Tree phylogenetic diversity promotes host-parasitoid interactions.

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Staab, Michael; Bruelheide, Helge; Durka, Walter; Michalski, Stefan; Purschke, Oliver; Zhu, Chao-Dong; Klein, Alexandra-Maria

2016-07-13

Evidence from grassland experiments suggests that a plant community's phylogenetic diversity (PD) is a strong predictor of ecosystem processes, even stronger than species richness per se This has, however, never been extended to species-rich forests and host-parasitoid interactions. We used cavity-nesting Hymenoptera and their parasitoids collected in a subtropical forest as a model system to test whether hosts, parasitoids, and their interactions are influenced by tree PD and a comprehensive set of environmental variables, including tree species richness. Parasitism rate and parasitoid abundance were positively correlated with tree PD. All variables describing parasitoids decreased with elevation, and were, except parasitism rate, dependent on host abundance. Quantitative descriptors of host-parasitoid networks were independent of the environment. Our study indicates that host-parasitoid interactions in species-rich forests are related to the PD of the tree community, which influences parasitism rates through parasitoid abundance. We show that effects of tree community PD are much stronger than effects of tree species richness, can cascade to high trophic levels, and promote trophic interactions. As during habitat modification phylogenetic information is usually lost non-randomly, even species-rich habitats may not be able to continuously provide the ecosystem process parasitism if the evolutionarily most distinct plant lineages vanish. © 2016 The Author(s).

Differences in Induced Volatile Emissions among Rice Varieties Result in Differential Attraction and Parasitism of Nilaparvata lugens Eggs by the Parasitoid Anagrus nilaparvatae in the Field

OpenAIRE

Lou , Yong-Gen; Hua, Xiaoyan; Turlings, Ted C. J.; Cheng, Jiaan; Chen, Xuexin; Ye, Gongyin

2007-01-01

We compared the volatiles of JA-treated plants of six rice varieties and then determined, in the laboratory and field, if they differed in attractiveness to Anagrus nilaparavate Pand et Wang, an egg parasitoid of rice planthoppers. Analyses of volatiles revealed significant differences among varieties, both in total quantity and quality of the blends emitted. On the basis of these differences, the six varieties could be roughly divided into three groups. In a Y-tube olfactometer, female wasps...

Side-Effects of Glyphosate to the Parasitoid Telenomus remus Nixon (Hymenoptera: Platygastridae).

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Stecca, C S; Bueno, A F; Pasini, A; Silva, D M; Andrade, K; Filho, D M Z

2016-04-01

The aim of this study was to compare the side-effects of glyphosate to the parasitoid Telenomus remus Nixon (Hymenoptera: Platygastridae) when parasitoids were exposed to this chemical at the pupal (inside host eggs) and adult stages. Bioassays were conducted under laboratory conditions according to the International Organization for Biological Control (IOBC) standard methods for testing side-effects of pesticides to egg parasitoids. Different glyphosate-based pesticides (Roundup Original®, Roundup Ready®, Roundup Transorb®, Roundup WG®, and Zapp Qi®) were tested at the same acid equivalent concentration. Treatments were classified following the IOBC toxicity categories as (1) harmless, (2) slightly harmful, (3) moderately harmful, and (4) harmful. When tested against T. remus adults, Roundup Original®, Roundup Ready®, Roundup Transorb®, and Roundup WG® reduced parasitism 2 days after parasitoid emergence, being classified as slightly harmful. Differently, when tested against T. remus pupae, all tested glyphosate-based products did not differ in their lethal effect and therefore did not reduce T. remus adult emergence or parasitism capacity, being classified as harmless. However, differences on sublethal toxicity were found. Parasitism of individuals emerging from parasitized eggs sprayed at the pupal stage of T. remus with Zapp Qi® was lower compared to control, but parasitism was still higher than 66%, and therefore, Zapp Qi® was still classified as harmless. In conclusion, all tested glyphosate-based products can be used in agriculture without negative impact to T. remus as none was classified as harmful or moderately harmful to this parasitoid when exposure occurred at the pupal or adult stages.

The effects of host-feeding on stability of discrete-time host-parasitoid population dynamic models.

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Emerick, Brooks; Singh, Abhyudai

2016-02-01

Discrete-time models are the traditional approach for capturing population dynamics of a host-parasitoid system. Recent work has introduced a semi-discrete framework for obtaining model update functions that connect host-parasitoid population levels from year-to-year. In particular, this framework uses differential equations to describe the host-parasitoid interaction during the time of year when they come in contact, allowing specific behaviors to be mechanistically incorporated. We use the semi-discrete approach to study the effects of host-feeding, which occurs when a parasitoid consumes a potential host larva without ovipositing. We find that host-feeding by itself cannot stabilize the system, and both populations exhibit behavior similar to the Nicholson-Bailey model. However, when combined with stabilizing mechanisms such as density-dependent host mortality, host-feeding contracts the region of parameter space that allows for a stable host-parasitoid equilibrium. In contrast, when combined with a density-dependent parasitoid attack rate, host-feeding expands the non-zero equilibrium stability region. Our results show that host-feeding causes inefficiency in the parasitoid population, which yields a higher population of hosts per generation. This suggests that host-feeding may have limited long-term impact in terms of suppressing host levels for biological control applications. Copyright © 2015 Elsevier Inc. All rights reserved.

Analisis senyawa volatil dari ekstrak tanaman yang berpotensi sebagai atraktan parasitoid telur wereng batang coklat, Anagrus nilaparvatae (Pang et Wang (Hymenoptera: Mymaridae

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Surjani Wonorahardjo

2015-09-01

Full Text Available Plants produce volatiles as communication cues intra- or inter- species. Infested plants by herbivores will produce volatiles as indirect defense mechanism that attracts natural enemies of herbivores. Analysis of volatiles compounds produced by rice plant as result of infested brown plant hopper (BPH, Nilaparvata lugens Stâl, was done to identify compounds in the volatiles that potentially can be used as attractant for egg parasitoids of BPH, Anagrus nilaparvatae (Pang et Wang (Hymenoptera: Mymaridae. This research was an early stage to develop formulation of parasitoid attractant. The research activities include volatiles extraction of infested rice stem by BPH eggs using acetone, n-hexane as the extraction solvents; analyses of volatile compounds with GC-MS; and bioassay of parasitoid orientation behavior to the volatiles using olfactometer methods. Extraction methods applied were maceration and continuous extraction followed by concentration. Bioassay on the parasitoid orientation behavior was done by using Y-tube olfactometer and every lot of bioassay using 30 parasitoid females with 3 replicates. The results showed that the volatile compounds of extract of infested rice stem by BPH eggs comprise of 16 components. The highest proportion of the components extracted with acetone is 2-Pentanone, 4-hydroxy-4-methyl (19,9%, while those with n-hexane is Hexanedioic acid, dioctyl ester (65%. A. nilaparvatae showed positive response to the volatiles extracted from infested rice plant by N. lugens eggs. Therefore, the volatiles can be used as an attractant for the egg A. nilaparvatae to support rice pest management.

Effect of the parasitoid Diaeretiella rapae on the feeding rate of its host Brevicoryne brassicae

International Nuclear Information System (INIS)

Couchman, J.R.; King, P.E.

1979-01-01

The food uptake by Brevicoryne brassicae, as measured by accumulation of radiophosphorus, is influenced by the presence of developing larvae of the parasitoid Diaeretiella rapae. Though the egg and embryonic stages of the parasitoid have no effect on host feeding the presence of a first-instar larva lowers the food uptake. Feeding returns to a level similar to that of non-parasitised aphids when a second-instar parasitoid is present within a host, but drops again when the third instar is reached. Host death occurs during the fourth-larval instar. (Auth.)

Describing a multitrophic plant-herbivore-parasitoid system at four spatial scales

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Cuautle, M.; Parra-Tabla, V.

2014-02-01

Herbivore-parasitoid interactions must be studied using a multitrophic and multispecies approach. The strength and direction of multiple effects through trophic levels may change across spatial scales. In this work, we use the herbaceous plant Ruellia nudiflora, its moth herbivore Tripudia quadrifera, and several parasitoid morphospecies that feed on the herbivore to answer the following questions: Do herbivore and parasitoid attack levels vary depending on the spatial scale considered? With which plant characteristics are the parasitoid and the herbivore associated? Do parasitoid morphospecies vary in the magnitude of their positive indirect effect on plant reproduction? We evaluated three approximations of herbivore and parasitoid abundance (raw numbers, ratios, and attack rates) at four spatial scales: regional (three different regions which differ in terms of abiotic and biotic characteristics); population (i.e. four populations within each region); patch (four 1 m2 plots in each population); and plant level (using a number of plant characteristics). Finally, we determined whether parasitoids have a positive indirect effect on plant reproductive success (seed number). Herbivore and parasitoid numbers differed at three of the spatial scales considered. However, herbivore/fruit ratio and attack rates did not differ at the population level. Parasitoid/host ratio and attack rates did not differ at any scale, although there was a tendency of a higher attack in one region. At the plant level, herbivore and parasitoid abundances were related to different plant traits, varying the importance and the direction (positive or negative) of those traits. In addition, only one parasitoid species (Bracon sp.) had a positive effect on plant fitness saving up to 20% of the seeds in a fruit. These results underline the importance of knowing the scales that are relevant to organisms at different trophic levels and distinguish between the specific effects of species.

Selection of Wild Plant Species from Organic Rice Field in Sumberngepoh Village in Malang as Attractant of Trichogramma spp. (Hymenoptera, Trichogrammatidae

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Wahyu Kusumayanti Putri

2014-09-01

Full Text Available One of the actions in biological control is the use of parasitoid. Some wild plant species can attract those parasitoid. By the fact, the objective of this research are to select some of wild plant species attracting Trichogramma spp. These wild plant were belong to Asteraceae (Eupatorium odoratum, Bidens pilosa, Crassocephalum crepidioides and Mimosaceae (Parkia speciosa, Leucaena glauca, Mimosa pudica. Mass rearing of trichogramma spp. was prepared for those purpose. The selection were conducted by using four armed olfactometer. The percentage of the tested Trichogramma spp. attracted to the wild plant species was noted as well as their orientation duration to select the plant species. The difference of the mean of their orientation duration was analyzed statistically by T-Test. Both of plant familia can attract the parasitoid. This were the plant species that attracted Trichogramma spp. From the most attractive to the lowest one : B. pilosa 22 %, E. odoratum 18.6 %, M. pudica 18.2 %, C. crepidioides 13.8 %, P. speciosa 13.6 %, and L. glauca 13.6 %. For the orientation duration, this are the plant species that can attract the parasitoid from the fastest one to the slowest one : P. speciosa 45.5 seconds, C. crepidioides 46.2 seconds, L. glauca 49 seconds, E. odoratum 50.6 seconds , B. pilosa 53.4 seconds, and M. pudica 55.2 seconds. Keywords : Asteraceae, Mimosaceae, Trichogramma spp.

Body odors of parasitized caterpillars give away the presence of parasitoid larvae to their primary hyperparasitoid enemies.

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Zhu, Feng; Weldegergis, Berhane T; Lhie, Boris; Harvey, Jeffrey A; Dicke, Marcel; Poelman, Erik H

2014-09-01

Foraging success of parasitoids depends on the utilization of reliable information on the presence of their often, inconspicuous hosts. These parasitic wasps use herbivore-induced plant volatiles (HIPVs) that provide reliable cues on host presence. However, host searching of hyperparasitoids, a group of parasitoids that parasitize the larvae and pupae of other parasitoids, is more constrained. Their hosts do not feed on plants, and often are even concealed inside the body of the herbivore host. Hyperparasitoids recently have been found to use HIPVs of plants damaged by herbivore hosts in which the parasitoid larvae develop. However, hyperparasitoids that search for these parasitoid larvae may be confronted with healthy and parasitized caterpillars on the same plant, further complicating their host location. In this study, we addressed whether the primary hyperparasitoid Baryscapus galactopus uses caterpillar body odors to discriminate between unparasitized herbivores and herbivores carrying larvae of parasitoid hosts. We show that the hyperparasitoids made faster first contact and spent a longer mounting time with parasitized caterpillars. Moreover, although the three parasitoid hosts conferred different fitness values for the development of B. galactopus, the hyperparasitoids showed similar behavioral responses to caterpillar hosts carrying different primary parasitoid hosts. In addition, a two-chamber olfactometer assay revealed that volatiles emitted by parasitized caterpillars were more attractive to the hyperparasitoids than those emitted by unparasitized caterpillars. Analysis of volatiles revealed that body odors of parasitized caterpillars differ from unparasitized caterpillars, allowing the hyperparasitoids to detect their parasitoid host.

Biological control of Indianmeal moth (Lepidoptera: Pyralidae) on finished stored products using egg and larval parasitoids.

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Grieshop, Matthew J; Flinn, Paul W; Nechols, James R

2006-08-01

Biological control using hymenopteran parasitoids presents an attractive alternative to insecticides for reducing infestations and damage from the Indianmeal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), in retail and warehouse environments. We examined the potential for using combinations of the egg parasitoid Trichogramma deion Riley (Hymenoptera: Trichogrammatidae), and the larval parasitoid Habrobracon hebetor (Say) (Hymenoptera: Braconidae) for preventing infestations of P. interpunctella in coarse-ground cornmeal as well as the influence of packaging on parasitoid effectiveness. Treatments included one or both parasitoids and either cornmeal infested with P. interpunctella eggs or eggs deposited on the surface of plastic bags containing cornmeal. H. hebetor had a significant impact on the number of live P. interpunctella, suppressing populations by approximately 71% in both unbagged and bagged cornmeal. In contrast, T. deion did not suppress P. interpunctella in unbagged cornmeal. However, when released on bagged cornmeal, T. deion significantly increased the level of pest suppression (87%) over bagging alone (15%). When H. hebetor was added to bagged cornmeal, there was a significant reduction of live P. interpunctella compared with the control (70.6%), with a further reduction observed when T. deion was added (96.7%). These findings suggest that, in most situations, a combined release of both T. deion and H. hebetor would have the greatest impact; because even though packaging may protect most of the stored products, there are usually areas in the storage landscape where poor sanitation is present.

Parasitoid competition and the dynamics of host-parasitoid models

Science.gov (United States)

Andrew D. Taylor

1988-01-01

Both parasitoids and predators compete intraspecifically for prey or hosts. The nature of this competition, however, is potentially much more complex and varied for parasitoids than for predators. With predators, prey are generally consumed upon capture and thus cease to be bones of contention: competition is simply for discovery (or capture) of prey. In contrast,...

Lethal and sublethal effects of four essential oils on the egg parasitoids Trissolcus basalis.

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Werdin González, Jorge Omar; Laumann, Raúl Alberto; da Silveira, Samantha; Moraes, Maria Carolina Blassioli; Borges, Miguel; Ferrero, Adriana Alicia

2013-07-01

The essential oils from leaves of Schinus molle var. areira, Aloysia citriodora, Origanum vulgare and Thymus vulgaris have showed potential as phytoinsecticides against the green stink bug, Nezara viridula. In this work were evaluated their toxicological and behavioral effects on the parasitoid Trissolcus basalis, a biological control agent of this pest insect. Essential oils were obtained via hydrodestillation from fresh leaves. Insecticide activity in T. basalis females was evaluated in direct contact and fumigation bioassays. Behavioral effects were evaluated in olfactometer bioassays. To evaluate the residual toxicity, females of the parasitoids were exposed to oil residues; in these insects, the sublethal effects were evaluated (potential parasitism and survivorship of immature stages). The essential oils from O. vulgare and T. vulgaris proved to be highly selective when used as fumigant and did not change parasitoid behavior. After one week, the residues of these oils were harmless and did not show sublethal effects against T. basalis. According with these results, essential oils have potential applications for the integrated management of N. viridula. Published by Elsevier Ltd.

Effect of Different Diets of Flour Moth on its Parasitoid Wasp Fitness, Trichogramma brassicae (Hym.:Trichogrammatidae

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Paria Soltaninejad

2017-03-01

Full Text Available Introduction: Parasitoid wasp, Trichogramma brassicae (Bezdenko (Hym.: Trichogrammatidae has excellent position in mass production technology, scope of application, wide geographical distribution and unmatched talent to adapt to different climatic conditions that can be easily reared on Mediterranean flour moth (MFM, Ephestia kuehniella Zeller (Lep.: Pyralidae. The parasitoid use is in order to control Chilo suppressalis (Walker (Lep.: Pyralidae, Helicoverpa armigera (Lep.: Noctuidae, Ostrinia nubilalis (Hübner (Lep.: Pyralidae, Ectomyelois ceratoniae (Zeller (Lep.: Phycitidae and Cydia pomonella (Lep.: Tortricidae (38. The studies have been shown that the quantity and quality of the host diet affect growth period, size of adults, adult longevity, fecundity and sex ratio of the parasitoid. The objective of current research was to evaluate the effect of four different MFM diets on the fitness of second and forth generations of the parasitoid wasp, T. brassicae. Materials and Methods: The four diets ((I wheat flour, wheat bran, corn flour, bread yeast and glycerin; (II wheat flour, wheat bran, barley flour, bread yeast and glycerin; (III barley flour, bread yeast and glycerin and (IV wheat flour, barley flour and corn flour were sterilized at 51 °C for 24 hours. After cooling at ambient temperature, the diets were contaminated with the eggs of MFM and then were maintained at 25±1° C, 60±5 % RH and a photoperiod of 14 L: 10 D. The MFM adults emerged after 35 to 40 days and their eggs were collected daily to use for investigation of the parasitoid biology. For rearing the parasitoid wasps on the MFM eggs obtained from each diet, some cards containing the parasitoid pre-pupae were put inside cages (25 × 25 × 25 cm and reared for one generation. The adults were fed honey (20% for one day and then were provided with one-day-old sterile MFM eggs. To prevent egg hatching and sterile them, they were kept at 15°C for four h. The tests were

Study of two conditioning methods of parasitoids used in biological control prior to inundative releases in apple orchards

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Valérie-Anne Dumont

2011-12-01

Full Text Available The rosy apple aphid, Dysaphis plantaginea Pass., is a major pest in apple orchards in Belgium. Two micro-hymenopteran parasitoids Aphidius matricariae Haliday and Ephedrus cerasicola Stary are potentially capable of controlling this pest. However, when released in orchards the adult parasitoids tend to disperse. Based on the results of previous work it is proposed that the reason is that the artificial diet in which they are raised does not contain the odors that enable the parasitoids to identify the habitat where there are suitable aphid hosts. To optimize the control and make it economically effective it is important to reduce dispersal. This might be done by conditioning parasitoids during rearing by exposing them to the odors associated with orchards. The odor used in this study was a hydrodistillate of apple leaves, the main host-plant of the targeted aphid. Two methods of conditioning were used: 1 soaking mummies of the parasitoid in p ure hydrodistillate, 2 including a defined concentration of hydrodistillate in the artificial diet used for rearing the parasitoid. They were exposed to either a dilution of 100×, 200× and 1000× in two consecutive generations. The response of adult parasitoids to odors was determined using a dual choice olfactometer. Of the E. cerasicola conditioned by soaking the mummies 70–75% of individuals were attracted to the odor of plants infested with D. plantaginea compared to the 55–60% in the controls. The A.matricariae that were conditioned by feeding them artificial diets containing different concentrations of apple odor for one or two generations, showed no preference for the odor of apple leaves. Second generation adults of E. cerasicola exposed to a 200 times dilution of pure hydrodistillate showed a more marked response to apple odor.

Packing of Fruit Fly Parasitoids for Augmentative Releases

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Pablo Montoya

2012-09-01

Full Text Available The successful application of Augmentative Biological Control (ABC to control pest fruit flies (Diptera: Tephritidae confronts two fundamental requirements: (1 the establishment of efficient mass rearing procedures for the species to be released, and (2 the development of methodologies for the packing and release of parasitoids that permit a uniform distribution and their optimal field performance under an area-wide approach. Parasitoid distributions have been performed by ground and by air with moderate results; both options face challenges that remain to be addressed. Different devices and strategies have been used for these purposes, including paper bags and the chilled adult technique, both of which are commonly used when releasing sterile flies. However, insect parasitoids have morphological and behavioral characteristics that render the application of such methodologies suboptimal. In this paper, we discuss an alternate strategy for the augmentative release of parasitoids and describe packing conditions that favor the rearing and emergence of adult parasitoids for increased field performance. We conclude that the use of ABC, including the packaging of parasitoids, requires ongoing development to ensure that this technology remains a viable and effective control technique for pest fruit flies.

At Lunch with a Killer: The Effect of Weaver Ants on Host-Parasitoid Interactions on Mango.

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Valentina Migani

Full Text Available Predator-prey interactions can affect the behaviour of the species involved, with consequences for population distribution and competitive interactions. Under predation pressure, potential prey may adopt evasive strategies. These responses can be costly and could impact population growth. As some prey species may be more affected than others, predation pressure could also alter the dynamics among species within communities. In field cages and small observation cages, we studied the interactions between a generalist predator, the African weaver ant, Oecophylla longinoda, two species of fruit flies that are primary pests of mango fruits, Ceratitis cosyra and Bactrocera dorsalis, and their two exotic parasitoids, Fopius arisanus and Diachasmimorpha longicaudata. In all experiments, either a single individual (observation cage experiments or groups of individuals (field cage experiments of a single species were exposed to foraging in the presence or absence of weaver ants. Weaver ant presence reduced the number of eggs laid by 75 and 50 percent in B. dorsalis and C. cosyra respectively. Similarly, parasitoid reproductive success was negatively affected by ant presence, with success of parasitism reduced by around 50 percent for both F. arisanus and D. longicaudata. The negative effect of weaver ants on both flies and parasitoids was mainly due to indirect predation effects. Encounters with weaver ant workers increased the leaving tendency in flies and parasitoids, thus reduced the time spent foraging on mango fruits. Parasitoids were impacted more strongly than fruit flies. We discuss how weaver ant predation pressure may affect the population dynamics of the fruit flies, and, in turn, how the alteration of host dynamics could impact parasitoid foraging behaviour and success.

Caterpillar hairs as an anti-parasitoid defence.

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Kageyama, Azusa; Sugiura, Shinji

2016-10-01

Caterpillar hairs are thought to act as a physical barrier against natural enemies, including parasitoids. However, very few studies have experimentally demonstrated how hairs protect caterpillars from parasitoid oviposition. To clarify the importance of caterpillar hairs as an anti-parasitoid defence, we observed the generalist endoparasitoid Meteorus pulchricornis (Hymenoptera: Braconidae) attacking both smooth and hairy caterpillars under laboratory conditions. A female Meteorus pulchricornis uses its ovipositor to inject venom and lay a single egg inside host larvae. We placed a smooth Spodoptera litura (Lepidoptera: Noctuidae) caterpillar or a hairy Lymantria dispar japonica (Lepidoptera: Erebidae) caterpillar in front of parasitoid females. We observed that 100 % and 84 % of the parasitoids could successfully stab their ovipositors into the smooth larvae of S. litura and first instars of the hairy caterpillar L. dispar japonica, respectively. However, only 24 % of parasitoids could successfully stab their ovipositors into second-instar L. dispar japonica. A higher rate of successful stabs (94 %) by parasitoids was obtained by cutting the hairs of second instar L. dispar japonica much shorter than the parasitoid ovipositor. The results demonstrate that the long, thick hairs of second and later instars of L. dispar japonica function as a physical barrier against parasitoid oviposition.

Investigation of the lethal and behavioral effects of commercial insecticides on the parasitoid wasp Copidosoma truncatellum.

