonzalez, Cayetano

    2015-08-31

    Sensory cilia are organelles that convey information to the cell from the extracellular environment. In vertebrates, ciliary dysfunction results in ciliopathies that in humans comprise a wide spectrum of developmental disorders. In Drosophila, sensory cilia are found only in the neurons of type I sensory organs, but ciliary dysfunction also has dramatic consequences in this organism because it impairs the mechanosensory properties of bristles and chaetae and leads to uncoordination, a crippling condition that causes lethality shortly after eclosion. The cilium is defined by the ciliary membrane, a protrusion of the cell membrane that envelops the core structure known as the axoneme, a microtubule array that extends along the cilium from the basal body. In vertebrates, basal body function requires centriolar distal and subdistal appendages and satellites. Because these structures are acquired through centriole maturation, only mother centrioles can serve as basal bodies. Here, we show that although centriole maturity traits are lacking in Drosophila, basal body fate is reserved to mother centrioles in Drosophila type I neurons. Moreover, we show that depletion of the daughter-centriole-specific protein Centrobin (CNB) enables daughter centrioles to dock on the cell membrane and to template an ectopic axoneme that, although structurally defective, protrudes out of the cell and is enveloped by a ciliary membrane. Conversely, basal body capability is inhibited in mother centrioles modified to carry CNB. These results reveal the crucial role of CNB in regulating basal body function in Drosophila ciliated sensory organs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Melon flies: dosage-response and sexual competitiveness after treatment with gamma irradiation in a nitrogen atmosphere

    International Nuclear Information System (INIS)

    Ashraf, M.; Chatha, N.; Ohinata, K.; Harris, E.J.

    1975-01-01

    Doses of 18-19 krad of gamma irradiation were needed to produce a level of sterility of 99.5% or higher in males Dacus cucurbitae Coquillett treated in nitrogen as pupae 2 days before eclosion or as 2- or 5-day-old adults. The same level of sterility was obtained with 6-8 krad when pupae or 2-day-old adults were irradiated in air. Males irradiated in nitrogen either as pupae or as 2-day-old adults were fully competitive with normal males, but males treated in nitrogen as 5-day-old adults and males irradiated in air as 2-day-old adults or as pupae were only 40-60% as competitive as normal males. Recovery of fertility with time occurred in males treated in nitrogen as 2-day-old adults, although not in males treated in nitrogen in the late pupal stage. However, mortality in males treated in nitrogen in the pupal stage at 6 wk was about twice that of the former groups

  13. Systematic analysis of fly models with multiple drivers reveals different effects of ataxin-1 and huntingtin in neuron subtype-specific expression.

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    Risa Shiraishi

    Full Text Available The fruit fly, Drosophila melanogaster, is a commonly used model organism for neurodegenerative diseases. Its major advantages include a short lifespan and its susceptibility to manipulation using sophisticated genetic techniques. Here, we report the systematic comparison of fly models of two polyglutamine (polyQ diseases. We induced expression of the normal and mutant forms of full-length Ataxin-1 and Huntingtin exon 1 in cholinergic, dopaminergic, and motor neurons, and glial cells using cell type-specific drivers. We systematically analyzed their effects based on multiple phenotypes: eclosion rate, lifespan, motor performance, and circadian rhythms of spontaneous activity. This systematic assay system enabled us to quantitatively evaluate and compare the functional disabilities of different genotypes. The results suggest different effects of Ataxin-1 and Huntingtin on specific types of neural cells during development and in adulthood. In addition, we confirmed the therapeutic effects of LiCl and butyrate using representative models. These results support the usefulness of this assay system for screening candidate chemical compounds that modify the pathologies of polyQ diseases.

  14. Clutch morphology and the timing of exposure impact the susceptibility of aquatic insect eggs to esfenvalerate.

    Science.gov (United States)

    Palmquist, Katherine R; Jenkins, Jeffrey J; Jepson, Paul C

    2008-08-01

    We investigated Baetis spp. (mayfly), Hesperoperla pacifica (stonefly), and Brachycentrus americanus (caddisfly) susceptibility at the egg stage to esfenvalerate, a synthetic pyrethroid insecticide. Eggs were obtained from the field or from field-collected gravid females at sites near Corvallis (OR, USA) and the Metolius River at Camp Sherman (OR, USA) for static exposures under controlled conditions for temperature and light. Eggs were exposed to esfenvalerate for 48 h at concentrations ranging from 0.025 to 4.0 microg/L. No effect on mortality or posthatch growth was detected in H. pacifica eggs exposed to esfenvalerate concentrations up to 1.0 microg/L. Exposure to 0.07 microg/L of esfenvalerate, however, caused a significant increase in Baetis spp. egg mortality, and exposure of near-eclosion eggs to lower concentrations (0.025 and 0.05 microg/L) resulted in behavioral effects and reduced survivorship in newly hatched Baetis nymphs. Early stage B. americanus eggs were 10-fold more sensitive to esfenvalerate when removed from the gelatinous clutch before exposure, an indication that the gelatin affords protection from toxicant exposure. Exposures of near-hatch B. americanus clutches to esfenvalerate concentrations ranging between 0.035 and 0.2 microg/L, however, resulted in significant clutch death within clutches resulting from behavioral aberrations of first-instar larvae. The results of the present study suggest that aquatic insect egg clutch morphology can be a strong influence on susceptibility of embryos to esfenvalerate exposure.

  15. Rearing Tenebrio molitor in BLSS: Dietary fiber affects larval growth, development, and respiration characteristics

    Science.gov (United States)

    Li, Leyuan; Stasiak, Michael; Li, Liang; Xie, Beizhen; Fu, Yuming; Gidzinski, Danuta; Dixon, Mike; Liu, Hong

    2016-01-01

    Rearing of yellow mealworm (Tenebrio molitor L.) will provide good animal nutrition for astronauts in a bioregenerative life support system. In this study, growth and biomass conversion data of T. molitor larvae were tested for calculating the stoichiometric equation of its growth. Result of a respiratory quotient test proved the validity of the equation. Fiber had the most reduction in mass during T. molitor‧s consumption, and thus it is speculated that fiber is an important factor affecting larval growth of T. molitor. In order to further confirm this hypothesis and find out a proper feed fiber content, T. molitor larvae were fed on diets with 4 levels of fiber. Larval growth, development and respiration in each group were compared and analyzed. Results showed that crude-fiber content of 5% had a significant promoting effect on larvae in early instars, and is beneficial for pupa eclosion. When fed on feed of 5-10% crude-fiber, larvae in later instars reached optimal levels in growth, development and respiration. Therefore, we suggest that crude fiber content in feed can be controlled within 5-10%, and with the consideration of food palatability, a crude fiber of 5% is advisable.

  16. Notes on the Reproductive Ecology and Description of the Preimaginal Morphology of Elaphrus sugai Nakane, the Most Endangered Species of Elaphrus Fabricius (Coleoptera: Carabidae Ground Beetle Worldwide.

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    Kôji Sasakawa

    Full Text Available Elucidating the basic life-history of endangered species is the first important step in the conservation of such species. This study examined the reproductive ecology and the preimaginal morphology of the endangered ground beetle Elaphrus sugai Nakane (Coleoptera: Carabidae; currently, the Watarase wetland of the central Kanto Plain, Japan is the only confirmed locality of this beetle species. Laboratory rearing of reproductive adults collected in early April revealed that females can lay more than 131 eggs. Eggs were laid in mud, without an egg chamber. Larvae reached adulthood when fed a diet of mealworms, indicating that E. sugai larvae are insect larvae feeders. An earthworm diet, the optimal diet for larvae of a congeneric species (E. punctatus Motschulsky, was lethal to E. sugai larvae. The egg stage was 3-4 days in duration under a 16L8D cycle (22°C. The duration from hatching to adult eclosion was 23-42 days at various temperatures simulating those of the reproductive period. Larval morphology was similar to that of consubgeneric species described previously. The pupa is unusual, in that the setae on the abdominal tergites are long (twice as long as those of the abdominal segment and have somewhat "coiled" apices. Finally, the current endangered status of E. sugai was compared to that of E. viridis Horn, which has been regarded as the most endangered species of the genus worldwide.

  17. Temporal Coordination of Carbohydrate Metabolism during Mosquito Reproduction.

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    Yuan Hou

    2015-07-01

    Full Text Available Hematophagous mosquitoes serve as vectors of multiple devastating human diseases, and many unique physiological features contribute to the incredible evolutionary success of these insects. These functions place high-energy demands on a reproducing female mosquito, and carbohydrate metabolism (CM must be synchronized with these needs. Functional analysis of metabolic gene profiling showed that major CM pathways, including glycolysis, glycogen and sugar metabolism, and citrate cycle, are dramatically repressed at post eclosion (PE stage in mosquito fat body followed by a sharply increase at post-blood meal (PBM stage, which were also verified by Real-time RT-PCR. Consistent to the change of transcript and protein level of CM genes, the level of glycogen, glucose and trehalose and other secondary metabolites are also periodically accumulated and degraded during the reproductive cycle respectively. Levels of triacylglycerols (TAG, which represent another important energy storage form in the mosquito fat body, followed a similar tendency. On the other hand, ATP, which is generated by catabolism of these secondary metabolites, showed an opposite trend. Additionally, we used RNA interference studies for the juvenile hormone and ecdysone receptors, Met and EcR, coupled with transcriptomics and metabolomics analyses to show that these hormone receptors function as major regulatory switches coordinating CM with the differing energy requirements of the female mosquito throughout its reproductive cycle. Our study demonstrates how, by metabolic reprogramming, a multicellular organism adapts to drastic and rapid functional changes.

  18. Developing an in vivo toxicity assay for RNAi risk assessment in honey bees, Apis mellifera L.

    Science.gov (United States)

    Vélez, Ana María; Jurzenski, Jessica; Matz, Natalie; Zhou, Xuguo; Wang, Haichuan; Ellis, Marion; Siegfried, Blair D

    2016-02-01

    Maize plants expressing dsRNA for the management of Diabrotica virgifera virgifera are likely to be commercially available by the end of this decade. Honey bees, Apis mellifera, can potentially be exposed to pollen from transformed maize expressing dsRNA. Consequently, evaluation of the biological impacts of RNAi in honey bees is a fundamental component for ecological risk assessment. The insecticidal activity of a known lethal dsRNA target for D. v. virgifera, the vATPase subunit A, was evaluated in larval and adult honey bees. Activity of both D. v. virgifera (Dvv)- and A. mellifera (Am)-specific dsRNA was tested by dietary exposure to dsRNA. Larval development, survival, adult eclosion, adult life span and relative gene expression were evaluated. The results of these tests indicated that Dvv vATPase-A dsRNA has limited effects on larval and adult honey bee survival. Importantly, no effects were observed upon exposure of Am vATPase-A dsRNA suggesting that the lack of response involves factors other than sequence specificity. The results from this study provide guidance for future RNAi risk analyses and for the development of a risk assessment framework that incorporates similar hazard assessments. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Life cycle and reproductive patterns of Triatoma rubrovaria (Blanchard, 1843 (Hemiptera: Reduviidae under constant and fluctuating conditions of temperature and humidity

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    Damborsky Miryam P.

    2005-01-01

    Full Text Available The aim of this study was to evaluate the temperature and relative humidity influence in the life cycle, mortality and fecundity patterns of Triatoma rubrovaria. Four cohorts with 60 recently laid eggs each were conformed. The cohorts were divided into two groups. In the controlled conditions group insects were maintained in a dark climatic chamber under constant temperature and humidity, whereas triatomines of the ambiental temperature group were maintained at room temperature. Average incubation time was 15.6 days in the controlled conditions group and 19.1 days in the ambiental temperature. In group controlled conditions the time from egg to adult development lasted 10 months while group ambiental temperature took four months longer. Egg eclosion rate was 99.1% and 98.3% in controlled conditions and ambiental temperature, respectively. Total nymphal mortality in controlled conditions was 52.6% whereas in ambiental temperature was 51.8%. Mean number of eggs/female was 817.6 controlled conditions and 837.1 ambiental temperature. Fluctuating temperature and humidity promoted changes in the life cycle duration and in the reproductive performance of this species, although not in the species mortality.

  20. The effect of indoxacarb and five other insecticides on Phytoseiulus persimilis (Acari: Phytoseiidae), Amblyseius fallacis (Acari: Phytoseiidae) and nymphs of Orius insidiosus (Hemiptera: Anthocoridae).

    Science.gov (United States)

    Bostanian, Noubar J; Akalach, Mohammed

    2006-04-01

    A laboratory study assessed the contact toxicity of indoxacarb, abamectin, endosulfan, insecticidal soap, S-kinoprene and dimethoate to Amblyseius fallacis (Garman), Phytoseiulus persimilis Athias-Henriot and nymphs of Orius insidiosus (Say). Amblyseius fallacis is a predacious phytoseiid mite and an integral part of integrated pest management (IPM) programmes in North American apple orchards. The other two beneficials are widely used in greenhouses to manage various arthropod pests infesting vegetable and ornamental crops. Indoxacarb is a slow-acting insecticide, so toxicity data were recorded 7 days post-treatment when the data had stabilised. It showed no toxicity to O. insidiosus nymphs or to A. fallacis or P. persimilis adults. The LC50 values for O. insidiosus nymphs and P. persimilis could not be estimated with their associated confidence limits, because the g values were greater than 0.5 and under such circumstances the lethal concentration would lie outside the limits. The LC50 for A. fallacis was 7.6x the label rate. The fecundity of P. persimilis was reduced by 26.7%. The eclosion of treated eggs from both species of beneficial mites was not affected adversely. Among the other pest control products, S-kinoprene and endosulfan affected adversely at least one species of the predators, whereas dimethoate, abamectin and insecticidal soap were very toxic to all three beneficials. Indoxacarb should be evaluated as a pest control product in IPM programmes. Copyright (c) 2006 Crown in the right of Canada.

  1. Effects of gamma irradiation used to inhibit potato sprouting on potato tuber moth eggs, larvae and pupae Phthorimaea Operculella zeller (Lep., Gelechiidae)

    International Nuclear Information System (INIS)

    Saour, G.; Makee, H.

    2002-12-01

    Different age groups of potato tuber moth, Phthorimaea Operculella zeller, eggs were exposed to gamma irradiation at incremental doses up to 150 Gy (the upper dose limit allowed for potato sprout inhibition). Young eggs were more sensitive to gamma irradiation than older eggs and the sensitivity level declined with eggs age. The exposure of 3 - 3.5 d-old eggs to 150 Gy resulted in an 26% increase in egg incubation period compared with unirradiated eggs. The minimum dose required to 75 Gy, 9.7% of larvae survived to the adult stage but emerged as deformed moths. At 100 and 125 Gy, 10.2 and 9.6% of larvae pupated, respectively; however no adult eclosion was recorded. Whereas at 150 Gy, the larvae remained in mid-instar stage and eventually died. Young larvae and pupae were more susceptible to irradiation injuries than older ones. When larvae and of different ages were exposed to doses equal or higher than 100 Gy, only 13 to 35% pupated, but no adult emergence was obtained . The exposure of 1 - 1.5 or 3 - 3.5 day old pupae to 150 Gy induced high level of sterility and remarkable reduction in female mating ability and fecundity whereas, the reduction was less noticeable for 5 - 5.5 day-old pupae. Gamma irradiation doses applied to inhibit potato sprouting could used as an efficient control approach against potato tuber moth eggs, larval and pupal infestations (authors)

  2. Effects of temperature and food on the development of Dysdercus maurus Distant (Hemiptera, Pyrrhocoridae)

    International Nuclear Information System (INIS)

    Almeida, Fabio Souto; Goncalves, Lenicio

    2007-01-01

    Dysdercus maurus Distant, 1901 (Hemiptera, Pyrrhocoridae) is an important pest on Gossypium spp. (cotton tree), Citrus sinensis Osbeck (Rutaceae) and Citrus reticulata Blanco (Rutaceae) crops. This insect also feeds on seeds of Chorisia speciosa St. Hil. (Bombacaceae). This work aimed to evaluate the effects of temperature and food on the development of D. maurus. Eight treatments were carried out, in six of them bugs were fed with seeds of C. speciosa and kept at 15, 18, 20, 25 and 30 ± 1 deg C, 80 ± 3% RH and 12h photo phase or in laboratory conditions (23.5 ± 2.6 deg C, 73.3 ± 9.9 % RH), and in the other two treatments bugs were fed with seeds of cotton variety IAC-22 and kept at 25 or 30 deg C. In all treatments five immature stages were observed. The increase of temperature caused reduction in the developmental time. The temperature of 15 deg C disabled nymphal eclosion and was also lethal to those nymphs ecloded at other temperatures. The lower mortality of nymphs occurred in the temperature of 25 deg C with cotton as food (24.07%). The lower threshold temperature (Tb) occurred for the first instar (11.54 deg C) and the higher for the second instar (15.33 deg C). The females of D. maurus required more degree-days (329.93 degree-days) than males (300.49 degree-days) until adult emergence. (author)

  3. The ontogeny of bumblebee flight trajectories: from naïve explorers to experienced foragers.

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    Juliet L Osborne

    Full Text Available Understanding strategies used by animals to explore their landscape is essential to predict how they exploit patchy resources, and consequently how they are likely to respond to changes in resource distribution. Social bees provide a good model for this and, whilst there are published descriptions of their behaviour on initial learning flights close to the colony, it is still unclear how bees find floral resources over hundreds of metres and how these flights become directed foraging trips. We investigated the spatial ecology of exploration by radar tracking bumblebees, and comparing the flight trajectories of bees with differing experience. The bees left the colony within a day or two of eclosion and flew in complex loops of ever-increasing size around the colony, exhibiting Lévy-flight characteristics constituting an optimal searching strategy. This mathematical pattern can be used to predict how animals exploring individually might exploit a patchy landscape. The bees' groundspeed, maximum displacement from the nest and total distance travelled on a trip increased significantly with experience. More experienced bees flew direct paths, predominantly flying upwind on their outward trips although forage was available in all directions. The flights differed from those of naïve honeybees: they occurred at an earlier age, showed more complex looping, and resulted in earlier returns of pollen to the colony. In summary bumblebees learn to find home and food rapidly, though phases of orientation, learning and searching were not easily separable, suggesting some multi-tasking.

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

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    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.

  5. Ontogenic studies of the neural control of adenohypophyseal hormones in the rat. II. Prolactin.

    Science.gov (United States)

    Becú-Villalobos, D; Lacau-Mengido, I M; Díaz-Torga, G S; Libertun, C

    1992-02-01

    1. Serum prolactin levels are low during the first 20 days of life and gradually increase toward puberty, in both male and female rats. 2. There is an age-related increase in the cell population engaged in prolactin secretion, as well as an increase in the synthesis of prolactin and of the amount of prolactin secreted from individual lactotropes. 3. The gradual increase in prolactin levels in the third week of life is not related to a decrease in dopaminergic inhibition but to an increase in the efficiency of prolactin releasing factors such as estrogen, serotonin, opiates, and posterior pituitary extracts. 4. Prolactin release induced by physiological factors, such as stress, cervical stimulation, or the expression of spontaneous diurnal and nocturnal surges, requires maturational events within the hypothalamic-pituitary axis which are evident at the end of the third week of life. 5. In the female rat the steadily increasing levels of prolactin are involved in the timing of puberty eclosion acting at the ovary and at the brain. 6. In the prepubertal male rat increasing titers of prolactin may be involved in testicular and accessory organ development and may facilitate the actions of luteinizing hormone, follicle stimulating hormone, and testosterone on male sexual organs.

  6. Estudos sobre a resistência ao jejum e aspectos nutricionais de Cavernicola lenti Barrett & Arias, 1985 (Hemiptera, Reduviidae, Triatominae Studies on the resistance to fasting and nutritional aspects of Cavernicola lenti Barret & Arias, 1985 (Hemiptera, Reduviida, Triatominae

    Directory of Open Access Journals (Sweden)

    Jane Margaret Costa

    1989-01-01

    Full Text Available In order to widen the present knowledge on the biology of this species, a study on the resistance to starvation was carried out among all nymphal stages and the adult stage (male and female. All evolutive stages were weighed on precision scale in three different nutritional situations: fed, non-fed and death registered after starvation. This procedure has allowed us to calculate the amount of blood taken in each stage and during the whole cycle, the average loss of weight during starvation and its relations with the initial weight. The insects were fed on mice and after eclosion or ecdisis they were isolated for observation of the starving period. Throuhout the whole experiment they were kept in a B. O. D./DOB incubator (28ºC and 90%R.U.. The resistance to starvation of the insects has grown from the first stage on (average of 15.5 days to the fifth stage (average of 75.64 days; on the adult stage, the resistance period was equal to the third stage with an average of 41.76 for the males and 44.82 for the females. The amount of ingested blood was greater at the fifth stage worth 34.14 mg, corresponding to 2,04 times its initial weight. The average weight loss during the starvation was greater at the adult stage (23.95 mg, corresponding to 61.52% of the total weight.

  7. Analysis of ovary-specific genes in relation to egg maturation and female nutritional condition in the mosquitoes Georgecraigius atropalpus and Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Telang, Aparna; Rechel, Julie A; Brandt, Jessica R; Donnell, David M

    2013-03-01

    Analysis of the reproductive physiology of anautogenous mosquitoes at the molecular level is complicated by the simultaneity of ovarian maturation and the digestion of a blood meal. In contrast to anautogenous mosquitoes, autogenous female mosquitoes can acquire greater nutrient stores as larvae and exhibit higher ovarian production of ecdysteroids at adult eclosion. These features essentially replace the role of a blood meal in provisioning the first batch of eggs and initiating egg development. To gain insight into the process of ovary maturation we first performed a transcript analysis of the obligatory autogenous mosquito Georgecraigius atropalpus (formerly Ochlerotatus atropalpus). We identified ESTs using suppressive subtractive hybridization (SSH) of transcripts from ovaries at critical times during oogenesis in the absence of blood digestion. Preliminary expression studies of genes such as apolipophorin III (APO) and oxysterol binding protein (OSBP) suggested these genes might be cued to female nutritional status. We then applied our findings to the medically important anautogenous mosquito Aedes aegypti. RNAi-based analyses of these genes in Ae. aegypti revealed a reduction in APO transcripts leads to reduced lipid levels in carcass and ovaries and that OSBP may play a role in overall lipid and sterol homeostasis. In addition to expanding our understanding of mosquito ovarian development, the continued use of a comparative approach between autogenous and anautogenous species may provide novel intervention points for the regulation of mosquito egg production. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Ecdysteroids in the adults and eggs of Opogona sacchari (Bojer), an invasive alien pest.

    Science.gov (United States)

    Wang, FangHai; Zhang, GuRen; Wen, RuiZhen; He, GuoFeng

    2008-02-01

    In order to understand the composition and quantitative variation of ecdysteroids in the adults and eggs of Opogona sacchari (Bojer), an invasive alien pest, we analyzed the ecdysteroid composition and titers in the adult and egg of this pest. On day 4 after eclosion, the titer of ecdysteroids in the male adult was 0.080 ng/adult, much lower than 5.978 ng/adult in the female adult. During the development of ovaries, the titer of ecdysteroids was low on the first two days, and high in the late period, with the peak (10.48 ng/ovary) appearing on day 3. During the development of eggs, the titer of ecdysteroids was about 0.010 ng/egg from day 1 to day 3, and then decreased to 0.006 ng/egg on day 4. In both adults and eggs, three main components of ecdysteroids were found by identification of HPLC/RIA. They were 20-hydroxyecdysone, 26-hydroxyecdysone, and an unidentified component.

  9. Development of the Oriental Latrine Fly, Chrysomya megacephala (Diptera: Calliphoridae), at Five Constant Temperatures.

    Science.gov (United States)

    Gruner, S V; Slone, D H; Capinera, J L; Turco, M P

    2017-03-01

    Chrysomya megacephala (Fabricius) is a forensically important fly that is found throughout the tropics and subtropics. We calculated the accumulated development time and transition points for each life stage from eclosion to adult emergence at five constant temperatures: 15, 20, 25, 30, and 35 °C. For each transition, the 10th, 50th, and 90th percentiles were calculated with a logistic linear model. The mean transition times and % survivorship were determined directly from the raw laboratory data. Development times of C. megacephala were compared with that of two other closely related species, Chrysomya rufifacies (Macquart) and Phormia regina (Meigen). Ambient and larval mass temperatures were collected from field studies conducted from 2001-2004. Field study data indicated that adult fly activity was reduced at lower ambient temperatures, but once a larval mass was established, heat generation occurred. These development times and durations can be used for estimation of a postmortem interval (PMI). © 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.

  10. Rates of oxygen uptake increase independently of changes in heart rate in late stages of development and at hatching in the green iguana, Iguana iguana.

    Science.gov (United States)

    Sartori, Marina R; Abe, Augusto S; Crossley, Dane A; Taylor, Edwin W

    2017-03-01

    Oxygen consumption (VO 2 ), heart rate (f H ), heart mass (M h ) and body mass (M b ) were measured during embryonic incubation and in hatchlings of green iguana (Iguana iguana). Mean f H and VO 2 were unvarying in early stage embryos. VO 2 increased exponentially during the later stages of embryonic development, doubling by the end of incubation, while f H was constant, resulting in a 2.7-fold increase in oxygen pulse. Compared to late stage embryos, the mean inactive level of VO 2 in hatchlings was 1.7 fold higher, while f H was reduced by half resulting in a further 3.6 fold increase in oxygen pulse. There was an overall negative correlation between mean f H and VO 2 when data from hatchlings was included. Thus, predicting metabolic rate as VO 2 from measurements of f H is not possible in embryonic reptiles. Convective transport of oxygen to supply metabolism during embryonic incubation was more reliably indicated as an index of cardiac output (CO i ) derived from the product of f H and M h . However, a thorough analysis of factors determining rates of oxygen supply during development and eclosion in reptiles will require cannulation of blood vessels that proved impossible in the present study, to determine oxygen carrying capacity by the blood and arteriovenous oxygen content difference (A-V diff), plus patterns of blood flow. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. New insights into the amphibious life of Biomphalaria glabrata and susceptibility of its egg masses to fungal infection.

    Science.gov (United States)

    Duarte, Glennyha F; Rodrigues, Juscelino; Fernandes, Éverton K K; Humber, Richard A; Luz, Christian

    2015-02-01

    The air-breathing snail Biomphalaria glabrata proliferates in stagnant freshwater, and nothing is known about the survival of eggs in intermittently (rather than perpetually) wet habitats. In the present study their egg masses matured, and juveniles subsequently eclosed and were mobile in a stable water film of transitory habitats simulated by two different simple test devices described here. The viability of eggs maintained in an unstable film however, was diminished. The maturation of egg masses in a water film or in water was significantly prevented by the entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae. The efficiency depended on the fungal propagule and test environment. Hyphal bodies were more effective against egg masses than conidia. This appears to be a first report of activity of either entomopathogen against a mollusc. Both devices offer accurate and reproducible conditions to test both biological questions and the effects of substances or pathogens against B. glabrata egg masses in water films. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Fipronil application on rice paddy fields reduces densities of common skimmer and scarlet skimmer

    Science.gov (United States)

    Kasai, Atsushi; Hayashi, Takehiko I.; Ohnishi, Hitoshi; Suzuki, Kazutaka; Hayasaka, Daisuke; Goka, Koichi

    2016-01-01

    Several reports suggested that rice seedling nursery-box application of some systemic insecticides (neonicotinoids and fipronil) is the cause of the decline in dragonfly species noted since the 1990s in Japan. We conducted paddy mesocosm experiments to investigate the effect of the systemic insecticides clothianidin, fipronil and chlorantraniliprole on rice paddy field biological communities. Concentrations of all insecticides in the paddy water were reduced to the limit of detection within 3 months after application. However, residuals of these insecticides in the paddy soil were detected throughout the experimental period. Plankton species were affected by clothianidin and chlorantraniliprole right after the applications, but they recovered after the concentrations decreased. On the other hand, the effects of fipronil treatment, especially on Odonata, were larger than those of any other treatment. The number of adult dragonflies completing eclosion was severely decreased in the fipronil treatment. These results suggest that the accumulation of these insecticides in paddy soil reduces biodiversity by eliminating dragonfly nymphs, which occupy a high trophic level in paddy fields. PMID:26979488

  13. Identification of Albizia lebbeck seed coat chitin-binding vicilins (7S globulins) with high toxicity to the larvae of the bruchid Callosobruchus maculatus

    Energy Technology Data Exchange (ETDEWEB)

    Souza, A.J. [Laboratório de Química e Função de Proteínas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ (Brazil); Ferreira, A.T.S.; Perales, J.; Beghini, D.G. [Laboratório de Toxinologia, Departamento de Fisiologia e Farmacodinâmica, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ (Brazil); Fernandes, K.V.S.; Xavier-Filho, J.; Venancio, T.M.; Oliveira, A.E.A. [Laboratório de Química e Função de Proteínas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ (Brazil)

    2011-01-27

    Seed coat is a specialized maternal tissue that interfaces the embryo and the external environment during embryogenesis, dormancy and germination. In addition, it is the first defensive barrier against penetration by pathogens and herbivores. Here we show that Albizia lebbeck seed coat dramatically compromises the oviposition, eclosion and development of the bruchid Callosobruchus maculatus. Dietary supplementation of bruchid larvae with A. lebbeck seed coat flour causes severe weight loss and reduces survival. By means of protein purification, mass spectrometry and bioinformatic analyses, we show that chitinbinding vicilins are the main source of A. lebbeck tegumental toxicity to C. maculatus. At concentrations as low as 0.1%, A. lebbeck vicilins reduce larval mass from 8.1 ± 1.7 (mass of control larvae) to 1.8 ± 0.5 mg, which corresponds to a decrease of 78%. Seed coat toxicity constitutes an efficient defense mechanism, hindering insect predation and preventing embryo damage. We hypothesize that A. lebbeck vicilins are good candidates for the genetic transformation of crop legumes to enhance resistance to bruchid predation.