Science.gov (United States)

Ramos, Rodrigo S; de Araújo, Vitor C R; Pereira, Renata R; Martins, Júlio C; Queiroz, Obiratanea S; Silva, Ricardo S; Picanço, Marcelo C

2018-01-01

Copidosoma truncatellum (Hymenoptera: Encyrtidae) is an important parasitoid wasp of the soybean looper, Chrysodeixis includens, but its effectiveness can be severely curtailed by the application of certain insecticides. Therefore, to identify insecticides that are potentially compatible with C. truncatellum, the lethal and behavioral effects of nine chemicals used to control the soybean looper were evaluated for their toxicity to the wasp. Chlorantraniliprole, chlorfenapyr, flubendiamide, and indoxacarb were the least toxic insecticides to the parasitoid, resulting in mortalities of less than 25%. In contrast, cartap, deltamethrin, and methomyl caused 100% mortality, and acephate and spinosad caused 76% and 78% mortality, respectively. At least one of the detoxifying enzymes (monooxygenase, glutathione S-transferase, and/or esterases) may be involved in the mechanisms underlying the selectivity of chlorantraniliprole, chlorfenapyr, flubendiamide, and indoxacarb for the parasitoid based on the results for the insecticide plus synergist treatment. Changes in the behavioral patterns (walking time and resting time) of the parasitoid were found with exposure to acephate, flubendiamide, indoxacarb and methomyl, but behavioral avoidance was not observed. Our results indicate that the insecticides chlorantraniliprole and chlorfenapyr are the most suitable for inclusion in integrated pest management strategies for the control of C. includens. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dynamic complexities in a parasitoid-host-parasitoid ecological model

International Nuclear Information System (INIS)

Yu Hengguo; Zhao Min; Lv Songjuan; Zhu Lili

2009-01-01

Chaotic dynamics have been observed in a wide range of population models. In this study, the complex dynamics in a discrete-time ecological model of parasitoid-host-parasitoid are presented. The model shows that the superiority coefficient not only stabilizes the dynamics, but may strongly destabilize them as well. Many forms of complex dynamics were observed, including pitchfork bifurcation with quasi-periodicity, period-doubling cascade, chaotic crisis, chaotic bands with narrow or wide periodic window, intermittent chaos, and supertransient behavior. Furthermore, computation of the largest Lyapunov exponent demonstrated the chaotic dynamic behavior of the model

Dynamic complexities in a parasitoid-host-parasitoid ecological model

Energy Technology Data Exchange (ETDEWEB)

Yu Hengguo [School of Mathematic and Information Science, Wenzhou University, Wenzhou, Zhejiang 325035 (China); Zhao Min [School of Life and Environmental Science, Wenzhou University, Wenzhou, Zhejiang 325027 (China)], E-mail: zmcn@tom.com; Lv Songjuan; Zhu Lili [School of Mathematic and Information Science, Wenzhou University, Wenzhou, Zhejiang 325035 (China)

2009-01-15

Chaotic dynamics have been observed in a wide range of population models. In this study, the complex dynamics in a discrete-time ecological model of parasitoid-host-parasitoid are presented. The model shows that the superiority coefficient not only stabilizes the dynamics, but may strongly destabilize them as well. Many forms of complex dynamics were observed, including pitchfork bifurcation with quasi-periodicity, period-doubling cascade, chaotic crisis, chaotic bands with narrow or wide periodic window, intermittent chaos, and supertransient behavior. Furthermore, computation of the largest Lyapunov exponent demonstrated the chaotic dynamic behavior of the model.

Predation on rose galls: parasitoids and predators determine gall size through directional selection.

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Zoltán László

Full Text Available Both predators and parasitoids can have significant effects on species' life history traits, such as longevity or clutch size. In the case of gall inducers, sporadically there is evidence to suggest that both vertebrate predation and insect parasitoid attack may shape the optimal gall size. While the effects of parasitoids have been studied in detail, the influence of vertebrate predation is less well-investigated. To better understand this aspect of gall size evolution, we studied vertebrate predation on galls of Diplolepis rosae on rose (Rosa canina shrubs. We measured predation frequency, predation incidence, and predation rate in a large-scale observational field study, as well as an experimental field study. Our combined results suggest that, similarly to parasitoids, vertebrate predation makes a considerable contribution to mortality of gall inducer larvae. On the other hand, its influence on gall size is in direct contrast to the effect of parasitoids, as frequency of vertebrate predation increases with gall size. This suggests that the balance between predation and parasitoid attack shapes the optimal size of D. rosae galls.

Habitat amount modulates the effect of patch isolation on host-parasitoid interactions

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Valérie eCoudrain

2014-06-01

Full Text Available 1.Habitat amount and patch isolation are important determinants of biodiversity and ecosystem functioning. We studied the separate and interactive effects of these two components of habitat fragmentation on host-parasitoid interactions in a replicated landscape-scale study. 2.We used trap-nesting solitary bees, wasps and their natural enemies as study system. We exposed trap nests in 30 tree patches in agricultural landscapes in northern Switzerland. Study sites were either (i adjacent to forest (adjacent, (ii distant from forest but connected through woody elements (connected or (iii distant from forest with no connecting woody elements (isolated. Independent of the three levels of isolation, the amount of woody habitat in the landscapes covered a gradient from 4 to 74%. 3.Host and parasitoid species richness increased with the amount of habitat in the landscape and was strongly reduced at isolated compared to adjacent and connected sites. Loss of host species richness was 21% at isolated compared to non-isolated sites, whereas parasitoid species richness decreased by 68%, indicating that the higher trophic level was more adversely affected by isolation. Most importantly, habitat amount and isolation had a pronounced interactive effect on parasitism: while isolation resulted in a strong decrease in parasitism in landscapes with low habitat amount, this effect was mitigated by high habitat amount. These interactive effects were consistent across the three years of the study. 4.The observed interplay between habitat amount and patch isolation may explain the often conflicting results in the habitat fragmentation literature and should be considered in future research on multitrophic communities and ecosystem functioning in fragmented landscapes.

Plant surface wax affects parasitoid's response to host footprints

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Rostás, Michael; Ruf, Daniel; Zabka, Vanessa; Hildebrandt, Ulrich

2008-10-01

The plant surface is the substrate upon which herbivorous insects and natural enemies meet and thus represents the stage for interactions between the three trophic levels. Plant surfaces are covered by an epicuticular wax layer which is highly variable depending on species, cultivar or plant part. Differences in wax chemistry may modulate ecological interactions. We explored whether caterpillars of Spodoptera frugiperda, when walking over a plant surface, leave a chemical trail (kairomones) that can be detected by the parasitoid Cotesia marginiventris. Chemistry and micromorphology of cuticular waxes of two barley eceriferum wax mutants ( cer-za.126, cer-yp.949) and wild-type cv. Bonus (wt) were assessed. The plants were then used to investigate potential surface effects on the detectability of caterpillar kairomones. Here we provide evidence that C. marginiventris responds to chemical footprints of its host. Parasitoids were able to detect the kairomone on wild-type plants and on both cer mutants but the response to cer-yp.949 (reduced wax, high aldehyde fraction) was less pronounced. Experiments with caterpillar-treated wt and mutant leaves offered simultaneously, confirmed this observation: no difference in wasp response was found when wt was tested against cer-za.126 (reduced wax, wt-like chemical composition) but wt was significantly more attractive than cer-yp.949. This demonstrates for the first time that the wax layer can modulate the detectability of host kairomones.

Host habitat assessment by a parasitoid using fungal volatiles

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Steidle Johannes LM

2007-02-01

Full Text Available Abstract Background The preference – performance hypothesis predicts that oviposition preference of insects should correlate with host suitability for offspring development. Therefore, insect females have to be able to assess not only the quality of a given host but also the environmental conditions of the respective host habitat. Chemical cues are a major source of information used by insects for this purpose. Primary infestation of stored grain by stored product pests often favors the intense growth of mold. This can lead to distinct sites of extreme environmental conditions (hot-spots with increased insect mortality. We studied the influence of mold on chemical orientation, host recognition, and fitness of Lariophagus distinguendus, a parasitoid of beetle larvae developing in stored grain. Results Volatiles of wheat infested by Aspergillus sydowii and A. versicolor repelled female parasitoids in an olfactometer. Foraging L. distinguendus females are known to be strongly attracted to the odor of larval host feces from the granary weevil Sitophilus granarius, which may adhere in remarkable amounts to the surface of the grains. Feces from moldy weevil cultures elicited neutral responses but parasitoids clearly avoided moldy feces when non-moldy feces were offered simultaneously. The common fungal volatile 1-octen-3-ol was the major component of the odor of larval feces from moldy weevil cultures and repelled female parasitoids at naturally occurring doses. In bioassays investigating host recognition behavior of L. distinguendus, females spent less time on grains containing hosts from moldy weevil cultures and showed less drumming and drilling behavior than on non-moldy controls. L. distinguendus had a clearly reduced fitness on hosts from moldy weevil cultures. Conclusion We conclude that L. distinguendus females use 1-octen-3-ol for host habitat assessment to avoid negative fitness consequences due to secondary mold infestation of host

Effects of environmental parameters on the chestnut gall wasp and its complex of indigenous parasitoids

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Bonsignore, Carmelo Peter; Bernardo, Umberto

2018-04-01

The chestnut gall wasp (CGW), Dryocosmus kuriphilus, an invasive pest native to China, has caused severe yield and economic losses to chestnut production in Europe since its arrival in 2002. In Southern Italy, the complex of indigenous parasitoids colonizing CGW was monitored between 2013 and 2015, with the aim of estimating the composition of the indigenous parasitoid complex, its ability to control CGW populations, and the interactions of both factors with several measured environmental parameters. We compared results among three differently managed field types. Results showed an increase in the rate of parasitism both when the host population density was lower and in unmanaged chestnut stands with more natural conditions. The percentage of parasitism in galls was related to morphological traits of the galls and to higher seasonal temperatures, which reduced the parasitism intensity because CGW develops earlier under such conditions. The host-parasitoid mortality inside galls varied among sites and was associated mostly with rot fungi during wet spring and summer months. Parasitoid species richness was similar among the study sites, but the proportion of parasitoid species differed between orchards and unmanaged coppice stands. The timing of attack by parasitoids followed a species-specific successional sequence throughout the larva-to-adult life cycle of the CGW. These interactions should be considered in future research on trophic relationships and when modeling invasive scenarios for new pest species.

New parasitoid-predator associations: female parasitoids do not avoid competition with generalist predators when sharing invasive prey

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Chailleux, Anaïs; Wajnberg, Eric; Zhou, Yuxiang; Amiens-Desneux, Edwige; Desneux, Nicolas

2014-12-01

Optimal habitat selection is essential for species survival in ecosystems, and interspecific competition is a key ecological mechanism for many observed species association patterns. Specialized animal species are commonly affected by resource and interference competition with generalist and/or omnivorous competitors, so avoidance behavior could be expected. We hypothesize that specialist species may exploit broad range cues from such potential resource competitors (i.e., cues possibly common to various generalist and/or omnivorous predators) to avoid costly competition regarding food or reproduction, even in new species associations. We tested this hypothesis by studying short-term interactions between a native larval parasitoid and a native generalist omnivorous predator recently sharing the same invasive host/prey, the leaf miner Tuta absoluta. We observed a strong negative effect of kleptoparasitism (food resource stealing) instead of classical intraguild predation on immature parasitoids. There was no evidence that parasitoid females avoided the omnivorous predator when searching for oviposition sites, although we studied both long- and short-range known detection mechanisms. Therefore, we conclude that broad range cue avoidance may not exist in our biological system, probably because it would lead to too much oviposition site avoidance which would not be an efficient and, thus, beneficial strategy. If confirmed in other parasitoids or specialist predators, our findings may have implications for population dynamics, especially in the current context of increasing invasive species and the resulting creation of many new species associations.

Partial aphid resistance in lettuce negatively affects parasitoids.

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Lanteigne, Marie-Eve; Brodeur, Jacques; Jenni, Sylvie; Boivin, Guy

2014-10-01

This study investigated the effects of partial plant resistance on the lettuce aphid Nasonovia ribisnigri (Mosley) (Hemiptera: Aphididae), a major pest of cultivated lettuce (Lactuca sativa L.), and one of its parasitoids, Aphidius ervi Haliday (Hymenoptera: Braconidae). Aphids were reared on susceptible (L. sativa variety Estival; S) or partially resistant (Lactuca serriola L. PI 491093; PR) lettuce, and next parasitized by A. ervi females. Fitness proxies were measured for both aphids and parasitoids. Developmental time to adult stage took longer for alate and apterous aphids (an average of 3.5 and 1.5 additional days, respectively) on PR than on S lettuce, and fecundity of alate aphids reared on PR lettuce was reduced by 37.8% relative to those reared on S lettuce. Size (tibia length) and weight of aphids reared on PR lettuce were lower than for aphids reared on S lettuce from the third and second instar onward, respectively. Parasitism of aphids reared on PR plants resulted in lower parasitoid offspring emergence (-49.9%), lower adult female (-30.3%) and male (-27.5%) weight, smaller adult female (-17.5%) and male (-11.9%) size, and lower female fecundity (37.8% fewer eggs) than when parasitoids developed from aphids reared on S plants. Our results demonstrate that partial aphid resistance in lettuce negatively affects both the second and third trophic levels. Host plant resistance in cultivated lettuce may therefore create an ecological sink for aphid parasitoids.

Trans-generational effects of mild heat stress on the life history traits of an aphid parasitoid.

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Ismaeil, Ibrahim; Doury, Géraldine; Desouhant, Emmanuel; Dubois, Françoise; Prevost, Geneviève; Couty, Aude

2013-01-01

Temperature changes are common in nature and insects are particularly exposed and sensitive to such variations which can be potential stresses, ultimately affecting life history traits and overall fitness. Braconids have been widely used to study the effects of temperature on host-parasitoid interactions and the present work focused on the solitary endoparasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae Aphidiidae), an efficient biological control agent commercially used against aphids such as the potato aphid Macrosiphum euphorbiae Thomas (Sternorrhyncha: Aphididae). Contrary to previous studies using heat shocks at extreme temperatures, we evaluated the effects of mild heat stresses by transferring young parasitoid adults from the constant temperature of 20°C to either a warm (25°C) or hot (28°C) temperature, for either 1 h or 48 h. Such treatments are consistent with situations commonly experienced by parasitoids when moved from their rearing conditions to greenhouses or field conditions. The effects were evaluated both on the heat stressed A. ervi adults (G0) (immediate effects) and on their first generation (G1) progeny (trans-generational effects). G0 wasps' mortality was significantly affected by the temperature in interaction with the duration of the stress. Longevity of G0 wasps surviving the heat stress was negatively affected by the temperature and females lived longer than males. Heat stress applied to A. ervi parents also had consequences on their G1 progeny whose developmental time, rates of mummification and percentage of parasitoid completing total development were negatively affected. Surprisingly, the egg load at emergence of the G1 female progeny was increased when their mothers had been submitted to a mild heat stress of 25°C or 28°C. These results clearly demonstrate trans-generational phenotypic plasticity, showing that adaptation to thermal stresses may be achieved via maternal effects. This study also sheds light on the complexity

Trans-generational effects of mild heat stress on the life history traits of an aphid parasitoid.

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Ibrahim Ismaeil

Full Text Available Temperature changes are common in nature and insects are particularly exposed and sensitive to such variations which can be potential stresses, ultimately affecting life history traits and overall fitness. Braconids have been widely used to study the effects of temperature on host-parasitoid interactions and the present work focused on the solitary endoparasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae Aphidiidae, an efficient biological control agent commercially used against aphids such as the potato aphid Macrosiphum euphorbiae Thomas (Sternorrhyncha: Aphididae. Contrary to previous studies using heat shocks at extreme temperatures, we evaluated the effects of mild heat stresses by transferring young parasitoid adults from the constant temperature of 20°C to either a warm (25°C or hot (28°C temperature, for either 1 h or 48 h. Such treatments are consistent with situations commonly experienced by parasitoids when moved from their rearing conditions to greenhouses or field conditions. The effects were evaluated both on the heat stressed A. ervi adults (G0 (immediate effects and on their first generation (G1 progeny (trans-generational effects. G0 wasps' mortality was significantly affected by the temperature in interaction with the duration of the stress. Longevity of G0 wasps surviving the heat stress was negatively affected by the temperature and females lived longer than males. Heat stress applied to A. ervi parents also had consequences on their G1 progeny whose developmental time, rates of mummification and percentage of parasitoid completing total development were negatively affected. Surprisingly, the egg load at emergence of the G1 female progeny was increased when their mothers had been submitted to a mild heat stress of 25°C or 28°C. These results clearly demonstrate trans-generational phenotypic plasticity, showing that adaptation to thermal stresses may be achieved via maternal effects. This study also sheds light on

Impact of change in winter strategy of one parasitoid species on the diversity and function of a guild of parasitoids.

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Andrade, Thiago Oliveira; Krespi, Liliane; Bonnardot, Valérie; van Baaren, Joan; Outreman, Yannick

2016-03-01

The rise of temperatures may enable species to increase their activities during winter periods and to occupy new areas. In winter, resource density is low for most species and an increased number of active consumers during this season may produce heightened competitive pressure. In Western France, the aphid parasitoid species Aphidius avenae Haliday has been known to adopt a winter diapausing strategy adjacent to newly sown cereal crops, until recent reports of active winter populations in cereal crops. We investigate how the addition of this species to the winter guild of parasitoids may change the structure of the aphid-parasitoid food web and the host-exploitation strategies of previously occurring parasitoids. We showed that in winter, Aphidius avenae was mostly associated with two aphid species, Sitobion avenae Fabricius and Metopolophium dirhodum Walker, while the generalist species Aphidius rhopalosiphi was restricted to the aphid species Rhopalosiphum padi L. in the presence of Aphidius avenae. Due to this new competition, winter food webs present a higher degree of compartmentalization and lower proportional similarity index values than spring ones. Parasitoid and aphid abundances responded significantly to changes in daily high temperatures, suggesting that the host-parasitoid community structure can be partly predicted by climate. This study demonstrates how a change in the winter strategy of one species of a guild can modify complex interspecific relationships in host-parasitoid systems.

Local and Landscape Drivers of Parasitoid Abundance, Richness, and Composition in Urban Gardens.

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Burks, Julia M; Philpott, Stacy M

2017-04-01

Urbanization negatively affects biodiversity, yet some urban habitat features can support diversity. Parasitoid wasps, an abundant and highly diverse group of arthropods, can inhabit urban areas and do well in areas with higher host abundance, floral resources, or local or landscape complexity. Parasitoids provide biological control services in many agricultural habitats, yet few studies have examined diversity and abundance of parasitoids in urban agroecosystems to understand how to promote conservation and function. We examined the local habitat and landscape drivers of parasitoid abundance, superfamily and family richness, and parasitoid composition in urban gardens in the California central coast. Local factors included garden size, ground cover type, herbaceous plant species, and number of trees and shrubs. Landscape characteristics included land cover and landscape diversity around gardens. We found that garden size, mulch cover, and urban cover within 500 m of gardens predicted increases in parasitoid abundance within gardens. The height of herbaceous vegetation and tree and shrub richness predicted increases in superfamily and family richness whereas increases in urban cover resulted in declines in parasitoid richness. Abundance of individual superfamilies and families responded to a wide array of local and landscape factors, sometimes in opposite ways. Composition of parasitoid communities responded to changes in garden size, herbaceous plant cover, and number of flowers. Thus, both local scale management and landscape planning may impact the abundance, diversity, and community composition of parasitoids in urban gardens, and may result in differences in the effectiveness of parasitoids in biological control. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Dynamical System and Nonlinear Regression for Estimate Host-Parasitoid Relationship

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Ileana Miranda Cabrera

2010-01-01

Full Text Available The complex relationships of a crop with the pest, its natural enemies, and the climate factors exist in all the ecosystems, but the mathematic models has studied only some components to know the relation cause-effect. The most studied system has been concerned with the relationship pest-natural enemies such as prey-predator or host-parasitoid. The present paper shows a dynamical system for studying the relationship host-parasitoid (Diaphorina citri, Tamarixia radiata and shows that a nonlinear model permits the estimation of the parasite nymphs using nymphs healthy as the known variable. The model showed the functional answer of the parasitoid, in which a point arrives that its density is not augmented although the number host increases, and it becomes necessary to intervene in the ecosystem. A simple algorithm is used to estimate the parasitoids level using the priori relationship between the host and the climate factors and then the nonlinear model.

Effects of soybean resistance on variability in life history traits of the higher trophic level parasitoid Meteorus pulchricornis (Hymenoptera: Braconidae).

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Li, X; Li, B; Xing, G; Meng, L

2017-02-01

To extrapolate the influence of plant cultivars varying in resistance levels to hosts on parasitoid life history traits, we estimated variation in parasitoid developmental and reproductive performances as a function of resistance in soybean cultivars, which were randomly chosen from a line of resistant genotypes. Our study showed that the parasitoid Meteorus pulchricornis varied widely in offspring survival and lifetime fecundity, but varied slightly in development time and adult body size, in response to the soybean cultivars that varied in resistance to the host Spodoptera litura. Furthermore, the variability in survival and lifetime fecundity was different between attacking the 2nd and the 4th instar host larvae, varying more in survival but less in lifetime fecundity when attacking the 4th than 2nd instar larvae. Our study provides further evidence supporting that plant resistance to herbivorous hosts have variable effects on different life history traits of higher trophic level parasitoids.

Systemic Imidacloprid Affects Intraguild Parasitoids Differently

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Roe, R. Michael; Bacheler, Jack S.

2015-01-01

Toxoneuron nigriceps (Viereck) (Hymenoptera, Braconidae) and Campoletis sonorensis (Cameron) (Hymenoptera, Ichneumonidae) are solitary endoparasitoids of the tobacco budworm, Heliothis virescens (Fabricius) (Lepidoptera, Noctuidae). They provide biological control of H. virescens populations in Southeastern US agricultural production systems. Field and greenhouse experiments conducted from 2011–2014 compared parasitism rates of parasitoids that developed inside H. virescens larvae fed on tobacco plants treated with and without imidacloprid. The parasitoids in our study did not have a similar response. Toxoneuron nigriceps had reduced parasitism rates, but parasitism rates of C. sonorensis were unaffected. Preliminary data indicate that adult female lifespans of T. nigriceps are also reduced. ELISA was used to measure concentrations of neonicotinoids, imidacloprid and imidacloprid metabolites in H. virescens larvae that fed on imidacloprid-treated plants and in the parasitoids that fed on these larvae. Concentrations were detectable in the whole bodies of parasitized H. virescens larvae, T. nigriceps larvae and T. nigriceps adults, but not in C. sonorensis larvae and adults. These findings suggest that there are effects of imidacloprid on multiple trophic levels, and that insecticide use may differentially affect natural enemies with similar feeding niches. PMID:26658677

Systemic Imidacloprid Affects Intraguild Parasitoids Differently.

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Sally V Taylor

Full Text Available Toxoneuron nigriceps (Viereck (Hymenoptera, Braconidae and Campoletis sonorensis (Cameron (Hymenoptera, Ichneumonidae are solitary endoparasitoids of the tobacco budworm, Heliothis virescens (Fabricius (Lepidoptera, Noctuidae. They provide biological control of H. virescens populations in Southeastern US agricultural production systems. Field and greenhouse experiments conducted from 2011-2014 compared parasitism rates of parasitoids that developed inside H. virescens larvae fed on tobacco plants treated with and without imidacloprid. The parasitoids in our study did not have a similar response. Toxoneuron nigriceps had reduced parasitism rates, but parasitism rates of C. sonorensis were unaffected. Preliminary data indicate that adult female lifespans of T. nigriceps are also reduced. ELISA was used to measure concentrations of neonicotinoids, imidacloprid and imidacloprid metabolites in H. virescens larvae that fed on imidacloprid-treated plants and in the parasitoids that fed on these larvae. Concentrations were detectable in the whole bodies of parasitized H. virescens larvae, T. nigriceps larvae and T. nigriceps adults, but not in C. sonorensis larvae and adults. These findings suggest that there are effects of imidacloprid on multiple trophic levels, and that insecticide use may differentially affect natural enemies with similar feeding niches.

Plants attract parasitic wasps to defend themselves against insect pests by releasing hexenol.

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Jianing Wei

2007-09-01

Full Text Available Plant volatiles play an important role in defending plants against insect attacks by attracting their natural enemies. For example, green leaf volatiles (GLVs and terpenoids emitted from herbivore-damaged plants were found to be important in the host location of parasitic wasps. However, evidence of the functional roles and mechanisms of these semio-chemicals from a system of multiple plants in prey location by the parasitoid is limited. Little is known about the potential evolutionary trends between herbivore-induced host plant volatiles and the host location of their parasitoids.The present study includes hierarchical cluster analyses of plant volatile profiles from seven families of host and non-host plants of pea leafminer, Liriomyza huidobrensis, and behavioral responses of a naive parasitic wasp, Opius dissitus, to some principal volatile compounds. Here we show that plants can effectively pull wasps, O. dissitus, towards them by releasing a universally induced compound, (Z-3-hexenol, and potentially keep these plants safe from parasitic assaults by leafminer pests, L. huidobrensis. Specifically, we found that volatile profiles from healthy plants revealed a partly phylogenetic signal, while the inducible compounds of the infested-plants did not result from the fact that the induced plant volatiles dominate most of the volatile blends of the host and non-host plants of the leafminer pests. We further show that the parasitoids are capable of distinguishing the damaged host plant from the non-host plant of the leafminers.Our results suggest that, as the most passive scenario of plant involvement, leafminers and mechanical damages evoke similar semio-chemicals. Using ubiquitous compounds, such as hexenol, for host location by general parasitoids could be an adaptation of the most conservative evolution of tritrophic interaction. Although for this, other compounds may be used to improve the precision of the host location by the parasitoids.

A survey of hymenopteran parasitoids of forest macrolepidoptera in the central Appalachians.

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Petrice, T R; Strazanac, J S; Butler, L

2004-04-01

In 1995 and 1996, we conducted a study of the hymenopteran parasitoids of macrolepidopteran larvae in the George Washington National Forest (GWNF), Augusta County, Virginia, and the Monongahela National Forest (MNF), Pocahontas County, West Virginia. Macrolepidopteran larvae were collected from canopy foliage and from under canvas bands placed around tree boles. A total of 115 macrolepidopteran species and 5,235 individual larvae were reared. Forty-two percent (2,221) of the larvae were gypsy moth, Lymantria dispar (L.) (Lymantriidae). A total of 43 primary and secondary (hyperparasitoid) hymenopteran parasitoid species were reared from 46 macrolepidopteran species. Hymenopteran families represented included Ichneumonidae (23 species), Braconidae (19), Eulophidae (6), Perilampidae (1), and Trigonalidae (1). We reared 41 and 28 parasitoid species from the GWNF and the MNF, respectively, with 19 species reared from both forests. Many parasitoid species were collected infrequently, suggesting that they are relatively rare on the sampled hosts. The introduced species Cotesia melanoscela (Ratzeburg) (Braconidae), and Euplectrus bicolor (Swederus) (Eulophidae) were among the most commonly reared parasitoids, the latter reared from native hosts. The four most commonly reared native parasitoids were Meteorus hyphantriae, Riley (Braconidae), Microplitis near hyphantriae (Ashmead) (Braconidae), Aleiodes preclarus Marsh & Shaw, and Euplectrus maculiventris (Westwood) (Eulophidae). A total of 53 new hymenopteran parasitoid-macrolepidopteran host records were documented. Results from this study will be used to evaluate long-term treatment effects of regional applications of Bacillus thuringiensis kurstaki, and the gypsy moth fungus Entomophaga maimaiga Humber, Shimazu & Soper on hymenopteran parasitoids of macrolepidopteran larvae.

Influence of temperature on patch residence time in parasitoids: physiological and behavioural mechanisms

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Moiroux, Joffrey; Abram, Paul K.; Louâpre, Philippe; Barrette, Maryse; Brodeur, Jacques; Boivin, Guy

2016-04-01

Patch time allocation has received much attention in the context of optimal foraging theory, including the effect of environmental variables. We investigated the direct role of temperature on patch time allocation by parasitoids through physiological and behavioural mechanisms and its indirect role via changes in sex allocation and behavioural defences of the hosts. We compared the influence of foraging temperature on patch residence time between an egg parasitoid, Trichogramma euproctidis, and an aphid parasitoid, Aphidius ervi. The latter attacks hosts that are able to actively defend themselves, and may thus indirectly influence patch time allocation of the parasitoid. Patch residence time decreased with an increase in temperature in both species. The increased activity levels with warming, as evidenced by the increase in walking speed, partially explained these variations, but other mechanisms were involved. In T. euproctidis, the ability to externally discriminate parasitised hosts decreased at low temperature, resulting in a longer patch residence time. Changes in sex allocation with temperature did not explain changes in patch time allocation in this species. For A. ervi, we observed that aphids frequently escaped at intermediate temperature and defended themselves aggressively at high temperature, but displayed few defence mechanisms at low temperature. These defensive behaviours resulted in a decreased patch residence time for the parasitoid and partly explained the fact that A. ervi remained for a shorter time at the intermediate and high temperatures than at the lowest temperature. Our results suggest that global warming may affect host-parasitoid interactions through complex mechanisms including both direct and indirect effects on parasitoid patch time allocation.

Importance of host feeding for parasitoids that attack honeydew-producing hosts

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Burger, J.M.S.; Komany, A.; Lenteren, van J.C.; Vet, L.E.M.

2005-01-01

Insect parasitoids lay their eggs in arthropods. Some parasitoid species not only use their arthropod host for oviposition but also for feeding. Host feeding provides nutrients to the adult female parasitoid. However, in many species, host feeding destroys an opportunity to oviposit. For parasitoids

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

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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.

The parasitoids of the asparagus miner (Diptera: Agromyzidae): field parasitism and the influence of food resources on life history.

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Morrison, William R; Gibson, Gary A P; Szendrei, Zsofia

2014-12-01

The goals of this study were to identify pupal parasitoids of the asparagus miner, Ophiomyia simplex Loew (Diptera: Agromyzidae), and examine the effect of different diets and floral resources on the lifespan of adult asparagus miners and their parasitoids. We also measured the effect of parasitism on stem damage caused by the asparagus miner. The identity and abundance of the parasitoids of the asparagus miner were determined in asparagus fields in Michigan from weekly asparagus miner pupal collections during the 2010-2013 seasons. Twelve species of hymenopterous parasitoids were reared from asparagus miner pupae, including Chorebus rondanii (Giard) (Ichneumonoidea: Braconidae), 10 species in three families of Chalcidoidea, and one species of Bethylidae (Chrysidoidea), that represent new host records for the asparagus miner. C. rondanii and Thinodytes cephalon (Walker) (Pteromalidae) were the most common parasitoids. The effects of different diets and flowers on the lifespan of the pest and parasitoid adults were also evaluated. Buckwheat resulted in the shortest life span for the asparagus miner, whereas Riddell's goldenrod significantly increased its lifespan relative to the control. Parasitoid lifespan was doubled when individuals were fed sugar-rich diets. In the field, parasitoids preferred stems that contained more pupae and damage. The two most commonly reared parasitoids should be considered as targets for future conservation biological control efforts of the asparagus miner.

Toxicity of chemicals commonly used in Indonesian vegetable crops to Liriomyza huidobrensis populations and the Indonesian parasitoids Hemiptarsenus varicornis, Opius sp., and Gronotoma micromorpha, as well as the Australian parasitoids Hemiptarsenus varicornis and Diglyphus isaea.

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Prijono, Djoko; Robinson, Michelle; Rauf, Aunu; Bjorksten, Tracey; Hoffmann, Ary A

2004-08-01

Liriomyza huidobrensis (Blanchard) and Liriomyza sativae (Blanchard) are important pests of vegetable crops in Indonesia and are likely to spread to neighboring countries. Three pesticides (dimehypo, abamectin, and cyromazine) are currently used to control these pests, but there is little information on their effectiveness against field populations and on their impact on parasitoids controlling Liriomyza species. The toxicity of these chemicals to L. huidobrensis and three common parasitoids (Hemiptarsenus varicornis Gerault, Opius sp., and Gronotoma micromorpha Perkins) was therefore evaluated in Indonesia with mortality laboratory assays. All three chemicals were effective against larvae of three populations of L. huidobrensis with different histories of chemical exposure. Dimehypo caused mortality in adult Opius sp., G. micromorpha, and H. varicornis, whereas abamectin was toxic only at concentrations substantially higher than the field rate. Cyromazine did not influence survival of the parasitoids. A commonly used fungicide, mancozeb, had no impact on parasitoid mortality. Trials were repeated with a strain of H. varicornis from Australia and a different parasitoid (Diglyphus isaea) recently found in Australia. Neither parasitoid was influenced by mancozeb or cyromazine. Abamectin applied at field rates caused some mortality among the adults of both species, but was less toxic than chlorpyrifos. Abamectin produced lower LC50s against Australian H. varicornis than against Indonesian H. varicornis. These results suggest that cyromazine can be incorporated into Liriomyza control programs in Indonesia that conserve parasitoids, whereas dimehypo and abamectin need to be used cautiously. Local Australian parasitoids should help control L. huidobrensis as long as only cyromazine and nontoxic fungicides are applied.

Effect of insecticides on mealybug destroyer (Coleoptera: Coccinellidae) and parasitoid Leptomastix dactylopii (Hymenoptera: Encyrtidae), natural enemies of citrus mealybug (Homoptera: Pseudococcidae).

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Cloyd, Raymond A; Dickinson, Amy

2006-10-01

In this study, we measured, under laboratory conditions, the direct and indirect effects of insecticides on mealybug destroyer, Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae), and parasitoid Leptomastix dactylopii Howard (Hymenoptera: Encyrtidae), natural enemies of citrus mealybug, Planococcus citri (Risso) (Homoptera: Pseudococcidae). The adult stages of both natural enemies were exposed to sprays of the insecticides buprofezin, pyriproxyfen, flonicamid, acetamiprid, dinotefuran, and clothianidin at label-recommended rates to assess direct mortality after 24, 48, and 72 h, respectively. The effects of the insecticides on L. dactylopii parasitization rate and percentage of parasitoid emergence also were monitored using the label and 4x the recommended label rate. Dinotefuran was extremely detrimental to the adult parasitoid at the label rate with 100% mortality after 24 h. Buprofezin, pyriproxyfen, and flonicamid were not harmful to L. dactylopii when applied at the label rate. At 4x the recommended label rate, dinotefuran, acetamiprid, and clothianidin were all harmful to the parasitoid with 100% mortality 72 h after application. Both buprofezin and flonicamid were not toxic to L. dactylopii with 100% adult survival after 72 h. Pyriproxyfen and flonicamid, at both the label and 4x the recommended label rate, did not negatively affect L. dactylopii parasitization rate or percentage of parasitoid emergence. Acetamiprid, dinotefuran, and clothianidin were toxic to C. montrouzieri adults with 100% mortality after 48 h, whereas buprofezin, pyriproxyfen, and flonicamid demonstrated minimal (10-20% mortality after 48 h) harmful effects to the predator. Based on the results from our study, the indirect effects of the insect growth regulator (IGR) buprofezin were not decisive; however, the IGR pyriproxyfen and the insecticide flonicamid were not directly or indirectly harmful to the predator C. montrouzieri and parastioid L. dactylopii, indicating that

Trade-Off Between Fitness Gain and Cost Determines Profitability of a Peach Aphid Parasitoid.

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Khatri, Diwas; He, Xiong Z; Wang, Qiao

2016-08-01

Aphidius colemani (Viereck) (Hymenoptera: Aphidiidae) is commercially produced and utilized for biological control of peach aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae) on greenhouse crops in many countries. To provide knowledge for the evaluation of parasitoid-host interactions and development of effective mass rearing programs, we investigated how and why host age or size affected fitness gain in A. colemani We show that the parasitoid was significantly more likely to encounter larger hosts and that an encounter almost always triggered an attack attempt. However, the attack attempt did not proportionally translate into oviposition because larger aphids had greater ability to defend themselves and the parasitoid spent more time in handling larger aphids. The host age at parasitization had no effect on emergence rates and sex ratio of parasitoid progeny, suggesting that pupae and larvae have similar survival rate in hosts of different ages and/or the parasitoid females do not adjust sex allocation based on host size. When parasitizing mid-aged hosts, the parasitoid gained maximum fitness for their progeny in developmental period, body size, and parasitism. Taking all findings together, we suggest that parasitizing mid-aged green peach aphid nymphs is most profitable for A. colemani. © 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.

Variation in natural plant products and the attraction of bodyguards involved in indirect plant defense

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Mumm, R.; Dicke, M.

2010-01-01

Plants can respond to feeding or egg deposition by herbivorous arthropods by changing the volatile blend that they emit. These herbivore-induced plant volatiles (HIPVs) can attract carnivorous natural enemies of the herbivores, such as parasitoids and predators, a phenomenon that is called indirect

Side effects of some pesticides on the silverleaf whitefly’s parasitoid, Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae under laboratory conditions

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Mustafa PORTAKALDALI

2015-12-01

Full Text Available The silverleaf whitefly, Bemisia tabaci (Gennadius (Hemiptera: Aleyrodidae is one of major pests in greenhouses vegetable cultivation. Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae has an important role among effective parasitoids used in biological control of the silverleaf whitefly. Nondestructive or less destructive pesticides against this parasitoid should be preferred in the scope of biological control. For this goal, side effects of 8 plant protection products, including spinosad, pyriproxyfen, abamectin, emamectin benzoate, copper oxychloride, kresoxim-methyl+boscalid, dimethoate and propineb+cymoxanil on pupae and adults of E. mundus were tested in this laboratory study conducted according to IOBC standards. As a result, pesticides containing spinosad, abamectin and dimethoate were determined as highly destructive to pupae and adults of E. mundus, and pesticide containing emamectin benzoate was found as moderately harmful. As for propineb+cymoxanil, pyriproxyfen, kresoxim-methyl+boscalid and copper oxychloride, they were determined as ineffective on the parasitoid under laboratory conditions. These results obtained from experiments that were conducted under laboratory conditions also have to be supported by field or semi-field experiment’s results.

Pengaruh insektisida deltametrin terhadap perilaku orientasi parasitoid Anagrus nilaparvatae (Pang et Wang (Hymenoptera: Mymaridae

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Araz Meilin

2016-09-01

Full Text Available Host searching behaviour by a parasitoid includes orientation to the volatile compounds (odor relesead by host or host plant. The aim of this study was to determine the changes in the orientation behaviour of Anagrus nilaparvatae (Pang et Wang, the egg parasitoid of rice brown planthoppers (Nilaparvata lugens (Stål, after being exposed to sublethal concentrations of deltamethrin. The impact of residue on plants to the behaviour of parasitoid was also studied. The sublethal concentrations (LC10 and LC40 used were 0.023 ppm and 2.235 ppm, respectively. Deltamethrin applied to the rice plants were 12.5 ppm and 6.25 ppm, and its effect was observed at 3 hours, 1, 3 and 7 days after application. Orientation behavior was studied using Y-tube olfactometer. Application of deltamethrin at subletal concentration reduced the ability of surviving A. nilaparvatae to detect odors (volatile ompounds released by the host, N. lugens. The higher the concentration of deltamethrin applied to the parasitoid or to the rice plants, the more prominent effect observed in the changing in the parasitoid behavious, in particular disruption to the parasitoid’s orientation to find their host. As consequences, effects of deltamethrin may lead to reduce the effectiveness of A. nilaparvatae as biological control agents in the field as a result of declining their searching capacity. 

Population Dynamics of Native Parasitoids Associated with the Asian Chestnut Gall Wasp (Dryocosmus kuriphilus in Italy

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Tiziana Panzavolta

2018-01-01

Full Text Available Native parasitoids may play an important role in biological control. They may either support or hinder the effectiveness of introduced nonnative parasitoids released for pest control purposes. Results of a three-year survey (2011–2013 of the Asian chestnut gall wasp (ACGW Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae populations and on parasitism rates by native indigenous parasitoids (a complex of chalcidoid hymenopterans in Italian chestnut forests are given. Changes in D. kuriphilus gall size and phenology were observed through the three years of study. A total of 13 species of native parasitoids were recorded, accounting for fluctuating parasitism rates. This variability in parasitism rates over the three years was mainly due to the effect of Torymus flavipes (Walker (Hymenoptera: Torymidae, which in 2011 accounted for 75% of all parasitoid specimens yet decreased drastically in the following years. This strong fluctuation may be related to climatic conditions. Besides, our data verified that parasitoids do not choose host galls based on their size, though when they do parasitize smaller ones, they exploit them better. Consequently, ACGWs have higher chances of surviving parasitism if they are inside larger galls.

Toxicity of Piper aduncum (Piperaceae) Essential Oil Against Euschistus heros (F.) (Hemiptera: Pentatomidae) and Non-Effect on Egg Parasitoids.

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Turchen, L M; Piton, L P; Dall'Oglio, E L; Butnariu, A R; Pereira, M J B

2016-10-01

Plant essential oils have been recognized as significant natural resources for insecticides. Herein, we have assessed the toxicity of the essential oil of Piper aduncum (Piperaceae) against Euschistus heros (F.) (Hemiptera: Pentatomidae), a key soybean pest in Neotropical America. In addition, we have assessed its effect on the performance of egg parasitoids. The essential oil was obtained from the leaves of P. aduncum via hydrodistillation. Subsequently, bioassays of the concentration response to eggs (contact and immersion methods), nymphs, and adults (topical application) were conducted, to assess the lethal effects on the stink bug. We also evaluated the performance of parasitism and adult emergence of egg parasitoids, when the host eggs were treated with essential oil. In the egg bioassay, both exposure methods were efficient for unviable eggs (immersion LC 50  = 15.64 mg mL -1 ; contact LC 50  = 21.29 mg mL -1 ), with the highlight on the immersion method. The bioassay with nymphs indicated a higher toxicity of essential oil, with lower concentrations (LC 50  = 11.37 mg mL -1 ) being required to cause the death of insects. For adults, a reduction in survival of insects was observed, and consequently, there was a reduction in the number of individuals in the next generation. Although the essential oil was toxic to E. heros, it exhibited lower toxicity for egg parasitoids, as there was no effect on parasitism and the emergence of wasps. We discuss likely explanations for such selectivity. In summary, we found that the essential oil was promising for the control of E. heros, because it caused deleterious effects at all development stages of the stink bug and had no effect on parasitism and emergence of the egg parasitoids, which suggested compatibility with biological control.

Assessing non-target effects and host feeding of the exotic parasitoid Apanteles taragamae, a potential biological control agent of the cowpea pod borer Maruca vitrata

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Dannon, A.E.; Tamo, M.; Huis, van A.; Dicke, M.

2012-01-01

Apanteles taragamae Viereck is a larval parasitoid introduced in Benin for classical biological control of the cowpea pod borer Maruca vitrata Fabricius. In the laboratory, we evaluated the effects of A. taragamae on non-target herbivore species, and on another parasitoid of M. vitrata, i.e. the

Effects of various insecticides on the development of the egg parasitoid Trichogramma dendrolimi (Hymenoptera: Trichogrammatidae).

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Takada, Y; Kawamura, S; Tanaka, T

2001-12-01

The toxicity of six insecticides, acephate, methomyl, ethofenprox, cartap, chlorfluazuron, and Bacillus thuringiensis (Bt) was tested on different developmental stages of the egg parasitoid, Trichogramma dendrolimi (Matsumura). Each of the insecticides tested showed different degrees of toxicity to the parasitoid, Ethofenprox showed the highest toxicity and cartap showed relatively higher toxicity compared with the other insecticides. The development of the parasitoids treated with these two insecticides was normal, similar to that of the control group. Only the emergence of adult wasps from host eggs was disturbed. Emergence of the host, Mamestra brassicae larva was reduced following treatment with ethofenprox, cartap and methomyl. However, adult female wasps, which emerged from host eggs treated with the insecticides had the ability to oviposit normally.

Surveys for Stenoma catenifer (Lepidoptera: Elachistidae) and associated parasitoids infesting avocados in Perú.

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Hoddle, Mark S; Hoddle, Christina D

2012-04-01

Surveys for Stenoma catenifer Walsingham, the avocado seed moth, and its associated larval parasitoids were conducted in the Departments of Junín, Huánuco, Cusco, and Madre de Dios in Perú. Fruit infestation levels in some areas ranged from 0 to 58%, and parasitism of S. catenifer larvae in Junín and Huánuco was 23%. Five species of hymenopteran parasitoid in two families, Braconidae (Apanteles sp., Hypomicrogaster sp., and Chelonus sp.) and Ichneumonidae (Pristeromerus sp. and Xiphosomella sp.), were reared from larvae, and one species of tachinid fly (Chrysodoria sp.) emerged from pupae. The dominant larval parasitoid, a gregarious Apanteles sp., accounted for 55% of parasitized hosts. Branch and twig tunneling by S. catenifer larvae in a commercial Hass avocado orchard was observed in Cusco. The field attractiveness of the sex pheromone of S. catenifer was demonstrated with 73% of monitoring traps deployed in three departments (Junín, Huánuco, and Cusco) catching male moths. Approximately 55% of avocado fruit sourced from the Province of Chanchamayo (Junin) and purchased at the Mercado Modelo de Frutas in La Victoria, in central Lima were infested with larvae of S. catenifer. Infested avocado fruit sold at this market could represent a potential incursion threat to coastal Hass avocado production regions in Perú that are reportedly free of this pest.

Effects of rearing conditions on reproduction of Spathius agrili (Hymenoptera: Braconidae), a parasitoid of the emerald ash borer (Coleoptera: Buprestidae).

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Gould, Juli R; Ayer, Tracy; Fraser, Ivich

2011-04-01

Spathius agrili Yang (Hymenoptera: Braconidae) can be successfully reared on emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), larvae feeding in chambers drilled in small ash twigs that are wrapped with floral tape. Females maintained in groups with males for one week can receive enough sperm for production of female progeny throughout their lives. Volatiles released by emerald ash borer adults feeding on ash foliage increased parasitoid fecundity over ash foliage alone or no stimulus. The temperature at which the parasitoids were reared ranged from 20 to 25 degrees C in a daily cycle; however, raising the daily maximum temperature to 28 degrees C did not affect parasitoid longevity or fecundity. Adult females lived between 12 and 127 d, with an average of 60.8 +/- 4.5 d. Males lived slightly longer, with an average of 66 +/- 4.5 d. The first clutch of eggs was laid when the female was between 2 and 42 d old, with the average preoviposition period lasting 11.4 +/- 1.4 or 19.5 +/- 2.0 d in 2007 and 2009 trials, respectively. A higher proportion of the emerald ash borer larvae were feeding and thus attractive to parasitoids in the 2009 trial, and female S. agrili laid an average of 9.5 +/- 1.0 clutches containing 5.4 +/- 0.2 eggs, for an average of 51.2 eggs per female. Approximately three quarters of the progeny were female. The number of eggs per clutch was significantly greater when deposited on larger emerald ash borer larvae, further highlighting the need for quality larvae in rearing. Chilling S. agrili pupae at 10 degrees C to stockpile them for summer release was not successful; chilling resulted in lower survival and lower fecundity of emerging progeny. Female S. agrili proved capable of attacking emerald ash borer larvae through even the thickest bark of an ash tree that was 30-cm diameter at breast height. Even emerald ash borer larvae that were creating overwintering chambers in the outer sapwood of the tree were successfully

Fitness costs of intrinsic competition in two egg parasitoids of a true bug.