  14. A Venom Gland Extracellular Chitin-Binding-Like Protein from Pupal Endoparasitoid Wasps, Pteromalus Puparum, Selectively Binds Chitin

    Directory of Open Access Journals (Sweden)

    Yu Zhu

    2015-11-01

    Full Text Available Chitin-binding proteins (CBPs are present in many species and they act in a variety of biological processes. We analyzed a Pteromalus puparum venom apparatus proteome and transcriptome and identified a partial gene encoding a possible CBP. Here, we report cloning a full-length cDNA of a sequence encoding a chitin-binding-like protein (PpCBP from P. puparum, a pupal endoparasitoid of Pieris rapae. The cDNA encoded a 96-amino-acid protein, including a secretory signal peptide and a chitin-binding peritrophin-A domain. Phylogenetic analysis of chitin binding domains (CBDs of cuticle proteins and peritrophic matrix proteins in selected insects revealed that the CBD of PpCBP clustered with the CBD of Nasonia vitripennis. The PpCBP is specifically expressed in the venom apparatus of P. puparum, mostly in the venom gland. PpCBP expression was highest at day one after adult eclosion and much lower for the following five days. We produced a recombinant PpCBP and binding assays showed the recombinant protein selectively binds chitin but not cellulose in vitro. We infer that PpCBP serves a structural role in the venom reservoir, or may be injected into the host to help wound healing of the host exoskeleton.

  15. Transient habitats limit development time for periodical cicadas.

    Science.gov (United States)

    Karban, Richard

    2014-01-01

    Periodical cicadas (Magicicada spp.) mature in 13 or 17 years, the longest development times for any non-diapausing insects. Selection may favor prolonged development since nymphs experience little mortality and individuals taking 17 years have been shown to have greater fecundity than those taking 13 years. Why don't periodical cicadas take even longer to develop? Nymphs feed on root xylem fluid and move little. Ovipositing females prefer fast-growing trees at forest edges. I hypothesized that (1) adults emerging at edges would be heavier than those from forest interiors and (2) habitat changes could limit development time. I collected newly eclosed females that had neither fed as adults nor moved from their site of development. For M. septendecim, females from edges were 4.9% heavier than those from the interior. I assumed that emergence density indicated habitat quality and measured density at eight sites in 1979, 1996, and 2013. Over three generations, variation in densities was great; densities at two sites crashed, and at one site they exploded to 579/m2 Habitat transience may limit development time because only adults can reassess habitats and reposition offspring. In conclusion, cicadas are affected by habitat characteristics, habitats change over 17 years, and cicadas may emerge, mate, and redistribute their offspring to track habitat dynamics.

  16. Rearing of Lymnaea columella (Say, 1817, intermediate host of Fasciola hepatica (Linnaeus, 1758

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    Souza Cecília Pereira de

    2000-01-01

    Full Text Available The intermediate host of Fasciola hepatica, Lymnaea columella, collected in Belo Horizonte, Minas Gerais, Brazil, was reared in our laboratory. The aim of the current study was to standardize a rearing and maintenance technique. Two kinds of diet were tested: fresh lettuce (A and rodent ration + 10% CaCO3 plus fresh lettuce (B. The age for the beginning of oviposition ranged from 27 to 57 days. Ten days after oviposition at 24.7°C, 100% eclosion occurred. The complete life cycle varied from 37 to 67 days. The average numbers of eggs per egg mass were 26.3 and 31.1 with diets (A and (B, respectively. The lettuce and ration fed snails presented a increased growth although the difference was not statistically significant (p > 0.05. The mortality rate varied from 40 to 64% after 90 days. The maximum longevity was 183 days, 21.5 mm length and 11 mm wide. The methodology to mass breed and maintain these snails was found to be suitable in the laboratory

  17. Fluctuations of the population of Daphnia laevis Birge 1878: a six-year study in a tropical lake

    Directory of Open Access Journals (Sweden)

    LPM. Brandão

    Full Text Available The fluctuation of the population of Daphnia laevis in Lake Jacaré (Middle River Doce, Minas Gerais was monitored monthly (at one point in the limnetic region for six years (2002-2007 as part of the Program of Long-Term Ecological Research (LTER/UFMG. The following parameters were also monitored: water temperature, pH, electrical conductivity, dissolved oxygen, chlorophyll a, total phosphorus, phosphate, total nitrogen, nitrate, nitrite, ammonia, and densities of Chaoborus and ephippia of Daphnia laevis in the sediment. A seasonal pattern was observed in the fluctuation of D. laevis, with higher densities recorded during periods of circulation (May-August. A significant correlation was found between the density of D. laevis and temperature (r = -0.47, p = 0.0001, chlorophyll-a (r = -0.32, p = 0.016 and indicators of the lake's trophic status (total phosphorus, r = 0.32, p = 0.007 and trophic state, r = 0.36, p = 0.003, as well as Chaoborus density (r = 0.43 and p = 0.002. These results indicate that changes in the physical and chemical characteristics of the water related with stratification and circulation of the lake may have a direct (temperature, total phosphorous or an indirect (food availability, presence of predators, ephippia eclosion influence on the fluctuation of the D. laevis population.

  18. Life History of the Emerald Jewel Wasp Ampulex compressa

    Directory of Open Access Journals (Sweden)

    Ryan Arvidson

    2018-04-01

    Full Text Available The Emerald Jewel Wasp Ampulex compressa (Fabricius is an endoparasitoid of the American cockroach Periplaneta americana (Linnaeus. Its host subjugation strategy is unusual in that envenomation is directed into the host central nervous system, eliciting a long-term behavior modification termed hypokinesia, turning stung cockroaches into a lethargic and compliant, but not paralyzed, living food supply for wasp offspring. A. compressa manipulates hypokinesic cockroaches into a burrow, where it oviposits a single egg onto a mesothoracic leg, hatching three days later. Herein we describe the life history and developmental timing of A. compressa. Using head capsule measurements and observations of mandibular morphology, we found that the larvae develop through three instars, the first two ectoparasitoid, and the third exclusively endoparasitoid. The first two instars have mandibles sufficient for piercing and cutting the cuticle respectively, while the third instar has a larger and blunter mandibular structure. During ecdysis to the third instar, the larva enters the body cavity of the cockroach, consuming internal tissues selectively, including fat body and skeletal muscle, but sparing the gut and Malpighian tubules. The developmental timing to pupation is similar between males and females, but cocoon volume and mass, and pupation duration are sexually dimorphic. Further, we show that the difference in cocoon mass and volume can be used to predict sex before eclosion, which is valuable for studies in venom pharmacology, as only females produce venom.

  19. Comparative antennal transcriptome of Apis cerana cerana from four developmental stages.

    Science.gov (United States)

    Zhao, Huiting; Peng, Zhu; Du, Yali; Xu, Kai; Guo, Lina; Yang, Shuang; Ma, Weihua; Jiang, Yusuo

    2018-03-21

    Apis cerana cerana, an important endemic honey bee species in China, possesses valuable characteristics such as a sensitive olfactory system, good foraging ability, and strong resistance to parasitic mites. Here, we performed transcriptome sequencing of the antenna, the major chemosensory organ of the bee, using an Illumina sequencer, to identify typical differentially expressed genes (DEGs) in adult worker bees of different ages, namely, T1 (1 day); T2 (10 days); T3 (15 days); and T4 (25 days). Surprisingly, the expression levels of DEGs changed significantly between the T1 period and the other three periods. All the DEGs were classified into 26 expression profiles by trend analysis. Selected trend clusters were analyzed, and valuable information on gene expression patterns was obtained. We found that the expression levels of genes encoding cuticle proteins declined after eclosion, while those of immunity-related genes increased. In addition, genes encoding venom proteins and major royal jelly proteins were enriched at the T2 stage; small heat shock proteins showed significantly higher expression at the T3 stage; and some metabolism-related genes were more highly expressed at the T4 stage. The DEGs identified in this study may serve as a valuable resource for the characterization of expression patterns of antennal genes in A. cerana cerana. Furthermore, this study provides insights into the relationship between labor division in social bees and gene function. Copyright © 2017. Published by Elsevier B.V.

  20. Life cycle, Ecological Characteristics, and Control of Trachys yanoi (Coleoptera: Buprestidae), an Important Pest of Zelkova serrata.

    Science.gov (United States)

    Ohsawa, Masashi

    2017-03-24

    This study was conducted to elucidate the life cycle and the ecological characteristics of Trachys yanoi Y. Kurosawa, an important pest of Zelkova serrata (Thunb.) Makino. Life cycle, mortality rates in developmental stages, annual population dynamics, and early leaf abscission were investigated. Adults emerged from under the bark of Zelkova trees in April and fed on Zelkova leaves. Females laid 49 eggs on average, mainly in May and early June. Eggs hatched after 17 days, and the larvae fed inside the leaves. They developed through three instars. In July, leaves with the final stage of larvae were abscised. Four days after abscission, the larvae pupated. New adults eclosed from pupae seven days after pupation, and the adults emerged from abscised leaves after an additional two days. In total, 1650 adults emerged per 1 m² of forest floor, resulting in a major population increase. The newly emerged adults fed on the remaining Zelkova leaves, compounding the damage. In October, adults overwintered under the tree bark. Mortality rates in the egg, larval, and pupal stages were 41%, 58%, and 31%, respectively. The mortality rate among overwintering individuals was 43%. Because only Zelkova leaves that were abscised in July contained the larvae, and because only a small number of beetles emerged from non-abscised, mined leaves, the removal of abscised leaves at nine-day intervals over period of early leaf abscission is a simple and effective way to control the beetle.

  1. Repair and regeneration of heavy ion beam locally irradiated embryonic hemopoietic organs of silkworm, Bombyx mori

    International Nuclear Information System (INIS)

    Xu Shiqing; Tu Zhenli

    2003-01-01

    Eggs of silkworm, Bombyx mori were irradiated by 12 C 5+ ions, at the embryonic wings, where the hemopoietic organs attached. Changes in the development of the silkworm larvae and pupae, especially in the repair and regeneration of the hemopoietic organs represented by their morphological and functional characteristics, were observed. The results showed that the silkworm larvae and pupae developed from the irradiated eggs grew with the physiological obstruction due to exsanguinations, such as difficulty in their metamorphosis and their marked lower survival rates. After 100 Gy irradiation, some of the larvae and pupae died during the periods of larval molting stages, pupation stage and eclosion stage. With increased doses, the deficiencies in the silkworm development became more significant. After 200 Gy irradiation, the average hemocyte density for the 5 th larvae decreased markedly, but the hemocyte density for some individuals were comparable to the control, and regenerated hemopoietic organs was found in these larvae. The results suggested that the silkworm larvae might be capable of self-repair and self-regeneration of the hemopoietic organs after the heave ion irradiation

  2. Temperature Requirements of Some Common Forensically Important Blow and Flesh Flies (Diptera) under Laboratory Conditions

    Science.gov (United States)

    Shiravi, AH; Mostafavi, R; Akbarzadeh, K; Oshaghi, MA

    2011-01-01

    Background: The aim of his study was to determine development time and thermal requirements of three myiasis flies including Chrysomya albiceps, Lucilia sericata, and Sarcophaga sp. Methods: Rate of development (ROD) and accumulated degree day (ADD) of three important forensic flies in Iran, Chrysomya albiceps, Lucilia sericata, and Sarcophaga sp. by rearing individuals under a single constant temperature (28° C) was calculated using specific formula for four developmental events including egg hatching, larval stages, pupation, and eclosion. Results: Rates of development decreased step by step as the flies grew from egg to larvae and then to adult stage; however, this rate was bigger for blowflies (C. albiceps and L. sericata) in comparison with the flesh fly Sarcophaga sp. Egg hatching, larval stages, and pupation took about one fourth and half of the time of the total pre-adult development time for all of the three species. In general, the flesh fly Sarcophaga sp. required more heat for development than the blowflies. The thermal constants (K) were 130–195, 148–222, and 221–323 degree-days (DD) for egg hatching to adult stages of C. albiceps, L. sericata, and Sarcophaga sp., respectively. Conclusion: This is the first report on thermal requirement of three forensic flies in Iran. The data of this study provide preliminary information for forensic entomologist to establish PMI in the area of study. PMID:22808410

  3. Temperature Requirements of Some Common Forensically Important Blow and Flesh Flies (Diptera under Laboratory Conditions

    Directory of Open Access Journals (Sweden)

    AH Shiravi

    2011-06-01

    Full Text Available Background: The aim of his study was to determine development time and thermal requirements of three myiasis flies including Chrysomya albiceps, Lucilia sericata, and Sarcophaga sp.Methods: Rate of development (ROD and accumu­lated degree day (ADD of three important forensic flies in Iran, Chrysomya albiceps, Lucilia sericata, and Sarcophaga sp. by rearing individuals under a single constant temperature (28° C was calcu­lated using specific formula for four developmental events including egg hatching, larval stages, pupation, and eclosion. Results: Rates of development decreased step by step as the flies grew from egg to larvae and then to adult stage; however, this rate was bigger for blowflies (C. albiceps and L. sericata in comparison with the flesh fly Sarcophaga sp. Egg hatching, larval stages, and pupation took about one fourth and half of the time of the total pre-adult development time for all of the three species. In general, the flesh fly Sarcophaga sp. required more heat for development than the blowflies. The thermal constants (K were 130–195, 148–222, and 221–323 degree-days (DD for egg hatching to adult stages of C. albiceps, L. sericata, and Sarcophaga sp., respectively.Conclusion: This is the first report on thermal requirement of three forensic flies in Iran. The data of this study provide preliminary information for forensic entomologist to establish PMI in the area of study.

  4. Radiation-induced substerility of Ostrinia furnacalis (Lepidoptera: Pyralidae) integrated with the release of Trichogramma ostriniae (Hymenoptera: Trichogrammatidae) for area-wide control

    International Nuclear Information System (INIS)

    Wang, H.S.; Liu, Q.R.; Lu, D.G.; Wang, E.D.; Kang, W.; Liu, X.H.; Li, Y.J.; He, Q.L.; Zhang, H.Q.

    2002-01-01

    The mating competitiveness of Ostrinia furnacalis F 1 male moths (progeny of male parents irradiated with 200 Gy) was compared with the mating competitiveness of untreated moths. These studies revealed that F 1 male moths were involved in more than 50% of the matings with normal females. The flight ability and response towards sex pheromone was similar for F 1 and untreated moths, although the number of F 1 moths captured was slightly less than the number of untreated moths captured. The number of eupyrene sperm in the testes of P 1 moths treated with 200 Gy was similar to the number of eupyrene sperm in the testes of normal moths. However, the number of sperm bundles was significantly reduced in the testes of 200 Gy F 1 moths. Compared to normal moths, daily sperm descent into the duplex ejaculatorius was affected only at day 3 after eclosion of F 1 moths. Sperm transfer to spermatheca by 200 Gy F 1 male moths was less than that of their irradiated (200 Gy) parents and of normal moths. Successive releases of Trichogramma ostriniae in the egg stage of first and second generation Ostrinia furnacalis were combined with the release of F 1 moths from male parents treated with 200 Gy. The combination of the F 1 sterility technique with augmentative biological control suppressed the wild population of this pest in 500 hectares of field corn. (author)

  5. Identification of Albizia lebbeck seed coat chitin-binding vicilins (7S globulins) with high toxicity to the larvae of the bruchid Callosobruchus maculatus

    International Nuclear Information System (INIS)

    Souza, A.J.; Ferreira, A.T.S.; Perales, J.; Beghini, D.G.; Fernandes, K.V.S.; Xavier-Filho, J.; Venancio, T.M.; Oliveira, A.E.A.

    2011-01-01

    Seed coat is a specialized maternal tissue that interfaces the embryo and the external environment during embryogenesis, dormancy and germination. In addition, it is the first defensive barrier against penetration by pathogens and herbivores. Here we show that Albizia lebbeck seed coat dramatically compromises the oviposition, eclosion and development of the bruchid Callosobruchus maculatus. Dietary supplementation of bruchid larvae with A. lebbeck seed coat flour causes severe weight loss and reduces survival. By means of protein purification, mass spectrometry and bioinformatic analyses, we show that chitinbinding vicilins are the main source of A. lebbeck tegumental toxicity to C. maculatus. At concentrations as low as 0.1%, A. lebbeck vicilins reduce larval mass from 8.1 ± 1.7 (mass of control larvae) to 1.8 ± 0.5 mg, which corresponds to a decrease of 78%. Seed coat toxicity constitutes an efficient defense mechanism, hindering insect predation and preventing embryo damage. We hypothesize that A. lebbeck vicilins are good candidates for the genetic transformation of crop legumes to enhance resistance to bruchid predation

  6. Identification of Albizia lebbeck seed coat chitin-binding vicilins (7S globulins) with high toxicity to the larvae of the bruchid Callosobruchus maculatus.

    Science.gov (United States)

    Souza, A J; Ferreira, A T S; Perales, J; Beghini, D G; Fernandes, K V S; Xavier-Filho, J; Venancio, T M; Oliveira, A E A

    2012-02-01

    Seed coat is a specialized maternal tissue that interfaces the embryo and the external environment during embryogenesis, dormancy and germination. In addition, it is the first defensive barrier against penetration by pathogens and herbivores. Here we show that Albizia lebbeck seed coat dramatically compromises the oviposition, eclosion and development of the bruchid Callosobruchus maculatus. Dietary supplementation of bruchid larvae with A. lebbeck seed coat flour causes severe weight loss and reduces survival. By means of protein purification, mass spectrometry and bioinformatic analyses, we show that chitin-binding vicilins are the main source of A. lebbeck tegumental toxicity to C. maculatus. At concentrations as low as 0.1%, A. lebbeck vicilins reduce larval mass from 8.1 ± 1.7 (mass of control larvae) to 1.8 ± 0.5 mg, which corresponds to a decrease of 78%. Seed coat toxicity constitutes an efficient defense mechanism, hindering insect predation and preventing embryo damage. We hypothesize that A. lebbeck vicilins are good candidates for the genetic transformation of crop legumes to enhance resistance to bruchid predation.

  7. Reduction of spontaneous somatic mutation frequency by a low-dose X irradiation of Drosophila larvae and possible involvement of DNA single-strand damage repair.

    Science.gov (United States)

    Koana, Takao; Takahashi, Takashi; Tsujimura, Hidenobu

    2012-03-01

    The third instar larvae of Drosophila were irradiated with X rays, and the somatic mutation frequency in their wings was measured after their eclosion. In the flies with normal DNA repair and apoptosis functions, 0.2 Gy irradiation at 0.05 Gy/min reduced the frequency of the so-called small spot (mutant cell clone with reduced reproductive activity) compared with that in the sham-irradiated flies. When apoptosis was suppressed using the baculovirus p35 gene, the small spot frequency increased four times in the sham-irradiated control group, but the reduction by the 0.2-Gy irradiation was still evident. In a non-homologous end joining-deficient mutant, the small spot frequency was also reduced by 0.2 Gy radiation. In a mutant deficient in single-strand break repair, no reduction in the small spot frequency by 0.2 Gy radiation was observed, and the small spot frequency increased with the radiation dose. Large spot (mutant cell clone with normal reproductive activity) frequency was not affected by suppression of apoptosis and increased monotonically with radiation dose in wild-type larvae and in mutants for single- or double-strand break repair. It is hypothesized that some of the small spots resulted from single-strand damage and, in wild-type larvae, 0.2 Gy radiation activated the normal single-strand break repair gene, which reduced the background somatic mutation frequency.

  8. Effects of Radiation on the Fertility of the Ethiopian Fruit Fly, Dacus ciliatus

    International Nuclear Information System (INIS)

    Rempoulakis, Polychronis; Castro, Rossana; Nemny-Lavy, Esther; Nestel, David

    2016-01-01

    The Ethiopian fruit fly, Dacus ciliatus (Loew) (Diptera: Tephritidae), is a significant pest of cucurbit crops in Asia and Africa and is currently controlled with insecticides. The sterilizing effect of gamma radiation on D. ciliatus adults was investigated to assess the suitability of sterile insect technique (SIT) for use as an alternative, nonchemical strategy for the control of this pest. Late pupae (48 h before emergence) were irradiated with 60, 80, 100, 120, and 140 Gy of gamma rays emitted by a 60 Co source. Following emergence, the biological characteristics of the experimental cohorts (including all possible male-female combinations of irradiated and untreated flies) were recorded. No significant negative effects of irradiation on pupal eclosion or the ability of newly emerged flies to fly were observed. Samples of eggs at reproductive fly-ages (12-, 15-, and 17-day-old pairs) were collected and their hatch rates were assessed. At 60 Gy, females were completely sterilized, whereas complete sterilization of the males was observed only at 140 Gy (a small amount of fertility persisted even at 120 Gy). In addition to the above experiments, three fruit infestation trials were conducted with zucchini [Cucurbita pepo L. (Cucurbitaceae)] as the plant host and the pupae produced in those trials were collected and recorded. We observed significant (ca. 10%) infestation following treatment with up to 120 Gy and zero progeny only at 140 Gy, mirroring the egg-hatch results. Our findings support the feasibility of SIT for the control of D. ciliatus. (author)

  9. Facultative slave-making ants Formica sanguinea label their slaves with own recognition cues instead of employing the strategy of chemical mimicry.

    Science.gov (United States)

    Włodarczyk, Tomasz; Szczepaniak, Lech

    2017-01-01

    Slave-making ant species use the host workforce to ensure normal colony functioning. Slaves are robbed as pupae from their natal nest and after eclosion, assume the parasite colony as their own. A possible factor promoting the successful integration of slaves into a foreign colony is congruence with the slave-makers in terms of cuticular hydrocarbons, which are known to play the role of recognition cues in social insects. Such an adaptation is observed in the obligate slave-making ant species, which are chemically adjusted to their slaves. To date, however, no reports have been available on facultative slave-making species, which represent an earlier stage of the evolution of slavery. Such an example is Formica sanguinea, which exploit F. fusca colonies as their main source of a slave workforce. Our results show that F. sanguinea ants have a distinct cuticular hydrocarbon profile, which contains compounds not present in free-living F. fusca ants from potential target nests. Moreover, enslaved F. fusca ants acquire hydrocarbons from their slave-making nestmates to such an extent that they become chemically differentiated from free-living, conspecific ants. Our study shows that F. sanguinea ants promote their own recognition cues in their slaves, rather than employing the strategy of chemical mimicry. Possible reasons why F. sanguinea is not chemically well adjusted to its main host species are discussed in this paper. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Permethrin resistance in Aedes albopictus (Diptera: Culicidae) and associated fitness costs.

    Science.gov (United States)

    Chan, Hiang Hao; Zairi, Jaal

    2013-03-01

    Insecticide resistance has become a serious issue in vector management programs. Information on insecticidal resistance and its associated mechanisms is important for successful insecticide resistance management. The selection of a colony of permethrin-resistant Aedes albopictus (Skuse) (Diptera: Culicidae), originating from Penang Island, Malaysia, yielded high larval-specific resistance to permethrin and cross-resistance to deltamethrin. Synergism assays showed that the major mechanism underlying this resistance involves cytochrome P450 monooxygenase. The resistance is autosomal, polygenically inherited and incompletely dominant (D = 0.26). Resistant larvae were reared under different conditions to assess the fitness costs. Under high larval density, larval development time of the resistant SGI strain was significantly longer than the susceptible VCRU strain. In both high- and low-density conditions SGI showed a lower rate of emergence and survival compared with the VCRU strain. Resistant larvae were more susceptible to predation by Toxorhynchites splendens (Wiedemann) (Diptera: Culicidae) larvae. The body size of SGI females reared under high-density conditions was larger compared with females of the susceptible strain. SGI females survived longer when starved than did VCRU females. The energy reserve upon eclosion was positively correlated with the size of the adults.

  11. 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, EnShan

    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. PMID:20879922

  12. Acanthopria and Mimopriella parasitoid wasps (Diapriidae) attack Cyphomyrmex fungus-growing ants (Formicidae, Attini)

    Science.gov (United States)

    Fernández-Marín, Hermógenes; Zimmerman, Jess K.; Wcislo, William T.

    2006-01-01

    New World diapriine wasps are abundant and diverse, but the biology of most species is unknown. We provide the first description of the biology of diapriine wasps, Acanthopria spp. and Mimopriella sp., which attack the larvae of Cyphomyrmex fungus-growing ants. In Puerto Rico, the koinobiont parasitoids Acanthopria attack Cyphomyrmex minutus, while in Panama at least four morphospecies of Acanthopria and one of Mimopriella attack Cyphomyrmex rimosus. Of the total larvae per colony, 0 100% were parasitized, and 27 70% of the colonies per population were parasitized. Parasitism rate and colony size were negatively correlated for C. rimosus but not for C. minutus. Worker ants grasped at, bit, and in some cases, killed adult wasps that emerged in artificial nests or tried to enter natural nests. Parasitoid secondary sex ratios were female-biased for eclosing wasps, while field collections showed a male-biased sex ratio. Based on their abundance and success in attacking host ants, these minute wasps present excellent opportunities to explore how natural enemies impact ant colony demography and population biology.

  13. First evidence for slave rebellion: enslaved ant workers systematically kill the brood of their social parasite protomognathus americanus.

    Science.gov (United States)

    Achenbach, Alexandra; Foitzik, Susanne

    2009-04-01

    During the process of coevolution, social parasites have evolved sophisticated strategies to exploit the brood care behavior of their social hosts. Slave-making ant queens invade host colonies and kill or eject all adult host ants. Host workers, which eclose from the remaining brood, are tricked into caring for the parasite brood. Due to their high prevalence and frequent raids, following which stolen host broods are similarly enslaved, slave-making ants exert substantial selection upon their hosts, leading to the evolution of antiparasite adaptations. However, all host defenses shown to date are active before host workers are parasitized, whereas selection was thought to be unable to act on traits of already enslaved hosts. Yet, here we demonstrate the rebellion of enslaved Temnothorax workers, which kill two-thirds of the female pupae of the slave-making ant Protomognathus americanus. Thereby, slaves decrease the long-term parasite impact on surrounding related host colonies. This novel antiparasite strategy of enslaved workers constitutes a new level in the coevolutionary battle after host colony defense has failed. Our discovery is analogous to recent findings in hosts of avian brood parasites where perfect mimicry of parasite eggs leads to the evolution of chick recognition as a second line of defense.

  14. Seasonal life history trade-offs in two leafwing butterflies: Delaying reproductive development increases life expectancy.

    Science.gov (United States)

    McElderry, Robert M

    2016-04-01

    Surviving inhospitable periods or seasons may greatly affect fitness. Evidence of this exists in the prevalence of dormant stages in the life cycles of most insects. Here I focused on butterflies with distinct seasonal morphological types (not a genetic polymorphism) in which one morphological type, or form, delays reproduction until favorable conditions return, while the other form develops in an environment that favors direct reproduction. For two butterflies, Anaea aidea and A. andria, I tested the hypothesis that the development of each seasonal form involves a differential allocation of resources to survival at eclosion. I assayed differences in adult longevity among summer and winter forms in either a warm, active environment or a cool, calm environment. Winter form adults lived 40 times longer than summer form but only in calm, cool conditions. The magnitude of this difference provided compelling evidence that the winter form body plan and metabolic strategy (i.e. resource conservatism) favor long term survival. This research suggests that winter form adults maintain lowered metabolic rate, a common feature of diapause, to conserve resources and delay senescence while overwintering. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Identification of Albizia lebbeck seed coat chitin-binding vicilins (7S globulins with high toxicity to the larvae of the bruchid Callosobruchus maculatus

    Directory of Open Access Journals (Sweden)

    A.J. Souza

    2012-02-01

    Full Text Available Seed coat is a specialized maternal tissue that interfaces the embryo and the external environment during embryogenesis, dormancy and germination. In addition, it is the first defensive barrier against penetration by pathogens and herbivores. Here we show that Albizia lebbeck seed coat dramatically compromises the oviposition, eclosion and development of the bruchid Callosobruchus maculatus. Dietary supplementation of bruchid larvae with A. lebbeck seed coat flour causes severe weight loss and reduces survival. By means of protein purification, mass spectrometry and bioinformatic analyses, we show that chitin-binding vicilins are the main source of A. lebbeck tegumental toxicity to C. maculatus. At concentrations as low as 0.1%, A. lebbeck vicilins reduce larval mass from 8.1 ± 1.7 (mass of control larvae to 1.8 ± 0.5 mg, which corresponds to a decrease of 78%. Seed coat toxicity constitutes an efficient defense mechanism, hindering insect predation and preventing embryo damage. We hypothesize that A. lebbeck vicilins are good candidates for the genetic transformation of crop legumes to enhance resistance to bruchid predation.

  16. Gene expression changes in male accessory glands during ageing are accompanied by reproductive decline in Drosophila melanogaster.

    Science.gov (United States)

    Koppik, Mareike; Fricke, Claudia

    2017-12-01

    Senescence is accompanied by loss of reproductive functions. Here, we studied reproductive ageing in Drosophila melanogaster males and asked whether the expected decline in male reproductive success is due to diminished functionality of the male accessory gland (AG). The male AG produces the majority of seminal fluid proteins (SFPs) transferred to the female at mating. SFPs induce female postmating changes and are key to male reproductive success. We measured age-dependent gene expression changes for five representative SFP genes in males from four different age groups ranging from 1 to 6 weeks after eclosion. Simultaneously, we also measured male reproductive success in postmating traits mediated by transfer of these five SFPs. We found a decreased in male SFP gene expression with advancing age and an accompanying decline in male postmating success. Hence, male reproductive senescence is associated with a decline in functionality of the male AG. While overall individual SFP genes decreased in expression, our results point towards the idea that the composition of an ejaculate might change with male age as the rate of change was variable for those five genes. © 2017 John Wiley & Sons Ltd.