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Cusumano, Antonino; Peri, Ezio; Boivin, Guy; Colazza, Stefano

2015-10-01

Intrinsic competition in insect parasitoids occurs when supernumerary larvae develop in the same host as consequence of multiple ovipositions by females of the same species (intra-specific competition) or by females of different species (inter-specific competition). Studies on intrinsic competition have mainly focused on understanding the factors that play a role in the outcome of competition, while fitness-related effects for the parasitoid surviving the competition have been poorly investigated, especially in egg parasitoids. Interestingly, even the winning parasitoid can experience fitness costs due to larval development in a host in which multiple factors have been injected by the ovipositing females or released by their larvae. In this paper we studied fitness-related traits associated with intra- and inter-specific competition between Trissolcus basalis (Wollaston) and Ooencyrtus telenomicida (Vassiliev), the main egg parasitoids associated with the southern green stink bug Nezara viridula (L.) in Italy. We investigated the impact of intrinsic competition for the surviving parasitoid in terms of body size, developmental time, number and size of oocytes. Our results indicated that T. basalis adults did not experience fitness-related costs when surviving intra-specific competition; however, adults were smaller, took longer to develop and females produced fewer oocytes after surviving inter-specific competition. A different outcome was found for O. telenomicida where the emerging females were smaller, produced fewer and smaller oocytes when suffering intra-specific competition whereas no fitness costs were found when adults survived inter-specific competition. These results support the hypothesis that the impact of intrinsic competition in egg parasitoids depends on the severity of the competitive interaction, as fitness costs were more pronounced when the surviving parasitoid interacted with the most detrimental competitor. Copyright © 2015 Elsevier Ltd. All

Changes in host-parasitoid food web structure with elevation.

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Maunsell, Sarah C; Kitching, Roger L; Burwell, Chris J; Morris, Rebecca J

2015-03-01

Gradients in elevation are increasingly used to investigate how species respond to changes in local climatic conditions. Whilst many studies have shown elevational patterns in species richness and turnover, little is known about how food web structure is affected by elevation. Contrasting responses of predator and prey species to elevation may lead to changes in food web structure. We investigated how the quantitative structure of a herbivore-parasitoid food web changes with elevation in an Australian subtropical rain forest. On four occasions, spread over 1 year, we hand-collected leaf miners at twelve sites, along three elevational gradients (between 493 m and 1159 m a.s.l). A total of 5030 insects, including 603 parasitoids, were reared, and summary food webs were created for each site. We also carried out a replicated manipulative experiment by translocating an abundant leaf-mining weevil Platynotocis sp., which largely escaped parasitism at high elevations (≥ 900 m a.s.l.), to lower, warmer elevations, to test if it would experience higher parasitism pressure. We found strong evidence that the environmental change that occurs with increasing elevation affects food web structure. Quantitative measures of generality, vulnerability and interaction evenness decreased significantly with increasing elevation (and decreasing temperature), whilst elevation did not have a significant effect on connectance. Mined plant composition also had a significant effect on generality and vulnerability, but not on interaction evenness. Several relatively abundant species of leaf miner appeared to escape parasitism at higher elevations, but contrary to our prediction, Platynotocis sp. did not experience greater levels of parasitism when translocated to lower elevations. Our study indicates that leaf-mining herbivores and their parasitoids respond differently to environmental conditions imposed by elevation, thus producing structural changes in their food webs. Increasing

Impact of water-deficit stress on tritrophic interactions in a wheat-aphid-parasitoid system.

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Syed Suhail Ahmed

Full Text Available Increasing temperature and CO2 concentrations can alter tritrophic interactions in ecosystems, but the impact of increasingly severe drought on such interactions is not well understood. We examined the response of a wheat-aphid-parasitoid system to variation in water-deficit stress levels. Our results showed that arid area clones of the aphid, Sitobion avenae (Fabricius, tended to have longer developmental times compared to semiarid and moist area clones, and the development of S. avenae clones tended to be slower with increasing levels of water-deficit. Body sizes of S. avenae clones from all areas decreased with increasing water-deficit levels, indicating their declining adaptation potential under drought. Compared to arid area clones, moist area clones of S. avenae had a higher frequency of backing under severe water stress only, but a higher frequency of kicking under well-watered conditions only, suggesting a water-deficit level dependent pattern of resistance against the parasitoid, Aphidius gifuensis (Ashmead. The number of S. avenae individuals attacked by the parasitoid in 10 min showed a tendency to decrease with increasing water-deficit levels. Clones of S. avenae tended to have lower parasitism rates under treatments with higher water-deficit levels. The development of the parasitoid tended to be slower under higher levels of water-deficit stress. Thus, the bottom-up effects of water-deficit stressed plants were negative on S. avenae. However, the top-down effects via parasitoids were compromised by water-deficit, which could favor the growth of aphid populations. Overall, the first trophic level under water-deficit stress was shown to have an indirect and negative impact on the third trophic level parasitoid, suggesting that parasitoids could be increasingly vulnerable in future warming scenarios.

The sublethal effects of endosulfan on the circadian rhythms and locomotor activity of two sympatric parasitoid species.

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Delpuech, Jean-Marie; Bussod, Sophie; Amar, Aurelien

2015-08-01

The organochlorine insecticide endosulfan is dispersed worldwide and significantly contributes to environmental pollution. It is an antagonist of the neurotransmitter gamma-aminobutyric acid (GABA), which is also indirectly involved in photoperiodic time measurement. In this study, we show that endosulfan at a dose as low as LC 0.1 modified the rhythm of locomotor activity of two sympatric parasitoid species, Leptopilina boulardi and Leptopilina heterotoma. The insecticide strongly increased the nocturnal activity of both species and synchronized their diurnal activity; these activities were not synchronized under control conditions. Parasitoids are important species in ecosystems because they control the populations of other insects. In this paper, we discuss the possible consequences of these sublethal effects and highlight the importance of such effects in evaluating the consequences of environmental pollution due to insecticides. Copyright © 2015 Elsevier Ltd. All rights reserved.

Encapsulation and Hemocyte Numbers in Crocidolomia pavonana and Spodoptera litura Fabricius (Lepidoptera Attacked by Parasitoid Eriborus argenteopilosus Cameron (Hymenoptera

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DAMAYANTI BUCHORI

2009-12-01

Full Text Available Eriborus argenteopilosus is the most important parasitoid attacking cabbage pest Crocidolomia pavonana in Indonesia. Previous studies proved that parasitoid encapsulation was found to be an important factor limiting the effectiveness of the parasitoid in controlling pest population in the field. Since 1998, we have conducted series studies to investigate encapsulation mechanism developed by hosts against parasitoid, responses of parasitoid toward encapsulation ability and to determine factors that may help parasitoid avoid encapsulation. Parasitoid responses were examined on two different hosts C. pavonana and Spodoptera litura. Our findings showed that parasitization level was found to be high both on C. pavonana and S. litura. Encapsulation occurred to be high in all larva stages of C. pavonana, in contrast encapsulation was recorded very low in all larvae stages of S. litura. We recorded that encapsulation in the larval body of C. pavonana was completed in 72 hours and mostly occurred in higher larval stage. Melanization was only recorded in encapsulated parasitoid inside larva body of C. pavonana, not in S. litura. We recorded that encapsulation increased blood cell number of both larvae C. pavonana and S. litura. Encapsulation may affect development of immature parasitoid. Weight of S. litura's pupae containing encapsulated parasitoid was found to be lower in S. litura, but not in C. pavonana. Our investigation also proved that superparasitism may help parasitoid avoid encapsulation.

Diversity of Species and Behavior of Hymenopteran Parasitoids of Ants: A Review

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Jean-Paul Lachaud

2012-01-01

Full Text Available Reports of hymenopterans associated with ants involve more than 500 species, but only a fraction unambiguously pertain to actual parasitoids. In this paper, we attempt to provide an overview of both the diversity of these parasitoid wasps and the diversity of the types of interactions they have formed with their ant hosts. The reliable list of parasitoid wasps using ants as primary hosts includes at least 138 species, reported between 1852 and 2011, distributed among 9 families from 3 superfamilies. These parasitoids exhibit a wide array of biologies and developmental strategies: ecto- or endoparasitism, solitary or gregarious, and idio- or koinobiosis. All castes of ants and all developmental stages, excepting eggs, are possible targets. Some species parasitize adult worker ants while foraging or performing other activities outside the nest; however, in most cases, parasitoids attack ant larvae either inside or outside their nests. Based on their abundance and success in attacking ants, some parasitoid wasps like diapriids and eucharitids seem excellent potential models to explore how parasitoids impact ant colony demography, population biology, and ant community structure. Despite a significant increase in our knowledge of hymenopteran parasitoids of ants, most of them remain to be discovered.

Parasitoid complex of Zygaena filipendulae L. (Lepidoptera: Zygaenidae

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Žikić V.

2013-01-01

Full Text Available Caterpillars of Zygaena filipendulae Linnaeus were sampled during May and June in the Sićevo Gorge in southern Serbia. All parasitized larvae were found on grey elm trees (Ulmus canescens. During the short period before metamorphosis of Z. filipendulae, we found the whole specter of parasitoid wasps: Cotesia zygaenarum Marshall (Braconidae, Gelis agilis (Fabricius and Mesochorus velox Holmgren (Ichneumonidae, Elasmus platyedrae Ferrière and Pediobius sp. (Eulophidae, Eupelmus vesicularis (Retzius (Eupelmidae and Brachymeria tibialis (Walker (Chalcididae. Beside hymenopteran parasitoids, we found parasitoid flies from the family Tachinidae, Phryxe nemea (Meigen (Diptera. All 46 observed Z. filipendulae larvae found on grey elm trees were parasitized, but three pupae were found directly on Lotus corniculatus. Two species are newly reported as parasitoids of Z. filipendulae: E. platyedrae and Eupelmus vesicularis and three species (G. agilis, M. velox and E. platyedrae are new to the fauna of Serbia. [Projekat Ministarstva nauke Republike Srbije, br. 43001

Defensive behaviors of the Oriental armyworm Mythimna separata in response to different parasitoid species (Hymenoptera: Braconidae).

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Zhou, Jincheng; Meng, Ling; Li, Baoping

2017-01-01

This study examined defensive behaviors of Mythimna separata (Lepidoptera: Noctuidae) larvae varying in body size in response to two parasitoids varying in oviposition behavior; Microplitis mediator females sting the host with the ovipositor after climbing onto it while Meteorus pulchricornis females make the sting by standing at a close distance from the host. Mythimna separata larvae exhibited evasive (escaping and dropping) and aggressive (thrashing) behaviors to defend themselves against parasitoids M. mediator and M. pulchricornis . Escaping and dropping did not change in probability with host body size or parasitoid species. Thrashing did not vary in frequency with host body size, yet performed more frequently in response to M. mediator than to M. pulchricornis . Parasitoid handling time and stinging likelihood varied depending not only on host body size but also on parasitoid species. Parasitoid handling time increased with host thrashing frequency, similar in slope for both parasitoids yet on a higher intercept for M. mediator than for M. pulchricornis . Handling time decreased with host size for M. pulchricornis but not for M. mediator . The likelihood of realizing an ovipositor sting decreased with thrashing frequency of both small and large hosts for M. pulchricornis , while this was true only for large hosts for M. mediator . Our results suggest that the thrashing behavior of M. separata larvae has a defensive effect on parasitism, depending on host body size and parasitoid species with different oviposition behaviors.

Defensive behaviors of the Oriental armyworm Mythimna separata in response to different parasitoid species (Hymenoptera: Braconidae

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Jincheng Zhou

2017-08-01

Full Text Available This study examined defensive behaviors of Mythimna separata (Lepidoptera: Noctuidae larvae varying in body size in response to two parasitoids varying in oviposition behavior; Microplitis mediator females sting the host with the ovipositor after climbing onto it while Meteorus pulchricornis females make the sting by standing at a close distance from the host. Mythimna separata larvae exhibited evasive (escaping and dropping and aggressive (thrashing behaviors to defend themselves against parasitoids M. mediator and M. pulchricornis. Escaping and dropping did not change in probability with host body size or parasitoid species. Thrashing did not vary in frequency with host body size, yet performed more frequently in response to M. mediator than to M. pulchricornis. Parasitoid handling time and stinging likelihood varied depending not only on host body size but also on parasitoid species. Parasitoid handling time increased with host thrashing frequency, similar in slope for both parasitoids yet on a higher intercept for M. mediator than for M. pulchricornis. Handling time decreased with host size for M. pulchricornis but not for M. mediator. The likelihood of realizing an ovipositor sting decreased with thrashing frequency of both small and large hosts for M. pulchricornis, while this was true only for large hosts for M. mediator. Our results suggest that the thrashing behavior of M. separata larvae has a defensive effect on parasitism, depending on host body size and parasitoid species with different oviposition behaviors.

High nymphal host density and mortality negatively impact parasitoid complex during an insect herbivore outbreak.

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Hall, Aidan A G; Johnson, Scott N; Cook, James M; Riegler, Markus

2017-08-26

Insect herbivore outbreaks frequently occur and this may be due to factors that restrict top-down control by parasitoids, for example, host-parasitoid asynchrony, hyperparasitization, resource limitation and climate. Few studies have examined host-parasitoid density relationships during an insect herbivore outbreak in a natural ecosystem with diverse parasitoids. We studied parasitization patterns of Cardiaspina psyllids during an outbreak in a Eucalyptus woodland. First, we established the trophic roles of the parasitoids through a species-specific multiplex PCR approach on mummies from which parasitoids emerged. Then, we assessed host-parasitoid density relationships across three spatial scales (leaf, tree and site) over one year. We detected four endoparasitoid species of the family Encyrtidae (Hymenoptera); two primary parasitoid and one heteronomous hyperparasitoid Psyllaephagus species (the latter with female development as a primary parasitoid and male development as a hyperparasitoid), and the hyperparasitoid Coccidoctonus psyllae. Parasitoid development was host-synchronized, although synchrony between sites appeared constrained during winter (due to temperature differences). Parasitization was predominantly driven by one primary parasitoid species and was mostly inversely host-density dependent across the spatial scales. Hyperparasitization by C. psyllae was psyllid-density dependent at the site scale, however, this only impacted the rarer primary parasitoid. High larval parasitoid mortality due to density-dependent nymphal psyllid mortality (a consequence of resource limitation) compounded by a summer heat wave was incorporated in the assessment and resulted in density independence of host-parasitoid relationships. As such, high larval parasitoid mortality during insect herbivore outbreaks may contribute to the absence of host density-dependent parasitization during outbreak events. © 2017 Institute of Zoology, Chinese Academy of Sciences.

A group's physical attractiveness is greater than the average attractiveness of its members: the group attractiveness effect.

Science.gov (United States)

van Osch, Yvette; Blanken, Irene; Meijs, Maartje H J; van Wolferen, Job

2015-04-01

We tested whether the perceived physical attractiveness of a group is greater than the average attractiveness of its members. In nine studies, we find evidence for the so-called group attractiveness effect (GA-effect), using female, male, and mixed-gender groups, indicating that group impressions of physical attractiveness are more positive than the average ratings of the group members. A meta-analysis on 33 comparisons reveals that the effect is medium to large (Cohen's d = 0.60) and moderated by group size. We explored two explanations for the GA-effect: (a) selective attention to attractive group members, and (b) the Gestalt principle of similarity. The results of our studies are in favor of the selective attention account: People selectively attend to the most attractive members of a group and their attractiveness has a greater influence on the evaluation of the group. © 2015 by the Society for Personality and Social Psychology, Inc.

Host switching in a generalist parasitoid: contrasting transient and transgenerational costs associated with novel and original host species.

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Jones, Thomas S; Bilton, Adam R; Mak, Lorraine; Sait, Steven M

2015-01-01

Parasitoids face challenges by switching between host species that influence survival and fitness, determine their role in structuring communities, influence species invasions, and affect their importance as biocontrol agents. In the generalist parasitoid, Venturia canescens (Gravenhorst) (Hymenoptera: Ichneumonidae), we investigated the costs in encapsulation, survival, and body size on juveniles when adult parasitoids switched from their original host, Plodia interpunctella (Hübner) (Lepidotera, Pyralidae) to a novel host, Ephestia kuehniella (Zeller) (Lepidoptera, Pyralidae), over multiple generations. Switching had an initial survival cost for juvenile parasitoids in the novel host, but increased survival occurred within two generations. Conversely, mortality in the original host increased. Body size, a proxy for fecundity, also increased with the number of generations in the novel host species, reflecting adaptation or maternal effects due to the larger size of the novel host, and therefore greater resources available to the developing parasitoid. Switching to a novel host appears to have initial costs for a parasitoid, even when the novel host may be better quality, but the costs rapidly diminish. We predict that the net cost of switching to a novel host for parasitoids will be complex and will depend on the initial reduction in fitness from parasitizing a novel host versus local adaptations against parasitoids in the original host.

Bottom-up effects on a plant-endophage-parasitoid system: The role of flower-head size and chemistry.

NARCIS (Netherlands)

Tavares Correa Dias, A.; Roberto Trigo, J.; Lewinsohn, Th.M.

2010-01-01

The effects of water and nutrient addition on a trophic chain were studied in a plant-endophage-parasitoid system comprised of insects associated with flower heads of Chromolaena squalida (Asteraceae). Nine species of endophages associated with C. squalida flower heads were found, belonging to two

Can the Understory Affect the Hymenoptera Parasitoids in a Eucalyptus Plantation?

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Onice Teresinha Dall'Oglio

Full Text Available The understory in forest plantations can increase richness and diversity of natural enemies due to greater plant species richness. The objective of this study was to test the hypothesis that the presence of the understory and climatic season in the region (wet or dry can increase the richness and abundance of Hymenoptera parasitoids in Eucalyptus plantations, in the municipality of Belo Oriente, Minas Gerais State, Brazil. In each eucalyptus cultivation (five areas of cultivation ten Malaise traps were installed, five with the understory and five without it. A total of 9,639 individuals from 30 families of the Hymenoptera parasitoids were collected, with Mymaridae, Scelionidae, Encyrtidae and Braconidae being the most collected ones with 4,934, 1,212, 619 and 612 individuals, respectively. The eucalyptus stands with and without the understory showed percentage of individuals 45.65% and 54.35% collected, respectively. The understory did not represent a positive effect on the overall abundance of the individuals Hymenoptera in the E. grandis stands, but rather exerted a positive effect on the specific families of the parasitoids of this order.

Can the Understory Affect the Hymenoptera Parasitoids in a Eucalyptus Plantation?

Science.gov (United States)

Dall’Oglio, Onice Teresinha; Ribeiro, Rafael Coelho; Ramalho, Francisco de Souza; Fernandes, Flávio Lemes; Wilcken, Carlos Frederico; de Assis Júnior, Sebastião Lourenço; Rueda, Rosa Angélica Plata; Serrão, José Eduardo; Zanuncio, José Cola

2016-01-01

The understory in forest plantations can increase richness and diversity of natural enemies due to greater plant species richness. The objective of this study was to test the hypothesis that the presence of the understory and climatic season in the region (wet or dry) can increase the richness and abundance of Hymenoptera parasitoids in Eucalyptus plantations, in the municipality of Belo Oriente, Minas Gerais State, Brazil. In each eucalyptus cultivation (five areas of cultivation) ten Malaise traps were installed, five with the understory and five without it. A total of 9,639 individuals from 30 families of the Hymenoptera parasitoids were collected, with Mymaridae, Scelionidae, Encyrtidae and Braconidae being the most collected ones with 4,934, 1,212, 619 and 612 individuals, respectively. The eucalyptus stands with and without the understory showed percentage of individuals 45.65% and 54.35% collected, respectively. The understory did not represent a positive effect on the overall abundance of the individuals Hymenoptera in the E. grandis stands, but rather exerted a positive effect on the specific families of the parasitoids of this order. PMID:26954578

Mating Frequency and Effects on Sex Ratio in Female Parasitoids of xanthopimpla Stemmator (Thunberg). Implications in biological control Programmes

International Nuclear Information System (INIS)

Gitau, C.W.

2002-01-01

Cereals, especially maize and sorghum are the most important field crops in Africa. classical biological Control is a management strategy that employs natural enemies against exotic pests on cereal crops. The method has been used against Chilo partellus (Swinhoe) (Lepidoptera: Crambidae), an introduced pest of maize, using the larval parasitoid cotesia flavipes (Cameron). However, C. flavipes is not able to attack all stem borer species in targeted areas. to complement its work, Xanthopimpla stemmator has successfully been established in Mauritius on Chilo sacchariphagus (Bojer). It is a common phenomenon for haplo-diploid parasitoids to give rise to male progeny when insemination does not take place. Mating becomes important to the parasitoid population since a male biased sex ratio can bring about collapse of the population. The aim of this study was to determine wether xanthopimpla stemmator females mat more than once and wether sex ratio of progeny is affected by multiple mating in female X. stemmator. The female showed a tendency to mate once. Multiple mating did not have any significant effect on either sex ratio or longevity. More males were produced in multiple mated females than once mated females.The effect of multiple mating in X. stemmator on sex ratio in relation to biocontrol programmes are discussed

Pengaruh lama ketiadaan inang terhadap kapasitas reproduksi parasitoid Snellenius manilae Ashmead (Hymenoptera: Braconidae

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Mohamad Eldiary Akbar

2015-09-01

Full Text Available The objective of this research was to study the  influence  of host deprivation on the oviposition and physiological condition of Snellenius manilae Ashmead. The research was conducted at Laboratory of Bioecology of Parasitoid and Predator, Department of Plant Protection, Faculty of Agriculture, IPB. Ten parasitoids of the same age and cohort were used in this experiment. Deprivation of hosts were done for 1, 2, 3, 4, 5, 6 and 7 days at the beginning and toward the end of their life. All hosts were replaced every 24 hours. Result indicated that host deprivation affects the reproductive capacity of Snellenius manilae. Even though parasitoids were able to lay eggs even when they were deprived of hosts for seven consecutive days, the overall results of host deprivation experiment showed that the length and timing of deprivation period can affect reproductive capacity. Deprivation of hosts tends to increase the parasitism rate and the numbers of eggs laid upon their first encounter of hosts after the treatment. The difference is more pronounced on treatements that allowed parasitism to occur before the deprivation treatment. However, the overall results suggests that deprivation overall decrease the reproductive capacity of the parasitoid. The longevity of deprived individuals was also lengthened. Parasitoids that were given host before deprivation treatments tend to produced more eggs than those were not. These results showed that deprivation of hosts in the field may affect the effectiveness of parasitoids and the success of biological control.

Climate variation alters the synchrony of host–parasitoid interactions

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Although some research has examined how parasitoids will respond to colder temperatures or experimental warming, we know relatively little about how increased variation in temperature could affect interactions between parasitoids and their hosts. Using a study system consisting of emerald ash borer...

Location of Host and Host Habitat by Fruit Fly Parasitoids

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Pascal Rousse

2012-11-01

Full Text Available Augmentative releases of parasitoids may be a useful tool for the area-wide management of tephritid pests. The latter are parasitized by many wasp species, though only a few of them are relevant for augmentative biocontrol purposes. To date, nearly all the actual or potential biocontrol agents for such programs are egg or larval Opiinae parasitoids (Hymenoptera: Braconidae. Here, we review the literature published on their habitat and host location behavior, as well as the factors that modulate this behavior, which is assumed to be sequential; parasitoids forage first for the host habitat and then for the host itself. Parasitoids rely on chemical, visual, and mechanical stimuli, often strongly related to their ecology. Behavioral modulation factors include biotic and abiotic factors including learning, climatic conditions and physiological state of the insect. Finally, conclusions and perspectives for future research are briefly highlighted. A detailed knowledge of this behavior may be very useful for selecting the release sites for both inundative/augmentative releases of mass-reared parasitoids and inoculative releases for classical biocontrol.

A group's physical attractiveness is greater than the average attractiveness of its members : The group attractiveness effect

NARCIS (Netherlands)

van Osch, Y.M.J.; Blanken, Irene; Meijs, Maartje H. J.; van Wolferen, Job

2015-01-01

We tested whether the perceived physical attractiveness of a group is greater than the average attractiveness of its members. In nine studies, we find evidence for the so-called group attractiveness effect (GA-effect), using female, male, and mixed-gender groups, indicating that group impressions of

Sex differences in metabolic rates in field crickets and their dipteran parasitoids.