  17. Effect of Gamma Irradiation on Male Sterilization and Structure of the Male Reproductive Accessory Glands of the Khapra Beetle Trogoderma Granarium Everts

    International Nuclear Information System (INIS)

    Abdel-Kawy, F.K.; El-Naggar, S.E.

    2000-01-01

    Changes in the male reproductive ability of Trogoderma Granarium Everts as regards to sterilization and structural changes in the accessory glands due to gamma radiation were studied. The reproductive ability of males irradiated as full grown pupae and mated with normal females was dose-dependent. A dose 100 Gy increased sterility of males to about 61.1%, while 200 Gy dose sterilized males completely. The number of eggs per mated female was significantly different from the control. The number of eggs decreased from 51.1 at 50 Gy to 5.9 at 200 Gy. Eclosion and deformity of males irradiated from 50 to 200 Gy seemed to be less affected as compared to the reproductive ability. When full grown male pupae were irradiated with the sterilizing dose, a considerable effect on the structure of accessory glands was observed. The dose 200 Gy caused lysis and damage of all type of secretory cells. The secretory epithelial cells showed abnormal appearance and became separated from each other. The cytoplasm was often shrunk, leaving spaces. The muscular sheaths surrounding the gland and lining its lumen were shrunk and damaged in some parts. The mitochondria and golgi bodies were completely lost. The multi microvilli lining the lumen of the gland disappeared. The basement membrane became loose and acquired irregular appearance in most parts. Intercellular microtubules disappeared completely. The gland generally was greatly damaged and lost its normal structure

  18. Differential host growth regulation by the solitary endoparasitoid, Meteorus pulchricornis in two hosts of greatly differing mass.

    Science.gov (United States)

    Harvey, Jeffrey A; Sano, Takeshi; Tanaka, Toshiharu

    2010-09-01

    Solitary koinobiont endoparasitoids generally reduce the growth of their hosts by a significant amount compared with healthy larvae. Here, we compared the development and host usage strategies of the solitary koinobiont endoparasitoid, Meteorus pulchricornis, when developing in larvae of a large host species (Mythimna separata) and a much smaller host species (Plutella xylostella). Caterpillars of M. separata were parasitized as L2 and P. xylostella as L3, when they weighed approximately 2mg. The growth of parasitized M. separata larvae was reduced by almost 95% compared with controls, whereas parasitized P. xylostella larvae grew some 30% larger than controls. Still, adult wasps emerging from M. separata larvae were almost twice as large as wasps emerging from P. xylostella larvae, had larger egg loads after 5 days and produced more progeny. Survival to eclosion was also higher on M. separata than on P. xylostella, although parasitoids developed significantly faster when developing on P. xylostella. Our results provide evidence that koinobionts are able to differentially regulate the growth of different host species. However, there are clearly also limitations in the ability of parasitoids to regulate phenotypic host traits when size differences between different host species are as extreme as demonstrated here.

  19. Interactions between the solitary endoparasitoid, Meteorus gyrator (Hymenoptera: Braconidae) and its host, Lacanobia oleracea (Lepidoptera: Noctuidae), infected with the entomopathogenic microsporidium, Vairimorpha necatrix (Microspora: Microsporidia).

    Science.gov (United States)

    Down, R E; Smethurst, F; Bell, H A; Edwards, J P

    2005-04-01

    Infection of Lacanobia oleracea (Linnaeus) larvae with the microsporidium Vairimorpha necatrix (Kramer) resulted in significant effects on the survival and development of the braconid parasitoid, Meteorus gyrator (Thunberg). Female M. gyrator did not show any avoidance of V. necatrix-infected hosts when they were selecting hosts for oviposition. When parasitism occurred at the same time as infection by the pathogen, or up to four days later, no significant detrimental effects on the parasitoid were observed. However, when parasitism occurred six to eight days after infection, a greater proportion (12.5-14%) of hosts died before parasitoid larvae egressed. Successful eclosion of adult wasps was also reduced. When parasitism and infection were concurrent, parasitoid larval development was significantly faster in infected hosts, and cocoons were significantly heavier. However, as the time interval between infection and parasitism increased, parasitoid larval development was significantly extended by up to two days, and the cocoons formed were significantly (c. 20%) smaller. Vairimorpha necatrix spores were ingested by the developing parasitoid larvae, accumulated in the occluded midgut, and were excreted in the meconium upon pupation.

  20. Transgenic Cotton Plants Expressing the HaHR3 Gene Conferred Enhanced Resistance to Helicoverpa armigera and Improved Cotton Yield.

    Science.gov (United States)

    Han, Qiang; Wang, Zhenzhen; He, Yunxin; Xiong, Yehui; Lv, Shun; Li, Shupeng; Zhang, Zhigang; Qiu, Dewen; Zeng, Hongmei

    2017-08-30

    RNA interference (RNAi) has been developed as an efficient technology. RNAi insect-resistant transgenic plants expressing double-stranded RNA (dsRNA) that is ingested into insects to silence target genes can affect the viability of these pests or even lead to their death. HaHR3 , a molt-regulating transcription factor gene, was previously selected as a target expressed in bacteria and tobacco plants to control Helicoverpa armigera by RNAi technology. In this work, we selected the dsRNA- HaHR3 fragment to silence HaHR3 in cotton bollworm for plant mediated-RNAi research. A total of 19 transgenic cotton lines expressing HaHR3 were successfully cultivated, and seven generated lines were used to perform feeding bioassays. Transgenic cotton plants expressing ds HaHR3 were shown to induce high larval mortality and deformities of pupation and adult eclosion when used to feed the newly hatched larvae, and 3rd and 5th instar larvae of H. armigera . Moreover, HaHR3 transgenic cotton also demonstrated an improved cotton yield when compared with controls.

  1. Synergistic action of fatty acids, sulphides and stilbene against acaricide-resistant Rhipicephalus microplus ticks.

    Science.gov (United States)

    Arceo-Medina, G N; Rosado-Aguilar, J A; Rodríguez-Vivas, R I; Borges-Argaez, R

    2016-09-15

    Six compounds in a methanolic extract of Petiveria alliacea stem (cis-stilbene; benzyl disulphide; benzyl trisulphide; and methyl esters of hexadecanoic acid, octadecadienoic acid and octadecenoic acid) are known to exercise acaricide activity against cattle tick Rhipicephalus microplus larvae and adults. The synergistic effect of 57 combinations of these six compounds on acaricide activity against R. microplus was evaluated. Larvae immersion tests produced the lethal concentrations needed to kill 50% (LC 50 ) and 99% (LC 99 ) of the population. Adult immersion tests produced rates (%) for mortality, oviposition inhibition and eclosion inhibition. Individually, none of the compounds (1% concentration) exhibited acaricide activity (mortality ≤2.3%). When combined, however, nine mixtures exhibited a synergistic increase in activity, with high mortality rates (≥92%) in larvae. Values for LC 50 ranged from 0.07 to 0.51% and those for LC 99 from 0.66 to 5.16%. Thirty six compound mixtures had no significant activity (mortality ≤30%) against larvae. Two mixtures exhibited synergism against adults, with high rates (≥92%) of oviposition inhibition. The mixtures based on the benzyl disulphide+benzyl trisulphide pairing produced a synergistic effect against acaricide-resistant R. microplus larva and adults, and are therefore the most promising combination for controlling this ubiquitous ectoparasite. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Impact of climate change on filarial vector, Culex quinquefasciatus and control using bacterial pesticide, spinosad

    Directory of Open Access Journals (Sweden)

    Nareshkumar Arjunan

    2014-02-01

    Full Text Available Objective: To show the effect of temperature on the biology of Culex quinquefasciatus and also to show the effect of the bacterial pesticide, spinosad on developmental stages of the filarial vector. Methods: A laboratory colony of mosquito larvae was used for the larvicidal activity of temperature and spinosad. Twenty-five numbers of first, second, third, fourth instar larvae were introduced into the 500 mL glass beaker containing 250 mL of de-chlorinated water with desired temperatures (16 °C, 20 °C, 24 °C, 28 °C, 32 °C, 36 °C, similarly spinosad, at different concentrations. The development was observed for every 24 h. Results: The results showed that the rise in temperature acts as a growth inhibiting factor for mosquitoes. And no development was found in the temperature below 16 °C and above 36 °C. The hatchability was increased as the temperature was increased up to 32 °C, after which eclosion rates dropped gradually. Conclusions: 32 °C was obtained as the maximum sustainable temperature and after which the developmental rate was gradually reduced. The optimal temperature for development was lower than the temperatures at which development was quickest. The bacterial pesticide spinosad showed that it is an effective mosquito control agent and can be used for further integrated pest management programmes.

  3. Iron-coupled inactivation of phosphorus in sediments by macrozoobenthos (chironomid larvae) bioturbation: Evidences from high-resolution dynamic measurements

    International Nuclear Information System (INIS)

    Chen, Musong; Ding, Shiming; Liu, Ling; Xu, Di; Han, Chao; Zhang, Chaosheng

    2015-01-01

    The effects of chironomid larvae bioturbation on the lability of phosphorus (P) in sediments were investigated through sediment incubation for 140 days. High-resolution dialysis (HR-Peeper) and diffusive gradients in thin films (DGT) techniques were applied to obtain soluble and labile P/Fe profiles at a millimeter resolution, respectively. The larvae bioturbation decreased concentrations of soluble/labile P and Fe by up to over half of the control at the sediment depths of influence up to 70 and 90 mm respectively. These effects continued over 116 days and disappeared on the 140th days due to eclosion of chironomid larvae. Labile P was highly correlated with labile Fe, while a weak correlation was observed between soluble P and soluble Fe. It was concluded that Fe(II) oxidation and its enhanced adsorption were the major mechanisms responsible for the decreases of soluble and labile P. - Highlights: • High resolution techniques were employed to study bioturbation effects on P. • Larvae bioturbation decreased the concentrations of soluble/labile P and Fe. • Bioturbation effects continued over 116 days and disappeared on the 140th days. • Labile P was more sensitive than pore water SRP in response to bioturbation. • It proved the mechanism of Fe-coupled inactivation of P in bioturbation sediments. - Chironomid larvae bioturation decreased the lability of P in sediments from Fe(II) oxidation and enhanced adsorption of P

  4. Olfactory memory in the mosquito Culex quinquefasciatus.

    Science.gov (United States)

    McCall, P J; Eaton, G

    2001-06-01

    The cosmotropical urban mosquito Culex quinquefasciatus Say (Diptera: Culicidae) uses chemical cues to locate suitable water pools for oviposition. Although gravid females are innately attracted to or repelled by certain compounds, this study found that an individual mosquito's preferences for these odours could be altered greatly by prior experience. Mosquitoes reared in water containing skatole, at a level normally repellent to ovipositing females, preferred to oviposit in water containing that compound rather than in water with an otherwise attractive odour compound (P-cresol). This behaviour occurred regardless of whether mosquitoes were tested individually or in groups of up to 50 per cage. The F1 progeny of conditioned mosquitoes did not exhibit the parental preference, but were as susceptible to conditioning as their parents. Moreover, rearing mosquitoes in infusions of hay or animal (guinea-pig) faeces produced a similar although less dramatic change, such that the innate propensity for hay infusion could be cancelled by rearing in guinea-pig faeces infusion. The results demonstrated a change in odour preference by Cx. quinquefasciatus following exposure to the odour during development or pupal eclosion, suggesting that some form of larval conditioning or early adult imprinting occurred. Precisely when that conditioning occurred remains to be determined.

  5. 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

  6. Low-Temperature Stress during Capped Brood Stage Increases Pupal Mortality, Misorientation and Adult Mortality in Honey Bees

    Science.gov (United States)

    Wang, Qing; Xu, Xinjian; Zhu, Xiangjie; Chen, Lin; Zhou, Shujing; Huang, Zachary Y.; Zhou, Bingfeng

    2016-01-01

    Honey bees (Apis mellifera) are key pollinators, playing a vital role in ecosystem maintenance and stability of crop yields. Recently, reduced honey bee survival has attracted intensive attention. Among all other honey bee stresses, temperature is a fundamental ecological factor that has been shown to affect honey bee survival. Yet, the impact of low temperature stress during capped brood on brood mortality has not been systematically investigated. In addition, little was known about how low temperature exposure during capped brood affects subsequent adult longevity. In this study, capped worker broods at 12 different developmental stages were exposed to 20°C for 12, 24, 36, 48, 60, 72, 84 and 96 hours, followed by incubation at 35°C until emergence. We found that longer durations of low temperature during capped brood led to higher mortality, higher incidences of misorientation inside cells and shorter worker longevity. Capped brood as prepupae and near emergence were more sensitive to low-temperature exposure, while capped larvae and mid-pupal stages showed the highest resistance to low-temperature stress. Our results suggest that prepupae and pupae prior to eclosion are the most sensitive stages to low temperature stress, as they are to other stresses, presumably due to many physiological changes related to metamorphosis happening during these two stages. Understanding how low-temperature stress affects honey bee physiology and longevity can improve honey bee management strategies. PMID:27149383

  7. Effects of gamma irradiation used to inhibit potato sprouting on potato tuber moth eggs, larvae and pupae Phthorimaea Operculella zeller (Lep., Gelechiidae)

    International Nuclear Information System (INIS)

    Saour, G.; Makee, H.

    2003-01-01

    Different age groups of potato tuber moth, Phthorimaea Operculella zeller, eggs were exposed to gamma irradiation at incremental doses up to 150 Gy (the upper dose limit allowed for potato sprout inhibition). Young eggs were more sensitive to gamma irradiation than older eggs and the sensitivity level declined with eggs age. The exposure of 3 - 3.5 d-old eggs to 150 Gy resulted in an 26% increase in egg incubation period compared with unirradiated eggs. The minimum dose required to 75 Gy, 9.7% of larvae survived to the adult stage but emerged as deformed moths. At 100 and 125 Gy, 10.2 and 9.6% of larvae pupated, respectively. However no adult eclosion was recorded. Whereas at 150 Gy, the larvae remained in mid-in star stage and eventually died. Young larvae and pupae were more susceptible to irradiation injuries than older ones. When larvae and of different ages were exposed to doses equal or higher than 100 Gy, only 13 to 35% pupated, but no adult emergence was obtained . The exposure of 1 - 1.5 or 3 - 3.5 day old pupae to 150 Gy induced high level of sterility and remarkable reduction in female mating ability and fecundity whereas, the reduction was less noticeable for 5 - 5.5 day-old pupae. Gamma irradiation doses applied to inhibit potato sprouting could used as an efficient control approach against potato tuber moth eggs, larval and pupal infestations (authors)

  8. Exposure to low-dose X-rays promotes peculiar autophagic cell death in Drosophila melanogaster, an effect that can be regulated by the inducible expression of Hml dsRNA

    Energy Technology Data Exchange (ETDEWEB)

    Kanao, Tomoko [Department of Radiological Sciences, International University of Health and Welfare, Kitakanemaru 2600-1, Ohtawara-shi, Tochigi-ken 324-8501 (Japan); Miyachi, Yukihisa [Department of Radiological Sciences, International University of Health and Welfare, Kitakanemaru 2600-1, Ohtawara-shi, Tochigi-ken 324-8501 (Japan)]. E-mail: ymiyachi@iuhw.ac.jp

    2006-03-20

    We previously reported that to induce an early emergence effect with low-dose X-irradiation in Drosophila, exposure during the prepupae stage is necessary. The present study examined the mechanism by which low-dose radiation rapidly eliminates larval cells and activates the formation of the imaginal discs during metamorphosis. Upon exposure to 0.5 Gy X-rays at 2 h after puparium formation (APF), the larval salivary glands swelled and were surrounded by remarkably thick structures containing an acid phosphatase (Acph) enzyme, implicating a peculiar autophagic cell death. TUNEL staining revealed the presence of DNA fragmentations compared with cells from sham controls which remained unchanged until 12 h APF. Additionally, the salivary glands of exposed flies were completely destroyed by 10 h APF. Furthermore, exposure to 0.5 Gy X-rays also facilitated the activity of the engulfment function of dendritic cells (DCs); they were generated in the larval salivary glands, engulfed the cell corpses and finally moved to the fat body. Data from an experiment demonstrating the inducible expression of Hml double-stranded RNA (dsRNA) indicate that a slow rate of engulfment of larval cells results in a longer time to emergence. Thus, the animals subjected to low-dose X-rays activated autophagic processes, resulting in significantly faster adult eclosion.

  9. Exposure to low-dose X-rays promotes peculiar autophagic cell death in Drosophila melanogaster, an effect that can be regulated by the inducible expression of Hml dsRNA

    International Nuclear Information System (INIS)

    Kanao, Tomoko; Miyachi, Yukihisa

    2006-01-01

    We previously reported that to induce an early emergence effect with low-dose X-irradiation in Drosophila, exposure during the prepupae stage is necessary. The present study examined the mechanism by which low-dose radiation rapidly eliminates larval cells and activates the formation of the imaginal discs during metamorphosis. Upon exposure to 0.5 Gy X-rays at 2 h after puparium formation (APF), the larval salivary glands swelled and were surrounded by remarkably thick structures containing an acid phosphatase (Acph) enzyme, implicating a peculiar autophagic cell death. TUNEL staining revealed the presence of DNA fragmentations compared with cells from sham controls which remained unchanged until 12 h APF. Additionally, the salivary glands of exposed flies were completely destroyed by 10 h APF. Furthermore, exposure to 0.5 Gy X-rays also facilitated the activity of the engulfment function of dendritic cells (DCs); they were generated in the larval salivary glands, engulfed the cell corpses and finally moved to the fat body. Data from an experiment demonstrating the inducible expression of Hml double-stranded RNA (dsRNA) indicate that a slow rate of engulfment of larval cells results in a longer time to emergence. Thus, the animals subjected to low-dose X-rays activated autophagic processes, resulting in significantly faster adult eclosion

  10. Sexy sons from re-mating do not recoup the direct costs of harmful male interactions in the Drosophila melanogaster laboratory model system.

    Science.gov (United States)

    Orteiza, N; Linder, J E; Rice, W R

    2005-09-01

    The empirical foundation for sexual conflict theory is the data from many different taxa demonstrating that females are harmed while interacting with males. However, the interpretation of this keystone evidence has been challenged because females may more than counterbalance the direct costs of interacting with males by the indirect benefits of obtaining higher quality genes for their offspring. A quantification of this trade-off is critical to resolve the controversy and is presented here. A multi-generation fitness assay in the Drosophila melanogaster laboratory model system was used to quantify both the direct costs to females due to interactions with males and indirect benefits via sexy sons. We specifically focus on the interactions that occur between males and nonvirgin females. In the laboratory environment of our base population, females mate soon after eclosion and store sufficient sperm for their entire lifetime, yet males persistently court these nonvirgin females and frequently succeed in re-mating them. Females may benefit from these interactions despite direct costs to their lifetime fecundity if re-mating allows them to trade-up to mates of higher genetic quality and thereby secure indirect benefits for their offspring. We found that direct costs of interactions between males and nonvirgin females substantially exceeded indirect benefits through sexy sons. These data, in combination with past studies of the good genes route of indirect benefits, demonstrate that inter-sexual interactions drive sexually antagonistic co-evolution in this model system.

  11. Virulence of a malaria parasite, Plasmodium mexicanum, for its sand fly vectors, Lutzomyia vexator and Lutzomyia stewarti (Diptera: Psychodidae).

    Science.gov (United States)

    Schall, Jos J

    2011-11-01

    Evolutionary theory predicts that virulence of parasites for mobile vector insects will be low for natural parasite-host associations that have coevolved. I determined virulence of the malaria parasite of lizards, Plasmodium mexicanum, for its vectors, two species of sand fly (Diptera: Psychodidae), Lutzomyia vexator (Coquillett 1907) and Lutzomyia stewarti (Mangabeira Fo & Galindo 1944), by measuring several life history traits. Developmental rate from egg to eclosion differed for the two species when noninfected. For both sand fly species, developmental rate for each stage (egg to larval hatching, larval period, pupal period) and life span were not altered by infection. Infected sand flies, however, produced fewer eggs. This reduction in fecundity may be a result of lower quality of the blood meal taken from infected lizards (lower concentration of hemoglobin). This report is the first measure of virulence of Plasmodium for an insect vector other than a mosquito and concords with both expectations of theory and previous studies on natural parasite-host associations that revealed low virulence.

  12. Effects of temperature and food on the development of Dysdercus maurus Distant (Hemiptera, Pyrrhocoridae); Efeitos da temperatura e do alimento no desenvolvimento de Dysdercus maurus Distant (Hemiptera, Pyrrhocoridae)

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Fabio Souto [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil). Dept. de Ciencias Ambientais], e-mail: fbio_almeida@yahoo.com.br; Goncalves, Lenicio [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil). Dept. de Biologia Animal. Area de Biologia], e-mail: lencygon@globo.com

    2007-10-15

    Dysdercus maurus Distant, 1901 (Hemiptera, Pyrrhocoridae) is an important pest on Gossypium spp. (cotton tree), Citrus sinensis Osbeck (Rutaceae) and Citrus reticulata Blanco (Rutaceae) crops. This insect also feeds on seeds of Chorisia speciosa St. Hil. (Bombacaceae). This work aimed to evaluate the effects of temperature and food on the development of D. maurus. Eight treatments were carried out, in six of them bugs were fed with seeds of C. speciosa and kept at 15, 18, 20, 25 and 30 {+-} 1 deg C, 80 {+-} 3% RH and 12h photo phase or in laboratory conditions (23.5 {+-} 2.6 deg C, 73.3 {+-} 9.9 % RH), and in the other two treatments bugs were fed with seeds of cotton variety IAC-22 and kept at 25 or 30 deg C. In all treatments five immature stages were observed. The increase of temperature caused reduction in the developmental time. The temperature of 15 deg C disabled nymphal eclosion and was also lethal to those nymphs ecloded at other temperatures. The lower mortality of nymphs occurred in the temperature of 25 deg C with cotton as food (24.07%). The lower threshold temperature (Tb) occurred for the first instar (11.54 deg C) and the higher for the second instar (15.33 deg C). The females of D. maurus required more degree-days (329.93 degree-days) than males (300.49 degree-days) until adult emergence. (author)

  13. Life cycle of female ticks of Amblyomma cooperi Nuttal & Warburton, 1908 (Acari: Ixodidae under laboratory conditions Ciclo biológico de fêmeas do carrapato Amblyomma cooperi Nuttal & Warburton, 1908 (Acari:Ixodidae sob condições de laboratório

    Directory of Open Access Journals (Sweden)

    A.T.S. Almeida

    2001-06-01

    Full Text Available The biological cycle of female ticks of Amblyomma cooperi was studied under controlled conditions. The study has begun with two engorged females collected in a naturally infested wild capybara. The larvae originated from the oviposition of these two females were used for collecting young adults through artificial infestations in rabbits. The female parasitic and free living phases were evaluated using artificial infestation of ticks in a capybara. The average body weight of females was 958.2± 175.6mg, the average pre-egg laying period was 8.5± 1.4 days, the reproductive efficiency index was 59.5± 4.2 and the nutritional efficiency index was 77.3± 4.8. The incubation and eclosion periods were 41.9 and 5.9 days, respectively, and the rate of eclosion was 64%. These figures were obtained under high relative humidity conditions which were necessary for the success of the egg incubation process of this species. The preliminary data obtained with the artificial infestation in rabbits raises the possibility of this and other domestic species be used as an epidemiologic link between the domestic and the wild environment with the potential exposure of human populations to A. cooperi and to the maculosa fever agent.O ciclo biológico de Amblyomma cooperi foi estudado sob condições de laboratório. O estudo iniciou-se com duas fêmeas ingurgitadas coletadas de uma capivara selvagem naturalmente infestada. As larvas provenientes da postura foram utilizadas para obtenção de adultos, por meio de infestação artificial em coelhos. As fases parasitária e de vida livre das fêmeas foram avaliadas utilizando-se infestação artificial em capivara. A média de peso corporal foi de 958,2± 175,6mg, a média do período de pré-postura de 8,5± 1,4 dias e dos índices de eficiência reprodutiva e nutricional de 59,5± 4,2 e 77,3± 4,6, respectivamente. Os períodos de incubação e eclosão foram de 41,9 e 5,9 dias, respectivamente. A taxa de eclosão foi

  14. Gamma-radiation treatment for disinfestation of the medfly in thirty-five varieties of California-grown fruits

    International Nuclear Information System (INIS)

    Kaneshiro, K.Y.; Ohta, A.T.; Kurihara, J.S.; Kanegawa, K.M.; Nagamine, L.R.

    1985-01-01

    Minimum absorbed dosages of gamma-radiation required to prevent egg hatch and eclosion of adults when fruits infested with mature larvae are treated with gamma-radiation were determined. Studies were conducted with 35 varieties of California-grown fruits including 10 varieties of nectarines; 5 of plums; 4 of apples; 2 of pears; 4 of grapes, and 1 each of cherries, apricots, oranges, lemons, tomatoes, persimmons, and kiwifruits. Egg hatchability studies indicated that fruit condition, i.e., ripeness, water content, etc. at the time of treatment can effect the amount of radiation reaching the target organism. Thus, there may be considerable differences in the dose levels required to prevent hatch of medfly eggs in the different varieties of fruits. Nevertheless, despite the need for higher dosages in certain fruits, in all cases, none of the larvae that did hatch survived to develop beyond the first or second larval instar. Similar results were obtained in the larval survival studies. That is, mature larvae infesting different varieties of fruits required different dosages of radiation to prevent pupation and/or emergence as adults. Again, at the 0.5-0.6 kGy dosages, varying rates of pupation occurred depending on the variety of fruit. However, in all cases, none of the individuals survived to emerge as adults. The studies indicate that postharvest treatment with gamma-radiation is certainly a potential alternative to treatment with chemical fumigants such as EDB. More research should be conducted in this area with special emphasis on the condition of the fruit with respect to dosage/mortality determinations. Also, the studies on the Navel oranges indicate that combination treatments, in conjunction with gamma radiation can have a synergistic effect, and this aspect should certainly be investigated for all varieties of fruits

  15. Larval feeding duration affects ecdysteroid levels and nutritional reserves regulating pupal commitment in the yellow fever mosquito Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Telang, Aparna; Frame, Laura; Brown, Mark R

    2007-03-01

    What little is known about the endocrine regulation of mosquito development suggests that models based on Lepidoptera and Drosophila may not apply. We report on basic parameters of larval development and the commitment to metamorphosis in the yellow fever mosquito Aedes aegypti that are affected by varying the length of feeding time for last instar larvae. A critical mass for pupal commitment was achieved after 24 h of feeding by last instars, also the age at which tissue production and hemolymph titers of ecdysteroids are increasing. A greater proportion of last instars successfully pupated and eclosed as adults as the length of their feeding time increased. Less than 24 h of feeding time resulted in last instars that were developmentally arrested; these larvae tolerated starvation conditions for up to 2 weeks and retained the capacity to pupate if re-fed. Starvation tolerance may be a common trait among container-inhabiting species, and this period is an important factor to be considered for vectorial capacity and control measures. To distinguish cues for metamorphosis related to a larva's nutritional status versus its age, newly molted last instars were fed for different periods of time but sampled at the same age; ecdysteroid levels, body mass and nutrient reserves were then measured for each group. Our data suggest that metamorphic capacity is dependent on a larva's nutritional condition and not just the age at which ecdysteroid titers increase. Last instars that have fed for a particular length of time may initiate their metamorphic molt when both threshold levels of nutrient reserves and ecdysteroid titer have been met. Future studies will lead to a conceptual model specific for the nutritional and hormonal regulation of mosquito post-embryonic development. This model should facilitate the exploitation of current and novel insect growth regulators that are among favored strategies for vector population suppression.

  16. Ecdysteroids affect in vivo protein metabolism of the flight muscle of the tobacco hornworm (Manduca sexta)

    Science.gov (United States)

    Tischler, M. E.; Wu, M.; Cook, P.; Hodsden, S.

    1990-01-01

    Ecdysteroid growth promotion of the dorsolongitudinal flight muscle of Manduca sexta was studied by measuring in vivo protein metabolism using both "flooding-dose" and "non-carrier" techniques. These procedures differ in that the former method includes injection of non-labelled phenylalanine (30 micromoles/insect) together with the [3H]amino acid. Injected radioactivity plateaued in the haemolymph within 7 min. With the flooding-dose method, haemolymph and intramuscular specific radioactivities were similar between 15 min and 2 h. Incorporation of [3H]phenylalanine into muscle protein was linear with either method between 30 and 120 min. Fractional rates (%/12 h) of synthesis with the flooding-dose technique were best measured after 1 h because of the initial delay in radioactivity equilibration. Estimation of body phenylalanine turnover with the non-carrier method showed 24-53%/h which was negligible with the flooding-dose method. Since the two methods yielded similar rates of protein synthesis, the large injection of non-labelled amino acid did not alter the rate of synthesis. Because the flooding-dose technique requires only a single time point measurement, it is the preferred method. The decline and eventual cessation of flight-muscle growth was mostly a consequence of declining protein synthesis though degradation increased between 76-86 h before eclosion and was relatively rapid. This decline in muscle growth could be prevented by treating pupae with 20-hydroxyecdysone (10 micrograms/insect). Protein accretion was promoted by a decline of up to 80% in protein breakdown, which was offset in part by a concurrent though much smaller decrease in protein synthesis. Therefore, ecdysteroids may increase flight-muscle growth by inhibiting proteolysis.

  17. Establishment Success of the Beetle Tapeworm Hymenolepis diminuta Depends on Dose and Host Body Condition

    Directory of Open Access Journals (Sweden)

    Suraj Dhakal

    2018-02-01

    Full Text Available Parasite effects on host fitness and immunology are often intensity-dependent. Unfortunately, only few experimental studies on insect-parasite interactions attempt to control the level of infection, which may contribute substantial variation to the fitness or immunological parameters of interest. The tapeworm Hymenolepis diminuta—flour beetle Tenebrio molitor model—has been used extensively for ecological and evolutionary host–parasite studies. Successful establishment of H. diminuta cysticercoids in T. molitor relies on ingestion of viable eggs and penetration of the gut wall by the onchosphere. Like in other insect models, there is a lack of standardization of the infection load of cysticercoids in beetles. The aims of this study were to: (1 quantify the relationship between exposure dose and establishment success across several H. diminuta egg concentrations; and (2 test parasite establishment in beetles while experimentally manipulating host body condition and potential immune response to infection. Different egg concentrations of H. diminuta isolated from infected rat feces were fed to individual beetles 7–10 days after eclosion and beetles were exposed to starvation, wounding, or insertion of a nylon filament one hour prior to infection. We found that the establishment of cysticercoids in relation to exposure dose could be accurately predicted using a power function where establishment success was low at three lowest doses and higher at the two highest doses tested. Long-term starvation had a negative effect on cysticercoid establishment success, while insertion of a nylon filament and wounding the beetles did not have any effect compared to control treatment. Thus, our results show that parasite load may be predicted from the exposure dose within the observed range, and that the relationship between dose and parasite establishment success is able to withstand some changes in host body condition.

  18. Establishment Success of the Beetle Tapeworm Hymenolepis diminuta Depends on Dose and Host Body Condition

    Science.gov (United States)

    Jane Cassidy, Elizabeth; Vitt Meyling, Nicolai

    2018-01-01

    Parasite effects on host fitness and immunology are often intensity-dependent. Unfortunately, only few experimental studies on insect-parasite interactions attempt to control the level of infection, which may contribute substantial variation to the fitness or immunological parameters of interest. The tapeworm Hymenolepis diminuta—flour beetle Tenebrio molitor model—has been used extensively for ecological and evolutionary host–parasite studies. Successful establishment of H. diminuta cysticercoids in T. molitor relies on ingestion of viable eggs and penetration of the gut wall by the onchosphere. Like in other insect models, there is a lack of standardization of the infection load of cysticercoids in beetles. The aims of this study were to: (1) quantify the relationship between exposure dose and establishment success across several H. diminuta egg concentrations; and (2) test parasite establishment in beetles while experimentally manipulating host body condition and potential immune response to infection. Different egg concentrations of H. diminuta isolated from infected rat feces were fed to individual beetles 7–10 days after eclosion and beetles were exposed to starvation, wounding, or insertion of a nylon filament one hour prior to infection. We found that the establishment of cysticercoids in relation to exposure dose could be accurately predicted using a power function where establishment success was low at three lowest doses and higher at the two highest doses tested. Long-term starvation had a negative effect on cysticercoid establishment success, while insertion of a nylon filament and wounding the beetles did not have any effect compared to control treatment. Thus, our results show that parasite load may be predicted from the exposure dose within the observed range, and that the relationship between dose and parasite establishment success is able to withstand some changes in host body condition. PMID:29401652

  19. Considerações sobre a reprodução artificial e alevinagem de pacu (Piaractus mesopotamicus, Holmberg, 1887 em viveiros Considerations on artificial reproduction and fingerling culture of pacu (Piaractus mesopotamicus, Holmberg, 1887 in ponds

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Padovani

    2000-05-01

    Full Text Available Este trabalho apresenta uma revisão bibliográfica sobre a reprodução artificial, incubação e alevinagem de pacu em viveiros de terra. As técnicas de propagação artificial possibilitam o suprimento de ovos para uma grande variedade de peixes destinados à criação em viveiros e outros corpos de água confinados, bem como para sistemas superintensivos. Essas técnicas tornaram igualmente possível introduzir várias espécies importantes de peixes em áreas geográficas separadas. Além disso, permitem a incubação, a eclosão de ovos e larvicultura em condições bem protegidas e independentes das condições climáticas. Dependendo do sistema, 20 a 70% dos ovos produzidos têm possibilidade de se transformarem em alevinos; em contrapartida, a taxa de sobrevivência, sob condições naturais, geralmente é muito inferior a 1% dos ovos produzidosThis paper presents a literature review on pacu artificial reproduction, incubation and fingerling culture of pacu in ponds. The techniques of artificial propagation facilitate egg supply for a great variety of fish set aside to be raised in ponds and other impounded water bodies, as well as for superintensive systems. Those techniques made it equally possible to introduce several important fish species in separate geographical areas. Besides, they allow incubation, eggs eclosion and larvae culture under protected conditions, independently of climatic conditions. Depending on the system perfection, 20 to 70% of the eggs are liable to hatch and produce fingerlings. On the other hand the survival rate under natural conditions is generally lower than 1% of eggs

  20. Transcriptome and peptidome characterisation of the main neuropeptides and peptidic hormones of a euphausiid: the Ice Krill, Euphausia crystallorophias.

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    Jean-Yves Toullec

    Full Text Available BACKGROUND: The Ice krill, Euphausia crystallorophias is one of the species at the base of the Southern Ocean food chain. Given their significant contribution to the biomass of the Southern Ocean, it is vitally important to gain a better understanding of their physiology and, in particular, anticipate their responses to climate change effects in the warming seas around Antarctica. METHODOLOGY/PRINCIPAL FINDINGS: Illumina sequencing was used to produce a transcriptome of the ice krill. Analysis of the assembled contigs via two different methods, produced 36 new pre-pro-peptides, coding for 61 neuropeptides or peptide hormones belonging to the following families: Allatostatins (A, B et C, Bursicon (α and β, Crustacean Hyperglycemic Hormones (CHH and MIH/VIHs, Crustacean Cardioactive Peptide (CCAP, Corazonin, Diuretic Hormones (DH, the Eclosion Hormone (EH, Neuroparsin, Neuropeptide F (NPF, small Neuropeptide F (sNPF, Pigment Dispersing Hormone (PDH, Red Pigment Concentrating Hormone (RPCH and finally Tachykinin. LC/MS/MS proteomics was also carried out on eyestalk extracts, which are the major site of neuropeptide synthesis in decapod crustaceans. Results confirmed the presence of six neuropeptides and six precursor-related peptides previously identified in the transcriptome analyses. CONCLUSIONS: This study represents the first comprehensive analysis of neuropeptide hormones in a Eucarida non-decapod Malacostraca, several of which are described for the first time in a non-decapod crustacean. Additionally, there is a potential expansion of PDH and Neuropeptide F family members, which may reflect certain life history traits such as circadian rhythms associated with diurnal migrations and also the confirmation via mass spectrometry of several novel pre-pro-peptides, of unknown function. Knowledge of these essential hormones provides a vital framework for understanding the physiological response of this key Southern Ocean species to climate change

  1. Relative Abundance of Carsonella ruddii (Gamma Proteobacterium) in Females and Males of Cacopsylla pyricola (Hemiptera: Psyllidae) and Bactericera cockerelli (Hemiptera: Triozidae)

    Science.gov (United States)

    Cooper, W. Rodney; Garczynski, Stephen F.; Horton, David R.

    2015-01-01

    Carsonella ruddii (Gamma Proteobacterium) is an obligate bacterial endosymbiont of psyllids that produces essential amino acids that are lacking in the insect’s diet. Accurate estimations of Carsonella populations are important to studies of Carsonella-psyllid interactions and to developing ways to target Carsonella for control of psyllid pests including pear psylla, Cacopsylla pyricola (Förster) (Hemiptera: Psyllidae) and potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae). We used two methods, namely fluorescence in situ hybridization and quantitative polymerase chain reaction (qPCR), to estimate relative abundance of Carsonella in bacteriocytes and whole bodies of psyllids, respectively. Using these two methods, we compared Carsonella populations between female and male insects. Estimations using fluorescence in situ hybridization indicated that Carsonella was more abundant in bacteriocytes of female C. pyricola than in those of males, but Carsonella abundance in bacteriocytes did not differ between sexes of B. cockerelli. Analyses by qPCR using whole-body specimens indicated Carsonella was more abundant in females than in males of both psyllids. Neither fluorescence in situ hybridization nor qPCR indicated that Carsonella populations differed in abundance among adults of different ages (0–3 wk after adult eclosion). Using fluorescence in situ hybridization, Carsonella was observed in ovarioles of newly emerged females and formed an aggregation in the posterior end of mature oocytes. Results of our study indicate that female psyllids harbor greater populations of Carsonella than do males and that sex should be controlled for in studies which require estimations of Carsonella populations. PMID:26056318

  2. Behavioral, Morphological, and Gene Expression Changes Induced by 60Co-γ Ray Irradiation in Bactrocera tau (Walker

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    Jun Cai

    2018-02-01

    Full Text Available The sterile insect technique (SIT may reduce pest populations by allowing sufficient amount of irradiation-induced sterile males to mate with wild females whilst maintaining mating ability comparable to wild males. Although the SIT methods are well understood, the optimal sterilizing dose and processing development stage for application vary among species. To ensure effective pest control programs, effects of irradiation on physiology, behavior, and gene function in the target species should be defined, however, little is known about irradiation effects in Bactrocera tau. Here, the effects of irradiation on rates of fecundity, egg hatch, eclosion, mating competitiveness, flight capability, morphology of reproductive organs, and yolk protein (YP gene expression were studied. The results showed that rates of female fecundity and egg hatch decreased significantly (51 ± 19 to 0.06 ± 0.06 and 98.90 ± 1.01 to 0, respectively when pupae were treated with >150 Gy irradiation. Flight capability and mating competitiveness were not significantly influenced at doses <250 Gy. Ovaries and fallopian tubes became smaller after irradiation, but there was no change in testes size. Finally, we found that expression of the YP gene was up-regulated by irradiation at 30 and 45 days post-emergence, but the mechanisms were unclear. Our study provides information on the determination of the optimal irradiation sterilizing dose in B. tau, and the effects of irradiation on physiology, morphology and gene expression that will facilitate an understanding of sub-lethal impacts of the SIT and expand its use to the control of other species.

  3. Dominant Drop mutants are gain-of-function alleles of the muscle segment homeobox gene (msh) whose overexpression leads to the arrest of eye development.

    Science.gov (United States)

    Mozer, B A

    2001-05-15

    Dominant Drop (Dr) mutations are nearly eyeless and have additional recessive phenotypes including lethality and patterning defects in eye and sensory bristles due to cis-regulatory lesions in the cell cycle regulator string (stg). Genetic analysis demonstrates that the dominant small eye phenotype is the result of separate gain-of-function mutations in the closely linked muscle segment homeobox (msh) gene, encoding a homeodomain transcription factor required for patterning of muscle and nervous system. Reversion of the Dr(Mio) allele was coincident with the generation of lethal loss-of-function mutations in msh in cis, suggesting that the dominant eye phenotype is the result of ectopic expression. Molecular genetic analysis revealed that two dominant Dr alleles contain lesions upstream of the msh transcription start site. In the Dr(Mio) mutant, a 3S18 retrotransposon insertion is the target of second-site mutations (P-element insertions or deletions) which suppress the dominant eye phenotype following reversion. The pattern of 3S18 expression and the absence of msh in eye imaginal discs suggest that transcriptional activation of the msh promoter accounts for ectopic expression. Dr dominant mutations arrest eye development by blocking the progression of the morphogenetic furrow leading to photoreceptor cell loss via apoptosis. Gal4-mediated ubiquitous expression of msh in third-instar larvae was sufficient to arrest the morphogenetic furrow in the eye imaginal disc and resulted in lethality prior to eclosion. Dominant mutations in the human msx2 gene, one of the vertebrate homologs of msh, are associated with craniosynostosis, a disease affecting cranial development. The Dr mutations are the first example of gain-of-function mutations in the msh/msx gene family identified in a genetically tractible model organism and may serve as a useful tool to identify additional genes that regulate this class of homeodomain proteins. Copyright 2001 Academic Press.

  4. Neuropeptides in the desert ant Cataglyphis fortis: Mass spectrometric analysis, localization, and age-related changes.

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    Schmitt, Franziska; Vanselow, Jens T; Schlosser, Andreas; Wegener, Christian; Rössler, Wolfgang

    2017-03-01

    Cataglyphis desert ants exhibit an age-related polyethism, with ants performing tasks in the dark nest for the first ∼4 weeks of their adult life before they switch to visually based long-distance navigation to forage. Although behavioral and sensory aspects of this transition have been studied, the internal factors triggering the behavioral changes are largely unknown. We suggest the neuropeptide families allatostatin A (AstA), allatotropin (AT), short neuropeptide F (sNPF), and tachykinin (TK) as potential candidates. Based on a neuropeptidomic analysis in Camponotus floridanus, nano-LC-ESI MS/MS was used to identify these neuropeptides biochemically in Cataglyphis fortis. Furthermore, we show that all identified peptide families are present in the central brain and ventral ganglia of C. fortis whereas in the retrocerebral complex only sNPF could be detected. Immunofluorescence staining against AstA, AT, and TK in the brain revealed arborizations of AstA- and TK-positive neurons in primary sensory processing centers and higher order integration centers, whereas AT immunoreactivity was restricted to the central complex, the antennal mechanosensory and motor center, and the protocerebrum. For artificially dark-kept ants, we found that TK distribution changed markedly in the central complex from days 1 and 7 to day 14 after eclosion. Based on functional studies in Drosophila, this age-related variation of TK is suggestive of a modulatory role in locomotion behavior in C. fortis. We conclude that the general distribution and age-related changes in neuropeptides indicate a modulatory role in sensory input regions and higher order processing centers in the desert ant brain. J. Comp. Neurol. 525:901-918, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Suboptimal nutrient balancing despite dietary choice in glucose-averse German cockroaches, Blattella germanica.

    Science.gov (United States)

    Jensen, Kim; Schal, Coby; Silverman, Jules

    2015-10-01

    Insects have evolved fine-tuned gustatory and post-ingestive physiological mechanisms that enable them to self-select an optimal composition of macronutrients. Their ability to forage optimally among multiple food sources and maximize fitness parameters depends on their ability not only to taste and perceive the nutritional value of potential foods but also to avoid deleterious components; the strength of such avoidance should reflect the severity of the perceived hazard. In German cockroaches (Blattella germanica), glucose aversion has evolved in some populations in response to anthropogenic selection with glucose-containing insecticidal baits. In four feeding treatments, we gave newly eclosed glucose-averse female cockroaches free choice to feed from two artificial, nutritionally complementary foods varying in protein and carbohydrate composition, with glucose or fructose as the sole carbohydrate source in either food. After 6days of feeding, we measured diet consumption and the length of basal oocytes as an estimate of sexual maturation. The females did not compromise on their aversion to glucose in order to balance their protein and carbohydrate intake, and experienced lower sexual maturation rates as a consequence. Nutrient specific hunger via feedback mechanisms, and adjustments to gustatory sensitivity thus do not override the deterrence of glucose, likely due to strong selection against ingesting even small amounts of toxin associated with glucose in baits. In the absence of baits, glucose aversion would be expected to incur a fitness cost compared to wild-type individuals due to lower overall food availability but also to larger difficulty in attaining a nutritionally balanced diet. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Evaluation of ionizing radiation applied to quarantine control of the false grape mite; Evaluacion de la radiacion ionizante como tratamiento de control cuarentenario de la falsa aranita de la vid (Brevipalpus chilensis Baker)

    Energy Technology Data Exchange (ETDEWEB)

    Jadue D, Yael; Vargas O, Claudio Andres

    1994-12-31

    The objectives of this study were to evaluate effect of three dosages of ionizing radiation in combination with cold storage (0-2{sup 0} C), and the effect of cold storage without irradiation, establishing time curves for eclosion of eggs and mortality of juvenile and adult stages, and adult oviposture. An experimental Cs-137 Brookhaven Portable Cesium Development Irradiator (BPCDI N. 3) at the Chilean Nuclear Energy Commission, located in the La Reina Commune of Santiago, Chile, was used at dosages of 0.500, 1.000, and 1,500 Gy (with a dosage rate of 28.95 Gy/min), combined with pretreatment cold (0-2{sup 0} C) during 24 h, and 15 days of cold storage postirradiation, to simulate the duration of a grape shipment to the U.S., onto 1-4 and 1-4 and {>=} 4 day-old eggs, juveniles and adult stages. The initial stages of development were more susceptible to radiation when combined with cold storage. The mortality of both egg development stages, juveniles and adults, with dosages from 500-1.500; 1.000-1.500; and 1500 Gy, respectively, satisfied the probity 9 (99.9968%) quarantine security level requirement. The few survivors from treated juveniles and adults were unable to continue their cycle, and did not present quarantine risk. All dosages used produced 100% mortality. Apparently, cold storage has a synergic effect when used in combination with radiation. Cold storage of stages not irradiated somewhat the population dynamics. (author). 58 refs, 24 figs, 12 tabs.

  7. Analysis of biological parameters of Boophilus microplus Canestrini, 1887 exposed to entomopathogenic nematodes Steinernema carpocapsae Santa Rosa and All strains (Steinernema: Rhabditida

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    Gláucia Marques Freitas-Ribeiro

    2005-11-01

    Full Text Available Engorged and partially engorged females of Boophilus microplus were exposed to 600; 3,000; 6,000 and 30,000 infective juveniles of Steinernema carpocapsae Weiser, 1955 Santa Rosa and All strains per dish, under lab conditions. Eggs weight, pre-laying period, laying period, survival period, reproductive efficiency rate, percentage of larval eclosion and lethal concentrations of 50% and 90% (CL50 and CL90 were calculated for engorged females. In the case of partially engorged females, only egg weight, survival period and CL50 and CL90 were calculated. All biological parameters of engorged or partially engorged females were altered by exposition of S. carpocapsae infective juveniles (IJs, Santa Rosa and All strains (pFêmeas ingurgitadas e parcialmente ingurgitadas de B. microplus foram expostas a 600, 3000, 6000 e 30000 juvenis infectivos de Steinernema carpocapsae Weiser, 1955 linhagens Santa Rosa e ALL por placa, sob condições de laboratório. Foram investigados para fêmeas ingurgitadas: peso da massa de ovos, período pré-postura, período de postura, tempo de sobrevivência, índice de eficiência reprodutiva, percentual de aclosão de larvas e concentrações letais 50% e 90% (CL50 e CL90. Para fêmeas parcialmente ingurgitadas somente foram observados peso da massa de ovos, tempo de sobrevivência, CL50 e CL90. Todos os parâmetros biológicos de fêmeas ingurgitadas foram e parcialmente ingurgitadas foram alterados pela exposição a juvenis infectivos de S. carpocapsae linhagens Santa Rosa e ALL (P<0,05. O aumento das resposta foi diretamente proporcional ao aumento das concentrações de juvenis infectivos por placa (P<0,05. Os resultados sugerem que nematóides entomopatogênicos podem ter papel primissor no controle de carrapatos dos bovinos.

  8. Protein deficiency lowers resistance of Mormon crickets to the pathogenic fungus Beauveria bassiana.

    Science.gov (United States)

    Srygley, R B; Jaronski, S T

    Little is known about the effects of dietary macronutrients on the capacity of insects to ward off a fungal pathogen. Here we tested the hypothesis that Mormon crickets fed restricted protein diets have lower enzymatic assays of generalized immunity, slower rates of encapsulation of foreign bodies, and greater mortality from infection by Beauveria bassiana, a fungal pathogen. Beginning in the last nymphal instar, Mormon crickets were fed a high, intermediate, or low protein diet with correspondingly low, intermediate, or high carbohydrate proportions. After they eclosed to adult, we drew hemolymph, topically applied B. bassiana, maintained them on diet treatments, and measured mortality for 21 days. Mormon crickets fed high protein diets had higher prophenoloxidase titers, greater encapsulation response, and higher survivorship to Beauveria fungal infection than those on low protein diets. We replicated the study adding very high and very low protein diets to the treatments. A high protein diet increased phenoloxidase titers, and those fed the very high protein diet had more circulating prophenoloxidase. Mormon crickets fed the very low protein diet were the most susceptible to B. bassiana infection, but the more concentrated phenoloxidase and prophenoloxidase associated with the highest protein diets did not confer the greatest protection from the fungal pathogen as in the first replicate. We conclude that protein-restricted diets caused Mormon crickets to have lower phenoloxidase titers, slower encapsulation of foreign bodies, and greater mortality from B. bassiana infection than those fed high protein diets. These results support the nutrition-based dichotomy of migrating Mormon crickets, protein-deficient ones are more susceptible to pathogenic fungi whereas carbohydrate-deficient ones are more vulnerable to bacterial challenge. Published by Elsevier Ltd.

  9. Recent advances in the rearing of Glossina pallidipes Austen

    International Nuclear Information System (INIS)

    Leegwater-Van der Linden, M.E.

    1980-01-01

    The rearing technique of Glossina pallidipes Austen in Amsterdam is described. The flies are kept at 25 0 C, 80% relative humidity in very dim light which operates 12 hours a day. Flies are fed on ears of lop-eared rabbits inside the colony room. Nine-day-old females are massmated with an equal number of 12-day-old males for approximately three days. Mated females are kept without males. Under these circumstances the interlarval period is nine years. The first larva is deposited on the 20th day after emergence and the mean longevity hereafter is 60 days average or 101 days with individual attention. Productivity has been observed from 1977 onward. The insemination rate gradually increased from 66 to 97%, and fecundity from about 0.5 to 0.8. Premating deaths remained at a level of 4%. The eclosion rate was 92% and pupal weight 39 mg. In the Amsterdam practice these figures imply that nearly one third of the weekly pupal production is needed to maintain the colony at a set number. The remainder can be used for other purposes. Judging from observations and experience it seems that prevention of chemical contamination and any disturbance, mass-mating at the appropriate time and a very high humidity are relevant points in the various techniques used in rearing G. pallidipes. Attention is now being given to the viability of the colony in Amsterdam for eradicating G. pallidipes in East Africa. Females emerging from pupae sent from a test area near Tanga, Tanzania, were readily inseminated by males from the Amsterdam colony, indicating the possibility of using the sterile male technique for reduction of G. pallidipes in East Africa. (author)

  10. Nem só de pão vive o homem Man shall not live by bread alone

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    Rodrigo da Cunha Pereira

    2006-12-01

    Full Text Available Este artigo pretende contribuir com a discussão sobre as prerrogativas da paternidade sob o prisma da valorização das funções paternas, das limitações de direitos e da afirmação de deveres do pai. Uma polêmica instigante se instalou a partir da eclosão de demandas judiciais em que filhos denunciam o abandono afetivo, psíquico e moral de seus pais, pedindo reparação pelos danos causados, em processos que chegaram aos tribunais, Alguns entendem que o abandono afetivo deve ser reparado por meio de indenização pecuniária. Outros, com o argumento de que não se pode obrigar um pai a amar e a conviver com seu filho, se opõem à exigência de reparação por abandono. Argumentam que, uma vez cumprido o dever de prestar alimentos, o pai se desincumbiria de suas obrigações perante o filho. Entretanto, nem só de pão vive o homem...The present article contributes to the discussions regarding the prerrogatives of paternity, under the aspect of valueing paternal functions, the limitation of rights and the affirmation of the paternal duties. A provocative polemic has been installed stemming from the eclosion of judicial demands in which children denounce the affective, psychic and moral abandon suffered from their fathers, claiming reparations for damages caused, all in court. Some of the children demand financial remunerations to compensate affective abandon. Others, claiming that a father can’t be forced to love or live with a child, oppose claiming for financial compensations. They state that, once living up to the function of providing alimony, a father would be exempt from his obligations towards the child. However, a person needs more than bread to survive...

  11. Prediction of the neuropeptidomes of members of the Astacidea (Crustacea, Decapoda) using publicly accessible transcriptome shotgun assembly (TSA) sequence data.

    Science.gov (United States)

    Christie, Andrew E; Chi, Megan

    2015-12-01

    The decapod infraorder Astacidea is comprised of clawed lobsters and freshwater crayfish. Due to their economic importance and their use as models for investigating neurochemical signaling, much work has focused on elucidating their neurochemistry, particularly their peptidergic systems. Interestingly, no astacidean has been the subject of large-scale peptidomic analysis via in silico transcriptome mining, this despite growing transcriptomic resources for members of this taxon. Here, the publicly accessible astacidean transcriptome shotgun assembly data were mined for putative peptide-encoding transcripts; these sequences were used to predict the structures of mature neuropeptides. One hundred seventy-six distinct peptides were predicted for Procambarus clarkii, including isoforms of adipokinetic hormone-corazonin-like peptide (ACP), allatostatin A (AST-A), allatostatin B, allatostatin C (AST-C) bursicon α, bursicon β, CCHamide, crustacean hyperglycemic hormone (CHH)/ion transport peptide (ITP), diuretic hormone 31 (DH31), eclosion hormone (EH), FMRFamide-like peptide, GSEFLamide, intocin, leucokinin, neuroparsin, neuropeptide F, pigment dispersing hormone, pyrokinin, RYamide, short neuropeptide F (sNPF), SIFamide, sulfakinin and tachykinin-related peptide (TRP). Forty-six distinct peptides, including isoforms of AST-A, AST-C, bursicon α, CCHamide, CHH/ITP, DH31, EH, intocin, myosuppressin, neuroparsin, red pigment concentrating hormone, sNPF and TRP, were predicted for Pontastacus leptodactylus, with a bursicon β and a neuroparsin predicted for Cherax quadricarinatus. The identification of ACP is the first from a decapod, while the predictions of CCHamide, EH, GSEFLamide, intocin, neuroparsin and RYamide are firsts for the Astacidea. Collectively, these data greatly expand the catalog of known astacidean neuropeptides and provide a foundation for functional studies of peptidergic signaling in members of this decapod infraorder. Copyright © 2015 Elsevier Inc

  12. Prediction of Scylla olivacea (Crustacea; Brachyura) peptide hormones using publicly accessible transcriptome shotgun assembly (TSA) sequences.

    Science.gov (United States)

    Christie, Andrew E

    2016-05-01

    The aquaculture of crabs from the genus Scylla is of increasing economic importance for many Southeast Asian countries. Expansion of Scylla farming has led to increased efforts to understand the physiology and behavior of these crabs, and as such, there are growing molecular resources for them. Here, publicly accessible Scylla olivacea transcriptomic data were mined for putative peptide-encoding transcripts; the proteins deduced from the identified sequences were then used to predict the structures of mature peptide hormones. Forty-nine pre/preprohormone-encoding transcripts were identified, allowing for the prediction of 187 distinct mature peptides. The identified peptides included isoforms of adipokinetic hormone-corazonin-like peptide, allatostatin A, allatostatin B, allatostatin C, bursicon β, CCHamide, corazonin, crustacean cardioactive peptide, crustacean hyperglycemic hormone/molt-inhibiting hormone, diuretic hormone 31, eclosion hormone, FMRFamide-like peptide, HIGSLYRamide, insulin-like peptide, intocin, leucokinin, myosuppressin, neuroparsin, neuropeptide F, orcokinin, pigment dispersing hormone, pyrokinin, red pigment concentrating hormone, RYamide, short neuropeptide F, SIFamide and tachykinin-related peptide, all well-known neuropeptide families. Surprisingly, the tissue used to generate the transcriptome mined here is reported to be testis. Whether or not the testis samples had neural contamination is unknown. However, if the peptides are truly produced by this reproductive organ, it could have far reaching consequences for the study of crustacean endocrinology, particularly in the area of reproductive control. Regardless, this peptidome is the largest thus far predicted for any brachyuran (true crab) species, and will serve as a foundation for future studies of peptidergic control in members of the commercially important genus Scylla. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Ultraviolet filters differentially impact the expression of key endocrine and stress genes in embryos and larvae of Chironomus riparius.

    Science.gov (United States)

    Ozáez, Irene; Morcillo, Gloria; Martínez-Guitarte, José-Luis

    2016-07-01

    Several organic UV filters have hormonal activity in vertebrates, as demonstrated in fishes, rodents and human cells. Despite the accumulation of filter contaminants in aquatic systems, research on their effects on the endocrine systems of freshwaters invertebrates is scarce. In this work, the effects of five frequently used UV filters were investigated in embryos and larvae of Chironomus riparius, which is a reference organism in ecotoxicology. LC50 values for larvae as well as the percentage of eclosion of eggs were determined following exposures to: octyl-p-methoxycinnamate (OMC) also known as 2-ethylhexyl-4-methoxycinnamate (EHMC); 4-methylbenzylidene camphor (4MBC); 4-hydroxybenzophenone (4HB); octocrylene (OC); and octyldimethyl-p-aminobenzoate (OD-PABA). To assess sublethal effects, expression levels of the genes coding for the ecdysone receptor (EcR) and heat shock protein HSP70 were investigated as biomarkers for endocrine and stress effects at the cellular level. Life-stage-dependent sensitivity was found. In embryos, all of the UV filters provoked a significant overexpression of EcR at 24h after exposure. OC, 4MBC and OD-PABA also triggered transcriptional activation of the hsp70 stress gene in embryos. In contrast, in larvae, only 4MBC and OMC/EHMC increased EcR and hsp70 mRNA levels and OD-PABA upregulated only the EcR gene. These results revealed that embryos are particularly sensitive to UV filters, which affect endocrine regulation during development. Most UV filters also triggered the cellular stress response, and thus exhibit proteotoxic effects. The differences observed between embryos and larvae and the higher sensitivity of embryos highlight the importance of considering different life stages when evaluating the environmental risks of pollutants, particularly when analyzing endocrine effects. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Comparative toxicities and synergism of apple orchard pesticides to Apis mellifera (L. and Osmia cornifrons (Radoszkowski.