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Kolluru, G R; Chappell, M A; Zuk, M

2004-11-01

Sex differences in metabolic rate (MR) can result from dimorphism in the performance of energetically demanding activities. Male crickets (Teleogryllus oceanicus) engage in costly calling and aggressive activity not performed by females. Consistent with this difference, we found higher maximal MR, factorial scope, and fat content in males than females. T. oceanicus song is also costly because it attracts the parasitoid fly Ormia ochracea. Parasitized crickets had reduced maximal MR consistent with a metabolic cost to harboring larvae. This cost was greater for females, either because females invest more heavily into reproduction at the expense of metabolic capacity, or because males are under stronger selection to respond to infection. Little is known about O. ochracea outside of its auditory system and parasitic lifestyle. We observed greater resting MR in male flies, possibly reflecting a sex difference in the requirement for metabolic power output, because male flies perform potentially costly mating behavior not seen in females. We found a positive relationship between larval density within a cricket and pupal resting MR, suggesting that crickets in good condition are able to both harbor more larvae and produce larvae with higher resting MR. These results reveal a complex interplay between the metabolism of crickets and their fly parasitoids.

Effect of Maruca vitrata (Lepidoptera: Crambidae) host plants on life-history parameters of the parasitoid Apanteles taragamae (Hymenoptera: Braconidae)

NARCIS (Netherlands)

Dannon, A.E.; Tamo, M.; Agboton, C.; Huis, van A.; Dicke, M.

2012-01-01

The effect of four host plant species of the herbivore Maruca vitrata Fabricius (Lepidoptera: Crambidae) on development time, longevity, fecundity and sex ratio of the parasitoid Apanteles taragamae Viereck (Hymenoptera: Braconidae) was investigated under laboratory conditions. The larvae were

Age-specific interaction between the parasitoid, Encarsia formosa and its host, the silverleaf whitefly, Bemisia tabaci (Strain B

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Jing S. Hu

2003-08-01

Full Text Available The effect of hostage, the instar of Bemisia tabaci (Gennadius parasitized, on the growth and development of Encarsia formosa (Gahan was studied. E. formosa was able to parasitize and complete its life cycle no matter which instar of B. tabaci (Strain B, [also identified as B. argentifolii (Bellows and Perring], was provided for oviposition, but parasitoid development was significantly slower when 1st or 2nd instar B. tabaci rather than 3rd or 4th instars were parasitized. Host age influenced the day on which E. formosa nymphs hatching from eggs was first observed. Mean embryonic development was significantly longer when 1st (5.4 days rather than 2nd, 3rd or 4th instars (4.1, 3.4 and 3.5 days, respectively were parasitized. The duration of the 1st instar parasitoid and the pupa, but not the 2nd or 3rd instar parasitoid, were also significantly greater when 1st instars were parasitized than when older host instars were parasitized. Interestingly, no matter which instar was parasitized, the parasitoid did not molt to the 3rd instar until the 4th instar host had reached a depth of about 0.23 mm (Stage 4-5 and had initiated the nymphal-adult molt and adult development. Histological studies revealed that whitefly eye and wing structures had either disintegrated or were adult in nature whenever a 3rd instar parasitoid was present. It appears, then, that the molt of the parasitoid to its last instar is associated with the host whitefly's nymphal-adult molt. However, the initiation of the host's final molt, while a prerequisite for the parasitoid's 2nd-3rd instar molt, did not necessarily trigger this molt. In contrast to its significant effect on various aspects of parasitoid development, host instar did not significantly influence the mean size of the parasitoid larva, pupa, or adult. Larval and pupal length and adult head width were similar for all parasitoids, regardless of which host instar was parasitized as was adult longevity. Adult parasitoid

HPLC sugar analysis reveals the nutritional state and the feeding history of parasitoids

NARCIS (Netherlands)

Steppuhn, A.; Wäckers, F.L.

2004-01-01

1. Adult parasitoids depend on sugar-rich foods such as nectar and honeydew to meet their energy requirements. Many laboratory studies have established fitness benefits of sugar feeding for parasitoids. 2. Nevertheless, we know little about the nutritional ecology of parasitoids in the field,

Decision-making dynamics in parasitoids of Drosophila.

Science.gov (United States)

Thiel, Andra; Hoffmeister, Thomas S

2009-01-01

Drosophilids and their associated parasitoids live in environments that vary in resource availability and quality within and between generations. The use of information to adapt behavior to the current environment is a key feature under such circumstances and Drosophila parasitic wasps are excellent model systems to study learning and information use. They are among the few parasitoid model species that have been tested in a wide array of situations. Moreover, several related species have been tested under similar conditions, allowing the analysis of within and between species variability, the effect of natural selection in a typical environment, the current physiological status, and previous experience of the individual. This holds for host habitat and host location as well as for host choice and search time allocation. Here, we review patterns of learning and memory, of information use and updating mechanisms, and we point out that information use itself is under strong selective pressure and thus, optimized by parasitic wasps.

Complex dynamics and bifurcation analysis of host–parasitoid models with impulsive control strategy

International Nuclear Information System (INIS)

Yang, Jin; Tang, Sanyi; Tan, Yuanshun

2016-01-01

Highlights: • We develop novel host-parasitoid models with impulsive control strategy. • The effects of key parameters on the successful control have been addressed. • The complex dynamics and related biological significance are investigated. • The results between two types of host-parasitoid models have been discussed. - Abstract: In this paper, we propose and analyse two type host–parasitoid models with integrated pest management (IPM) interventions as impulsive control strategies. For fixed pulsed model, the threshold condition for the global stability of the host-eradication periodic solution is provided, and the effects of key parameters including the impulsive period, proportionate killing rate, instantaneous search rate, releasing constant, survival rate and the proportionate release rate on the threshold condition are discussed. Then latin hypercube sampling /partial rank correlation coefficients are used to carry out sensitivity analyses to determine the significance of each parameters. Further, bifurcation analyses are presented and the results show that coexistence of attractors existed for a wide range of parameters, and the switch-like transitions among these attractors indicate that varying dosages and frequencies of insecticide applications and numbers of parasitoid released are crucial for IPM strategy. For unfixed pulsed model, the results show that this model exists very complex dynamics and the host population can be controlled below ET, and it implies that the modelling methods are helpful for improving optimal strategies to design appropriate IPM.

Displacement of Aphytis chrysomphali by Aphytis melinus, parasitoids of the California red scale, in the Iberian Peninsula

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Juan Ramon Boyero

2014-02-01

Full Text Available Parasitoids are the main natural enemies of the California red scale, Aonidiella aurantii (Maskell and on occasion can regulate their populations. To increase their effectiveness, inoculative or augmentative releases of parasitoids are promoted. Previous to the implementation of any release strategy an important and necessary step is to acquire knowledge on the parasitoid fauna associated with this key phytophagous pest. Parasitoids were surveyed and quantified in Spanish citrus orchards between 2005 and 2009. Aphytis melinus DeBach (87.1% resulted as the dominant species, followed by Aphytis chrysomphali (Mercet (15.9%, Encarsia perniciosi (Tower (2.4% and Aphycus hederaceus (Westwood (0.004%. Overall, higher levels of parasitism were recorded in fruit than in twigs. Scales in fruit were parasitized at similar levels by the different parasitoid species whereas E. perniciosi was more active in twigs. Data eventually reveal the recent displacement of A. chrysomphali by A. melinus. The implications of these results on the biological control of A. aurantii are discussed and this information will be useful in the decision of IPM strategies for this pest.

Pengujian kekhususan inang parasitoid Anagyrus lopezi (De Santis (Hymenoptera: Encyrtidae pada empat spesies kutu putih yang berasosiasi dengan tanaman singkong

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Rani Dessy Karyani

2016-12-01

Full Text Available A parasitoid, Anagyrus lopezi (De Santis (Hymenoptera: Encyrtidae was introduced from Thailand into Indonesia  in early 2014 to control the cassava mealybug Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae. To determine its potential uses and effect on non-target species, behavioural observation of the parasitoids were made on four species of mealybugs, i.e. P. manihoti, Paracoccus marginatus Williams-Granara de Willink, Pseudococcus jackbeardsleyi Gimpel-Miller, and Ferrisia virgata Cockerell (Hemiptera: Pseudococcidae. For that purposes, a set of tests were conducted wich includes host susceptability, preference, and suitability. Tests were conducted by exposing a female parasitoid to 3rd instar nymphs of each mealybug species in a petri dish. For susceptability test, parasitoid A. lopezi encounterend P. manihoti more often (13.70 ± 7.18 visits per 30 minutes as compared to P. marginatus (985 ± 10.24, P. jackbeardsleyi (6.60 ± 3.62, and F. virgata (5.75 ± 4.09. So did ovipositor probing occurred more on P. manihoti (8.20 ± 5.68 probes per 30 minutes than on P. marginatus (0.70 ± 1.84, P. jackbeardsleyi (0.35 ± 0.68, and F. virgata (0.10 ± 0.45. For preference test, host encounter and ovipositor probing by the parasitoid were more common on P. manihoti as opposed to other mealybug species. Out of four mealybug species tested, P. manihoti was the only suitable host for parasitoid development, with the number of progenies emerged 7.40 ± 2.17 individuals per 3 female parasitoids exposed in 24 hour. Host specifity exhibited by parasitoid A. lopezi may prevent adverse effect to other mealybug species inhabiting cassava fields.

Effects of dietary nicotine on the development of an insect herbivore, its parasitoid and secondary hyperparasitoid over four trophic levels

NARCIS (Netherlands)

Harvey, J.A.; Dam, van N.M.; Witjes, L.M.A.; Soler, R.; Gols, R.

2007-01-01

1. Allelochemicals in herbivore diet are known to affect the development of higher trophic levels, such as parasitoids and predators. 2. This study examines how differing levels of nicotine affects the development of a herbivore, its parasitoid and secondary hyperparasitoid over four trophic levels.

The Roles of Parasitoid Foraging for Hosts, Food and Mates in the Augmentative Control of Tephritidae.

Science.gov (United States)

Sivinski, John; Aluja, Martin

2012-07-20

Ultimately, the success of augmentative fruit fly biological control depends upon the survival, dispersal, attack rate and multi-generational persistence of mass-reared parasitoids in the field. Foraging for hosts, food and mates is fundamental to the above and, at an operational level, the choice of the parasitoid best suited to control a particular tephritid in a certain environment, release rate estimates and subsequent monitoring of effectiveness. In the following we review landscape-level and microhabitat foraging preferences, host/fruit ranges, orientation through environmental cues, host vulnerabilities/ovipositor structures, and inter and intraspecific competition. We also consider tephritid parasitoid mating systems and sexual signals, and suggest the directions of future research.

Efficiency of vibrational sounding in parasitoid host location depends on substrate density.

Science.gov (United States)

Fischer, S; Samietz, J; Dorn, S

2003-10-01

Parasitoids of concealed hosts have to drill through a substrate with their ovipositor for successful parasitization. Hymenopteran species in this drill-and-sting guild locate immobile pupal hosts by vibrational sounding, i.e., echolocation on solid substrate. Although this host location strategy is assumed to be common among the Orussidae and Ichneumonidae there is no information yet whether it is adapted to characteristics of the host microhabitat. This study examined the effect of substrate density on responsiveness and host location efficiency in two pupal parasitoids, Pimpla turionellae and Xanthopimpla stemmator (Hymenoptera: Ichneumonidae), with different host-niche specialization and corresponding ovipositor morphology. Location and frequency of ovipositor insertions were scored on cylindrical plant stem models of various densities. Substrate density had a significant negative effect on responsiveness, number of ovipositor insertions, and host location precision in both species. The more niche-specific species X. stemmator showed a higher host location precision and insertion activity. We could show that vibrational sounding is obviously adapted to the host microhabitat of the parasitoid species using this host location strategy. We suggest the attenuation of pulses during vibrational sounding as the energetically costly limiting factor for this adaptation.

First foreign exploration for asian parasitoids of Drosophila suzukii

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The invasive spotted wing drosophila, Drosophila suzukii Matsumura (Dipt.: Drosophilidae), is a native of East Asia and is now widely established in North America and Europe, where it is a serious pest of small and stone fruit crops. The lack of effective indigenous parasitoids of D. suzukii in the ...

Effects of student physical attractiveness

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Krnjajić Stevan B.

2005-01-01

Full Text Available Implicit personality theories suggest that people draw conclusions about other persons by using a relatively small number of visible features. The formation of "the first impression" is influenced by the factors, such as sex, age, appearances, race or nationality. Frequently, conclusions based on those factors lead to developing social stereotypes. Attractiveness is a good example of "the first impression" effect, because physical attractiveness entails the creation of impression about another person along a relatively great number of dimensions. Experimental paradigm, introduced in the sphere of interpersonal perception around the mid-20th century, led to a relatively great number of studies on stereotype based on physical attractiveness. One of the most often quoted conclusions of studies on physical attractiveness is summarized by the idiom "what is beautiful is good". For example, socially desirable personality traits (responsibility kindness, energy quality, modesty, more successful private and professional life, are all attributed to physically attractive persons. In addition physical attractiveness is coupled with positive expectations, peer acceptance, academic achievement etc. On the basis of studies on the "what is beautiful is good" stereotype, we have situated our analysis within the domain of roles regulating social interaction between teachers and students i.e. effects of physical attractiveness on teacher expectations, peer acceptance and academic achievement.

Honey and honey-based sugars partially affect reproductive trade-offs in parasitoids exhibiting different life-history and reproductive strategies.

Science.gov (United States)

Harvey, Jeffrey A; Essens, Tijl A; Las, Rutger A; van Veen, Cindy; Visser, Bertanne; Ellers, Jacintha; Heinen, Robin; Gols, Rieta

2017-04-01

Adult dietary regimes in insects may affect egg production, fecundity and ultimately fitness. This is especially relevant in parasitoid wasps where many species serve as important biological control agents of agricultural pests. Here, we tested the effect of honey and sugar diets on daily fecundity schedules, lifetime reproductive success and longevity in four species of parasitoid wasps when reared on their respective hosts. The parasitoid species were selected based on dichotomies in host usage strategies and reproductive traits. Gelis agilis and G. areator are idiobiont ecto-parasitoids that develop in non-growing hosts, feed on protein-rich host fluids to maximize reproduction as adults and produce small numbers of large eggs. Meteorus pulchricornis and Microplitis mediator are koinobiont endoparasitoids that develop inside the bodies of growing hosts, do not host-feed, and produce greater numbers of small eggs. Parasitoids were reared on diets of either pure honey (containing trace amounts of proteins), heated honey (with denatured proteins) and a honey-mimic containing sugars only. We hypothesized that the benefits of proteins in honey would enhance reproduction in the ectoparasitoids due to their high metabolic investment per egg, but not in the koinobionts. Pure honey diet resulted in higher lifetime fecundity in G. agilis compared with the honey-mimic, whereas in both koinobionts, reproductive success did not vary significantly with diet. Longevity was less affected by diet in all of the parasitoids, although there were variable trade-offs between host access and longevity in the four species. We argue that there are both trait-based and association-specific effects of supplementary nutrients in honey on reproductive investment and success in parasitoid wasps. Copyright © 2016 Elsevier Ltd. All rights reserved.

From the depletion attraction to the bridging attraction: the effect of solvent molecules on the effective colloidal interactions.

Science.gov (United States)

Chen, Jie; Kline, Steven R; Liu, Yun

2015-02-28

Depletion attraction induced by non-adsorbing polymers or small particles in colloidal solutions has been widely used as a model colloidal interaction to understand aggregation behavior and phase diagrams, such as glass transitions and gelation. However, much less attention has been paid to study the effective colloidal interaction when small particles/molecules can be reversibly attracted to large colloidal particles. At the strong attraction limit, small particles can introduce bridging attraction as it can simultaneously attach to neighbouring large colloidal particles. We use Baxter's multi-component method for sticky hard sphere systems with the Percus-Yevick approximation to study the bridging attraction and its consequence to phase diagrams, which are controlled by the concentration of small particles and their interaction with large particles. When the concentration of small particles is very low, the bridging attraction strength increases very fast with the increase of small particle concentration. The attraction strength eventually reaches a maximum bridging attraction (MBA). Adding more small particles after the MBA concentration keeps decreasing the attraction strength until reaching a concentration above which the net effect of small particles only introduces an effective repulsion between large colloidal particles. These behaviors are qualitatively different from the concentration dependence of the depletion attraction on small particles and make phase diagrams very rich for bridging attraction systems. We calculate the spinodal and binodal regions, the percolation lines, the MBA lines, and the equivalent hard sphere interaction line for bridging attraction systems and have proposed a simple analytic solution to calculate the effective attraction strength using the concentrations of large and small particles. Our theoretical results are found to be consistent with experimental results reported recently.

The Roles of Parasitoid Foraging for Hosts, Food and Mates in the Augmentative Control of Tephritidae

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Martin Aluja

2012-07-01

Full Text Available Ultimately, the success of augmentative fruit fly biological control depends upon the survival, dispersal, attack rate and multi-generational persistence of mass-reared parasitoids in the field. Foraging for hosts, food and mates is fundamental to the above and, at an operational level, the choice of the parasitoid best suited to control a particular tephritid in a certain environment, release rate estimates and subsequent monitoring of effectiveness. In the following we review landscape-level and microhabitat foraging preferences, host/fruit ranges, orientation through environmental cues, host vulnerabilities/ovipositor structures, and inter and intraspecific competition. We also consider tephritid parasitoid mating systems and sexual signals, and suggest the directions of future research.

Chemical Control for Host-Parasitoid Model within the Parasitism Season and Its Complex Dynamics

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Tao Wang

2016-01-01

Full Text Available In the present paper, we develop a host-parasitoid model with Holling type II functional response function and chemical control, which can be applied at any time of each parasitism season or pest generation, and focus on addressing the importance of the timing of application pesticide during the parasitism season or pest generation in successful pest control. Firstly, the existence and stability of both the host and parasitoid populations extinction equilibrium and parasitoid-free equilibrium have been investigated. Secondly, the effects of key parameters on the threshold conditions have been discussed in more detail, which shows the importance of pesticide application times on the pest control. Thirdly, the complex dynamics including multiple attractors coexistence, chaotic behavior, and initial sensitivity have been studied by using numerical bifurcation analyses. Finally, the uncertainty and sensitivity of all the parameters on the solutions of both the host and parasitoid populations are investigated, which can help us to determine the key parameters in designing the pest control strategy. The present research can help us to further understand the importance of timings of pesticide application in the pest control and to improve the classical chemical control and to make management decisions.

Manure Preferences and Postemergence Learning of Two Filth Fly Parasitoids, Spalangia cameroni and Muscidifurax raptor (Hymenoptera: Pteromalidae.

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Caitlin E Taylor

Full Text Available The efficiency of host-seeking behavior is crucial to the reproductive performance of female parasitoids. Initially, parasitoids may use chemical information garnered from the microhabitat in which they emerge to locate hosts. Spalangia cameroni and Muscidifurax raptor are commercially available parasitoids of filth flies. Postemergence exposure to a specific manure may provide a way to increase parasitism in specific microhabitats found at livestock facilities upon release. In this study, female parasitoids of both species were exposed to equine manure, bovine manure, or clean pupae. Females from each emergence exposure were tested in a two-choice arena (house fly hosts in bovine manure versus clean pupae, equine manure versus clean pupae, and equine manure versus bovine manure for progeny production. There was a detectable but small effect of postemergence exposure on S. cameroni, but it was not sufficient to reverse innate preferences. Females consistently produced more progeny in hosts found in any manure over clean pupae, and in equine manure over bovine manure. The effect of postemergence exposure on M. raptor was also detectable but small. Females produced equal numbers of progeny in bovine manure versus clean pupae, as opposed to preferring to oviposit in clean pupae as with all other treatments. Preferences by M. raptor were overall less marked than for S. cameroni; indeed most of the variability observed for this species did not result from the treatment design. Residual host mortality was also detectably altered by exposure in both species, but the effect was small. Thus, postemergence exposure did not consistently and effectively manipulate these parasitoids to producing progeny in different exposure manures, suggesting that microhabitat preferences are largely determined by other factors.

Combined Non-Target Effects of Insecticide and High Temperature on the Parasitoid Bracon nigricans.

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Khaled Abbes

Full Text Available We studied the acute toxicity and the sublethal effects, on reproduction and host-killing activity, of four widely used insecticides on the generalist parasitoid Bracon nigricans (Hymenoptera: Braconidae, a natural enemy of the invasive tomato pest, Tuta absoluta (Lepidoptera: Gelechiidae. Laboratory bioassays were conducted applying maximum insecticide label rates at three constant temperatures, 25, 35 and 40°C, considered as regular, high and very high, respectively. Data on female survival and offspring production were used to calculate population growth indexes as a measure of population recovery after pesticide exposure. Spinetoram caused 80% mortality at 25°C and 100% at higher temperatures, while spinosad caused 100% mortality under all temperature regimes. Cyantraniliprole was slightly toxic to B. nigricans adults in terms of acute toxicity at the three temperatures, while it did not cause any sublethal effects in egg-laying and host-killing activities. The interaction between the two tested factors (insecticide and temperature significantly influenced the number of eggs laid by the parasitoid, which was the lowest in the case of females exposed to chlorantraniliprole at 35°C. Furthermore, significantly lower B. nigricans demographic growth indexes were estimated for all the insecticides under all temperature conditions, with the exception of chlorantraniliprole at 25°C. Our findings highlight an interaction between high temperatures and insecticide exposure, which suggests a need for including natural stressors, such as temperature, in pesticide risk assessments procedures.

The effects of aphid traits on parasitoids host use and specialist advantage

Czech Academy of Sciences Publication Activity Database

Gagic, V.; Petrović-Obradović, O.; Fründ, J.; Kavallieratos, N. G.; Athanassiou, C. G.; Starý, Petr; Tomanović, Ž.

2016-01-01

Roč. 11, č. 6 (2016), č. článku e0157674. E-ISSN 1932-6203 Institutional support: RVO:60077344 Keywords : aphid * parasitoid species * European countries Subject RIV: EH - Ecology, Behaviour Impact factor: 2.806, year: 2016 http://journals.plos.org/plosone/article/asset?id=10.1371%2Fjournal.pone.0157674.PDF

Parasitoids of boll weevil Anthonomus grandis and resident predators in kaolin-treated cotton

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Roberta Leme Santos

2013-12-01

Full Text Available Simultaneous use of control methods is essential to reach success in managing arthropod pests. The current study investigated the effect of kaolin application on resident predators in the cotton plant canopy and parasitism of boll weevil on abscised squares in the field, and parasitism of boll weevil in the laboratory. Predators Araneae, Formicidae, Chrysopidae, and Coccinellidae showed similar seasonal densities for kaolin-treated and untreated cotton fields as well as the emergence rate of the parasitoids Bracon vulgaris Ashmead (Hymenoptera: Braconidae and Catolaccus grandis Burks (Hymenoptera: Pteromalidae from abscised field-collected structures. Under laboratory conditions, the parasitism of boll weevil larvae infesting squares was similar when treated and untreated squares with kaolin were offered to the parasitoid under free choice test. Therefore, the results show that spraying cotton fields with kaolin does not affect the natural biological control by parasitoids of boll weevil and pink bollworm and resident predators naturally occurring in cotton fields.

Ecosystem-based incorporation of nectar-producing plants for stink bug parasitoids

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Adult parasitoids of pest insects rely on floral resources for survival and reproduction but can be food-deprived in intensively managed agricultural systems lacking these resources. Stink bugs are serious pests of crops in southwest Georgia. Provisioning nectar-producing plants for parasitoids of s...