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    David J Biddinger

    Full Text Available The topical toxicities of five commercial grade pesticides commonly sprayed in apple orchards were estimated on adult worker honey bees, Apis mellifera (L. (Hymenoptera: Apidae and Japanese orchard bees, Osmia cornifrons (Radoszkowski (Hymenoptera: Megachilidae. The pesticides were acetamiprid (Assail 30SG, λ-cyhalothrin (Warrior II, dimethoate (Dimethoate 4EC, phosmet (Imidan 70W, and imidacloprid (Provado 1.6F. At least 5 doses of each chemical, diluted in distilled water, were applied to freshly-eclosed adult bees. Mortality was assessed after 48 hr. Dose-mortality regressions were analyzed by probit analysis to test the hypotheses of parallelism and equality by likelihood ratio tests. For A. mellifera, the decreasing order of toxicity at LD₅₀ was imidacloprid, λ-cyhalothrin, dimethoate, phosmet, and acetamiprid. For O. cornifrons, the decreasing order of toxicity at LD₅₀ was dimethoate, λ-cyhalothrin, imidacloprid, acetamiprid, and phosmet. Interaction of imidacloprid or acetamiprid with the fungicide fenbuconazole (Indar 2F was also tested in a 1∶1 proportion for each species. Estimates of response parameters for each mixture component applied to each species were compared with dose-response data for each mixture in statistical tests of the hypothesis of independent joint action. For each mixture, the interaction of fenbuconazole (a material non-toxic to both species was significant and positive along the entire line for the pesticide. Our results clearly show that responses of A. mellifera cannot be extrapolated to responses of O.cornifrons, and that synergism of neonicotinoid insecticides and fungicides occurs using formulated product in mixtures as they are commonly applied in apple orchards.

  15. Sexual Competitiveness of Anastrepha ludens (Diptera: Tephritidae) Males Exposed to Citrus aurantium and Citrus paradisi Essential Oils.

    Science.gov (United States)

    Morató, Santiago; Shelly, Todd; Rull, Juan; Aluja, Martin

    2015-04-01

    Males of the Mediterranean fruit fly (Ceratitis capitata (Wiedemann)) display increased mating competitiveness following exposure to the odor of certain host and nonhost plants, and this phenomenon has been used in the sterile insect technique to boost the mating success of released, sterile males. Here, we aimed to establish whether males of the Mexican fruit fly (Anastrepha ludens (Loew)) gain a mating advantage when exposed to the aroma of two preferred hosts, grapefruit (Citrus paradisi Macfadyen) and bitter orange (Citrus aurantium L.). Under seminatural conditions, we observed that, in trials using wildish males (from a young laboratory colony started with wild flies) exclusively, exposure to the aroma of bitter orange had no effect on male mating success but exposure to the odor grapefruit oil increased male mating success significantly. In a separate test involving both exposed and nonexposed wildish and mass-reared, sterile males, although wildish males were clearly more competitive than sterile males, exposure to grapefruit oil had no detectable effect on either male type. Exposure to oils had no effect on copulation duration in any of the experiments. We discuss the possibility that the positive effect of grapefruit essential oils on wildish male competitiveness may have been linked to exposure of females to grapefruit as a larval food, which may have imprinted them with grapefruit odors during pupal eclosion and biased their response as adults to odors of their maternal host. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. From conservationism to sustainable territorial development

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    Paulo Freire Vieira

    2009-10-01

    Full Text Available Since the end of the 1960s, the eclosion of a planetary problematics related to the recognition of the “ecological limits of material growth” has mobilized growing attention on the part of scientific communities and public opinion. The systemic concept of eco-development has emerged from this context and been gradually disseminated as a an expression of the radical critique of the economistic ideology underlying industrial-technological “civilization”. Over the course of the 1980s and 1990s, the proliferation of case studies on experiences of local and territorial development in different national contexts has contributed to a deepening of (systemic notions of endogeneity, de-centralization, self-reliance, local autonomy and integrated local productive systems, which have always considered bases of the ecodevelopmentalist position. Against the background of the uncertainties, constraints and opportunities imposed by assymetrical globalization, special attention began to be given to the analysis of the innovative and synergic responses – in terms of socio-economic, socio-cultural and political-institutional reorganization – that have been generated within these spaces. Furthermore, and in a rather paradoxical way, most of the studies linked to a territorial focus give little attention to the treatment of the immense challenges brought about through the elosion of socioenvironmental crisis and the appearance of a vast literature dealing with the connection between environment and development. The present article offers exploratory subsidies that attempt to overcome the aforementioned lacunae, evaluating both the pertinence and general conditions of viability of the sustainable territorial development approach at the current stage of evolution of the Brazilian environmental agenda. Keywords: systemic research, ecological policy, environmental policy, sustainable territorial development.

  17. Drosophila eye color mutants as therapeutic tools for Huntington disease.

    Science.gov (United States)

    Green, Edward W; Campesan, Susanna; Breda, Carlo; Sathyasaikumar, Korrapati V; Muchowski, Paul J; Schwarcz, Robert; Kyriacou, Charalambos P; Giorgini, Flaviano

    2012-01-01

    Huntington disease (HD) is a fatal inherited neurodegenerative disorder caused by a polyglutamine expansion in the huntingtin protein (htt). A pathological hallmark of the disease is the loss of a specific population of striatal neurons, and considerable attention has been paid to the role of the kynurenine pathway (KP) of tryptophan (TRP) degradation in this process. The KP contains three neuroactive metabolites: 3-hydroxykynurenine (3-HK), quinolinic acid (QUIN), and kynurenic acid (KYNA). 3-HK and QUIN are neurotoxic, and are increased in the brains of early stage HD patients, as well as in yeast and mouse models of HD. Conversely, KYNA is neuroprotective and has been shown to be decreased in HD patient brains. We recently used a Drosophila model of HD to measure the neuroprotective effect of genetic and pharmacological inhibition of kynurenine monoxygenase (KMO)-the enzyme catalyzing the formation of 3-HK at a pivotal branch point in the KP. We found that KMO inhibition in Drosophila robustly attenuated neurodegeneration, and that this neuroprotection was correlated with reduced levels of 3-HK relative to KYNA. Importantly, we showed that KP metabolites are causative in this process, as 3-HK and KYNA feeding experiments modulated neurodegeneration. We also found that genetic inhibition of the upstream KP enzyme tryptophan-2,3-dioxygenase (TDO) was neuroprotective in flies. Here, we extend these results by reporting that genetic impairment of KMO or TDO is protective against the eclosion defect in HD model fruit flies. Our results provide further support for the possibility of therapeutic KP interventions in HD.

  18. A Single-Wing Removal Method to Assess Correspondence Between Gene Expression and Phenotype in Butterflies: The Case of Distal-less.

    Science.gov (United States)

    Adhikari, Kiran; Otaki, Joji M

    2016-02-01

    It is often desirable but difficult to retrieve information on the mature phenotype of an immature tissue sample that has been subjected to gene expression analysis. This problem cannot be ignored when individual variation within a species is large. To circumvent this problem in the butterfly wing system, we developed a new surgical method for removing a single forewing from a pupa using Junonia orithya; the operated pupa was left to develop to an adult without eclosion. The removed right forewing was subjected to gene expression analysis, whereas the non-removed left forewing was examined for color patterns. As a test case, we focused on Distal-less (Dll), which likely plays an active role in inducing elemental patterns, including eyespots. The Dll expression level in forewings was paired with eyespot size data from the same individual. One third of the operated pupae survived and developed wing color patterns. Dll expression levels were significantly higher in males than in females, although male eyespots were smaller in size than female eyespots. Eyespot size data showed weak but significant correlations with the Dll expression level in females. These results demonstrate that a single-wing removal method was successfully applied to the butterfly wing system and suggest the weak and non-exclusive contribution of Dll to eyespot size determination in this butterfly. Our novel methodology for establishing correspondence between gene expression and phenotype can be applied to other candidate genes for color pattern development in butterflies. Conceptually similar methods may also be applicable in other developmental systems.

  19. Evaluation of ionizing radiation applied to quarantine control of the false grape mite

    International Nuclear Information System (INIS)

    Jadue D, Yael; Vargas O, Claudio Andres.

    1994-01-01

    The objectives of this study were to evaluate effect of three dosages of ionizing radiation in combination with cold storage (0-2 0 C), and the effect of cold storage without irradiation, establishing time curves for eclosion of eggs and mortality of juvenile and adult stages, and adult oviposture. An experimental Cs-137 Brookhaven Portable Cesium Development Irradiator (BPCDI N. 3) at the Chilean Nuclear Energy Commission, located in the La Reina Commune of Santiago, Chile, was used at dosages of 0.500, 1.000, and 1,500 Gy (with a dosage rate of 28.95 Gy/min), combined with pretreatment cold (0-2 0 C) during 24 h, and 15 days of cold storage postirradiation, to simulate the duration of a grape shipment to the U.S., onto 1-4 and 1-4 and ≥ 4 day-old eggs, juveniles and adult stages. The initial stages of development were more susceptible to radiation when combined with cold storage. The mortality of both egg development stages, juveniles and adults, with dosages from 500-1.500; 1.000-1.500; and 1500 Gy, respectively, satisfied the probity 9 (99.9968%) quarantine security level requirement. The few survivors from treated juveniles and adults were unable to continue their cycle, and did not present quarantine risk. All dosages used produced 100% mortality. Apparently, cold storage has a synergic effect when used in combination with radiation. Cold storage of stages not irradiated somewhat the population dynamics. (author). 58 refs, 24 figs, 12 tabs

  20. Mutation of a vitelline membrane protein, BmEP80, is responsible for the silkworm "Ming" lethal egg mutant.

    Science.gov (United States)

    Chen, Anli; Gao, Peng; Zhao, Qiaoling; Tang, Shunming; Shen, Xingjia; Zhang, Guozheng; Qiu, Zhiyong; Xia, Dingguo; Huang, Yongping; Xu, Yunmin; He, Ningjia

    2013-02-25

    The egg stage is an important stage in the silkworm (Bombyx mori) life cycle. Normal silkworm eggs are usually short, elliptical, and laterally flattened, with a sometimes hollowed surface on the lateral side. However, the eggs laid by homozygous recessive "Ming" lethal egg mutants (l-e(m)) lose water and become concaved around 1h, ultimately exhibiting a triangular shape on the egg surfaces. We performed positional cloning, and narrowed down the region containing the gene responsible for the l-e(m) mutant to 360 kb on chromosome 10 using 2287 F(2) individuals. Using expression analysis and RNA interference, the best l-e(m) candidate gene was shown to be BmEP80. The results of the inverse polymerase chain reaction showed that an ~1.9 kb region from the 3' untranslated region of BmVMP23 to the forepart of BmEP80 was replaced by a >100 kb DNA fragment in the l-e(m) mutant. Several eggs laid by the normal moths injected with BmEP80 small interfering RNAs were evidently depressed and exhibited a triangular shape on the surface. The phenotype exhibited was consistent with the eggs laid by the l-e(m) mutant. Moreover, two-dimensional gel electrophoresis showed that the BmEP80 protein was expressed in the ovary from the 9th day of the pupa stage to eclosion in the wild-type silkworm, but was absent in the l-e(m) mutant. These results indicate that BmEP80 is responsible for the l-e(m) mutation. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Proteomic analysis of Bombyx mori molting fluid: Insights into the molting process.

    Science.gov (United States)

    Liu, Hua-Wei; Wang, Luo-Ling; Tang, Xin; Dong, Zhao-Ming; Guo, Peng-Chao; Zhao, Dong-Chao; Xia, Qing-You; Zhao, Ping

    2018-02-20

    Molting is an essential biological process occurring multiple times throughout the life cycle of most Ecdysozoa. Molting fluids accumulate and function in the exuvial space during the molting process. In this study, we used liquid chromatography-tandem mass spectrometry to investigate the molting fluids to analyze the molecular mechanisms of molting in the silkworm, Bombyx mori. In total, 375 proteins were identified in molting fluids from the silkworm at 14-16h before pupation and eclosion, including 12 chitin metabolism-related enzymes, 35 serine proteases, 15 peptidases, and 38 protease inhibitors. Gene ontology analysis indicated that "catalytic" constitutes the most enriched function in the molting fluid. Gene expression patterns and bioinformatic analyses suggested that numerous enzymes are involved in the degradation of cuticle proteins and chitin. Protein-protein interaction network and activity analyses showed that protease inhibitors are involved in the regulation of multiple pathways in molting fluid. Additionally, many immune-related proteins may be involved in the immune defense during molting. These results provide a comprehensive proteomic insight into proteolytic enzymes and protease inhibitors in molting fluid, and will likely improve the current understanding of physiological processes in insect molting. Insect molting constitutes a dynamic physiological process. To better understand this process, we used LC-MS/MS to investigate the proteome of silkworm molting fluids and identified key proteins involved in silkworm molting. The biological processes of the old cuticle degradation pathway and immune defense response were analyzed in the proteome of silkworm molting fluid. We report that protease inhibitors serve as key factors in the regulation of the molting process. The proteomic results provide new insight into biological molting processes in insects. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Occurrence and host specificity of a neogregarine protozoan in four milkweed butterfly hosts (Danaus spp.).

    Science.gov (United States)

    Barriga, Paola A; Sternberg, Eleanore D; Lefèvre, Thierry; de Roode, Jacobus C; Altizer, Sonia

    2016-10-01

    Throughout their global range, wild monarch butterflies (Danaus plexippus) are infected with the protozoan Ophryocystis elektroscirrha (OE). In monarchs, OE infection reduces pupal eclosion, adult lifespan, adult body size and flight ability. Infection of other butterfly hosts with OE is rare or unknown, and the only previously published records of OE infection were on monarch and queen butterflies (D. gilippus). Here we explored the occurrence and specificity of OE and OE-like parasites in four Danaus butterfly species. We surveyed wild D. eresimus (soldier), D. gilippus (queen), D. petilia (lesser wanderer), and D. plexippus (monarch) from five countries to determine the presence of infection. We conducted five cross-infection experiments, on monarchs and queen butterflies and their OE and OE-like parasites, to determine infection probability and the impact of infection on their hosts. Our field survey showed that OE-like parasites were present in D. gilippus, D. petilia, and D. plexippus, but were absent in D. eresimus. Infection probability varied geographically such that D. gilippus and D. plexippus populations in Puerto Rico and Trinidad were not infected or had low prevalence of infection, whereas D. plexippus from S. Florida and Australia had high prevalence. Cross-infection experiments showed evidence for host specificity, in that OE strains from monarchs were more effective at infecting monarchs than queens, and monarchs were less likely to be infected by OE-like strains from queens and lesser wanderers relative to their own natal strains. Our study showed that queens are less susceptible to OE and OE-like infection than monarchs, and that the reduction in adult lifespan following infection is more severe in monarchs than in queens. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Mutagenic effect of radionuclides incorporated into DNA of Drosophila melanogaster. Progress report, 1977--1978

    International Nuclear Information System (INIS)

    Lee, W.R.

    1978-01-01

    Three experiments were conducted in which Drosophila melanogaster males were labeled with (5- 3 H)-deoxycytidine, (8- 3 H)-deoxyguanosine, or L-(3- 3 H)-arginine in the larval stage. In the first two experiments with 5- 3 H-dC and 8- 3 H-dG, the labeled males upon eclosion were divided into two groups: 1) those mated to females that from emergence as adults were sustained on a media deficient in protein, called sugar agar media; and 2) those mated to females that were on a standard nutritious media. All males from the arginine experiment were mated to females stored on the standard media. The labeled males were allowed to mate for two days during which time the females stored on standard media deposited fertile eggs. Those F 1 progenies developing from the brood of eggs laid during the first 48 hrs following mating were called the non-stored group, as the spermatozoa were not stored in the female for more than 48 hrs. Progenies of males that were mated to females sustained on the sugar agar media were referred to as the stored group because the females on the sugar agar did not lay eggs. After 14 days the females were transferred to regular corn meal agar to induce egg laying. The average time of storage of sperm in the females' seminal receptacles for the stored group was 18 days. The progenies from the non-stored and stored broods were analyzed for mutations thus giving a comparison of the mutation frequency for each class of mutants detected before and after storage of the tritium-labeled sperm. The difference between the mutation frequency following storage and that before storage is the increase in mutations attributed to tritium disintegrations occurring during the storage period. One determination for each experiment, 5- 3 H-dC, 8- 3 H-dG, or 3 H-Arg. has been made

  4. Screening for the genes involved in bombykol biosynthesis: Identification and functional characterization of Bombyx mori acyl carrier protein (BmACP

    Directory of Open Access Journals (Sweden)

    Atsushi eOhnishi

    2011-12-01

    Full Text Available Species-specific sex pheromones released by female moths to attract conspecific male moths are synthesized de novo in the pheromone gland (PG via fatty acid synthesis (FAS. Biosynthesis of moth sex pheromones is usually regulated by a neurohormone termed pheromone biosynthesis activating neuropeptide (PBAN, a 33-aa peptide that originates in the subesophageal ganglion. In the silkmoth, Bombyx mori, cytoplasmic lipid droplets (LDs, which store the sex pheromone (bombykol precursor fatty acid, accumulate in PG cells prior to eclosion. PBAN activation of the PBAN receptor stimulates lipolysis of the stored LD triacylglycerols (TAGs resulting in release of the bombykol precursor for final modification. While we have previously characterized a number of molecules involved in bombykol biosynthesis, little is known about the mechanisms of PBAN signaling that regulate the TAG lipolysis in PG cells. In the current study, we sought to further identify genes involved in bombykol biosynthesis as well as PBAN signaling, by using a subset of 312 expressed sequence tag (EST clones that are in either our B. mori PG cDNA library or the public B. mori EST databases, SilkBase and CYBERGATE, and which are preferentially expressed in the PG. Using RT-PCR expression analysis and an RNAi screening approach, we have identified another 8 EST clones involved in bombykol biosynthesis. Furthermore, we have determined the functional role of a clone designated BmACP that encodes B. mori acyl carrier protein (ACP. Our results indicate that BmACP plays an essential role in the biosynthesis of the bombykol precursor fatty acid via the canonical FAS pathway during pheromonogenesis.

  5. Consumption of Bt Rice Pollen Containing Cry1C or Cry2A Protein Poses a Low to Negligible Risk to the Silkworm Bombyx mori (Lepidoptera: Bombyxidae)

    Science.gov (United States)

    Yang, Yan; Liu, Yue; Cao, Fengqin; Chen, Xiuping; Cheng, Lisheng; Romeis, Jörg; Li, Yunhe; Peng, Yufa

    2014-01-01

    By consuming mulberry leaves covered with pollen from nearby genetically engineered, insect-resistant rice lines producing Cry proteins derived from Bacillus thuringiensis (Bt), larvae of the domestic silkworm, Bombyx mori (Linnaeus) (Lepidoptera: Bombyxidae), could be exposed to insecticidal proteins. Laboratory experiments were conducted to assess the potential effects of Cry1C- or Cry2A-producing transgenic rice (T1C-19, T2A-1) pollen on B. mori fitness. In a short-term assay, B. mori larvae were fed mulberry leaves covered with different densities of pollen from Bt rice lines or their corresponding near isoline (control) for the first 3 d and then were fed mulberry leaves without pollen. No effect was detected on any life table parameter, even at 1800 pollen grains/cm2 leaf, which is much higher than the mean natural density of rice pollen on leaves of mulberry trees near paddy fields. In a long-term assay, the larvae were fed Bt and control pollen in the same way but for their entire larval stage (approximately 27 d). Bt pollen densities ≥150 grains/cm2 leaf reduced 14-d larval weight, increased larval development time, and reduced adult eclosion rate. ELISA analyses showed that 72.6% of the Cry protein was still detected in the pollen grains excreted with the feces. The low exposure of silkworm larvae to Cry proteins when feeding Bt rice pollen may be the explanation for the relatively low toxicity detected in the current study. Although the results demonstrate that B. mori larvae are sensitive to Cry1C and Cry2A proteins, the exposure levels that harmed the larvae in the current study are far greater than natural exposure levels. We therefore conclude that consumption of Bt rice pollen will pose a low to negligible risk to B. mori. PMID:25014054

  6. Study of some biological aspects of the blowfly Chrysomya albiceps (Wiedemann 1819 (Diptera: Calliphoridae in Jeddah, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Layla A.H. Al-Shareef

    2016-03-01

    Full Text Available We reared Chrysomya albiceps (Wiedemann 1819 unadult stages (first larval instar, second larval instar, third larval instar and pupal stage under four constant temperatures. Results proved that increasing temperature from 20 to 25, 30 and 35 °C reduced total larval stage duration (9–6, 4.83 and 4.75 days, respectively and pupal duration (7, 5.5, 4 and 1.5 days, respectively. C. albiceps larvae at first instar reached adult stage in the longest time at 20 °C (16 days, and in the shortest time at 35 °C (6.25 days. The accumulation degree-day (ADD at 20, 25, 30, 35 °C for first larval instar were 8.86, 13.86, 18.86, 23.86 DD, for second larval instar were 10.5, 12, 17, 22 DD and for third larval instar were 35.88, 42.08, 43.97, 56.43 DD. Heat requirements for larval stage at different temperatures; 20, 25, 30 and 35 °C (49.68, 63.12, 75.01 and 97.47 DD were more than the pupal requirements at the same temperatures (39.78, 58.76, 62.73 and 31.02 DD. Total heat requirements for C. albiceps to develop from the first larval instar to adult eclosion were the lowest at 20 °C (89.46 DD and the highest at 30 °C (129.138 DD. Decreasing of temperature increased larval body length at the same age. The development curves for C. albiceps were established at four constant temperatures using larval length and the time since egg hatching.

  7. Effect of morphine on the growth rate of Calliphora stygia (Fabricius) (Diptera: Calliphoridae) and possible implications for forensic entomology.

    Science.gov (United States)

    George, Kelly A; Archer, Melanie S; Green, Lauren M; Conlan, Xavier A; Toop, Tes

    2009-12-15

    Insect specimens collected from decomposing bodies enable forensic entomologists to estimate the minimum post-mortem interval (PMI). Drugs and toxins within a corpse may affect the development rate of insects that feed on them and it is vital to quantify these effects to accurately calculate minimum PMI. This study investigated the effects of morphine on growth rates of the native Australian blowfly, Calliphora stygia (Fabricius) (Diptera: Calliphoridae). Several morphine concentrations were incorporated into pet mince to simulate post-mortem concentrations in morphine, codeine and/or heroin-dosed corpses. There were four treatments for feeding larvae; T 1: control (no morphine); T 2: 2 microg/g morphine; T 3: 10 microg/g morphine; and T 4: 20 microg/g morphine. Ten replicates of 50 larvae were grown at 22 degrees C for each treatment and their development was compared at four comparison intervals; CI 1: 4-day-old larvae; CI 2: 7-day-old larvae; CI 3: pupae; and CI 4: adults. Length and width were measured for larvae and pupae, and costae and tibiae were measured for adults. Additionally, day of pupariation, day of adult eclosion, and survivorship were calculated for each replicate. The continued presence of morphine in meat was qualitatively verified using high-performance liquid chromatography with acidic potassium permanganate chemiluminescence detection. Growth rates of C. stygia fed on morphine-spiked mince did not differ significantly from those fed on control mince for any comparison interval or parameter measured. This suggests that C. stygia is a reliable model to use to accurately age a corpse containing morphine at any of the concentrations investigated.

  8. A fungal root symbiont modifies plant resistance to an insect herbivore.

    Science.gov (United States)

    Borowicz, Victoria A

    1997-11-01

    Vesicular-arbuscular mycorrhizal (VAM) fungi are common root-colonizing symbionts that affect nutrient uptake by plants and can alter plant susceptibility to herbivores. I conducted a factorial experiment to test the hypotheses that colonization by VAM fungi (1) improves soybean (Glycine max) tolerance to grazing by folivorous Mexican bean beetle (Epilachna varivestis), and (2) indirectly affects herbivores by increasing host resistance. Soybean seedlings were inoculated with the VAM fungus Glomus etunicatum or VAM-free filtrate and fertilized with high-[P] or low-[P] fertilizer. After plants had grown for 7 weeks first-instar beetle larvae were placed on bagged leaves. Growth of soybean was little affected by grazing larvae, and no effects of treatments on tolerance of soybeans to herbivores were evident. Colonization by VAM fungus doubled the size of phosphorus-stressed plants but these plants were still half the size of plants given adequate phosphorus. High-[P] fertilizer increased levels of phosphorus and soluble carbohydrates, and decreased levels of soluble proteins in leaves of grazed plants. Colonization of grazed plants by VAM fungus had no significant effect on plant soluble carbohydrates, but increased concentration of phosphorus and decreased levels of proteins in phosphorus-stressed plants to concentrations similar to those of plants given adequate phosphorus. Mexican bean beetle mass at pupation, pupation rate, and survival to eclosion were greatest for beetles reared on phosphorus-stressed, VAM-colonized plants, refuting the hypothesis that VAM colonization improves host plant resistance. VAM colonization indirectly affected performance of Mexician bean beetle larvae by improving growth and nutrition of the host plant.

  9. Performance of reproductive system of Dichelops melacanthus (Hemiptera: Pentatomidae subjected to buprofezin and pyriproxyfen: morphological analysis of ovarioles and testes

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Gimenez Cremonez

    2017-08-01

    Full Text Available The use of insecticides known as insect growth regulators, which are considered more selective to natural enemies, may be an alternative to integrated pest management of stink bugs of the main crops in Brazil. The objective of this study was to evaluate histological changes in the reproductive system of Dichelops melacanthus as well as female fecundity and egg fertility after use of growth-regulating insecticides. The insecticides used were buprofezin (a chitin biosynthesis inhibitor at a sublethal concentration (LC30 of 2.99 g L-1 and pyriproxyfen (a juvenile hormone analog at a sublethal concentration (LC30 of 8.35 mL L-1. A completely randomized experimental design was used, with 10 repetitions and 10 insects per experimental unit. Two bioassays were performed: in the first bioassay, fecundity (eggs/female and fertility (nymph eclosion of the insects that survived the insecticides were evaluated; in the second bioassay, morphological alterations of the ovarioles of adult females and of the testes of adult male insects that survived the insecticides were evaluated. Buprofezin and pyriproxyfen did not affect the adult sex ratio or female fecundity. Pyriproxyfen reduced the percentage of ecloded nymphs (71.6% compared with that of the control and buprofezin (96.4 and 90.6%, respectively treatments and had an ovicidal effect, with direct and indirect action on embryogenesis. Morphological changes were observed in both treatments with buprofezin and pyriproxyfen. The alterations observed in female and male reproductive systems may occur by the action of buprofezin and pyriproxyfen on the morphology of both ovarioles and testes.

  10. Morfologia e duração do desenvolvimento pós-embrionário de Chrysomya megacephala (Diptera: Calliphoridae em condições de laboratório

    Directory of Open Access Journals (Sweden)

    Karine Brenda Barros-Cordeiro

    2010-01-01

    Full Text Available A morfologia e o tempo de desenvolvimento pós-embrionário de Chrysomya megacephala (Fabricius criada em condições de laboratório e em dieta de carne bovina, foi descrita e comparada ao de outras espécies. Os parâmetros analisados foram à duração dos instares larvais e a morfologia. Para isso as larvas foram fixadas e preservadas em intervalos de tempo de 2 horas, desde a eclosão das larvas até a 50ª hora, a fim de se determinar o tempo de desenvolvimento de cada estágio. O tempo total de desenvolvimento larval para C. megacephala foi de 98 horas, com média de comprimento 15,51 mm. Essa espécie tem comportamento necrobiontófago e de importância sanitária e médico-legal, usada na estimativa do intervalo post-mortem em investigação criminal.Morphology and duration of the post-embryonary development of Chrysomya megacephala (Diptera: Calliphoridae in laboratory conditions. The morphology and developmental time of the post-embryonic stage of Chrysomya megacephala (Fabricius reared in laboratory on a beef diet, is described and compared to those of other blow-flies species. The parameters analyzed were the duration of the larval stages and the morphology. Larvae were fixed and preserved at 2 hours intervals, from larval eclosion until the 50th hour of life, in order to determine the duration of each stage. The total period of larval development in C. megacephala was 98 hours and their mean length was 15.51 mm. This species presents a necrobiontophagous behavior and has sanitary and medico-legal importance, being used for estimating postmortem interval in criminal investigations.

  11. 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.

  12. The innate immune and systemic response in honey bees to a bacterial pathogen, Paenibacillus larvae

    Directory of Open Access Journals (Sweden)

    Foster Leonard J

    2009-08-01

    Full Text Available Abstract Background There is a major paradox in our understanding of honey bee immunity: the high population density in a bee colony implies a high rate of disease transmission among individuals, yet bees are predicted to express only two-thirds as many immunity genes as solitary insects, e.g., mosquito or fruit fly. This suggests that the immune response in bees is subdued in favor of social immunity, yet some specific immune factors are up-regulated in response to infection. To explore the response to infection more broadly, we employ mass spectrometry-based proteomics in a quantitative analysis of honey bee larvae infected with the bacterium Paenibacillus larvae. Newly-eclosed bee larvae, in the second stage of their life cycle, are susceptible to this infection, but become progressively more resistant with age. We used this host-pathogen system to probe not only the role of the immune system in responding to a highly evolved infection, but also what other mechanisms might be employed in response to infection. Results Using quantitative proteomics, we compared the hemolymph (insect blood of five-day old healthy and infected honey bee larvae and found a strong up-regulation of some metabolic enzymes and chaperones, while royal jelly (food and energy storage proteins were down-regulated. We also observed increased levels of the immune factors prophenoloxidase (proPO, lysozyme and the antimicrobial peptide hymenoptaecin. Furthermore, mass spectrometry evidence suggests that healthy larvae have significant levels of catalytically inactive proPO in the hemolymph that is proteolytically activated upon infection. Phenoloxidase (PO enzyme activity was undetectable in one or two-day-old larvae and increased dramatically thereafter, paralleling very closely the age-related ability of larvae to resist infection. Conclusion We propose a model for the host response to infection where energy stores and metabolic enzymes are regulated in concert with direct

  13. dyschronic, a Drosophila homolog of a deaf-blindness gene, regulates circadian output and Slowpoke channels.