Trichogramma chilotraeae PARASITOID TELUR Helicoverpa armigera (Hubner PADA POPULASI INANG RENDAH

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- Sujak

2011-03-01

Full Text Available Helicoverpa armigera Hubner is an insect pest of corn and cotton crops. Eggs are laid by  H. armigera imago on corn silk and cotton crops often have high mortality, mainly caused by egg parasitoid. H. armigera egg on various agroecosystem reported can  be parasited by at least 12 species of  Trichogrammatidae. The purpose of this study was to determine the diversity of  Trichogrammatidae family as  parasitoid eggs of  H. armigera on  low population. H. armigera egg sample taken from Asembagus, Lamongan and Blora at 1 m2 field  both monoculture and intercropping. Observation of parasitoids and predators  done at the Laboratory of Biological Control Balittas Malang. Parasitoid that appears preserved in the Hoyer medium for identification purposes. low population of  H. armigera Egg in Asembagus is  4 eggs/m2 in both monoculture maize and intercropping with 86-100 days after transplanting (DAT cotton and  4.5 egg/m2 on cotton monoculture and intercropping with 75  DAT soybean, while 2 eggs/m2 in the Lamongan and Blora corn agroecosystem. The dominant egg parasitoid in Asembagus is T. chilotraea, as well as in Lamongan and Blora.

Five new associations of parasitoids in potter wasps (Vespidae, Eumeninae

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Tiago H. Auko

2014-12-01

Full Text Available Five new associations of parasitoids in potter wasps (Vespidae, Eumeninae. New associations of host and parasitoids involving potter wasps: Toxophora leucon and Pleurochrysis sp. were found parasitizing Cyphomenes anisitsii, Chrysis sp. (gr. intricans was found parasitizing Minixi suffusum, Plega beardi was found parasitizing Montezumia pelagica sepulchralis and Macrosiagon sp. was found parasitizing Pachodynerus nasidens.

Utilisation of the egg-larval parasitoid, Fopius (Biosteres) arisanus, for augmentative biological control of tephritid fruit flies

International Nuclear Information System (INIS)

Harris, Ernest J.; Bautista, Renato C.; Spencer, John P.

2000-01-01

more. The countries supplying the insects could ask for payment for use of their natural resources. In some situations, there is strong opposition to parasitoid introductions from the lay and scientific communities due to the argument that introduced parasitoids could have adverse effects on beneficial insects which control weeds. When new introductions are successful, they must be evaluated in quarantine for months before they can be released into the field. There is no guarantee that new parasitoid species will find a niche in the tephritid fruit fly infested areas for competing well against the existing parasitoid species. A strategy which we believe has been neglected is laboratory colonisation, mass rearing and augmentative release of F. arisanus, the parasitoid species which has proved to be most successful in the Hawaiian ecosystem. We envisioned that successful colonisation of F. arisanus could provide the insight and know-how for developing different strains of F. arisanus for different fruit fly species. This strategy would complement and support foreign explorations for tephritid fruit fly parasitoids. We describe how F. arisanus is colonised, explain the research developments leading to mass production and outline what we believe can be done to develop new strains of F. arisanus

Side effects of different pesticides used in citrus on the adult stage of the parasitoid Aphytis melinus DeBach (Hymenoptera Aphelinidae and its progeny

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J. E. Gonzalez-Zamora

2013-05-01

Full Text Available Twelve pesticides commonly used in citrus in Spain were tested on adults of Aphytis melinus DeBach to determine their effects on parasitoid survival and fecundity, and the duration of the residue of each pesticide. Six of these pesticides were found to be harmless to moderately harmful to this parasitoid in a laboratory assay in closed Petri dishes: spinosad (bait formulation, azadirachtin, fenbutatin, fosetyl-Al, copper oxichloride, and mancozeb, with their scores on the reduction of beneficial capacity (RBC index being between 21.4 and 94.6% after one week. The other six pesticides classified as harmful were tested on citrus plants to study their persistence over time under greenhouse conditions: Pirimicarb, pyriproxifen, paraffinic oil, abamectin, chlorpyrifos, and lambda-cyhalothrin. Most of these products reduced their negative effect on adults of A. melinus between one and six weeks after treatment, although lambda-cyhalothrin was still harmful to parasitoids 11 weeks after application. This information can help growers and consultants to make decisions about pesticide selection and application timing in citrus in order to support IPM implementation when A. melinus is present.

An assessment of interspecific competition between two introduced parasitoids of Diaphorina citri (Hemiptera: Liviidae) on caged citrus plants.

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Vankosky, Meghan A; Hoddle, Mark S

2017-06-07

Two parasitoids attacking nymphs of Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) and Diaphorencyrtus aligarhensis (Shafee, Alam & Agarwal) (Hymenoptera: Encyrtidae) are being released in California, USA in a classical biological control program. To evaluate the effect of multiple parasitoid species on D. citri mortality, we conducted mesocosm experiments under controlled conditions using a complete block design with 6 treatments (D. citri nymphs exposed to: no parasitoids; D. aligarhensis or T. radiata alone; D. aligarhensis or T. radiata released first (by 48 h); and both species released simultaneously). Parasitism of D. citri nymphs by T. radiata exceeded 60% and was unchanged when D. aligarhensis were present. Parasitism by D. aligarhensis was greatest when T. radiata was absent (∼28%) and was reduced in all treatments with T. radiata present (citri mortality and parasitoid-related mortality of D. citri was consistent across parasitoid treatments. Laboratory results suggest that competition between D. aligarhensis and T. radiata is asymmetric and favors T. radiata. It may be difficult for D. aligarhensis to contribute significantly to D. citri biological control where T. radiata is present. However, results reported here suggest that competition between T. radiata and D. aligarhensis is not likely to reduce parasitism by T. radiata or reduce parasitoid-induced mortality of D. citri. © 2017 Institute of Zoology, Chinese Academy of Sciences.

Parasitoid-host endocrine relations: self-reliance or co-optation?

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Cole, T J; Beckage, N E; Tan, F F; Srinivasan, A; Ramaswamy, S B

2002-12-01

High titers of juvenile hormone (JH) maintain developmental arrest in Manduca sexta larvae parasitized by Cotesia congregata. Parasitized hosts exhibit up to 9.5 times greater amounts of total hemolymph JH (from 0.6+/-0.09 to 2.51+/-0.43ng/ml) compared to non-parasitized controls. Elevated titers are observed throughout the fifth instar, even beyond egression of the parasitoids on day 5. GC-MS analysis revealed that in hemolymph of unparasitized control larvae, JH I is the major homolog and levels of JH III are negligible; in parasitized individuals the amounts of JH I, II, and III rise, and JH III predominates. Neck ligation ensured separation of M. sexta's corpora allata from the posterior section, which contained most of the parasitoids in the infected insects. When the posterior region was sampled, JHs were not detected in the non-parasitzed larvae, but in those parasitized, JH III was found (1.98+/-0.29ng/ml, 24 h post-ligation). JH III was the only homolog produced and secreted by the parasitoid in in vitro culture. This is the first report stating that a parasitoid secretes JH III and may contribute, at least in part, to the circulating titer in the host hemocoel, concurrently promoting host production of JH I and II.

Effects of Banana Plantation Pesticides on the Immune Response of Lepidopteran Larvae and Their Parasitoid Natural Enemies

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Angela M. Smilanich

2012-06-01

Full Text Available Basic research on the insect immune response has progressed dramatically within the last two decades, showing that immunity is one of the most effective defenses against foreign invaders. As such, it is important to understand the causes of variation in this response. Here, we investigate the effects of pesticides used in Costa Rican banana plantations on the immune response of the lepidopteran larva, Caligo memnon (Brassolinae. In addition, we performed a parasitism survey of the banana plantations and surrounding forests to provide a broader assessment of pesticide effects on parasitoid populations. All caterpillars for the immune assay were collected from two banana plantations and brought to La Selva Biology Station for immune challenge. Individuals were fed leaves from the plantations (pesticide or leaves from La Selva (pesticide-free, then immune challenged with injected sephadex beads. We found that individuals feeding on pesticide leaves had significantly lower bead melanization compared to individuals feeding on pesticide-free leaves. Nonetheless, the parasitism survey showed that caterpillars from the banana plantations had lower parasitism rates compared to caterpillars from the La Selva forest. This study adds to the growing body of evidence documenting negative effects of pesticides on the insect immune response and on adult parasitoids, and underscores the need for more research at the intersection between ecological entomology and immunology.

Keanekaragaman spesies parasitoid telur Helicoverpa armigera (Hübner pada sistem tanam monokultur dan polikultur kapas

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nurindah nurindah

2017-02-01

Full Text Available Polyculture system is one of techniques in pest management. In Indonesia, cotton is always intercropped with second food crops such as maize, soybean, mungbean or peanut. This research was aimed to evaluate the effect of culture system, i.e. cotton monoculture vs. cotton intercropped with soybean on the increase of species diversity of H. armigera egg parasitoids and the parasitoid contribution to mortality of H. armigera. The research was arranged in a split plot design with two main factors: three cotton varieties with three levels of trichome density (Tamcot SP 37, Kanesia 8 and LRA 5166 and the subplots were two cultivation systems (cotton monoculture and polyculture, with three replicates. Observations were made by collecting H. armigera eggs on population of first generation (45 days after planting and second generation (75 DAP. The results showed that on cotton polyculture the egg parasitoid complex which consisted of Trichogramma spp. and Trichogrammatoidea spp. was higher than that in cotton monoculture and so was the egg parasitism level. The increase of egg parasitism was 24% in the first generation and 15% in the second generation. Parasitoid species found belonged to the genera Trichogramma and Trichogrammatoidea. In the parasitoid complex, Trichogrammatoidea armigera was dominant on the first generation and Trichogramma chilotraeae on the second. The domination succession could be as a result of the higher host-searching capacity of T. chilotraeae than that of T. armigera.

KEMELIMPAHAN DAN KERAGAMAN JENIS PARASITOID HAMA PENGGULUNG DAUN PISANG ERIONOTA THRAX L. DI KABUPATEN LAMPUNG SELATAN

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Lestari Wibowo

2015-03-01

Full Text Available The abundance and diversity of the parasitoid of banana leaf skipper pest (Erionota thrax L. in South Lampung Regency. This research was conducted to determine the abundance, diversity, and parasitation ability of several parasitoids of the banana skipper or banana leafroller (Erionota thrax in South Lampung Regency. This research was carried out with a survey method by taking out samples of larvae and pupae of E. thrax in the District of Natar, Jati Agung, and Tanjung Bintang, South Lampung. Results of the survey showed that there were 8 types of parasitoids recovered from larvae or pupae of E. thrax, i.e. Brachymeria lasus (Chalcididae: Hymenoptera, B. thracis (Chalcididae: Hymenoptera, Charops sp. (Ichneumonidae: Hymenoptera, Casinaria sp. (Ichneumonidae: Hymenoptera, Xanthopimpla sp. (Ichneumonidae: Hymenoptera, Cotesia erionotae (Braconidae: Hymenoptera, and two parasitoids Diptera (Tachinidae and Sarcophagidae. The highest abundance of parasitoid was found in Tanjung Bintang with 171 parasitoids (index of diversity (H’ = 1.0256 and index of evenness (E = 0.5724. In Natar District, the abundance of parasitoid was 63 parasitoids, but it had a greater H’ value (1.4396 and E-value (0.7398. Meanwhile, in Jati Agung District, the abundance of parasitoid was 56 individuals but the value of H’ was also high, which was 1.012 with the value of E of 0.6064. The percentages of parasitation to the larvae and pupae E. thrax were 55.01% (Tanjung Bintang District, 31.68% (Natar District and 33.34% (Jati Agung District.

Attack and Success of Native and Exotic Parasitoids on Eggs of Halyomorpha halys in Three Maryland Habitats.

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Megan V Herlihy

Full Text Available Egg parasitoids of the exotic invasive brown marmorated stink bug, Halyomorpha halys (Stål, were investigated using lab-reared fresh (live and frozen (killed lab-reared sentinel egg masses deployed for 72h on foliage in three habitats-woods, orchard, and soybean field-in Maryland, USA, in summer 2014. Four native hymenopteran species, Telenomus podisi Ashmead (Scelionidae, Trissolcus euschisti (Ashmead and Tr. brochymenae Ashmead (Scelionidae, and Anastatus reduvii (Howard (Eupelmidae, developed and emerged from H. halys eggs. One exotic parasitoid, Trissolcus japonicus (Ashmead, emerged, providing the first known occurrence of this species in North America. Native parasitoids emerged from frozen eggs significantly more often than from fresh eggs (89.3% of egg masses and 98.1% of individual eggs, whereas the exotic Tr. japonicus did not show a similar difference, strongly suggesting adaptation to H. halys as a host by Tr. japonicus but not by the native species. Parasitoids were habitat-specific: all three Trissolcus species were significantly more likely to occur in the woods habitat, whereas Te. podisi was found exclusively in the soybean field. Further investigations are required to elucidate evolving host-parasitoid relationships, habitat specificity, and non-target effects of Tr. japonicus over the expanded range of H. halys in North America.

Mortality of Plutella xylostella (Lepidoptera, Plutellidae by parasitoids in the Province of Santa Fe, Argentina

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Isabel Bertolaccini

2011-09-01

Full Text Available Mortality of Plutella xylostella (Lepidoptera, Plutellidae by parasitoids in the Province of Santa Fe, Argentina. Plutella xylostella (Linnaeus, 1758 (Lepidoptera, Plutellidae larvae cause severe economic damage on cabbage, Brassica oleracea L. variety capitata (Brassicaceae, in the horticultural fields in the Province of Santa Fe, Argentina. Overuse of broad spectrum insecticides affects the action of natural enemies of this insect on cabbage. The objectives of this work were to identify the parasitoids of P. xylostella and to determine their influence on larva and pupa mortality. Weekly collections of larvae and pupae were randomly conducted in cabbage crops during spring 2006 and 2007. The immature forms collected were classified according to their developmental stage: L1 and L2 (Ls = small larvae, L3 (Lm = medium larvae, L4 (Ll = large larvae, pre-pupae and pupae (P. Each individual was observed daily in the laboratory until the adult pest or parasitoid emergence. We identified parasitoids, the number of instar and the percentage of mortality of P. xylostella for each species of parasitoid. Parasitoids recorded were: Diadegma insulare (Cresson, 1875 (Hymenoptera, Ichneumonidae, Oomyzus sokolowskii (Kurdjumov, 1912 (Hymenoptera, Eulophidae, Cotesia plutellae (Kurdjumov, 1912 (Hymenoptera, Braconidae and an unidentified species of Chalcididae (Hymenoptera. Besides parasitoids, an unidentified entomopathogenic fungus was also recorded in 2006 and 2007. In 2006, the most successful parasitoids were D. insulare and O. sokolowskii, while in 2007 only D. insulare exerted a satisfactory control and it attacked the early instars of the pest.

r and K strategies in some larval and pupal parasitoids of the gypsy moth.

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Barbosa, Pedro

1977-12-01

The investigations of the bionomics and parasitoid-host interactions of some gypsy moth parasitoids provide an opportunity to consider the role of r and K strategies in the life history of some tachinid and hymenopterous parasitoid species. Available historic data as well as results of recent studies are utilized in an attempt to evaluate the degree to which the data conform to this paradigm. Few studies have provided the information required to evaluate this concept particularly in a parasitoid complex. The concept of r and K also is discussed in relation to biological control strategies, and the implications of this analysis for those arguments are discussed.

Inhibition of predator attraction to kairomones by non-host plant volatiles for herbivores: a bypass-trophic signal.

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Qing-He Zhang

2010-06-01

Full Text Available Insect predators and parasitoids exploit attractive chemical signals from lower trophic levels as kairomones to locate their herbivore prey and hosts. We hypothesized that specific chemical cues from prey non-hosts and non-habitats, which are not part of the trophic chain, are also recognized by predators and would inhibit attraction to the host/prey kairomone signals. To test our hypothesis, we studied the olfactory physiology and behavior of a predaceous beetle, Thanasimus formicarius (L. (Coleoptera: Cleridae, in relation to specific angiosperm plant volatiles, which are non-host volatiles (NHV for its conifer-feeding bark beetle prey.Olfactory detection in the clerid was confirmed by gas chromatography coupled to electroantennographic detection (GC-EAD for a subset of NHV components. Among NHV, we identified two strongly antennally active molecules, 3-octanol and 1-octen-3-ol. We tested the potential inhibition of the combination of these two NHV on the walking and flight responses of the clerid to known kairomonal attractants such as synthetic mixtures of bark beetle (Ips spp. aggregation pheromone components (cis-verbenol, ipsdienol, and E-myrcenol combined with conifer (Picea and Pinus spp. monoterpenes (alpha-pinene, terpinolene, and Delta(3-carene. There was a strong inhibitory effect, both in the laboratory (effect size d = -3.2, walking bioassay and in the field (d = -1.0, flight trapping. This is the first report of combining antennal detection (GC-EAD and behavioral responses to identify semiochemical molecules that bypass the trophic system, signaling habitat information rather than food related information.Our results, along with recent reports on hymenopteran parasitoids and coleopteran predators, suggest that some NHV chemicals for herbivores are part of specific behavioral signals for the higher trophic level and not part of a background noise. Such bypass-trophic signals could be of general importance for third trophic level

Parasitoid Wasps in Flower Heads of Asteraceae in the Brazilian Cerrado: Taxonomical Composition and Determinants of Diversity.

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Nascimento, A R; Almeida-Neto, M; Almeida, A M; Fonseca, C R; Lewinsohn, T M; Penteado-Dias, A M

2014-08-01

This study provides the first survey of the parasitoid fauna reared in flower heads of Asteraceae in the Brazilian cerrado. We investigated the relative importance of herbivore richness and plant species commonness to differences in parasitoid species richness among the plant species. A total of 15,372 specimens from 192 morphospecies belonging to 103 genera of Hymenoptera were reared from the flower heads of 74 Asteraceae species. Chalcidoidea and Ichneumonoidea were the most common superfamilies, with Eulophidae and Braconidae as the main families of parasitoid wasps. Singletons and doubletons accounted for 45% of total parasitoid species richness. The number of parasitoid species per plant species ranged from 1 to 67, and the variation in parasitoid species richness among plants was mainly explained by the number of sites in which the plants were recorded. This study shows that there is a highly diversified fauna of Hymenoptera parasitoids associated with flower heads of Asteraceae in the Brazilian cerrado. Our findings suggest that the accumulation of parasitoid species on plants is mainly determined by the regional commonness of plant species rather than the number of herbivore species associated with the plants.

Multisensory foraging by hymenopterous parasitoids

NARCIS (Netherlands)

Waeckers, F.L.

1994-01-01

The use of parasitoids as biological control agents is gaining interest as an environmentally sound alternative to the use of chemical insecticides. In order to extend and optimize biological control systems, it is essential to gain insight in the stimuli and mechanisms by which natural enemies

The role of herbivore- and plant-related experiences in intraspecific host preference of a relatively specialized parasitoid.

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Morawo, Tolulope; Fadamiro, Henry

2017-09-06

Parasitoids use odor cues from infested plants and herbivore hosts to locate their hosts. Specialist parasitoids of generalist herbivores are predicted to rely more on herbivore-derived cues than plant-derived cues. Microplitis croceipes (Cresson) (Hymenoptera: Braconidae) is a relatively specialized larval endoparasitoid of Heliothis virescens (F.) (Lepidoptera: Noctuidae), which is a generalist herbivore on several crops including cotton and soybean. Using M. croceipes/H. virescens as a model system, we tested the following predictions about specialist parasitoids of generalist herbivores: (i) naive parasitoids will show innate responses to herbivore-emitted kairomones, regardless of host plant identity and (ii) herbivore-related experience will have a greater influence on intraspecific oviposition preference than plant-related experience. Inexperienced (naive) female M. croceipes did not discriminate between cotton-fed and soybean-fed H. virescens in oviposition choice tests, supporting our first prediction. Oviposition experience alone with either host group influenced subsequent oviposition preference while experience with infested plants alone did not elicit preference in M. croceipes, supporting our second prediction. Furthermore, associative learning of oviposition with host-damaged plants facilitated host location. Interestingly, naive parasitoids attacked more soybean-fed than cotton-fed host larvae in two-choice tests when a background of host-infested cotton odor was supplied, and vice versa. This suggests that plant volatiles may have created an olfactory contrast effect. We discussed ecological significance of the results and concluded that both plant- and herbivore-related experiences play important role in parasitoid host foraging. © 2017 Institute of Zoology, Chinese Academy of Sciences.

Light brown apple moth in California: a diversity of host plants and indigenous parasitoids.

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Wang, Xin-Geng; Levy, Karmit; Mills, Nicholas J; Daane, Kent M

2012-02-01

The light brown apple moth, Epiphyas postvittana (Walker), an Australia native tortricid, was found in California in 2006. A field survey of host plants used by E. postvittana was conducted in an urban region of the San Francisco Bay Area. An inspection of 152 plant species (66 families), within a 23-ha residential community, found E. postvittana on 75 species (36 families). Most (69 species) host plants were not Australian natives, but had a wide geographic origin; 34 species were new host records for E. postvittana. Heavily infested species were the ornamental shrubs Myrtus communis L., Pittosporum tobira (Thunb.) W.T. Aiton, Euonymus japonicus Thunb., and Sollya heterophylla Lindl. To survey for parasitoids, four urban locations were sampled, with E. postvittana collected from five commonly infested plants [M. communis, P. tobira, E. japonicus, Rosmarinus officinalis L., and Genista monspessulana (L.) L.A.S. Johnson]. Twelve primary parasitoid species and two hyperparasitoids were reared; the most common were the egg parasitoid Trichogramma fasciatum (Perkins), the larval parasitoids Meteorus ictericus Nees, and Enytus eureka (Ashmead), and the pupal parasitoid Pediobius ni Peck. Meteorus ictericus accounted for >80% of the larval parasitoids, and was recovered from larvae collected on 39 plant species. Across all samples, mean parasitism was 84.4% for eggs, 43.6% for larvae, and 57.5% for pupae. The results are discussed with respect to the potential for resident parasitoid species to suppress E. postvittana populations.

Natural Distribution of Parasitoids of Larvae of the Fall Armyworm, Spodoptera frugiperda, in Argentina

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Gabriela Murúa, M.; Molina-Ochoa, Jaime; Fidalgo, Patricio

2009-01-01

To develop a better understanding of the natural distribution of the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), and to update the knowledge of the incidence of its complex of parasitoids. S. frugiperda, samplings in whorl-stage corn were carried out in provinces of Argentina from 1999 to 2003. S. frugiperda larvae were collected from corn in localities of the provinces of Tucumán, Salta, Jujuy, Santiago del Estero, La Rioja, Córdoba, San Luis, Chaco and Misiones. In each locality 30 corn plants were sampled and only larvae located in those plants were collected. The parasitoids that emerged from S. frugiperda larvae were identified and counted. The abundance of the parasitoids and the parasitism rate were estimated. The S. frugiperda parasitoids collected were Campoletis grioti (Blanchard) (Hymenoptera: Ichneumonidae), Chelonus insularis (Cresson) (Hymenoptera: Braconidae), Archytas marmoratus (Townsend) (Diptera Tachinidae) and/or A. incertus (Macquart), Ophion sp. (Hymenoptera: Ichneumonidae), Euplectrus platyhypenae Howard (Hymenoptera: Eulophidae), and Incamyia chilensis (Aldrich) (Diptera Tachinidae). C. grioti was the most abundant and frequent during the five-year survey. Similar diversity of parasitoids was obtained in all the provinces, with the exception of I. chilensis and E. platyhypenae that were recovered only in the province of Salta. In the Northwestern region, in Tucumán, C. grioti and species of Archytas were the most abundant and frequent parasitoids. On the contrary, in Salta and Jujuy Ch. insularis was the parasitoid most abundant and frequently recovered. The parasitism rate obtained in Tucumán, Salta and Jujuy provinces were 21.96%, 17.87% and 6.63% respectively with an average of 18.93%. These results demonstrate that hymenopteran and dipteran parasitoids of S. frugiperda occurred differentially throughout the Argentinian provinces and played an important role on the natural control of the S. frugiperda larval

Identification and Behavioral Evaluation of Sex Pheromone in Xanthopimpla pedator (Fabricius—A Serious Pupal Parasitoid of Tropical Tasar Silkworm Anthereae mylitta Drury

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Lakshmi Marepally

2016-10-01

Full Text Available Xanthopimpla is a major parasitoid of silk worm cocoons. The female Xanthopimpla pedator (Fabricius lays the eggs in male cocoons. Control of this infestation with pesticides is not recommended because of its concealed behavior. Various control methods were found to be inefficient. Ecofriendly management is the best strategy that can be applied. We have studied the sex communication in Xanthopimpla pedator (Fabricius, which helps to develop management strategy. Bioassays were done in the laboratory by using olfactometer and pheromone extraction chambers. It was found that female Xanthopimpla produces sex pheromones. The results show a strong attraction of male by female Xanthopimpla. Present results with male and female volatiles also show that female volatiles attract male Xanthopimpla. Fractionation of female volatiles by column chromatography has proven that 20% fraction has highest attraction of males by females.