    Directory of Open Access Journals (Sweden)

    James E C Jepson

    Full Text Available Many aspects of behavior and physiology are under circadian control. In Drosophila, the molecular clock that regulates rhythmic patterns of behavior has been extensively characterized. In contrast, genetic loci involved in linking the clock to alterations in motor activity have remained elusive. In a forward-genetic screen, we uncovered a new component of the circadian output pathway, which we have termed dyschronic (dysc. dysc mutants exhibit arrhythmic locomotor behavior, yet their eclosion rhythms are normal and clock protein cycling remains intact. Intriguingly, dysc is the closest Drosophila homolog of whirlin, a gene linked to type II Usher syndrome, the leading cause of deaf-blindness in humans. Whirlin and other Usher proteins are expressed in the mammalian central nervous system, yet their function in the CNS has not been investigated. We show that DYSC is expressed in major neuronal tracts and regulates expression of the calcium-activated potassium channel SLOWPOKE (SLO, an ion channel also required in the circadian output pathway. SLO and DYSC are co-localized in the brain and control each other's expression post-transcriptionally. Co-immunoprecipitation experiments demonstrate they form a complex, suggesting they regulate each other through protein-protein interaction. Furthermore, electrophysiological recordings of neurons in the adult brain show that SLO-dependent currents are greatly reduced in dysc mutants. Our work identifies a Drosophila homolog of a deaf-blindness gene as a new component of the circadian output pathway and an important regulator of ion channel expression, and suggests novel roles for Usher proteins in the mammalian nervous system.

  14. Gamma radiation effects on mating behavior, inherited sterility, and competitiveness of Cadra cautella (Walker) (Lepidoptera:Pyralidae)

    International Nuclear Information System (INIS)

    Amoako-Atta, B.

    1976-01-01

    Mating efficiency of male Cadra cautella is restricted to within 72 hr of pose-eclosion. Gamma radiation of 8-day pupae did not affect the mating frequency of males in constant association with females for 72 hrs. When association was delayed for 1--7 days, there was progressive decrease in mating efficiency. The decline was related to reduced sperm viability. Increasing the dose accentuated the reduction in reproductive potential. Reproductive behavior of generation lines (F 1 --F 5 ) between irradiated males and normal females was studied. The sex ratio was distorted (more males) primarily in the F 1 and F 2 generations; the reproductive rate was lower in these early generations. When reproductive rate increased, the sex ratio was not distorted. A partially sterilizing dose of 20 krad to P 1 males induced complete inherited sterility in the progeny; the population of F 1 --F 2 collapsed. The ratio of sterile to fertile males needed to reduce reproductive nonirradiated females to 0 in the laboratory was studied. Release ratios of sterile males (S) : normal males (M) : fertile virgin females (N) varied from 0--20 S:M:N respectively. Population increases from various release ratios were lowered in each successive release ratio. The 20 S reduced the mean population increase of 2N from the expected 300-fold (as in the controls 0S:2M:2N) to only 4-fold. In that 20S:2M:2N release ratio, only 15% of the cultures produced any measurable F 1 progeny (average = 4F 1 progeny/culture) whereas the remaining 85% of the cultures did not produce any F 1 progeny. All control cultures were productive

  15. Eggs hatching and oncomiracidia lifespan of Dawestrema cycloancistrium, a monogenean parasitic on Arapaima gigas.

    Science.gov (United States)

    Maciel, Patricia Oliveira; Muniz, Celli Rodrigues; Alves, Rosiana Rodrigues

    2017-11-30

    Within the production chain of the Arapaima gigas (pirarucu), sanitary issues are still faced at the fingerling phase regarding infestations by the monogenean Dawestrema cycloancistrium. The present study had the objectives of describing the morphology and development phases of this parasite's eggs and oncomiracidia and determining the hatching time and lifespan of the oncomiracidia at different temperatures. D. cycloancistrium eggs were oval and elongated and had a single long appendage at one pole. The egg development was divided into four phases: embryonated egg, developing egg, larva appearance and ecloded egg. They were found in four forms: isolated in gill filaments; grouped in clusters that were anchored in a gill filament; grouped in clusters and entangled in part of a dead adult monogenean; and grouped in clusters in the environment, fixed to a substrate. Eclosion occurred after 72-96h, with faster development at 29°C and 32°C than at 24°C. The morphology of the oncomiracidia were rounded and elongated. They had two pairs of pigmented eye-spots as well as two ciliated areas located on each lateral part of the body and another on the anterior part of the body. The lifespan of the D. cycloancistrium oncomiracidia were 50 and 58h at 24°C and 27°C, respectively. Larvae were found in the mucus, indicating that the oncomiracidia penetrated the host integument. Understanding reproductive aspects of the D. cycloancistrium monogenean is important for developing specific prophylactic management strategies in aquaculture and providing valuable data for further studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Effects of gamma radiation on survival and reproduction of Callosobruchus chinensis (L.) (Coleoptera: Bruchidae)

    International Nuclear Information System (INIS)

    Hussain, T.; Imura, Osamu

    1989-01-01

    Studies on the effects of gamma radiation on different life stages of Callosobruchus chinensis were carried out in a growth chamber at 30±1degC and 70±2 % R.H. with 12:12 hr light and dark cycle. Eggs (1-, 2-, 3-, 4-, and 5-day-old), larvae (7- and 10-day-old), mature pupae (one day before adult eclosion) along with adzuki beans and 1-day-old adults were exposed to gamma radiation from a 60 Co source. Complete mortality of the 1-day-old eggs was obtained by exposure to 12 Gy, and a dose of 40 Gy caused 100 % mortality of the 7-day-old larvae after 24 hr of exposure. A dose of 640 Gy caused instant kill of the mature pupae and 1-day-old adults. The fecundity and fertility of adults irradiated either as mature pupae or 1-day-old adults decreased with the increase of the dose. Eggs, laid by females which had been exposed and/or had mates which had been exposed as mature pupae to 20 Gy or more, had negligible hatching rates. Complete sterility was obtained at 80 Gy in the 1-day-old adults. The sterilized males irradiated as 1-day-old at 80 Gy were capable of competing sexually with untreated ones. The percentage of egg hatch decreased as the ratio of sterile males to normal males increased, becoming less than 10 % at the ratios of 9 : 1 and 15 : 1. (author)

  17. Impact of macrozoobenthic bioturbation and wind fluctuation interactions on net methylmercury in freshwater lakes.

    Science.gov (United States)

    Wang, Peifang; Yao, Yu; Wang, Chao; Hou, Jun; Qian, Jin; Miao, Lingzhan

    2017-11-01

    The methylmercury (MeHg) as the toxic fractions has presented significant threats to biota in freshwater ecosystems. Hg methylation process is demonstrated to be manipulated by biota process (benthic disturbance and algae bloom existence) as well as the abiotic influence (wind fluctuation and illumination intensity) in freshwater ecosystems. However, the mechanisms influencing Hg methylation are still unclear, and the coupled influences of the biotic and abiotic process with the shifts in variation on methylmercury remain unexplored. Accordingly, an annular flume experiment which simulated the freshwater ecosystem, was conducted for 108 days to examine the influences of typical disturbance by chironomid larvae and wind fluctuations on MeHg variation in sediment profiles. The in-situ, passive sampler technique of revealing diffusive gradients in thin films (DGT) encompassed the special resin, based on referenced extraction and coloration-computer imaging densitometry, were employed to obtain labile MeHg, Fe, and S concentrations at high resolution. The results indicate that larval bioturbation during the initial period of the experiment could diminish bioavailable MeHg concentrations and change the diffusion direction of MeHg fluxes. However, this inhibitive effect on MeHg concentrations ceased with larvae eclosion. Compared to bioturbation, wind fluctuation exerted slow but sustained inhibition on MeHg release. Furthermore, the eight parameters (dissolved organic carbon (DOC), DO, labile Fe and S concentrations, pH, sulfate-reducing bacteria (SRB) abundance in sediment, oxidation-reduction potential (ORP) and EC) could explain more of variation in MeHg concentrations which indicated by the canonical correspondence analysis. And these eight parameters manifest higher explanatory power for MeHg distributed in newly formed sediment. More notably, the comparison results of the multiple and simple regression directly demonstrated the DOC was the fundamental and robust

  18. A multicopper oxidase-related protein is essential for insect viability, longevity and ovary development.

    Science.gov (United States)

    Peng, Zeyu; Green, Peter G; Arakane, Yasuyuki; Kanost, Michael R; Gorman, Maureen J

    2014-01-01

    Typical multicopper oxidases (MCOs) have ten conserved histidines and one conserved cysteine that coordinate four copper atoms. These copper ions are required for oxidase activity. During our studies of insect MCOs, we discovered a gene that we named multicopper oxidase-related protein (MCORP). MCORPs share sequence similarity with MCOs, but lack many of the copper-coordinating residues. We identified MCORP orthologs in many insect species, but not in other invertebrates or vertebrates. We predicted that MCORPs would lack oxidase activity due to the absence of copper-coordinating residues. To test this prediction, we purified recombinant Tribolium castaneum (red flour beetle) MCORP and analyzed its enzymatic activity using a variety of substrates. As expected, no oxidase activity was detected. To study MCORP function in vivo, we analyzed expression profiles of TcMCORP and Anopheles gambiae (African malaria mosquito) MCORP, and assessed RNAi-mediated knockdown phenotypes. We found that both MCORPs are constitutively expressed at a low level in all of the tissues we analyzed. Injection of TcMCORP dsRNA into larvae resulted in 100% mortality prior to adult eclosion, with death occurring mainly during the pharate pupal stage or late pharate adult stage. Injection of TcMCORP dsRNA into pharate pupae resulted in the death of approximately 20% of the treated insects during the pupal to adult transition and a greatly shortened life span for the remaining insects. In addition, knockdown of TcMCORP in females prevented oocyte maturation and, thus, greatly decreased the number of eggs laid. These results indicate that TcMCORP is an essential gene and that its function is required for reproduction. An understanding of the role MCORP plays in insect physiology may help to develop new strategies for controlling insect pests.

  19. Context-dependent interactive effects of non-lethal predation on larvae impact adult longevity and body composition.

    Science.gov (United States)

    Chandrasegaran, Karthikeyan; Kandregula, Samyuktha Rao; Quader, Suhel; Juliano, Steven A

    2018-01-01

    Predation impacts development, behavior and morphology of prey species thereby shaping their abundances, distribution and community structure. Non-lethal threat of predation, specifically, can have a strong influence on prey lifehistory characteristics. While investigations often focus on the impact of predation threat on prey in isolation, tests of its interactive effects with food availability and resource competition on prey survival and fitness can improve understanding of costs, benefits and trade-offs of anti-predator strategies. This study, involving Aedes aegypti mosquitoes as a model organism, investigates both simple and interactive effects of predation threat during the larval stage on survival, size at and time to maturity, stored teneral reserves of glycogen, protein and lipid in adults, and adult longevity. Our results show that development times of mosquito larvae were increased (by 14.84% in males and by 97.63% in females), and size of eclosing adults decreased (by 62.30% in males and by 58.33% in females) when exposed to lowered nutrition and elevated intraspecific competition, but that predation had no detectable effect on these simple traits. Teneral reserves of glycogen, protein and lipid and adult longevity were positively correlated with adult body size. Non-lethal predation threat had significant interactive effects with nutrition and larval competition on teneral reserves in males and adult longevity in males and females. The sexes responded differently to conditions encountered as larvae, with the larval environment affecting development and adult characteristics more acutely for females than for males. The outcome of this study shows how threat of predation on juveniles can have long-lasting effects on adults that are likely to impact mosquito population dynamics and that may impact disease transmission.

  20. Container Type Influences the Relative Abundance, Body Size, and Susceptibility of Ochlerotatus triseriatus (Diptera: Culicidae) to La Crosse Virus.

    Science.gov (United States)

    Bara, Jeffrey J; Muturi, Ephantus J

    2015-05-01

    Ochlerotatus triseriatus (Say), the primary vector of La Crosse virus (LAC), develops in a variety of natural and artificial aquatic containers where it often co-occurs with larvae of other mosquito species. We conducted a field study at two woodlots (South Farms and Trelease Woods) in Urbana, IL, to examine how container type influences vector abundance, body size, and susceptibility to LAC. Mosquito pupae were collected from tree holes, plastic bins, and waste tires, and eclosing adults were identified to species morphologically. Oc. triseriatus and Ochlerotatus japonicus (Theobald) females were orally challenged with LAC and midgut infection rate, disseminated infection rate, and body titer were determined by reverse-transcriptase real-time PCR. Oc. triseriatus was the dominant species collected in tree holes while Oc. japonicus and Culex restuans (Theobald) were mostly dominant in artificial containers. Female Oc. triseriatus and Oc. japonicus collected from plastic bins were significantly larger than those collected from tree holes or waste tires. Oc. japonicus females from South Farms were also significantly larger than those from Trelease Woods. Oc. triseriatus females collected from plastic bins and waste tires were significantly more susceptible to LAC infection relative to females collected from tree holes. In addition, Oc. triseriatus females from waste tires had significantly higher LAC titer relative to Oc. triseriatus from tree holes. For each container type and study site, wing length was not correlated to infection or dissemination rates. These findings suggest that the container type in which Oc.triseriatus develop may contribute to the spatial and temporal dynamics of LAC transmission. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Effects of gamma radiation on survival and reproduction of Callosobruchus chinensis (L.) (Coleoptera: Bruchidae)

    International Nuclear Information System (INIS)

    Hussain, T.; Imura, O.

    1989-01-01

    Studies on the effects of gamma radiation on different life stages of Callosobruchus chinensis were carried out in a growth chamber at 30 .+-. 1.degree.C and 70 .+-. 2% R.H. with a 12: 12 hr light and dark cycle. Eggs (1-, 2-, 3-, 4-, and 5-day-old), larvae (7- and 10-day-old), mature pupae (one day adult eclosion) along with adzuki beans and 1-day-old adults were exposed to gamma radiation from a 60Co source. Complete mortality of the 1-day-old eggs was obtained by exposure to 12 Gy, and a dose of 40 Gy caused 100% mortality of the 7-day-old larvae after 24 hr of exposure. A dose of 640 Gy caused instant kill of the mature pupae and 1-day-old adults. The fecundity and fertility of adults irradiated either as mature pupae or 1-day-old adults decreased with the increase of the dose. Eggs, laid by females which had been exposed and/or had mates which had been exposed as mature pupae to 20 Gy or more, had negligible hatching rates. Complete sterility was obtained at 80 Gy in the 1-day-old adults. The sterilized males irradiated as 1-day-old at 80 gy were capable of competing sexually with untreated ones. The percentage of egg hatch decreased as the ratio of sterile males to normal males increased, becoming less than 10% at the ratios of 9:1 and 15:1

  2. Parasitized honey bees are less likely to forage and carry less pollen.

    Science.gov (United States)

    Lach, Lori; Kratz, Madlen; Baer, Boris

    2015-09-01

    Research into loss of pollination capacity has focused primarily on documenting pollinator declines and their causes with comparatively little attention paid to how stressors may affect pollinating behavior of surviving pollinators. The European honey bee, Apis mellifera is one of the world's most important generalist pollinators, and Nosema apis is a widespread microsporidian gut parasite of adult A. mellifera. We individually fed 960 newly eclosed A. mellifera workers either a sucrose solution or 400 N. apis spores in a sucrose solution and tagged them with a unique radio frequency identification (RFID) tag to monitor their foraging behavior. We found spore-fed bees were less likely to forage than those fed sugar only. Those that did forage started foraging when they were older and stopped foraging when they were younger than bees fed sugar only. However, inoculated and non-inoculated bees did not significantly differ in the number of foraging trips taken per day, the total hours foraged over their lifetime, or homing ability. Inoculated returning foragers were 4.3 times less likely to be carrying available pollen than non-inoculated returning foragers and the number of pollen grains carried was negatively correlated with the number of N. apis spores. In an arena of artificial flowers, inoculated bees had a tendency (p=0.061) to choose sugar flowers over pollen flowers, compared to non-inoculated bees which visited pollen and sugar flowers equally. These results demonstrate that even a relatively low dose of a widespread disease of A. mellifera may adversely affect bees' ability to pollinate. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Ecological Succession in the Honey Bee Gut: Shift in Lactobacillus Strain Dominance During Early Adult Development.

    Science.gov (United States)

    Anderson, Kirk E; Rodrigues, Pedro A P; Mott, Brendon M; Maes, Patrick; Corby-Harris, Vanessa

    2016-05-01

    In many vertebrates, social interactions and nutrition can affect the colonization of gut symbionts across generations. In the highly social honey bee, it is unknown to what extent the hive environment and older worker individuals contribute to the generational transmission of core gut bacteria. We used high-throughput sequencing to investigate the effect of nest materials and social contact on the colonization and succession of core hindgut microbiota in workers. With only brief exposure to hive materials following natural eclosion, gut bacterial communities at 3 and 7 days contained phylotypes typically found in the guts of mature adults regardless of treatment. Continuous exposure to nest materials or direct social interactions with mature adults did not affect the diversity or abundance of gut bacterial communities at the scale examined. Similarly, a common pollen supplement fed by beekeepers during pollen dearth had no effect. A consideration of unique OTUs revealed extensive microbial succession independent of treatment. The dominant Lactobacillus strain at 3 days was largely replaced by a different strain at day 7, revealing the colonization signature of a pioneer species. Similar but less pronounced patterns were evident in less abundant OTU's, many of which may influence community succession via alteration of the gut environment. Our results indicate that the process of bacterial community colonization in the hindgut is resilient to changes in the nutritional, hive, and social environment. Greater taxonomic resolution is needed to accurately resolve questions of ecological succession and typical proportional variation within and between core members of the gut bacterial community.

  4. Chronic exposure to dim artificial light at night decreases fecundity and adult survival in Drosophila melanogaster.

    Science.gov (United States)

    McLay, L K; Green, M P; Jones, T M

    2017-07-01

    The presence of artificial light at night is expanding in geographical range and increasing in intensity to such an extent that species living in urban environments may never experience natural darkness. The negative ecological consequences of artificial night lighting have been identified in several key life history traits across multiple taxa (albeit with a strong vertebrate focus); comparable data for invertebrates is lacking. In this study, we explored the effect of chronic exposure to different night-time lighting intensities on growth, reproduction and survival in Drosophila melanogaster. We reared three generations of flies under identical daytime light conditions (2600lx) and one of four ecologically relevant ALAN treatments (0, 1, 10 or 100lx), then explored variation in oviposition, number of eggs produced, juvenile growth and survival and adult survival. We found that, in the presence of light at night (1, 10 and 100lx treatments), the probability of a female commencing oviposition and the number of eggs laid was significantly reduced. This did not translate into differences at the juvenile phase: juvenile development times and the probability of eclosing as an adult were comparable across all treatments. However, we demonstrate for the first time a direct link between chronic exposure to light at night (greater than 1lx) and adult survival. Our data highlight that ALAN has the capacity to cause dramatic shifts in multiple life history traits at both the individual and population level. Such shifts are likely to be species-specific, however a more in depth understanding of the broad-scale impact of ALAN and the relevant mechanisms driving biological change is urgently required as we move into an increasing brightly lit future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Effects of gamma radiation on the sterility and behavioral quality of the caribbean fruit fly, Anastrepha suspensa (Loew (Diptera:Tephritidae Efeitos da radiação gama na esterilização e comportamento da mosca-do-caribe, Anastrepha suspensa (Low (Diptera:Tephritidae

    Directory of Open Access Journals (Sweden)

    J.M.M. Walder

    1993-09-01

    Full Text Available Pupae of Anastrepha suspensa (Loew were irradiated 2 days before adult eclosión in an air atmosphere with 15, 20, 25, 30, 50 and 70 Gy of gamma radiation (Co-60. The radiation effects on sterility and other parameters of quality and behavior of males and females of caribfly were established. Males became fully sterile with a dose of 50 Gy and females laid no eggs when exposed to 25 Gy. Radiation had no significant effect on adult eclosion, sex ratio, flight ability and irritability, but female mortality was affected significantly by radiation, showing higher survival rates in low dosage treatments. The mating behavior of the males was reduced significantly by increasing the radiation doses.Pupas de Anastrepha suspensa (Loew foram irradiadas dois dias antes da emergência dos adultos em atmosfera de ar com as doses de 15, 20, 25, 30, 50 e 70 Gy de radiação gama (Co-60. Foram avaliados os efeitos da radiação sobre a esterilidade e outros parâmetros de qualidade e comportamento de machos e fêmeas de mosca-do-caribe. Machos tornaram-se totalmente estéreis com uma dose de 50 Gy e as fêmeas não ovipositaram quando expostas a 25 Gy. A radiação não teve efeito significativo sobre a taxa de emergência de adultos, na razão sexual, na habilidade de vôo e na irritabilidade desses insetos. Somente a mortalidade das fêmeas foi afetada significativamente pela radiação, causando unia maior sobrevivência nas dosagens mais baixas. A atividade de acasalamento dos machos foi reduzida significativamente com o incremento da dosagem de radiação.

  6. Trophic transfer of soil arsenate and associated toxic effects in a plant-aphid-parasitoid system

    Science.gov (United States)

    Lee, Y. S.; Wee, J.; Lee, M.; Hong, J.; Cho, K.

    2017-12-01

    Terrestrial toxic effects of soil arsenic were studied using a model system consisting of soil which artificially treated with arsenic, Capsicum annum,Myzus persicae and Aphidus colemani. We investigated the transfer of arsenic in a soil-plant-aphid system and toxic effect of elevated arsenic through a plant-aphid-parasitoid system. To remove the effect of poor plant growth on aphid performance, test concentrations which have a no effect on health plant growth were selected. Arsenic concentration of growth medium, plant tissues (root, stem, leaf) aphids were measured to observe the arsenic transfer. Correlation matrix was made with arsenic in growth medium which extracted with three extractants (aquaregia, 0.01 M CaCl2 and deionized water), arsenic in plant tissues and plant performance. Toxic effects of elevated arsenic concentrations on each species were investigated at population level. Studied plant performances were dry weight of each tissue, elongation of roots and stems, area of leaves, chlorophyll content of leaves, protein content of leaves and sugar content of leaves. Mean development time, fecundity and honeydew excretion of the aphids and host choice capacity and parasitism success of the parasitoids were examined. In addition, enzyme activities of the plants and the aphids against reactive oxygen species (ROS) induced by arsenic stress were also investigated. The results suggest that arsenic concentration in plant tissues and aphids were elevated with increased concentration of arsenic in soil. Decreased fecundity and honeydew excretion of aphids were observed and decreased eclosion rate of parasitoids were observed with increased arsenic treatment in growth medium. The results showed low concentration of arsenic in soil can transfer through food chain and can impact on higher trophic level species.

  7. Flight Synchrony among the Major Moth Pests of Cranberries in the Upper Midwest, USA

    Directory of Open Access Journals (Sweden)

    Shawn A. Steffan

    2017-02-01

    Full Text Available The cranberry fruitworm (Acrobasis vaccinii Riley, sparganothis fruitworm (Sparganothis sulfureana Clemens, and blackheaded fireworm (Rhopobota naevana Hübner are historically significant pests of cranberries (Vaccinium macrocarpon Aiton in the Upper Midwest (Wisconsin, USA. Their respective natural histories are well documented but correlations between developmental benchmarks (e.g., larval eclosion and degree-day accruals are not yet known. Treatment timings are critical to the optimization of any given control tactic, and degree-day accrual facilitates optimization by quantifying the developmental status of pest populations. When key developmental benchmarks in the pest life cycle are linked to degree-days, real-time weather data can be used to predict precise treatment timings. Here, we provide the degree-day accumulations associated with discrete biological events (i.e., initiation of flight and peak flight for the three most consistent moth pests of cranberries in Wisconsin. Moths were trapped each spring and summer from 2003 to 2011. To characterize flight dynamics and average timing of flight initiation, pheromone-baited trap-catch data were tallied for all three pest species within each of seven growing seasons. These flight dynamics were then associated with the corresponding degree-day accumulations generated using the cranberry plant’s developmental thresholds. Finally, models were fit to the data in order to determine the peak flight of each species. The initiation of the spring flight among all three moth species was highly synchronous, aiding in the timing of control tactics; however, there were substantial differences in the timing of peak flight among the moth species. Characterization of the relationship between temperature and pest development allows pest management professionals to target specific life stages, improving the efficacy of any given pest control tactic.

  8. Target organ specific activity of drosophila MRP (ABCC1) moderates developmental toxicity of methylmercury.

    Science.gov (United States)

    Prince, Lisa; Korbas, Malgorzata; Davidson, Philip; Broberg, Karin; Rand, Matthew Dearborn

    2014-08-01

    Methylmercury (MeHg) is a ubiquitous and persistent neurotoxin that poses a risk to human health. Although the mechanisms of MeHg toxicity are not fully understood, factors that contribute to susceptibility are even less well known. Studies of human gene polymorphisms have identified a potential role for the multidrug resistance-like protein (MRP/ABCC) family, ATP-dependent transporters, in MeHg susceptibility. MRP transporters have been shown to be important for MeHg excretion in adult mouse models, but their role in moderating MeHg toxicity during development has not been explored. We therefore investigated effects of manipulating expression levels of MRP using a Drosophila development assay. Drosophila MRP (dMRP) is homologous to human MRP1-4 (ABCC1-4), sharing 50% identity and 67% similarity with MRP1. A greater susceptibility to MeHg is seen in dMRP mutant flies, demonstrated by reduced rates of eclosion on MeHg-containing food. Furthermore, targeted knockdown of dMRP expression using GAL4>UAS RNAi methods demonstrates a tissue-specific function for dMRP in gut, Malpighian tubules, and the nervous system in moderating developmental susceptibility to MeHg. Using X-ray synchrotron fluorescence imaging, these same tissues were also identified as the highest Hg-accumulating tissues in fly larvae. Moreover, higher levels of Hg are seen in dMRP mutant larvae compared with a control strain fed an equivalent dose of MeHg. In sum, these data demonstrate that dMRP expression, both globally and within Hg-targeted organs, has a profound effect on susceptibility to MeHg in developing flies. Our findings point to a potentially novel and specific role for dMRP in neurons in the protection against MeHg. Finally, this experimental system provides a tractable model to evaluate human polymorphic variants of MRP and other gene variants relevant to genetic studies of mercury-exposed populations. © The Author 2014. Published by Oxford University Press on behalf of the Society of

  9. Male emergence schedule and dispersal behaviour are modified by mate availability in heterogeneous landscapes: evidence from the orange-tip butterfly

    Directory of Open Access Journals (Sweden)

    W James Davies

    2015-01-01

    Full Text Available Protandry (prior emergence of males in insect populations is usually considered to be the result of natural selection acting directly on eclosion timing. When females are monandrous (mate once, males in high density populations benefit from early emergence in the intense scramble competition for mates. In low density populations, however, scramble competition is reduced or absent, and theoretical models predict that protandry will be less favoured. This raises the question of how males behave in heterogeneous landscapes characterized by high density core populations in a low density continuum. We hypothesized that disadvantaged late emerging males in a core population would disperse to the continuum to find mates. We tested this idea using the protandrous, monandrous, pierid butterfly Anthocharis cardamines (the orange-tip in a core population in Cheshire, northwest England. Over a six-year period, predicted male fitness (the number of matings a male can expect during his residence time, determined by the daily ratio of virgin females to competing males consistently declined to <1 in late season. This decline affected a large proportion (∼44% of males in the population and was strongly associated with decreased male recapture-rates, which we attribute to dispersal to the surrounding continuum. In contrast, reanalysis of mark-release-recapture data from an isolated population in Durham, northeast England, showed that in the absence of a continuum very few males (∼3% emerged when fitness declined to <1 in late season. Hence the existence of a low density continuum may lead to the evolution of plastic dispersal behaviour in high density core populations, maintaining late emerging males which would otherwise be eliminated by selection. This has important theoretical consequences, since a truncated male emergence curve is a key prediction in game theoretic models of emergence timing which has so far received limited support. Our results have

  10. Field-Evolved Resistance in Corn Earworm to Cry Proteins Expressed by Transgenic Sweet Corn

    Science.gov (United States)

    Dively, Galen P.; Finkenbinder, Chad

    2016-01-01

    Background Transgenic corn engineered with genes expressing insecticidal toxins from the bacterium Bacillus thuringiensis (Berliner) (Bt) are now a major tool in insect pest management. With its widespread use, insect resistance is a major threat to the sustainability of the Bt transgenic technology. For all Bt corn expressing Cry toxins, the high dose requirement for resistance management is not achieved for corn earworm, Helicoverpa zea (Boddie), which is more tolerant to the Bt toxins. Methodology/Major Findings We present field monitoring data using Cry1Ab (1996–2016) and Cry1A.105+Cry2Ab2 (2010–2016) expressing sweet corn hybrids as in-field screens to measure changes in field efficacy and Cry toxin susceptibility to H. zea. Larvae successfully damaged an increasing proportion of ears, consumed more kernel area, and reached later developmental stages (4th - 6th instars) in both types of Bt hybrids (Cry1Ab—event Bt11, and Cry1A.105+Cry2Ab2—event MON89034) since their commercial introduction. Yearly patterns of H. zea population abundance were unrelated to reductions in control efficacy. There was no evidence of field efficacy or tissue toxicity differences among different Cry1Ab hybrids that could contribute to the decline in control efficacy. Supportive data from laboratory bioassays demonstrate significant differences in weight gain and fitness characteristics between the Maryland H. zea strain and a susceptible strain. In bioassays with Cry1Ab expressing green leaf tissue, Maryland H. zea strain gained more weight than the susceptible strain at all concentrations tested. Fitness of the Maryland H. zea strain was significantly lower than that of the susceptible strain as indicated by lower hatch rate, longer time to adult eclosion, lower pupal weight, and reduced survival to adulthood. Conclusions/Significance After ruling out possible contributing factors, the rapid change in field efficacy in recent years and decreased susceptibility of H. zea to Bt

  11. Transcriptional markers of sub-optimal nutrition in developing Apis mellifera nurse workers

    Science.gov (United States)

    2014-01-01

    Background Honey bees (Apis mellifera) contribute substantially to the worldwide economy and ecosystem health as pollinators. Pollen is essential to the bee’s diet, providing protein, lipids, and micronutrients. The dramatic shifts in physiology, anatomy, and behavior that accompany normal worker development are highly plastic and recent work demonstrates that development, particularly the transition from nurse to foraging roles, is greatly impacted by diet. However, the role that diet plays in the developmental transition of newly eclosed bees to nurse workers is poorly understood. To further understand honey bee nutrition and the role of diet in nurse development, we used a high-throughput screen of the transcriptome of 3 day and 8 day old worker bees fed either honey and stored pollen (rich diet) or honey alone (poor diet) within the hive. We employed a three factor (age, diet, age x diet) analysis of the transcriptome to determine whether diet affected nurse worker physiology and whether poor diet altered the developmental processes normally associated with aging. Results Substantial changes in gene expression occurred due to starvation. Diet-induced changes in gene transcription occurring in younger bees were largely a subset of those occurring in older bees, but certain signatures of starvation were only evident 8 day old workers. Of the 18,542 annotated transcripts in the A. mellifera genome, 150 transcripts exhibited differential expression due to poor diet at 3d of age compared with 17,226 transcripts that differed due to poor diet at 8d of age, and poor diet caused more frequent down-regulation of gene expression in younger bees compared to older bees. In addition, the age-related physiological changes that accompanied early adult development differed due to the diet these young adult bees were fed. More frequent down-regulation of gene expression was observed in developing bees fed a poor diet compared to those fed an adequate diet. Functional

  12. The effect of larval nutritional deprivation on the life history and DDT resistance phenotype in laboratory strains of the malaria vector Anopheles arabiensis

    Directory of Open Access Journals (Sweden)

    Oliver Shüné V

    2013-02-01

    Full Text Available Abstract Background Anopheles arabiensis is a major malaria vector in Africa. It thrives in agricultural areas and has been associated with increased malaria incidence in areas under rice and maize cultivation. This effect may be due to increased adult size and abundance as a consequence of optimal larval nutrition. The aim of this study was to examine the effect of larval nutrition on the life history and expression of insecticide resistance in adults of laboratory reared An. arabiensis. Methods Larvae drawn from an insecticide susceptible An. arabiensis strain (SENN as well as a DDT-resistant strain (SENN-DDT were subjected to three fasting regimes: 1 mg of food per larva offered once per day, once every second day and once every third day. Control cohorts included larvae offered 1 mg food thrice per day. The rate of larval development was compared between matched cohorts from each strain as well as between fasted larvae and their respective controls. The expression of DDT resistance/tolerance in adults was compared between the starved cohorts and their controls by strain. Factors potentially affecting variation in DDT resistance/tolerance were examined including: adult body size (wing length, knock-down resistance (kdr status and levels of detoxification enzyme activity. Results and conclusion Anopheles arabiensis larval development is prolonged by nutrient deprivation and adults that eclose from starved larvae are smaller and less tolerant to DDT intoxication. This effect on DDT tolerance in adults is also associated with reduced detoxification enzyme activity. Conversely, well fed larvae develop comparatively quickly into large, more DDT tolerant (SENN or resistant (SENN-DDT adults. This is important in those instances where cereal farming is associated with increased An. arabiensis transmitted malaria incidence, because large adult females with high teneral reserves and decreased susceptibility to insecticide intoxication may also

  13. Occurrence of sweet refuse at disposal sites: rainwater retention capacity and potential breeding opportunities for Aedes aegypti.