Multistep bioassay to predict recolonization potential of emerging parasitoids after a pesticide treatment.

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Desneux, Nicolas; Ramirez-Romero, Ricardo; Kaiser, Laure

2006-10-01

Neurotoxic pyrethroid insecticides are widely used for crop protection, and lethal and sublethal perturbations can be expected in beneficial insects. Under laboratory conditions, the lethal and sublethal effects of deltamethrin on the aphid parasitoid Diaeretiella rapae M'Intosh (Hymenoptera: Braconidae) were studied at the mummy stage and in emerging adults. Following a multistep bioassay, analyses were aimed at evaluating the effects of deltamethrin at various crucial steps in the recolonization process following a deltamethrin treatment: Parasitoid pupal development (emergence from the mummies), adult survival, and host-searching capacity. A four-armed olfactometer was used to investigate the effect of deltamethrin on host-searching behavior (a range of concentrations causing 0.4-79.4% mortality was tested), and a Potter tower was used to test the deltamethrin effect with a realistic application method (four concentrations were tested: 0.5, 5.0, 6.25, and 50 g active ingredient [a.i.]/ha). Deltamethrin reduced the percentage of emergence from mummies, but only when exposed to the 50 g a.i./ha concentration. However, for all concentrations tested, the insecticide induced a decrease in longevity after emergence from sprayed mummies and significant adult mortality when parasitoids walked on fresh residues on leaves. Indices were defined and predicted a high mortality and, thus, reduction of recolonization capacities. However, deltamethrin had no effect on orientation behavior toward aphid-infested plants for adults that survived a residual exposure to the insecticide. The impact of deltamethrin on recolonization via pupal emergence and interest in the methodology used are discussed.

Host availability affects the interaction between pupal parasitoid Coptera haywardi (Hymenoptera: Diiapridae) and larval-pupal parasitoid Diachasmimorpha longicaudata (Hymenoptera: Braconidae).

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Montoya, P; Gálvez, C; Díaz-Fleischer, F

2018-02-12

The use of multiple species in biological control programmes is controversial when interactions among them are not fully understood. We determined the response of the pupal parasitoid Coptera haywardi (Oglobin) to different availability of Anastrepha ludens (Loew) pupae previously parasitized or not by larval-pupal Diachasmimorpha longicaudata (Ashmead). The two types of pupae were exposed at different ages and proportions to different numbers of C. haywardi females for 48 h. The performance of C. haywardi adults emerging from parasitized and unparasitized pupae was measured. Coptera haywardi prefers to attack unparasitized A. ludens pupae rather than pupae parasitized by D. longicaudata. However, when the availability of unparasitized pupae was low or the number of foraging females was high, C. haywardi competed against early immature stages of the D. longicaudata, or hyperparasitized, feeding directly on the advanced-immature developmental stages of the early acting species. Adults of C. haywardi emerging as hyperparasitoids were no different in size, fecundity and longevity from those emerging as primary parasitoids. Our data suggest that simultaneous use of these species in augmentative biological control projects may be feasible but should be carefully planned in order to avoid any detrimental effect of its interaction.

Trophic assimilation efficiency markedly increases at higher trophic levels in four-level host-parasitoid food chain.

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Sanders, Dirk; Moser, Andrea; Newton, Jason; van Veen, F J Frank

2016-03-16

Trophic assimilation efficiency (conversion of resource biomass into consumer biomass) is thought to be a limiting factor for food chain length in natural communities. In host-parasitoid systems, which account for the majority of terrestrial consumer interactions, a high trophic assimilation efficiency may be expected at higher trophic levels because of the close match of resource composition of host tissue and the consumer's resource requirements, which would allow for longer food chains. We measured efficiency of biomass transfer along an aphid-primary-secondary-tertiary parasitoid food chain and used stable isotope analysis to confirm trophic levels. We show high efficiency in biomass transfer along the food chain. From the third to the fourth trophic level, the proportion of host biomass transferred was 45%, 65% and 73%, respectively, for three secondary parasitoid species. For two parasitoid species that can act at the fourth and fifth trophic levels, we show markedly increased trophic assimilation efficiencies at the higher trophic level, which increased from 45 to 63% and 73 to 93%, respectively. In common with other food chains, δ(15)N increased with trophic level, with trophic discrimination factors (Δ(15)N) 1.34 and 1.49‰ from primary parasitoids to endoparasitic and ectoparasitic secondary parasitoids, respectively, and 0.78‰ from secondary to tertiary parasitoids. Owing to the extraordinarily high efficiency of hyperparasitoids, cryptic higher trophic levels may exist in host-parasitoid communities, which could alter our understanding of the dynamics and drivers of community structure of these important systems. © 2016 The Authors.

The Effect of Target Sex, Sexual Dimorphism, and Facial Attractiveness on Perceptions of Target Attractiveness and Trustworthiness

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Yuanyan Hu

2018-06-01

Full Text Available Facial sexual dimorphism has widely demonstrated as having an influence on the facial attractiveness and social interactions. However, earlier studies show inconsistent results on the effect of sexual dimorphism on facial attractiveness judgments. Previous studies suggest that the level of attractiveness might work as a moderating variable among the relationship between sexual dimorphism and facial preference and have often focused on the effect of sexual dimorphism on general attractiveness ratings, rather than concentrating on trustworthiness perception. Male and female participants viewed target male and female faces that varied on attractiveness (more attractive or less attractive and sexual dimorphism (masculine or feminine. Participants rated the attractiveness of the faces and reported how much money they would give to the target person as a measure of trust. For the facial attractiveness ratings, (a both men and women participants preferred masculine male faces to feminine male ones under the more attractive condition, whereas preferred feminine male faces to masculine male ones under the less attractive condition; (b all participants preferred feminine female faces to masculine female ones under the less attractive condition, while there were no differences between feminine female faces and masculine female faces under the more attractive condition. For the target trustworthiness perception, (a participants showed no preference between masculine male faces and feminine male faces, neither under the more attractive condition nor the less attractiveness condition; (b however, all the participants preferred masculine female faces over feminine female faces under the more attractive condition, exhibiting no preference between feminine female faces and masculine female faces under the less attractive condition. These findings suggest that the attractiveness of facial stimulus may be a reason to interpret the inconsistent results from the

Infection of army ant pupae by two new parasitoid mites (Mesostigmata: Uropodina

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Adrian Brückner

2017-10-01

Full Text Available A great variety of parasites and parasitoids exploit ant societies. Among them are the Mesostigmata mites, a particularly common and diverse group of ant-associated arthropods. While parasitism is ubiquitous in Mesostigmata, parasitoidism has only been described in the genus Macrodinychus. Yet information about the basic biology of most Macrodinychus species is lacking. Out of 24 formally described species, information about basic life-history traits is only available for three species. Here we formally describe two new Macrodinychus species, i.e. Macrodinychus hilpertae and Macrodinychus derbyensis. In both species, immature stages developed as ecto-parasitoids on ant pupae of the South-East Asian army ant Leptogenys distinguenda. By piercing the developing ant with their chelicera, the mites apparently suck ant hemolymph, ultimately killing host individuals. We compare infection rates among all studied Macrodinychus species and discuss possible host countermeasures against parasitoidism. The cryptic lifestyle of living inside ant nests has certainly hampered the scientific discovery of Macrodinychus mites and we expect that many more macrodinychid species await scientific discovery and description.

Infection of army ant pupae by two new parasitoid mites (Mesostigmata: Uropodina).

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Brückner, Adrian; Klompen, Hans; Bruce, Andrew Iain; Hashim, Rosli; von Beeren, Christoph

2017-01-01

A great variety of parasites and parasitoids exploit ant societies. Among them are the Mesostigmata mites, a particularly common and diverse group of ant-associated arthropods. While parasitism is ubiquitous in Mesostigmata, parasitoidism has only been described in the genus Macrodinychus . Yet information about the basic biology of most Macrodinychus species is lacking. Out of 24 formally described species, information about basic life-history traits is only available for three species. Here we formally describe two new Macrodinychus species, i.e. Macrodinychus hilpertae and Macrodinychus derbyensis . In both species, immature stages developed as ecto-parasitoids on ant pupae of the South-East Asian army ant Leptogenys distinguenda . By piercing the developing ant with their chelicera, the mites apparently suck ant hemolymph, ultimately killing host individuals. We compare infection rates among all studied Macrodinychus species and discuss possible host countermeasures against parasitoidism. The cryptic lifestyle of living inside ant nests has certainly hampered the scientific discovery of Macrodinychus mites and we expect that many more macrodinychid species await scientific discovery and description.

Hymenopteran parasitoids associated with frugivorous larvae in a Brazilian caatinga-cerrado ecotone.

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De Souza, A R; Lopes-Mielezrski, G N; Lopes, E N; Querino, R B; Corsato, C D A; Giustolin, T A; Zucchi, R A

2012-04-01

The purpose of this study was to investigate native species of parasitoids of frugivorous larvae and their associations with host plants in commercial guava orchards and in typical native dry forests of a caatinga-cerrado ecotone in the State of Minas Gerais, Brazil. Nine species of parasitoids were associated with larvae of Anastrepha (Tephritidae) and Neosilba (Lonchaeidae) in fruit of Psidium guajava L. (Myrtaceae), Ziziphus joazeiro Mart. (Rhamnaceae), Spondias tuberosa Arruda (Anacardiaceae), Spondias dulcis Forst. (Anacardiaceae), Syzygium cumini (L.) Skeels (Myrtaceae), and Randia armata (Sw.) DC. (Rubiaceae). Doryctobracon areolatus was the most abundant species, obtained from puparia of Anastrepha zenildae, An. sororcula, An. fraterculus, An. obliqua, and An. turpiniae. This is the first report of Asobara obliqua in Brazil and of As. anastrephae and Tropideucoila weldi in dry forests of Minas Gerais State. The number of species of parasitoids was higher in areas with greater diversity of cultivated species and lower pesticide use. The forest fragments adjacent to the orchards served as shelter for parasitoids of frugivorous larvae.

First records of parasitoids attacking the Asian citrus psyllid in Ecuador

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Diego E. Portalanza

Full Text Available ABSTRACT First records of parasitoids attacking the Asian citrus psyllid in Ecuador. The objective of the current study was to investigate the presence of natural enemies of Diaphorina citri (Hemiptera: Liviidae (the Asian citrus psyllid in Ecuador. Incidence of parasitoid Diaphorencyrtus aligarhensis (Hymenoptera: Encyrtidae was assessed between November 2015 and March 2016, in Letamendi, Febres-Cordero and Tarqui, urban districts of Guayaquil. Highest incidence of parasitism occurred in those regions and seasons of the year with the highest temperatures commensurate with increase of citrus plant shoots. Similar to their host, these parasitoids appear to have established in Ecuador by accident, and were not the result of purposeful introduction. This fortuitous introduction is a potentially helpful tool in controlling the Asian citrus psyllid, and potentially Huanglongbing.

Identification and characterization of bacterial symbionts in three species of filth fly parasitoids.

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Betelman, Kfir; Caspi-Fluger, Ayelet; Shamir, Maayan; Chiel, Elad

2017-09-01

Facultative bacterial symbionts are widespread among insects and have diverse effects on their biology. Here, we focused on bacterial symbionts of three ecologically and economically important filth flies parasitoid species-Spalangia cameroni, Spalangia endius and Muscidifurax raptor. Both Spalangia species harbored a Sodalis bacterium that is closely related to Spalangia praecaptivus (a free-living bacterium) and to Sodalis symbionts of weevils. This is the only case of Sodalis infection in the important order Hymenoptera. We also found, for the first time in this parasitoid guild, a Rickettsia infecting the two Spalangia spp., albeit in much higher prevalence in S. cameroni. Molecular and phylogenetic analyses revealed that it is closely related to Rickettsia felis and other Rickettsia species from the 'transitional' group. All three parasitoid species harbored Wolbachia. Using multi-locus sequence typing, we found that M. raptor harbors a single Wolbachia strain whereas the Spalangia spp. have multiple strains. By controlled crossings, we found that Wolbachia infection in S. endius causes incomplete cytoplasmic incompatibility and increased longevity, thereby promoting Wolbachia's spread. In contrast, no effects of Wolbachia on the reproduction and longevity of M. raptor were found. This study underscores the diversity and nature of symbiotic interactions between microbes and insects. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Interactions to the fifth trophic level: secondary and tertiary parasitoid wasps show extraordinary efficiency in utilizing host resources

NARCIS (Netherlands)

Harvey, J.A.; Wagenaar, R.; Bezemer, T.M.

2009-01-01

1. Parasitoid wasps are highly efficient organisms at utilizing and assimilating limited resources from their hosts. This study explores interactions over three trophic levels, from the third (primary parasitoid) to the fourth (secondary parasitoid) and terminating in the fifth (tertiary

Primary and secondary parasitoids (Hymenoptera) of aphids (Hemiptera: Aphididae) on blueberry and other Vaccinium in the Pacific Northwest.

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Raworth, D A; Pike, K S; Tanigoshi, L K; Mathur, S; Graf, G

2008-04-01

Blueberry scorch virus, a commercially important Carlavirus in highbush blueberry, Vaccinium corymbosum L., is vectored by aphids (Hemiptera: Aphididae). We surveyed the aphids, primary parasitoids (Hymenoptera: Aphelinidae, Braconidae), and associated secondary parasitoids (Hymenoptera: Charipidae, Megaspilidae, Pteromalidae) on highbush blueberry and other Vaccinium in the Pacific Northwest from 1995 to 2006, with samples concentrated in 2005 and 2006, to lay the groundwork for augmentative biological control. Ericaphis fimbriata (Richards) was the principal aphid. The dominant parasitoid species were Praon unicum Smith, Aphidius n. sp., A. sp., and Aphidius ervi Haliday. Their frequency in relation to the other primary parasitoids varied significantly with geographical area; P. unicum dominated the frequency distribution in southwestern British Columbia, A. n. sp., west of the Cascades, and A. sp. and A. ervi east of the Cascades. Among the secondary parasitoids, pteromalids dominated, and their frequency in relation to the other secondary parasitoids was lowest in southwestern British Columbia. The parasitization rate for P. unicum and A. n. sp. in southwestern British Columbia increased from May or June to a maximum of 0.080 +/- 0.024 and 0.090 +/- 0.084 (SD), respectively, in late July or early August. P. unicum emerged in the spring 4 wk before A. n. sp. The parasitization rate for P. unicum was lower in conventional than organic fields. Whereas aphid density increased monotonically, P. unicum had two spring peaks. A simulation model showed that these peaks could reflect discrete generations. Releases of insectary-reared P. unicum at 150 or 450 DD above 5.6 degrees C, summing from 1 January, may effectively augment the natural spring populations by creating overlapping generations.

Effects of student physical attractiveness

OpenAIRE

Krnjajić Stevan B.

2005-01-01

Implicit personality theories suggest that people draw conclusions about other persons by using a relatively small number of visible features. The formation of "the first impression" is influenced by the factors, such as sex, age, appearances, race or nationality. Frequently, conclusions based on those factors lead to developing social stereotypes. Attractiveness is a good example of "the first impression" effect, because physical attractiveness entails the creation of impression about anothe...

Predators and parasitoids of Cacopsylla pyri (L.) (Hemiptera: Psyllidae) in Serbia

OpenAIRE

Jerinić-Prodanović Dušanka; Protić Ljiljana; Mihajlović Ljubodrag

2010-01-01

The presence of C. pyri and its natural enemies was studied in both treated and untreated pear orchards in Serbia from 2005 to 2009. Five parasitoid and 21 predator species were identified as present on a considerable number of sites. The following parasitoid species were found: Prionomitus mitratus (Dalman), Psyllaephagus procerus Marcet, Syrphophagus ariantes (Walker), Syrphophagus taeniatus (Forster) and Tamarixia sp. In the study, the species Psyllaephagus procerus, Syrphophagus ariantes ...

Conservation of Agroecosystem through Utilization of Parasitoid Diversity: Lesson for Promoting Sustainable Agriculture and Ecosystem Health

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DAMAYANTI BUCHORI

2008-12-01

Full Text Available For many years, agricultural intensification and exploitation has resulted in biodiversity loss and threaten ecosystem functioning. Developing strategies to bridge human needs and ecosystem health for harmonization of ecosystem is a major concern for ecologist and agriculturist. The lack of information on species diversity of natural enemies and how to utilize them with integration of habitat management that can renovate ecological process was the main obstacle. Parasitoids, a group of natural enemies, play a very important role in regulating insect pest population. During the last ten years, we have been working on exploration of parasitoid species richness, how to use it to restore ecosystem functions, and identifying key factors influencing host-parasitoid interaction. Here, we propose a model of habitat management that is capable of maintaining agricultural biodiversity and ecosystem functions. We present data on parasitoid species richness and distribution in Java and Sumatera, their population structure and its impact toward biological control, relationship between habitat complexes and parasitoid community, spatial and temporal dynamic of parasitoid diversity, and food web in agricultural landscape. Implications of our findings toward conservation of agroecosystem are discussed.

Biological Control of Solenopsis Fire Ants by Pseudacteon Parasitoids: Theory and Practice

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Lloyd W. Morrison

2012-01-01

Full Text Available Pseudacteon parasitoids are potential biocontrol agents of invasive Solenopsis fire ants. Pseudacteon species that parasitize the invasive S. invicta Buren and S. richteri Forel have been introduced to, and naturally dispersed across, the southeastern USA, although there is no evidence yet that Solenopsis host ant populations have decreased. The ability of introduced Pseudacteon species to regulate Solenopsis populations will depend upon the relative importance of top-down effects in the recipient communities. In this paper, I examine the characteristics of the Pseudacteon/Solenopsis parasitoid/host system and evaluate the extent to which research findings are consistent with top-down control. Laboratory and field experiments evaluating Solenopsis population regulation have been equivocal, and overall the available evidence provides little support for strong top-down effects in this system. Competitive exclusion may occur among introduced Pseudacteon species, and future efforts at biological control are likely to be more efficacious if they focus on other types of natural enemies.

Best Host Age of Anastrepha obliqua (Diptera: Tephritidae) for Multiplication of Four Native Parasitoids from the Americas

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Poncio, S; Montoya, P; Cancino, J; Nava, D E

2018-01-01

Abstract The success of the mass rearing of parasitoids is directly related to host quality, and it requires selecting the best biological host age to ensure the optimal performance of the parasitoids released into the field. The larval development of the parasitoids Utetes anastrephae (Viereck) (Hymenoptera: Braconidae) and Odontosema anastrephae Borgmeier (Hymenoptera: Eucoilidae) and the pupal development of the parasitoids Coptera haywardi (Ogloblin) (Hymenoptera: Diapriidae) and Dirhinus sp. (Hymenoptera: Chalcididae) on the native host Anastrepha obliqua (Macquart) (Diptera: Tephritidae) in different larvae and pupae ages were investigated under laboratory conditions. Not all parasitoid species developed with the same efficiency in immature individuals of A. obliqua; U. anastrephae and C. haywardi showed the higher parasitism rates. The emergence and parasitism of U. anastrephae were equal using larvae from 5 to 8 d, while C. haywardi reared in 1- to 8-d-old pupae showed higher averages of parasitism. These results suggest that native parasitoids can be used to strengthen the implementation of biological control projects against A. obliqua, a pest of economic importance in South America.

Botanical insecticides on Liriomyza huidobrensis Blanchard (Diptera: Agromyzidae and its parasitoids in string beans cultivated in a plastic greenhouse

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Sônia Thereza Bastos Dequech

2010-06-01

Full Text Available The string bean (Phaseolus vulgaris L. is Sul. Liriomyza huidobrensis (Dip.: Agromyzidae is one of the most important insect pests occurring in this culture. This research was conducted to evaluate the effect of aqueous extracts of plants and the commercial product DalNeem on L. huidobrensis and its parasitoids, as well as to analyse the population fluctuation of L. huidobrensis and parasitoids of this insect pest. The experiment was carried out on string beans cultivated in a greenhouse, where in each of the four central lines of culture, five plots were established with five plants per plot. The experimental design was random blocks with four replications. DalNeem was the treatment that best controlled L. huidobrensis. On the other hand, the treatments did not affect the parasitoids Chrysocharis bedius (Hym.: Eulophidae or Opius sp. (Hym.: Braconidae. In plants without the use of these treatments, the population of L. huidobrensis exhibited a sharp decline with the increase of the parasitoids C. bedius, Opius sp., Eucoilinae (Hym.: Figitidae and Diptera.

THE INFLUENCE OF CULTURAL PRACTICE ON POPULATION OF PEA LEAFMINER (Liriomyza huidobrensis AND ITS PARASITOIDS IN POTATO

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Ida Bagus Gde Suryawan

2016-10-01

Full Text Available Pea leafminer (Liriomyza huidobrensis is the major pest of potato crop in Indonesia. The use of insecticides to control the pest is ineffective and harmful to the natural enemies. The study aimed to find out a promising cultural practice for leafminer management on potato crop. The study was conducted at a farmer’s field in Bali in 2004. Potato plants (Granola variety were grown in a raised-bed plot of 10 m x 1 m. The treatments evaluated were standard cultural practice (C, C plus reflective plastic mulch (RPM (CM, farmer’s practice (F, vermicompost (V, and V plus RPM (VM. All treatments were arranged in RCBD with five replications. From each plot, 10 plant samples were randomly taken to observe the presence of larvae, mines, and adults. Larvae and adults of leafminer and mines were separately counted from the top, middle, and bottom parts of the plant samples. Parasitoids were collected from the infested leaves of the plant samples. Emerged parasitoids were counted and put into vials with 70% ethyl alcohol and then identified. The results showed that the population of adults, larvae of L. huidobrensis, and mines were less in C, CM, V, and VM treatments compared to farmer's practice (F. However, RPM (CM and VM treatments significantly reduced population of leafminer and mines. The highest population of adults, larvae, and mines on RPM treatment were less than 1.5, 8.5, and 10 per plant, respectively compared to other treatments which were greater than 3.2 for adults, 12.4 for larvae, and 12.7 for mines. Parasitoid population and parasitism level were more in vermicompost treatments (V and VM compared to other treatments (C, CM, and F. The results showed that application of pesticides was ineffective against leafminer and reduced parasitoid population; in the other hand RPM was effective to control leafminer although the effect on parasitoids was not clear. Parasitoid species that were found associated with potato crop were Hemiptarsenus

Lepidopterans and their parasitoids on okra plants in Riberão Preto (SP, Brazil Lepidópteros e seus parasitoides em cultura de quiabo em Ribeirão Preto, SP, Brasil

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Rogéria Inês Rosa Lara

2012-04-01

Full Text Available The aim of this study was to identify the defoliating lepidopterans and their parasitoids occurring on okra plants in the district of Riberão Preto city (SP. Brazil. Caterpillars were collected by hand from an experimental field of okra, in March and April, 2009. They were placed individually on Petri dishes lined with wet filter paper, containing shredded okra leaves, and kept in a climactic chamber (25±1°C, 12:12h light/dark photoperiod, RH 70±10% until the emergence of lepidopterans and/or parasitoids. In all, 63 lepidopterans were obtained: three species of Noctuidae, Anomis flava (Fabricius, Spodoptera frugiperda (Smith and Pseudoplusia includens (Walker; one of Pieridae, Ascia monuste orseis (Godart, and an unidentified species of Tortricidae. One unidentified tachinid fly (Diptera and the Hymenoptera parasitoids Copidosoma floridanum (Ashmead (Encyrtidae and Euplectrus sp. (Eulophidae emerged from A. flava, while C. floridanum and an unidentified tachinid, from P. includens. This is the first report of an association between the herbivores S. frugiperda, P. includens and A. monuste orceis, the parasitoids C. floridanum and Euplectrus sp. on okra plants.Este estudo objetivou identificar lepidópteros desfolhadores e seus parasitoides em cultura de quiabo em Ribeirão Preto, SP, Brasil. As lagartas foram coletadas através de catação manual entre março e abril de 2009, individualizadas em placas de Petri forradas com papel filtro umedecido contendo pedaços de folhas de quiabo e mantidas sob condições controladas (25±1°C, 12 horas de fotofase, 70±10% de UR até a obtenção dos adultos de lepidópteros e/ou de seus parasitoides. Foram obtidos 63 adultos de lepidópteros: três espécies de Noctuidae, Anomis flava (Fabricius, Spodoptera frugiperda (Smith, Pseudoplusia includens (Walker, uma de Pieridae, Ascia monuste orseis (Godart e uma de Tortricidae não identificada. Uma espécie não identificada de taquinídeo (Diptera e os

Impact of terbufos on Cotesia flavipes, a parasitoid of Diatraea saccharalis

International Nuclear Information System (INIS)

Vargas, E.; Valverde, B.; Carazo, E.