    Science.gov (United States)

    Dieng, Hamady; Satho, Tomomitsu; Meli, Nur Khairatun Khadijah Binti; Abang, Fatimah; Nolasco-Hipolito, Cirilo; Hakim, Hafijah; Miake, Fumio; Zuharah, Wan Fatma; Kassim, Nur Faeza A; Ab Majid, Abdul Hafiz; Morales Vargas, Ronald E; Morales, Noppawan P; Noweg, Gabriel Tonga

    2018-05-01

    Nectar is the staple diet of adult mosquitoes in the wild, but its availability is inconsistent and can be affected by rainfall. In urban centers, Aedes vectors commonly use man-made containers as their major habitat; however, they can colonize any items replenished by rainfall. Garbage output has increased significantly in recent years, at a time when collection frequency is reducing. Such garbage usually includes organic components, some of which are sweet and can be fed upon by other animals or become can containers for rainwater. Despite evidence that Aedes larvae can thrive in containers comprised of organic waste material, which can be produced by rodents gnawing on fruits or vegetables, and that adults can survive on sweet waste fluids, the capacity of organic waste materials to accumulate rainwater and act as egg deposition sites has not been examined. It is also unknown for how long sweet extracts can sustain the life of adult vectors. Here, we investigated the abundance of sweet leftovers at garbage sites and the rainwater retention capacity of some organic materials through a field survey and laboratory bioassays. We also examined whether sweet waste fluids impact egg hatching success and longevity of Aedes aegypti. The results of this study indicated that sweet products with leftovers are highly prevalent in garbage. When exposed to rain, food items (BAFrc, banana fruit resembling container; and BSPrc, boiled sweet potato resembling container) and the packaging of sweet foods (SMIc, sweetened condensed milk can) retained water. When provided an opportunity to oviposit in cups containing BAF extract (BAFex), BSP extract (BSPex), and SMI extract (SMIex), eggs were deposited in all media. Egg maturation in the BAFex environment resulted in similar larval eclosion success to that resulting from embryo development in a water milieu. Adults maintained on sweet waste extracts had long lifespans, although shorter than that of their sugar solution (SUS

  14. A temporal comparison of sex-aggregation pheromone gland content and dynamics of release in three members of the Lutzomyia longipalpis (Diptera: Psychodidae species complex.

    Directory of Open Access Journals (Sweden)

    Mikel A González

    2017-12-01

    Full Text Available Lutzomyia longipalpis is the South American vector of Leishmania infantum, the etiologic agent of visceral leishmaniasis (VL. Male L. longipalpis produce a sex-aggregation pheromone that is critical in mating, yet very little is known about its accumulation over time or factors involved in release. This laboratory study aimed to compare accumulation of pheromone over time and determine factors that might influence release in three members of the L. longipalpis species complex.We investigated male sex-aggregation pheromone gland content at different ages and the release rate of pheromone in the presence or absence of females under different light conditions by gas chromatography-mass spectrometry (GC-MS. Pheromone gland content was determined by extraction of whole males and pheromone release rate was determined by collection of headspace volatiles. Pheromone gland content appeared age-related and pheromone began to accumulate between 6 to 12 h post eclosion and gradually increased until males were 7-9 days old. The greatest amount was detected in 9-day old Campo Grande males ((S-9-methylgermacrene-B; X ± SE: 203.5 ± 57.4 ng/male followed by Sobral 2S males (diterpene; 199.9 ± 34.3 and Jacobina males ((1S,3S,7R-3-methyl-α-himachalene; 128.8 ± 30.3 at 7 days old. Pheromone release was not continuous over time. During a 4-hour period, the greatest quantities of pheromone were released during the first hour, when wing beating activity was most intense. It was then substantially diminished for the remainder of the time. During a 24 h period, 4-5 day old male sand flies released approximately 63 ± 11% of the pheromone content of their glands, depending on the chemotype. The presence of females significantly increased pheromone release rate. The light regime under which the sand flies were held had little influence on pheromone release except on Sobral 2S chemotype.Accumulation of pheromone appears to occur at different rates in the different

  15. The effect of larval nutritional deprivation on the life history and DDT resistance phenotype in laboratory strains of the malaria vector Anopheles arabiensis

    Science.gov (United States)

    2013-01-01

    Background Anopheles arabiensis is a major malaria vector in Africa. It thrives in agricultural areas and has been associated with increased malaria incidence in areas under rice and maize cultivation. This effect may be due to increased adult size and abundance as a consequence of optimal larval nutrition. The aim of this study was to examine the effect of larval nutrition on the life history and expression of insecticide resistance in adults of laboratory reared An. arabiensis. Methods Larvae drawn from an insecticide susceptible An. arabiensis strain (SENN) as well as a DDT-resistant strain (SENN-DDT) were subjected to three fasting regimes: 1 mg of food per larva offered once per day, once every second day and once every third day. Control cohorts included larvae offered 1 mg food thrice per day. The rate of larval development was compared between matched cohorts from each strain as well as between fasted larvae and their respective controls. The expression of DDT resistance/tolerance in adults was compared between the starved cohorts and their controls by strain. Factors potentially affecting variation in DDT resistance/tolerance were examined including: adult body size (wing length), knock-down resistance (kdr) status and levels of detoxification enzyme activity. Results and conclusion Anopheles arabiensis larval development is prolonged by nutrient deprivation and adults that eclose from starved larvae are smaller and less tolerant to DDT intoxication. This effect on DDT tolerance in adults is also associated with reduced detoxification enzyme activity. Conversely, well fed larvae develop comparatively quickly into large, more DDT tolerant (SENN) or resistant (SENN-DDT) adults. This is important in those instances where cereal farming is associated with increased An. arabiensis transmitted malaria incidence, because large adult females with high teneral reserves and decreased susceptibility to insecticide intoxication may also prove to be more

  16. Effect of emamectin benzoate on mortality, proboscis extension, gustation and reproduction of the corn earworm, Helicoverpa zea.

    Science.gov (United States)

    López, Juan D; Latheef, M A; Hoffmann, W C

    2010-01-01

    Newly emerged corn earworm adults, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) require a carbohydrate source from plant or other exudates and nectars for dispersal and reproduction. Adults actively seek and forage at feeding sites upon eclosion in the habitat of the larval host plant or during dispersal to, or colonization of, a suitable reproductive habitat. This nocturnal behavior of H. zea has potential for exploitation as a pest management strategy for suppression using an adult feeding approach. This approach entails the use of a feeding attractant and stimulant in combination with a toxicant that when ingested by the adult will either reduce fecundity/fertility at sub-lethal dosages or kill the adult. The intent of this study was to assess reproductive inhibition and toxicity of emamectin benzoate on H. zea when ingested by the adults when mixed in ppm active ingredient (wt:vol) with 2.5 M sucrose as a feeding stimulant. Because the mixture has to be ingested to function, the effect of emamectin benzoate was also evaluated at sub-lethal and lethal concentrations on proboscis extension and gustatory response of H. zea in the laboratory. Feral males captured in sex pheromone-baited traps in the field were used for toxicity evaluations because they were readily available and were more representative of the field populations than laboratory-reared adults. Laboratory-reared female moths were used for reproduction effects because it is very difficult to collect newly emerged feral females from the field. Emamectin benzoate was highly toxic to feral H. zea males with LC(50) values (95% CL) being 0.718 (0.532-0.878), 0.525 (0.316-0.751), and 0.182 (0.06-0.294) ppm for 24, 48 and 72 h responses, respectively. Sub-lethal concentrations of emamectin benzoate did not significantly reduce proboscis extension response of feral males and gustatory response of female H. zea. Sublethal concentrations of emamectin benzoate significantly reduced percent larval hatch of

  17. Corythaica cyathicollis (Costa, 1864, aspectos sistemáticos, biológicos e econômicos (Hemiptera, Tingidae

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    Marcos Kogan

    1960-09-01

    Full Text Available The present work deals with the systematic, biological and economic problems related to Corythaica cyathicollis (Costa, 1864 (Hemip., Tingidae. In the first part are presented the generic characteristics of Corythaica and is discussed the status of the specific name. The validity of C. cyathicollis, as stated by DRAKE and his collaborators, was denied by MONTE in his last works, he considered the species as C. passiflorae. Even in the modern literature no agreement has been achieved and three names are still used (cyathicollis, passiflorae and planaris to designate the same insect. In order to resolve definitively this problem, a Neotype is designed to fill the place of the missing type of C. cyathicollis. Also in the first parte is discussed the taxonomic value of both male and female genitalia. The whole male copulator apparatus is studied and are illustrated the genital capsules of 8 species of this genus. Special mention is made of the shape of the basal plates and the proportions of the segmental membrana. The female genitalia is studied based upon the work of FELDMAN & BAILEY (1952. In the second part the biological cycle of C. cyathicollis is carefully studied. Descriptions of the egg are done and the ways of oviposition. The number of eggs laid by the female was observed to be about 350, during a period of more than 45 days. The eclosion of the neanide I is illustrated in some of its phases and the 5 larval instars are described and illustrated. Ending this part are included the lists of parasites and predators observed as well as the plant hosts. The actual geographical distribution is presented, based chiefly on HURD (1945. The economic problems concerning this species are reported in the third part of the work, and the ways of control are discussed. An experiment was carried out involving 4 insecticides: Malathion and Parathion, commonly used against this "lace bug"; Toxaphene and Dimethoate (American Cyanamid 12.880, the last one is

  18. Aspectos reproductivos del acocil Cambarellus (Cambarellus montezumae (Crustacea: Decápoda: Cambaridae en condiciones controladas Breeding aspects of the crayfish Cambarellus (Cambarellus montezumae (Crustacea: Decapoda: Cambaridae under controlled conditions

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    José Luis Arredondo-Figueroa

    2011-03-01

    of 45 ± 23 eggs per spawn.. The eclosioned eggs averaged 83.7%, obtaining 3 162 juveniles. In RPL, F1 organisms obtained from RAS were maintained in a relation of 1 female: 2 male with 10 repetitions. Egg production was variable with an average of 34 eggs per females. Performance indicators showed significant differences (P ≤ 0.05 between males and females in 6 indicators. Results indicated the feasibility of culture and production of eggs and juveniles.

  19. Probiotic Lactobacillus rhamnosus Reduces Organophosphate Pesticide Absorption and Toxicity to Drosophila melanogaster.

    Science.gov (United States)

    Trinder, Mark; McDowell, Tim W; Daisley, Brendan A; Ali, Sohrab N; Leong, Hon S; Sumarah, Mark W; Reid, Gregor

    2016-10-15

    Organophosphate pesticides used in agriculture can pose health risks to humans and wildlife. We hypothesized that dietary supplementation with Lactobacillus, a genus of commensal bacteria, would reduce absorption and toxicity of consumed organophosphate pesticides (parathion and chlorpyrifos [CP]). Several Lactobacillus species were screened for toleration of 100 ppm of CP or parathion in MRS broth based on 24-h growth curves. Certain Lactobacillus strains were unable to reach stationary-phase culture maxima and displayed an abnormal culture morphology in response to pesticide. Further characterization of commonly used, pesticide-tolerant and pesticide-susceptible, probiotic Lactobacillus rhamnosus strain GG (LGG) and L. rhamnosus strain GR-1 (LGR-1), respectively, revealed that both strains could significantly sequester organophosphate pesticides from solution after 24-h coincubations. This effect was independent of metabolic activity, as L. rhamnosus GG did not hydrolyze CP and no difference in organophosphate sequestration was observed between live and heat-killed strains. Furthermore, LGR-1 and LGG reduced the absorption of 100 μM parathion or CP in a Caco-2 Transwell model of the small intestine epithelium. To determine the effect of sequestration on acute toxicity, newly eclosed Drosophila melanogaster flies were exposed to food containing 10 μM CP with or without supplementation with live LGG. Supplementation with LGG simultaneously, but not with administration of CP 3 days prior (prophylactically), mitigated CP-induced mortality. In summary, the results suggest that L. rhamnosus may be useful for reducing toxic organophosphate pesticide exposure via passive binding. These findings could be transferable to clinical and livestock applications due to affordability and practical ability to supplement products with food-grade bacteria. The consequences of environmental pesticide pollution due to widespread usage in agriculture and soil leaching are becoming a

  20. Ação do fungo Beauveria bassiana (Balsamo Vuillemin, 1912 sobre a fase parasitária do carrapato Anocentor nitens (Neumann, 1897 Schulze, 1937 (Acari: ixodidae Action of the fungus Beauveria bassiana (Balsamo Vuillemin, 1912 on the parasitic phase of the tick Anocentor nitens (Neumann, 1897 Schulze, 1937 (Acari: ixodidae

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    Silvia Gonzalez Monteiro

    2003-06-01

    Full Text Available A patogenicidade do fungo Beauveria bassiana (isolado 986 foi avaliada no desenvolvimento da fase parasitária do Anocentor nitens, acompanhando o desenvolvimento de larvas não alimentadas até o estágio adulto. Foram utilizados dois tratamentos e um grupo controle com cinco repetições cada. No tratamento 1 (T1, as orelhas dos bovinos foram banhadas com a suspensão fúngica de 10(8 conídios ml-1; no tratamento 2 (T2, as orelhas foram banhadas com água destilada e espalhante adesivo. No grupo controle (C, as orelhas foram banhadas com água destilada. Após 24 horas dos tratamentos, as orelhas de cada animal foram infestadas com 100mg de larvas. Os parâmetros analisados, em cada tratamento, foram: número e peso de fêmeas recuperadas; períodos de pré-postura, postura, incubação, eclosão e longevidade; percentual de eclosão; peso da massa de ovos e da quenógina; índices de eficiência reprodutiva e nutricional. Verificou-se que, no T1 e T2, o número de fêmeas recuperadas, após 35 dias, foi significantemente menor (PThis study evaluated the pathogenicity of the fungus Beauveria bassiana (Isolate 986 on the development of the parasitic phase of Anocentor nitens by accompanying the development of unfed larvae until the adult stage. Two treated and one control group were used with five repetitions each. In the first treated group (T1, cattle ears were bathed with a fungal suspension of 10(8 conidia ml-1, second treated group (T2, the ears were bathed with distilled water and Tween 80 1% and the control group (C, the ears were bathed with distilled water. One day after treatment, the ears of each animal were infested with 100 mg of larvae. The parameters analyzed in each treatment were: number and weight of females recovered; periods of pre-oviposition, oviposition, incubation, eclosion and longevity; percentage of eggs hatched; weight of the egg mass and of females after oviposition. We found that in the two treated groups the

  1. Developmental Acclimation of Drosophila suzukii (Diptera: Drosophilidae) and Its Effect on Diapause and Winter Stress Tolerance.

    Science.gov (United States)

    Wallingford, Anna K; Loeb, Gregory M

    2016-08-01

    We investigated the influence of developmental conditions on adult morphology, reproductive arrest, and winter stress tolerance of the invasive pest of small fruit, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). Cooler rearing temperatures (15 °C) resulted in larger, darker "winter morph" (WM) adults than "summer morph" flies reared at optimal temperatures (25 °C). Abdominal pigmentation scores and body size measurements of laboratory-reared WMs were similar to those of D. suzukii females captured in late autumn in Geneva, NY. We evaluated reproductive diapause and cold hardiness in live-captured D. suzukii WMs as well as WMs reared in the laboratory from egg to adult under four developmental conditions: static cool temperatures (SWM; 15 °C, 12:12 h L:D), fluctuating temperatures (FWM; 20 °C L: 10 °C D, 12:12 h L:D), and static cool temperatures (15 °C, 12:12 h L:D) followed by posteclosion chilling (CWM; 10 °C) under short-day (SD; 12:12 h L:D) or long-day photoperiods (LD; 16:8 h L:D). Live-captured D. suzukii WMs and CWMs had longer preoviposition times than newly eclosed summer morph adults, indicating a reproductive diapause that was not observed in SWMs or FWMs. Additionally, recovery after acute freeze stress was not different between CWM-SD females and live captured WM females. More 7-d-old CWMs survived 0, -1, or - 3 °C freeze stress than summer morph adults, and more CWM-SD adults survived -3 °C freeze stress than CWM-LD adults. Survival after -3 °C freeze stress was significantly higher in diapausing, CWMs than nondiapausing SWMs and FWMs. © 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.

  2. Live imaging of muscle histolysis in Drosophila metamorphosis.

    Science.gov (United States)

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

    2016-05-04

    The contribution of programmed cell death (PCD) to muscle wasting disorders remains a matter of debate. Drosophila melanogaster metamorphosis offers the opportunity to study muscle cell death in the context of development. Using live cell imaging of the abdomen, two groups of larval muscles can be observed, doomed muscles that undergo histolysis and persistent muscles that are remodelled and survive into adulthood. To identify and characterize genes that control the decision between survival and cell death of muscles, we developed a method comprising in vivo imaging, targeted gene perturbation and time-lapse image analysis. Our approach enabled us to study the cytological and temporal aspects of abnormal cell death phenotypes. In a previous genetic screen for genes controlling muscle size and cell death in metamorphosis, we identified gene perturbations that induced cell death of persistent or inhibit histolysis of doomed larval muscles. RNA interference (RNAi) of the genes encoding the helicase Rm62 and the lysosomal Cathepsin-L homolog Cysteine proteinase 1 (Cp1) caused premature cell death of persistent muscle in early and mid-pupation, respectively. Silencing of the transcriptional co-repressor Atrophin inhibited histolysis of doomed muscles. Overexpression of dominant-negative Target of Rapamycin (TOR) delayed the histolysis of a subset of doomed and induced ablation of all persistent muscles. RNAi of AMPKα, which encodes a subunit of the AMPK protein complex that senses AMP and promotes ATP formation, led to loss of attachment and a spherical morphology. None of the perturbations affected the survival of newly formed adult muscles, suggesting that the method is useful to find genes that are crucial for the survival of metabolically challenged muscles, like those undergoing atrophy. The ablation of persistent muscles did not affect eclosion of adult flies. Live imaging is a versatile approach to uncover gene functions that are required for the survival of

  3. Evolved Phenological Asynchrony as a Baseline for Climate-change Impacts. (Invited)

    Science.gov (United States)

    Singer, M. C.; Parmesan, C.

    2010-12-01

    Changing climate can disrupt existing phenological relations between interacting species. We might expect the historical baseline for these effects to be precise synchrony between the season at which a consumer most requires food and the time when its resources are most available. When this is the case, change in any direction would be detrimental to the consumer. But is baseline synchrony the appropriate assumption? Here, we develop the theme that the starting point for climate change impacts may often have been asynchrony or mismatch between consumer and resource. To the extent that this has been true, assumptions of baseline synchrony risk mis-detection, mis-estimation, and mis-attribution of climate change impacts. Natural selection can result in asynchrony between exploiter and victim when victims successfully evolve to occupy enemy-free time. Asynchrony can also result from life-history tradedoffs. We illustrate asynchrony arising from tradeoffs for two species: Edith’s checkerspot butterfly and the winter moth. Initial observations of phenological mismatch in both systems were made prior to the onset of major impacts of anthropogenically-driven climate change. Neither species can detect the phenological stage of its host plants with precision. In both species, evolution of life history has involved compromise between maximizing fecundity and minimizing mortality, with the outcome being superficially maladaptive strategies in which many or even most individuals die of starvation through poor synchrony with their host plants. Both species have evolved high-risk life history strategies. While winter moth eggs gamble with their own lives by hatching early, bay checkerspots gamble with the lives of their offspring by growing large and eclosing late as adults. In both cases the result is the evolution of populations in which large numbers of individuals die because, as individuals, they fail to fit their life cycles into the available timespan. Because such a

  4. A temporal comparison of sex-aggregation pheromone gland content and dynamics of release in three members of the Lutzomyia longipalpis (Diptera: Psychodidae) species complex.

    Science.gov (United States)

    González, Mikel A; Bandi, Krishna K; Bell, Melissa J; Brazil, Reginaldo P; Dilger, Erin; Guerrero, Angel; Courtenay, Orin; Hamilton, James G C

    2017-12-01

    Lutzomyia longipalpis is the South American vector of Leishmania infantum, the etiologic agent of visceral leishmaniasis (VL). Male L. longipalpis produce a sex-aggregation pheromone that is critical in mating, yet very little is known about its accumulation over time or factors involved in release. This laboratory study aimed to compare accumulation of pheromone over time and determine factors that might influence release in three members of the L. longipalpis species complex. We investigated male sex-aggregation pheromone gland content at different ages and the release rate of pheromone in the presence or absence of females under different light conditions by gas chromatography-mass spectrometry (GC-MS). Pheromone gland content was determined by extraction of whole males and pheromone release rate was determined by collection of headspace volatiles. Pheromone gland content appeared age-related and pheromone began to accumulate between 6 to 12 h post eclosion and gradually increased until males were 7-9 days old. The greatest amount was detected in 9-day old Campo Grande males ((S)-9-methylgermacrene-B; X ± SE: 203.5 ± 57.4 ng/male) followed by Sobral 2S males (diterpene; 199.9 ± 34.3) and Jacobina males ((1S,3S,7R)-3-methyl-α-himachalene; 128.8 ± 30.3) at 7 days old. Pheromone release was not continuous over time. During a 4-hour period, the greatest quantities of pheromone were released during the first hour, when wing beating activity was most intense. It was then substantially diminished for the remainder of the time. During a 24 h period, 4-5 day old male sand flies released approximately 63 ± 11% of the pheromone content of their glands, depending on the chemotype. The presence of females significantly increased pheromone release rate. The light regime under which the sand flies were held had little influence on pheromone release except on Sobral 2S chemotype. Accumulation of pheromone appears to occur at different rates in the different chemotypes

  5. Seletividade alimentar de organismos-alimento por formas jovens de pacu Piaractus mesopotamicus (Holmberg, 1887 e curimba Prochilodus lineatus (Valenciennes, 1836 - DOI: 10.4025/actascibiolsci.v29i2.523 Selective feeding of food organisms by fish larvae of Piaractus mesopotamicus (Holmberg, 1887 and Prochilodus lineatus (Valenciennes, 1836 - DOI: 10.4025/actascibiolsci.v29i2.523

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Bento Fernandes

    2007-12-01

    Full Text Available Objetivou-se avaliar a seleção alimentar de organismos-alimento por formas jovens de pacu (Piaractus mesopotamicus e curimba (Prochilodus lineatus com diferentes idades (6, 12, 19 e 26 dias, na presença e ausência de Pistia stratiotes. Foram utilizados quatro tratamentos (T1 = pacu + P. stratiotes; T2 = pacu; T3 = curimba + P. stratiotes; T4 = curimba e quatro repetições. A cada sete dias, foram coletadas 24 larvas de cada espécie de peixe dos tanques, sendo estas mantidas em jejum por 24 horas. Depois de distribuídas nos aquários com plâncton, as larvas permaneceram por três horas, sendo coletadas e fixadas para análise, juntamente com as amostras de água. Os tratos digestórios das larvas foram retirados e analisados sob microscópio óptico. Observaram-se diferenças estatísticas na seletividade alimentar de organismos planctônicos por larvas de mesma espécie, em diferentes idades e também entre larvas de espécies diferentes, com mesma idade, não diferindo quanto à presença ou ausência de P. stratiotes. As formas jovens de pacu e curimba selecionaram organismos similares aos seis dias de idade, passando por alterações até o 26º dia. À medida que se desenvolveram, as larvas de pacu passaram a selecionar cladóceros e ostrácodos e as de curimba, protozoários e algas.The objective was to evaluate the feeding selection of food organisms for two species of fish larvae (pacu and curimba at different ages (6, 12, 19 and 26 days after eclosion, in the presence or absence of Pistia stratiotes. Four treatments were used (T1 = pacu + P. stratiotes; T2 = pacu; T3 = curimba + P. stratiotes; T4 = curimba and four replications. Every seven days, 24 fish larvae of each species were collected, and kept without food for 24 hours. After being distributed in the aquariums with plankton, the larvae stayed for three hours, and were collected and prepared for analysis, along with the water samples. The digestive tract of the fish larvae

  6. INCIDENCE OF Boophilus microplus AND BLOOD PARAMETERS IN CROSSBRED STEERS FED OF SUNFLOWER INCIDÊNCIA DE Boophilus microplus E AVALIAÇÃO DOS PARÂMETROS SANGÜÍNEOS EM BOVINOS MESTIÇOS (HOLANDÊS x ZEBU ALIMENTADOS COM GIRASSOL

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    Sérgio Luíz S. Rezende

    2007-07-01

    Full Text Available This experiment aimed to evaluate the efficacy of sunflower meal and sunflower seeds to control Boophilus microplus in naturally infested steers. The experiment was developed in the Dairy Cattle Facilities of the Veterinary College - UFG. Two herds of steers (Holstein x zebu were allotted in a randomized block design in 2x10 factorial arrangement with six repetitions on Brachiaria decumbens pastures. After 14 days, weekly for two months, B. microplus females > 4 mm were counted, blood samples were collected and the animals were weighed. The B. microplus engorged females were collected to evaluate reproductive parameters. Blood samples were processed to determine: hematocrit, total protein, fibrinogen and leukocytes. The results had been submitted to the analysis of variance and the averages compared for the Scott-Knott test (5%. Tick counts, index (%, larval eclosion, hematocrit, total protein, fibrinogen and leukocytes were similar between treatments. The results do not corroborate the empirical reports concerning the effectiveness of the sunflower to control B. microplus in crossbred steers. KEY-WORDS: Blood values, oily seeds, parasites, tick count. Objetivou-se avaliar a ação do farelo ou das sementes de girassol no controle de Boophilus microplus em novilhos mestiços (holandês x zebu infestados naturalmente. O experimento foi desenvolvido no Setor de Bovinocultura do Departamento de Produção Animal da Escola de Veterinária (EV da UFG. Foram utilizados dois lotes de animais, distribuídos inteiramente ao acaso num fatorial 2 x 10 com seis repetições, em piquetes de Brachiaria decumbens, onde foram suplementados. Após quatorze dias de experimento e a cada sete dias, durante dois meses, num curral de manejo, efetuaram-se a contagem das fêmeas de B. microplus > 4 mm, as coletas de sangue e as pesagens dos bovinos. Colheram-se fêmeas ingurgitadas de B. microplus para avaliação de parâmetros reprodutivos. Amostras de sangue

  7. Seletividade alimentar de organismos-alimento por formas jovens de pacu Piaractus mesopotamicus (Holmberg, 1887 e curimba Prochilodus lineatus (Valenciennes, 1836 = Selective feeding of food organisms by fish larvae of Piaractus mesopotamicus (Holmberg, 1887 and Prochilodus lineatus (Valenciennes, 1836

    Directory of Open Access Journals (Sweden)

    Nandeyara Ribeiro Marques

    2007-04-01

    Full Text Available Objetivou-se avaliar a seleção alimentar de organismos-alimento por formas jovens de pacu (Piaractus mesopotamicus e curimba (Prochilodus lineatus com diferentes idades (6, 12, 19 e 26 dias, na presença e ausência de Pistia stratiotes. Foram utilizados quatrotratamentos (T1 = pacu + P. stratiotes; T2 = pacu; T3 = curimba + P. stratiotes; T4 = curimba e quatro repetições. A cada sete dias, foram coletadas 24 larvas de cada espécie de peixe dos tanques, sendo estas mantidas em jejum por 24 horas. Depois de distribuídas nos aquários com plâncton, as larvas permaneceram por três horas, sendocoletadas e fixadas para análise, juntamente com as amostras de água. Os tratos digestórios das larvas foram retirados e analisados sob microscópio óptico. Observaram-se diferenças estatísticas na seletividade alimentar de organismos planctônicos por larvas de mesmaespécie, em diferentes idades e também entre larvas de espécies diferentes, com mesma idade, não diferindo quanto à presença ou ausência de P. stratiotes. As formas jovens de pacu e curimba selecionaram organismos similares aos seis dias de idade, passando por alterações até o 26º dia. À medida que se desenvolveram, as larvas de pacu passaram a selecionar cladóceros e ostrácodos e as de curimba, protozoários e algas.Theobjective was to evaluate the feeding selection of food organisms for two species of fish larvae (pacu and curimba at different ages (6, 12, 19 and 26 days after eclosion, in the presence or absence of Pistia stratiotes. Four treatments were used (T1 = pacu + P. stratiotes; T2 = pacu; T3 = curimba + P. stratiotes; T4 = curimba and four replications. Every seven days, 24 fish larvae of each species were collected, and kept without food for 24 hours. Afterbeing distributed in the aquariums with plankton, the larvae stayed for three hours, and were collected and prepared for analysis, along with the water samples. The digestive tract of the fish larvae were

  8. Efecto in vitro del extracto acuoso de Dichrostachys cinerea (L. Wight & Arn. en el desarrollo de las fases exógenas de estrongílidos gastrointestinales de ovinos In vitro effect of the aqueous extract of Dichrostachys cinerea (L. Wight &Arn. on the development of exogenous stages of gastrointestinal strongyles in sheep

    Directory of Open Access Journals (Sweden)

    J Arece

    2012-09-01

    Full Text Available Se evaluó el efecto in vitro de extractos acuosos de hojas de marabú (Dichrostachys cinerea en la eclosión de huevecillos, el desarrollo larvario y la migración de las larvas del tercer estadio de estrongílidos gastrointestinales. Los tratamientos fueron tres concentraciones de extractos acuosos de hojas de marabú (500, 250 y 125 mg/mL, soluciones de albendazol y levamisol, así como el Phosphate Buffer Saline (PBS y el dimetilsulfóxido (DMSO como controles; el diseño fue completamente aleatorizado. Los porcentajes de eclosión presentaron diferencias significativas entre postratamientos. El PBS ocasionó la mayor tasa de eclosión (96,68%; el 30,51% eclosionó con el albendazol y los extractos de hojas de marabú mostraron tasas de eclosión moderadas (entre 49,75 y 66,54%, al parecer dependientes de la dosis. El desarrollo de las larvas L1/L2 a las L3 tratadas con extracto acuoso de marabú también presentó efectos dosis-dependientes y diferencias significativas con respecto a los grupos controles positivos y negativos. La dosis de 500 mg/mL inhibió el desarrollo larvario en porcentajes similares a los del albendazol (8,89 y 1,28%, respectivamente. El medio PBS no interfirió en la capacidad de migración de las larvas, mientras que con el levamisol los valores se redujeron de 86,45 a 93,92%; los extractos acuosos también redujeron significativamente dicha migración, con valores entre 77,67 y 48,97%. Los extractos acuosos de D. cinerea presentaron actividad antihelmíntica in vitro en los tres estadios de desarrollo del ciclo exógeno de los estrongílidos gastrointestinales de ovinos; esta actividad resultó más evidente en el desarrollo y la migración de las larvas de estos nemátodos.The in vitro effect of aqueous extract of leaves from Dichrostachys cinerea on egg hatching, larval development and migration of third-stage larvae of gastrointestinal strongyles, was evaluated. The treatments were three concentrations of aqueous

  9. Effect of salinity on the metabolism and osmoregulation of selected ontogenetic stages of an amazon population of Macrobrachium amazonicum shrimp (Decapoda, Palaemonidae

    Directory of Open Access Journals (Sweden)

    CCM. Mazzarelli

    acids gets diminished and oxygen consumption elevated, probably due to greater energy expenditure with the active transportation of salts through epithelial membranes. Osmotic challenges also seem to alter throughout development, given that in zoeae II oxygen consumption is elevated on brackish water of 18, but in zoeae V it happens in fresh water. After M. amazonicum metamorphosis, free amino acids begin to play an important role as intracellular osmolytes, because we verified an increase of up to 40% in post-larvae exposed to brackish water of 18. The main free amino acids involved in cell volume regulation of ontogenetic stages evaluated were the non essential ones: glutamic acid, glycine, alanine, arginine, and proline. Interestingly, larvae from estuarine population studied here survived until the zoeae V stage in fresh water, but in some populations far from the sea, zoeae die right after eclosion in fresh water or they do not reach zoeae III stage. In addition, given that in favorable conditions caridean shrimp larvae shorten their development, we may infer that the cultivation environment, in which larvae developed in the present work, was appropriate, because almost all zoeae VIII kept on brackish water underwent metamorphosis directly to post-larvae and did not go through zoeae IX stage.

  10. Effect of salinity on the metabolism and osmoregulation of selected ontogenetic stages of an Amazon population of Macrobrachium amazonicum shrimp (Decapoda, Palaemonidae).

    Science.gov (United States)

    Mazzarelli, C C M; Santos, M R; Amorim, R V; Augusto, A

    2015-05-01

    diminished and oxygen consumption elevated, probably due to greater energy expenditure with the active transportation of salts through epithelial membranes. Osmotic challenges also seem to alter throughout development, given that in zoeae II oxygen consumption is elevated on brackish water of 18, but in zoeae V it happens in fresh water. After M. amazonicum metamorphosis, free amino acids begin to play an important role as intracellular osmolytes, because we verified an increase of up to 40% in post-larvae exposed to brackish water of 18. The main free amino acids involved in cell volume regulation of ontogenetic stages evaluated were the non essential ones: glutamic acid, glycine, alanine, arginine, and proline. Interestingly, larvae from estuarine population studied here survived until the zoeae V stage in fresh water, but in some populations far from the sea, zoeae die right after eclosion in fresh water or they do not reach zoeae III stage. In addition, given that in favorable conditions caridean shrimp larvae shorten their development, we may infer that the cultivation environment, in which larvae developed in the present work, was appropriate, because almost all zoeae VIII kept on brackish water underwent metamorphosis directly to post-larvae and did not go through zoeae IX stage.

  11. Efeitos da temperatura e do alimento no desenvolvimento de Dysdercus maurus Distant (Hemiptera, Pyrrhocoridae Effects of temperature and food on the development of Dysdercus maurus Distant (Hemiptera, Pyrrhocoridae

    Directory of Open Access Journals (Sweden)

    Fábio Souto Almeida

    2007-12-01

    IAC-22 and kept at 25 or 30ºC. In all treatments five immature stages were observed. The increase of temperature caused reduction in the developmental time. The temperature of 15ºC disabled nymphal eclosion and was also lethal to those nymphs ecloded at other temperatures. The lower mortality of nymphs occurred in the temperature of 25ºC with cotton as food (24.07%. The lower threshold temperature (Tb occurred for the 1st instar (11.54ºC and the higher for the 2nd instar (15.33ºC. The females of D. maurus required more degree-days (329.93 degree-days than males (300.49 degree-days until adult emergence.

  12. Preliminary Note on the Use of Radioisotopes to Study Some Cotton-Plant Pests in Africa; Note preliminaire sur l 'utilisation des radioisotopes dans l 'etude des parasites du cotonnier en afrique; Predvaritel'nye zamechaniya o primenenii radioizotopov dlya izucheniya nekotorykh vreditelej khlopchatnika v afrike.; Nota preliminar sobre el empleo de radioisotopos en el estudio de parasitos del algodonero en africa

    Energy Technology Data Exchange (ETDEWEB)

    Delattre, R. [Institut de Recherches du Coton et Textiles, Paris (France)

    1963-09-15

    control experiment will now be required, consisting of labelling, during the season, cotton-plants in a field where cotton was also grown the previous year; this time non-diapause chrysalids will be labelled. Similar observations are also being performed on a number of other cotton-plant pests. (author) [French] Le chenille de Diparopsis wacersi Roth est nuisible au cotonnier en detruisant fleurs et capsules. Cette noctuelle, pratiquement monophage, passe l'inter-saison, soit dans le sol sous forme de chrysalides en-diapause a partir du 10 novembre, soit par des generations continues (polyvoltines) sur les plants non arraches. Des etudes de laboratoire ont permis d'elucider les principaux mecanismes declenchant la diapause et y mettant fin. Dans la nature, les pullulations en cours de culture s'etablissent a partir d'individus univoltins venant a eclosion vers avril-mai aussi bien que des generations sans diapause; la participation respective de ces deux souches differentes devrait etre determinee assez exactement pour connaitre les moyens de lutte appropries: arrachage du cotonnier, destruction des pupes en diapause dans le sol, avancement de la campagne, etc. Le marquage par des radioisotopes des chenilles venant a maturite aux epoques critiques devrait permettre de serrer ce probleme sur le plan pratique. Des experiences preliminaires ont eu lieu a Tikem (Republique de Tchad) en vue de determiner des techniques de marquage simples. Dans un premier essai, {sup 32}P a ete applique en pulverisation aqueuse directe sur le feuillage de cotonniers jeunes. Malgre la pluie, l'absorption fut de 10% environ par la plante en quelques heures. Diverses chenilles phyllophages (Sylepta derogata, Prodenia litura) ne retiennent pas de radioactivite, mais les chenilles qui se nourrissent d'organes fructiferes (Heliothis armigera, Earias insulana, Diparopsis watersi, etc.) sont facilement detectable trois mois apres l'application. Dans un deuxieme essai, {sup 32}P et {sup 35}S ont ete

  13. SUSCEPTIBILIDADE DE Chrysomya albiceps A Beauveria bassiana EM CONDIÇÕES DE LABORATÓRIO SUSCEPTIBILITY OF CHRYSOMYA ALBICEPS TO BEAUVERIA BASSIANA IN LABORATORY CONDITION

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    Ana Célia Rodrigues Athayde

    2008-10-01

    > were done, for the analysis of the biological parameters. In the bioassay with eggs, the percentage of eclosion varied from 84.81 to 97.22%. In the bioassay with larvae, pre-pupa period varied from 1 to 1.04 and of pupa, from 5 to 5.09 days; the percentage of adult emergency from treated larvae varied from 30.88 to 80.82%. As to the bioassay with adults, the longevity for male and female was of 4.51 to 6.77 and 10.19 to 14.67 days, respectively; the accumulated mortality death on the 7th day varied from 47.50 to 81.20% for males and of 23.70 to 55.00% for females; the period of posture varied from 10 to17.75 days and the percentage of larvae appeared from females infected varied from 71.39 to 91.25%.

     

    KEY WORDS: Biological parameters, entomopathogenic fungus, pathogenicity.

  14. Diet-induced developmental plasticity in life histories and energy metabolism in a beetle La dieta induce plasticidad del desarrollo en los rasgos de historia de vida y metabolismo energético en un escarabajo

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    SERGIO URREJOLA

    2011-12-01

    Full Text Available Adaptive phenotypic plasticity, has been recognized as an important strategy by which organisms maximize fitness in variable environments, which vary through development. A disassociation among stages should represent a null effect of the environment experienced during early ontogeny in the expression of adult traits. Food quality greatly influences survival, development and reproduction in many arthropod herbivores. We examined the effects of diet protein in physiological and life-history traits in the yellow mealworm beetle Tenebrio molitor through ontogeny. We established four experimental treatments: Low Protein (LP, Low Protein Control (LPC, High Protein (HP, and High Protein Control (HPC with recently eclosioned larvae each. Individuals were maintained on the same diet or transferred to the opposite diet for all pupae period and almost all adult period. Contrary to the expected, the duration of life-cycle, larval growth rate and body mass in T. molitor were similar in diet treatments. We found intra-individual trade-offs between environmental diet (rich or poor in protein content during larval phase and egg number. Larvae fed on a protein-deficient diet exhibited significantly higher respiratory rates than larvae fed on a rich protein diet. Compensatory feeding could act in T. molitor larvae indicating differences in metabolism but not in growth rate, body mass and life-cycle characteristics. Our results demonstrate the plasticity of reproductive and metabolic traits and life-cycle characteristics of T. molitor and how changes that occur in relation to diet can have profound effects on progeny and female fitness.La plasticidad fenotípica adaptativa ha sido reconocida como una estrategia importante por el cual los organismos maximizan su adecuación biológica en ambientes variables y la cual varía a lo largo del desarrollo. En los organismos la plasticidad fenotípica generalmente se refiere a como los diferentes tipos de rasgos pueden

  15. Laminación y bioturbación en carbonatos lagunares: interpretación genética (Cuenca del Guadiana, Badajoz

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    Armenteros, I.

    1986-10-01

    Full Text Available The sedimentological study of both polished and thin sections of samples taken from the 1-2 m thick unit of laminated carbonates overlying the Miocene succession infilling the Neogene Guadiana Basin (western Spain reveals the existence of prominent features that are discussed in the paper.
    The lamination visible in hand specimens is due to the alternance of massive and laminated layers. In thin sections, the massive layers are made or intraclastic, ooidal pelletoidal particles, whereas the laminated ones show gently undulating, alternating light and dark-coloured layers. Inside the laminated and, to a lesser extent, the massive leyers it is possible to recognize; (a abundant vestiges of algal filaments, (b abundant remains of charophites, (c small, usually grouped-up, cavities (mean diameter about 250 microns and bigger, pellet-filled cavities, both types related to burrowing; (d sparse prisms of calcite resembling those of Microcodium, and (e cclusters of trapezohedral crystals of calcite with rhomboidal and. lenticular sections,these being more abundant in the massive layers.
    The sedimentological interpretation assumes that sedimentation took place in swamps with periodic oscillations of the water level. The laminated layers, el stromatoIithic nature, correspond to quiet realms under constant water level during dry stages. The massive layers record higher environmental energy during flood stages, that is able to remobilize the cracked sediments of the former dry stages.
    The vital activity of Chironomid insects lead to the two described types of burrowing: the small grape-like cavities correspond to eclosing eggs whereas the bigger pellet-filled cavities resulted from mining by larvae

    El estudio sedimentológico al microscopio y en secciones pulidas de las muestras de la unidad de carbonatos laminados (1 a 2 m de espesor, situada a techo de la sucesión miocena, que rellena la cuenca neógena del Guadiana

  16. Energy and nitrogen budgets for larval and aduit Paropsis charybdis Stål (Coleoptera: Chrysomelidae) feeding on Eucalyptus viminalis.

    Science.gov (United States)

    Edwards, Penelope B; Wightman, John A

    1984-03-01

    | (1) Paropsis charybdis, the Eucalyptus tortoise beetle, is a serious defoliator of several Eucalyptus species in New Zealand. A series of laboratory experiments demonstrated the growth characteristics of larvae and adults when feeding on E. viminalis at 20°C. These were used as the data bases for quantifying its trophic relationships in terms of dry matter, energy and nitrogen. (2) The four larval stages lasted 4.0, 2.5, 3.0 and 9.5 days. Growth was exponential until the second day of the fourth instar, when the superficially inactive prepupal stage began. The pupal stage lasted 9.5 days. Female beetles started to lay eggs 15 days (av.) after eclosion. (3) Larvae attained a mean maximum dry weight (dwt) of 53.29 mg. Reproductive females weighed 63.40 mg, and males 46.71 mg. (4) The guts and their contents contributed up to 50% of total larval dry weight and 15% of adult dry weight. (5) Studies of the trophic relationships of P. charybdis larvae were based upon budgets whereby consumption (C) equals the sum of production (P), respiretion (R) and egesta (FU). Production was divided into gut-free larval production (P L * ) and exuvia (P EX )+R+FUin J: 3,561.5 = (491.3+43.4) + 284.5 +2,574.9 in mgN: 4.001 = (2.078 + 0.200) +1.657 (no R term) . P = P L * + P EX The derived R term (R c ), calculated as: R c = C - FU - (P = P L * + P EX ) = 34.84 (6) Daily budgets of an average adult, where ΔP AD reflects the change in body weight and P R =reproductive production, were: C =(ΔP AD + P R ) + R +FU in mg dwt: 27.36 = (ΔP +2.25) +R + 14.53 in J: 591.1 = ΔP + 65.4) + 82.0 +362.6 in mgN: 0368 = (ΔP AD + 0.252) + 0.285. The budget assumes that male P R is zero and includes a corrected R term whereby R C =1.43 R M . ΔP AD can be assumed to equal zero over a long term, although fluctuations were apparent during the experimental period. (7) The amount of leaf material removed but not eaten by larvae (NU) was 22.6 mg, 462.4 J or 0.526 mgN. Thus, the total material removed

  17. Feminilização de larvas de tilápia do Nilo (Oreochromis niloticus L. a partir de banhos de imersão com valerato-de-estradiol Feminization of larvae of Nile tilapia (Oreochromis niloticus L. by immersion baths with estradiol valerate

    Directory of Open Access Journals (Sweden)

    Robie Allan Bombardelli

    2005-04-01

    with a 2.0 mg solution of estradiol valerate17 (VE.L-1. One thousand and two hundred larvae of Nile tilapia, from the same reproduction bunch were used. Larvae were allotted to 24 0.5 L plastic containers in a completely randomized experimental design with six treatments and four replicates. An experimental unit consisted of a 0.5L plastic container with hormonal solution and 50 larvae. Treatments comprised immersion of larvae at different ontogenic phases, or rather, 175.2 UTA (days - degrees or 6.5 DAE (days after eclosion; 217.2 UTA or 8 DAE; 273.2. UTA or 10 DAE; 329.0 UTA or 12 DAE; 383.9 UTA or 14 DAE; and 438.1 UTA or 16 DAE. After treatments, the larvae were cultivated until they reached a standard length of 25 mm and thus their results could be estimated. Feminization results were best for younger larvae, with 6.5 DAE or 175.2 UTA, with 39.20% females. Results also suggested a negative linear relationship between the ontogenic period and feminization rates. There was no difference in treatments regarding indexes of average final length and weight, final condition factor and mortality. It was concluded that 175.2 UTA or 6.5 DAE is the best period for sexual reversion with EV, with 39.20% females.

  18. Vírus dengue em larvas de Aedes aegypti e sua dinâmica de infestação, Roraima, Brasil Virus dengue en larvas de Aedes aegypti y su dinámica de infestación, Roraima, Brasil Dengue virus in Aedes aegypti larvae and infestation dynamics in Roraima, Brazil

    Directory of Open Access Journals (Sweden)

    Julianna Dias Zeidler

    2008-12-01

    ciudad de Boa Vista (Norte de Brasil. Se instalaron dos ovitrampas por domicilio, y se removieron una semana después, mensualmente, de noviembre de 2006 a mayo de 2007. Se calcularon el índice de positividad por ovitrampa y el índice de densidad de huevos. Posterior a la eclosión de 1422 huevos colectados, se formaron 44 pools de máximo 30 larvas para evaluar presencia del virus dengue por medio de RT-PCR y hemi-nested PCR. El índice de incidencia de dengue en el período fue correlacionado con la precipitación pluvial. La asociación entre esas variables y número de huevos colectados fue analizada por el coeficiente de Pearson. RESULTADOS: Ninguno de los pools presentó positividad para el virus dengue, a pesar de que en la urbanización se presentaron elevados índices de incidencia de dengue en el período de estudio. La densidad de la población de Ae. aegypti aumentó conforme a la pluviosidad, pero no presentó correlación con los índices de incidencia de casos de dengue. CONCLUSIONES: Los resultados sugieren que la transmisión transovariana del virus en mosquitos ocurre con una frecuencia muy baja y por eso su persistencia en el medio urbano puede no depender de ese fenómeno. La población del mosquito aumentó en el período de lluvia debido a la formación de criaderos; la no correlación con el índice de incidencia del dengue se debe a la posibilidad de que ese dato es subestimado en períodos de epidemia.OBJECTIVE: To detect the presence of dengue virus in larval forms of Aedes aegypti and to associate vector presence with rainfall and incidence of disease. METHODS: Eighteen households were randomly selected for egg collection in a neighborhood of the city of Boa Vista, Roraima, in Northern Brazil. Two oviposition traps were installed per home, and removed after one week. This was repeated on a monthly basis between November 2006 and May 2007. Trap positivity rate and egg density were calculated. Following the eclosion of 1,422 eggs, 44 pools of

  19. Preliminary Studies on Irradiation of Some Common Stored-Grain Insects in Pakistan; Etudes preliminaires sur l'irradiation de certaines especes communes d'insectes nuisibles aux cereales engrangees au Pakistan; Predvaritel'noe izuchenie rezul'tatov oblucheniya nekotorykh obychnykh ambarnykh nasekomykh v Pakistane; Estudios preliminares sobre los efectos de la irradiacion en algunas de las plagas insectiles de los silos mas comunes en el Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Huque, Heshamul [Department of Plant Protection, Ministry of Food and Agriculture, Karachi (Pakistan)

    1963-09-15

    , en 26 j. Une dose maximum de 250 000 g a entraine une mort instantanee dans tous les cas; mais, outre le fait qu'elle est trop elevee, cette dose nuit a la conservation des cereales. Toutefois, la valeur nutritive des cereales ne s'en trouvant pas affectee, on pourrait appliquer des doses de cette intensite lorsqu'on veut rapidement desinsectiser des grains comestibles qui ne sont pas destines a la semence. Des oeufs de Bruchus quadrumaculatus exposes a une dose de 2500 r ne sont pas parvenus a eclosion. On poursuit les etudes sur des insectes a d'autres stades de leur developpement et pour des doses differentes. (author) [Spanish] El autor ha estudiado loe. efectos que en algunas de las principales plagas insectiles de los silos ejercen diversas dosis de irradiacion aplicadas con una fuente de {sup 60}Co que puso a su disposicion la Comision de Energia Atomica del Pakistan. Una dosis de 20 000 r causo ai cabo de 11 d una mortalidad del 100% entre los Rhizopertha dominica y Tribolium castaneum adultos. Una dosis de 10 000 r produjo los mismoe resultados al cabo de 23 d. El Sitophilus granarius adulto acuso una sensibilidad relativamente mucho mas elevada, pues con una dosis de 10 000 g se obtuvo una mortalidad del. 100% en solo 7 d. Las larvas de Trogoderma granarium demostraron ser las mas resistentes; con dosis inferiores no acusaron efecto alguno y su exterminio total exigio 25000 r y 26 d. Una dosis maxima de 250 000 r produjo inmediatamente efectos letales en todos los insectos, pero aparte de ser demasiado elevada resulto perjudicial para la vitalidad de los granos. Ahora bien, como no altera su poder nutritivo, se puede emplear cuando se quiera lograr la desinsectacion inmediata de granes comestibles que no sean para la siembra. Los huevecillos de Bruchus quadrumaculatus dejan de desarrollarse cuando sufren una irradiacion de 2500 r. El autor esta estudiando los efectos de otras dosis en otras fases de la metamorfosis. (author) [Russian] Byli izucheny otvetnye

  20. Radiosensitivity of Various Stages of Callosobruchus Chinensis L; Radiosensibilite du Callosobruchus Chinensis L. aux divers stades de son developpement; Chuvstvitel'nost' k oblucheniyu u razlichnykh stadij Callosobruchus Chinensis L.; Radiosensibilidad de las diversas fases de la metamorfosis del Callosobruchus Chinensis L.

    Energy Technology Data Exchange (ETDEWEB)

    Sayeed Quraishi, M.; Metin, M. [Cento Institute of Nuclear Science, Teheran (Iran, Islamic Republic of)

    1963-09-15

    les adultes du Callosobruchus chinensis L., insecte nuisible aux graines de legumineuses emmagasinees. Il est tres difficile de lutter contre cet insecte par les moyens classiques, du fait qu'il passe toute la periode larvaire et la pupation dans la graine elle-meme. Des insectes obtenus dans des graineteries locales ont ete eleves en laboratoire, dans un incubateur, sur des graines de mungo (Phaseolus mungo L.), a une temperature de 29{sup o}C {+-} l{sup o}C et un degre d'humidite de 70 a 75%. Dans ces conditions, le cycle vital de l'insecte est de 18 a 22 j. Pour les premieres experiences d'irradiation, on a utilise une source d'iridium-192 de 1 c. Son intensite a ensuite ete portee a 4 c. L'exposition a ete effectuee a une tres faible distance; le debit de dose a ete calcule d'apres une mesure faite a 50 cm avec un dosimetre a condensateur de Victoreen. Les oeufs a irradier ont ete places a 0,5 cm de la source et les larves, pupes et adultes a 1 cm, l'intensite de dose etant de 80 kr/h et de 20 kr/h, respectivement, avec la source de 4 c. Une dose de 15 000 krad a provoque une mortalite de 100% dans le cas des oeufs. Diverses doses de plus faible intensite ont donne des resultats quelque peu variables; il est possible qu'il existe un stade sensible pendant une breve periode des premieres 24 h du developpement des oeufs. Une dose de 20 krad a provoque une mortalite de 100% des larves agees de 8 j. Il semble que les pupes soient moins radiosensibles que les oeufs ou les larves: il a fallu des doses de 47krad pour obtenir une mortalite de 100%. Des doses de 42 krad ont provoque la sterilisation des males et des femelles, en ce sens que les oeufs produits apres l'irradiation de l'un des parents ne sont pas parvenus a eclosion. La ponte d'oeufs ''steriles'' a continue meme apres que l'un des parents ou les deux aient ete exposes a des doses de 67 krad, maximum applique dans ces experiences. (author) [Spanish] Los autores han estudiado los efectos de la irradiacion sobre

  1. Studies on the Utilization, Metabolism and Function of Sterols in the House-Fly, Musca Domestica; Utilisation. Metabolisme et fonctions des sterols chez la mouche domestique (Musca Domestica); Izuchenie usvoeniya, metabolizma i funktsii sterinov v organizme domashnej mukhi Musca Domestica; Estudios sobre la asimilacion, el metabolismo y la funcion de los esteroles in la mosca comun (Musca Domestica)

    Energy Technology Data Exchange (ETDEWEB)

    Robbins, W. E. [United States Department of Agriculture, Agricultural Research Service, Entomology Research Division, Beltsville, MD (United States)

    1963-09-15

    sterols found in the house-fly. (author) [French] On a determine que, de facon generale, les insectes ont besoin de sterols dans leur regime alimentaire pour que leurs larves se developpent et se metamorphosent normalement. Les travaux de l'auteur ont fait apparaitre deux autres fonctions physiologiques des sterols chez la mouche domestique (Musca domestica L.): 1. il est indispensable que le regime alimentaire de la femelle contienne des sterols pour que celle-ci ponde regulierement des oeufs viables; s'il y a carence de sterols, la femelle continue a pondre mais seul un faible pourcentage des oeufs parviennent a eclosion et sont viables; 2. le cholesterol joue egalement un role dans l'utilisation des reserves nutritives dont s'accompagne le debut du developpement des ovaires. On a etudie chez cet insecte les quantites de sterols qui sont necessaires pour que les processus physiologiques ci-dessus se deroulent, ainsi que les transformations metaboliques qui se produisent au cours du developpement, de la metamorphose et de la reproduction. Cette etude a ete faite a l'aide de sterols marques par {sup 14}C et {sup 3}H, en appliquant diverses methodes analytiques: dilution isotopique inversee, chromatographie a phase gazeuse et phase liquide, spectroscopie; on a eu recours a des methodes d'elevage en milieu aseptique et on a etabli des regimes alimentaires semi-controles pour les larves et les adultes. Le cholesterol marque par {sup 14}C et le sitosterol-{beta} marque par {sup 3}H ont ete utilises comme sources de sterols dans le regime alimentaire de la mouche domestique aux stades larvaire et adulte; il s'est revele que l'utilisation et le metabolisme de ces deux sterols etaient a peu pres identiques. Toutefois, on n'a pas observe de transformation du sitosterol- {beta} en cholesterol. Dans le regime alimentaire des larves on a egalement fait entrer du cholesterol en quantite inferieure aux besoins minima et on y a ajoute des ''sterols pauvres'' comme le cholestanol, qui