1999-01-01

The effect of terbufos on larvae of Diatraea saccharalis and its parasitoid, Cotesia flavipes was evaluated in the laboratory. Bioassays were conducted to determine the dose response of non-parasitized larvae of D. saccharalis feeding on artificial diet contaminated with terbufos. From the dose-response curve based on larval fresh weight, sublethal doses ranging from 1.32 ppm to 108 ppm of terbufos were selected for further studying the effect of the insecticide on both species. Both parasitized and non-parasitized larvae were exposed to the selected sublethal doses of terbufos in the diet. Consumption of the insecticide by the host resulted in mortality of the parasitoid, increased length of its larval and pupal periods, decreased adult fresh weight and changes in sex proportions. These negative effects were more severe as the dose of the insecticide increased. D. saccharalis was also affected by terbufos; larvae showed abnormalities, the length of the larval and pupal periods increased and the proportion of the females was reduced. In a preliminary greenhouse bioassay, only traces of terbufos or its metabolites were found in treated maize plants and in tissue of D. saccharalis larvae feeding on them. (author)

POTENTIAL IMPACT OF METARHIZIUM ANISOPLIAE ON THE DIAMONDBACK MOTH (LEPIDOPTERA: PLUTELLIDAE AND ITS PARASITOID DIADEGMA SEMICLAUSUM (HYMENOPTERA: ICHNEUMONIDAE

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Rosma Hasibuan, Nilly Christalia, F.X. Susilo1, and Nur Yasin .

2011-11-01

Full Text Available Potential Impact of Metarhizium anisopliae on the Diamondback Moth (Lepidoptera: Plutellidae and Its Parasitoid Diadegma semiclausum (Hymenoptera: Ichneumonidae.  Laboratory studies were conducted to evaluate the effect of the Metarhizium anisopliae against the diamondback moth, Plutella xylostella and its parasitoid, Diadegma  semiclausum. A completely randomized design consisted of 5 treatments (4 concentrations of conidial suspension: 5 x 104, 3.5 x 105, 2.5 x 106, 1.2 x 107 conidia/ml and control was used.  The results indicated that the mortality of P. xylostella larvae were significantly induced by the fungal treatments.  A significant reduction in pupation and adult emergence of P. xylostella was also detected in all treatments when compared with that in the control. The fungus might also result in a male-biased sex ratio of the surviving P. xylostella. When applied at a concentration of 1.2 x 107 conidia/ml, M.  anisopliae might significantly reduce the survival of the parasitoid, D. semiclausum. Thus, despite its potential as a biological control agent against P. xylostella, the entomomogenous fungus M. anisopliae was also detrimental to the larvae parasitoid D. semiclausum.

Effects of physical attractiveness on political beliefs.

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Peterson, Rolfe Daus; Palmer, Carl L

2017-01-01

Physical attractiveness is an important social factor in our daily interactions. Scholars in social psychology provide evidence that attractiveness stereotypes and the "halo effect" are prominent in affecting the traits we attribute to others. However, the interest in attractiveness has not directly filtered down to questions of political behavior beyond candidates and elites. Utilizing measures of attractiveness across multiple surveys, we examine the relationship between attractiveness and political beliefs. Controlling for socioeconomic status, we find that more attractive individuals are more likely to report higher levels of political efficacy, identify as conservative, and identify as Republican. These findings suggest an additional mechanism for political socialization that has further implications for understanding how the body intertwines with the social nature of politics.

Impact of insecticides on parasitoids of the leafminer, Liriomyza trifolii, in pepper in south Texas.

Science.gov (United States)

Hernández, Ricardo; Harris, Marvin; Liu, Tong-Xian

2011-01-01

Liriomyza leafminers (Diptera: Agromyzidae) are cosmopolitan, polyphagous pests of horticultural plants and many are resistant to insecticides. Producers in South Texas rely on insecticides as the primary management tool for leafminers, and several compounds are available. The objective of this study is to address the efficacy of these compounds for controlling Liriomyza while minimizing their effects against natural enemies. Research plots were established at Texas AgriLife research center at Weslaco, Texas in fall 2007 and spring 2008 seasons, and peppers were used as a model crop. Plots were sprayed with novaluron, abamectin, spinetoram, lambda-cyhalothrin and water as treatments according to leafminer infestation; insecticide efficacy was monitored by collecting leaves and infested foliage. Plant phenology was also monitored. Novaluron was the most effective insecticide and lambda-cyhalothrin showed resurgence in leafminer density in fall 2007 and no reduction in spring 2008. Other compounds varied in efficacy. Novaluron showed the least number of parasitoids per leafminer larva and the lowest parasitoid diversity index among treatments followed by spinetoram. Liriomyza trifolii (Burgess) was the sole leafminer species on peppers, and 19 parasitoid species were found associated with this leafminer. Application of these insecticides for management of leafminers with conservation of natural enemies is discussed.

Different approaches to labelling parasitoids using strontium

NARCIS (Netherlands)

Gu, H.; Wäckers, F.L.; Steindl, P.; Günther, D.; Dorn, S.

2001-01-01

Labelling parasitoids with trace elements is a potentially powerful technique for studying dispersal and trophic interactions in these usually small insects. Laboratory experiments were conducted to investigate the feasibility and efficiency of different methods for trace element labelling of the

Predatory behavior of long-legged flies (Diptera:Dolichopodidae) and their potential negative effects on the parasitoid biological control agent of the Asian citrus psyllid (Hemiptera:Liviidae)

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Impact of biological control agents such as parasitoids can be improved by determining best times for release when predation pressures will be reduced. Large populations of long-legged predatory flies (Diptera: Dolichopodidae) impose heavy predation pressure on inundative releases of the parasitoid ...

Inter and intra-guild interactions in egg parasitoid species of the soybean stink bug complex

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Sujii Edison Ryoiti

2002-01-01

Full Text Available The objective of this research was to evaluate the parasitism behavior of Telenomus podisi Ashmead, Trissolcus basalis (Wollaston e Trissolcus urichi Crawford (Hymenoptera: Scelionidae on eggs of Nezara viridula L., Euschistus heros F., Piezodorus guildinii Westwood and Acrosternum aseadum Rolston (Heteroptera: Pentatomidae, in no choice and multiple choice experiments. For all parasitoid species, the results demonstrated the existence of a main host species that maximizes the reproductive success. The competitive interactions among the parasitoid species were investigated in experiments of sequential and simultaneous release of different combinations of parasitoid pairs on the hosts N. viridula, E. heros and A. aseadum. Exploitative competition was observed for egg batches at the genus level (Telenomus vs. Trissolcus and interference competition at the species level (T. basalis vs. T. urichi. Trissolcus urichi was the most aggressive species, interfering with the parasitism of T. basalis. Generally, T. basalis showed an opportunistic behavior trying to parasitise eggs after T. urichi had abandoned the egg batch. The selection of parasitoid species for use in augmentative biological control programs should take into account the diversity of pentatomids present in soybean in addition to the interactions among the different species of parasitoids.

Fire ant venom alkaloids act as key attractants for the parasitic phorid fly, Pseudacteon tricuspis (Diptera: Phoridae)

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Chen, Li; Sharma, Kavita R.; Fadamiro, Henry Y.

2009-12-01

The phorid fly, Pseudacteon tricuspis Borgmeier, is an introduced parasitoid of imported fire ants, Solenopsis spp., in the USA. Although the assumption that phorid flies use fire ant alarm pheromones for host location is probably true, we demonstrated in a previous study the possible involvement of other ant semiochemicals in the response of P. tricuspis to fire ants. This study was conducted to determine the glandular sources and identity of the semiochemicals mediating this interaction. First, we tested the electroantennogram response of P. tricuspis to extracts of key body parts and glands of workers of the red imported fire ant, S. invicta Buren. The results confirm that the poison (venom) gland/sac is the key source of compounds which elicited strong antennal activity in P. tricuspis. Follow-up studies were conducted by using a combination of bioassay-guided fractionation and behavioral bioassays to test the hypothesis that attraction of this parasitoid to fire ants is mediated by venom alkaloids. The results confirm the response of P. tricuspis to physiologically relevant amounts of the two venom alkaloid fractions ( cis and trans alkaloid fractions) of S. invicta. Further analysis by coupled gas chromatography-electroantennogram detection revealed nine venom alkaloid components including two novel 2,6-dialkylpiperideines that elicited significant antennal activity in P. tricuspis. This is the first demonstration of the role of venom alkaloids of ants as attractants for their natural enemies. We propose a semiochemical-mediated host location mechanism for P. tricuspis involving both alarm pheromones and venom alkaloids. The ecological significance of these findings, including the attraction of male P. tricuspis to fire ant venom alkaloids, possibly for mate location, is discussed.

Do Biopesticides Affect the Demographic Traits of a Parasitoid Wasp and Its Biocontrol Services through Sublethal Effects?

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Biondi, Antonio; Zappalà, Lucia; Stark, John D.; Desneux, Nicolas

2013-01-01

Pesticide risk assessments are usually based on short-term acute toxicity tests, while longer-term population dynamic related traits, critical to the success of biological control and Integrated Pest Management (IPM) programs, are often overlooked. This is increasingly important with respect to new biopesticides that frequently cause no short-term acute effects, but that can induce multiple physiological and behavioral sublethal effects, leading to a decrease in population growth and ecosystem services. In this study we assessed the lethal and sublethal effects of six biopesticides [abamectin, azadirachtin, Bacillus thuringiensis, borax plus citrus oil (Prev-Am®), emamectin benzoate, and spinosad], used in tomato crops to control the invasive pest Tuta absoluta (Lepidoptera: Gelechiidae), on adults and pupae of the parasitoid Bracon nigricans (Hymenoptera: Braconidae). Data on female survival and production of female offspring were used to calculate population growth indexes as a measure of population recovery after pesticide exposure. Spinosad caused 100% and 80% mortality in exposed adults (even 10 d after the treatment) and pupae, respectively. Although most of the biopesticides had low levels of acute toxicity, multiple sublethal effects were observed. The biocontrol activity of both females that survived 1-h and 10-d old residues, and females that emerged from topically treated pupae was significantly affected by the application of the neurotoxic insecticides emamectin benzoate and abamectin. Furthermore, very low B. nigricans demographic growth indices were estimated for these two insecticides, indicating potential local extinction of the wasp populations. Among the tested products, Bt proved to be the safest for B. nigricans adults and pupae. Our findings emphasize that acute toxicity assessment alone cannot fully predict the actual impact of pesticides on non-target parasitoids. Thus, sublethal effects related to the species specific life-history variables

Botanical insecticides on Liriomyza huidobrensis Blanchard (Diptera: Agromyzidae and its parasitoids in string beans cultivated in a plastic greenhouse

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Sônia Thereza Bastos Dequech

2010-04-01

Full Text Available The string bean (Phaseolus vulgaris L. is one of the most cultivated vegetables in plastic greenhouses in the central region of the state of Rio Grande do Sul. Liriomyza huidobrensis (Dip.: Agromyzidae is one of the most important insect pests occurring in this culture. This research was conducted to evaluate the effect of aqueous extracts of plants and the commercial product DalNeem on L. huidobrensis and its parasitoids, as well as to analyse the population fluctuation of L. huidobrensis and parasitoids of this insect pest. The experiment was carried out on string beans cultivated in a greenhouse, where in each of the four central lines of culture, five plots were established with five plants per plot. The experimental design was random blocks with four replications. DalNeem was the treatment that best controlled L. huidobrensis. On the other hand, the treatments did not affect the parasitoids Chrysocharis bedius (Hym.: Eulophidae or Opius sp. (Hym.: Braconidae. In plants without the use of these treatments, the population of L. huidobrensis exhibited a sharp decline with the increase of the parasitoids C. bedius, Opius sp., Eucoilinae (Hym.: Figitidae and Diptera.

The Endosymbiont Arsenophonus Is Widespread in Soybean Aphid, Aphis glycines, but Does Not Provide Protection from Parasitoids or a Fungal Pathogen

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Wulff, Jason A.; Buckman, Karrie A.; Wu, Kongming; Heimpel, George E.; White, Jennifer A.

2013-01-01

Aphids commonly harbor bacterial facultative symbionts that have a variety of effects upon their aphid hosts, including defense against hymenopteran parasitoids and fungal pathogens. The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is infected with the symbiont Arsenophonus sp., which has an unknown role in its aphid host. Our research goals were to document the infection frequency and diversity of the symbiont in field-collected soybean aphids, and to determine whether Arsenophonus is defending soybean aphid against natural enemies. We performed diagnostic PCR and sequenced four Arsenophonus genes in soybean aphids from their native and introduced range to estimate infection frequency and genetic diversity, and found that Arsenophonus infection is highly prevalent and genetically uniform. To evaluate the defensive role of Arsenophonus, we cured two aphid genotypes of their natural Arsenophonus infection through ampicillin microinjection, resulting in infected and uninfected isolines within the same genetic background. These isolines were subjected to parasitoid assays using a recently introduced biological control agent, Binodoxys communis [Braconidae], a naturally recruited parasitoid, Aphelinus certus [Aphelinidae], and a commercially available biological control agent, Aphidius colemani [Braconidae]. We also assayed the effect of the common aphid fungal pathogen, Pandora neoaphidis (Remaudiere & Hennebert) Humber (Entomophthorales: Entomophthoraceae), on the same aphid isolines. We did not find differences in successful parasitism for any of the parasitoid species, nor did we find differences in P. neoaphidis infection between our treatments. Our conclusion is that Arsenophonus does not defend its soybean aphid host against these major parasitoid and fungal natural enemies. PMID:23614027

Host feeding in insect parasitoids: why destructively feed upon a host that excretes an alternative?

NARCIS (Netherlands)

Burger, J.S.M.; Reijnen, T.M.; Van Lenteren, J.C.; Vet, L.E.M.

2004-01-01

Host feeding is the consumption of host tissue by the adult female parasitoid. We studied the function of destructive host feeding and its advantage over non-destructive feeding on host-derived honeydew in the whitefly parasitoid Encarsia formosa Gahan (Hymenoptera: Aphelinidae). We allowed

Advances and perspectives in the mass rearing of fruit fly parasitoids in Mexico

Energy Technology Data Exchange (ETDEWEB)

Cancino, Jorge; Montoya, Pablo [Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion (DGSV/SENASICA/SAGARPA), Chiapas (Mexico). Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria. Programa Moscamed-Moscafrut

2006-07-01

Biological control by augmentation is applied in Mexico as part of an integrated pest management program against native fruit flies of the genus Anastrepha Schiner. The exotic parasitoid Diachasmimorpha longicaudata has been the most important species used within this context. A program for the mass rearing of 50 million parasitized pupa per week has been established in southeast Mexico, and these are released into the field according to a yearly national plan based on industry requirements. In order to reduce costs and optimize procedures, important advances have been made in the technology for mass production, including an increase in the weight of host larvae (24 mg), changes in the management of host exposition, improvements in the management of environmental conditions, suitability in time and motions are the main areas addressed. Furthermore, a quality control program is routinely applied, and the key parameters under constant evaluation are: 1) weight and volume of host larvae, 2) host mortality after exposure, 3) weight and volume of pupae, and 4) percent parasitoid viability and percent emergence. Good performance in these parameters produces adults with adequate longevity and fecundity, high flight ability and good searching behavior. The introduced egg parasitoid Fopius arisanus and the native pupal parasitoid Coptera hawardi are being evaluated for use in the future as a complement to releases into the field of D. longicaudata. Manipulating host size and exposition time, the use of starting diet and suppressing host development by irradiation, have permitted the effective use of Anastrepha eggs as hosts for the rearing of F. arisanus. Further achievements in the mass rearing of C. haywardi (e.g., the suppression of unparasitized hosts after irradiation), could give us the opportunity to employ new options to reinforce the augmentative biological control of Anastrepha fruit flies in Mexico. (author)

Advances and perspectives in the mass rearing of fruit fly parasitoids in Mexico

International Nuclear Information System (INIS)

Cancino, Jorge; Montoya, Pablo

2006-01-01

Biological control by augmentation is applied in Mexico as part of an integrated pest management program against native fruit flies of the genus Anastrepha Schiner. The exotic parasitoid Diachasmimorpha longicaudata has been the most important species used within this context. A program for the mass rearing of 50 million parasitized pupa per week has been established in southeast Mexico, and these are released into the field according to a yearly national plan based on industry requirements. In order to reduce costs and optimize procedures, important advances have been made in the technology for mass production, including an increase in the weight of host larvae (24 mg), changes in the management of host exposition, improvements in the management of environmental conditions, suitability in time and motions are the main areas addressed. Furthermore, a quality control program is routinely applied, and the key parameters under constant evaluation are: 1) weight and volume of host larvae, 2) host mortality after exposure, 3) weight and volume of pupae, and 4) percent parasitoid viability and percent emergence. Good performance in these parameters produces adults with adequate longevity and fecundity, high flight ability and good searching behavior. The introduced egg parasitoid Fopius arisanus and the native pupal parasitoid Coptera hawardi are being evaluated for use in the future as a complement to releases into the field of D. longicaudata. Manipulating host size and exposition time, the use of starting diet and suppressing host development by irradiation, have permitted the effective use of Anastrepha eggs as hosts for the rearing of F. arisanus. Further achievements in the mass rearing of C. haywardi (e.g., the suppression of unparasitized hosts after irradiation), could give us the opportunity to employ new options to reinforce the augmentative biological control of Anastrepha fruit flies in Mexico. (author)

Immunity of an alternative host can be overcome by higher densities of its parasitoids Palmistichus elaeisis and Trichospilus diatraeae.

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Gilberto Santos Andrade

Full Text Available Interactions of the parasitoids Palmistichus elaeisis Delvare & LaSalle and Trichospilus diatraeae Cherian & Margabandhu (Hymenoptera: Eulophidae with its alternative host Anticarsia gemmatalis (Hübner (Lepidoptera: Noctuidae affect the success or failure of the mass production of these parasitoids for use in integrated pest management programs. The aim of this study was to evaluate changes in the cellular defense and encapsulation ability of A. gemmatalis pupae against P. elaeisis or T. diatraeae in adult parasitoid densities of 1, 3, 5, 7, 9, 11 or 13 parasitoids/pupae. We evaluated the total quantity of circulating hemocytes and the encapsulation rate versus density. Increasing parasitoid density reduced the total number of hemocytes in the hemolymph and the encapsulation rate by parasitized pupae. Furthermore, densities of P. elaeisis above 5 parasitoids/pupae caused higher reduction in total hemocyte numbers. The encapsulation rate fell with increasing parasitoid density. However, parasitic invasion by both species induced generally similar responses. The reduction in defensive capacity of A. gemmatalis is related to the adjustment of the density of these parasitoids to their development in this host. Thus, the role of the density of P. elaeisis or T. diatraeae by pupa is induced suppression of cellular defense and encapsulation of the host, even without them possesses a co-evolutionary history. Furthermore, these findings can predict the success of P. elaeisis and T. diatraeae in the control of insect pests through the use of immunology as a tool for evaluation of natural enemies.

(Brief report Evaluation of Suitable Host Plant, as Banker Plant for Eretmocerus mundus, Whiteflies Parasitoid

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M. J. Ardeh

2016-03-01

Full Text Available Introduction: Whiteflies (Homoptera; Aleyrodidae are the key pests of agricultural crops worldwide. Two species, which seriously damage crops, are the Silver leaf whitefly “Bemisia tabaci (Gennadius” and the Greenhouse whitefly “Trialeorodes vaporariorum (Westwood”. These pests are active on the underside of the leaves where they are relatively protected from insecticide. Moreover, emergence of resistant biotypes of whitelies impose much more costs on its chemical control. Therefore, during falling the past population, several researches have been carried out to find and use efficient biocontrol methods. One of the biocontrol agents to control B. tabaci is “Eretmocerus mundus” (Hy., Aphelinidae. The parasitoid should be introduced to control pest in the greenhouses. One of the methods, which is used in introducing of biological control agents, is ‘Banker Plant System’. In this system, the host plant has a population of reproducing natural enemy used as a reservoir. Therefore, as soon as the pest infection occurs, the parasitoids can find them and control the damage. İn a banker plant system, several aspects should be considered. Some of the behavioral and biological aspects are important. For example characteristics of leaf surface influence on the host finding time of the parasitoid. The biochemical characteristics of the host plants affect the parasitoid fitness. Therefore, we tried to compare these aspects of E. mundus in two host plants (eggplant and cotton from banker plant point of view, to control B. tabaci in the greenhouses. Materials and Methods: The two host plants (eggplant and cotton, were planted in the greenhouse and a culture of B. tabaci was reared on the plants. After two weeks, some of the infested plants were put in separate cages, and the parasitoid, E. mundus, that was collected from the egg plant and cotton fields of the Varamin region were released on the plants. Then, the biological characteristics of

Predators and Parasitoids of Cacopsylla pyri (L. (Hemiptera: Psyllidae in Serbia

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Dušanka Jerinić Prodanović

2010-01-01

Full Text Available The presence of C. pyri and its natural enemies was studied in both treated and untreated pear orchards in Serbia from 2005 to 2009. Five parasitoid and 21 predator species were identified as present on a considerable number of sites. The following parasitoid species were found: Prionomitus mitratus (Dalman,Psyllaephagus procerus Marcet,Syrphophagus ariantes (Walker,Syrphophagus taeniatus Förster and Tamarixia sp. In the study, the species Psyllaephagus procerus,Syrphophagus ariantes and Tamarixia sp. were forthe first time identified as parasitoids of C. pyri and as new species in the Serbian fauna.Among the parasitoids determined, Prionomitus mitratus predominated. Of the predators, the following species in four orders were registered: Dermaptera [Forficula auricularia Linnaeus (Forficulidae], Heteroptera [Anthocoris nemoralis(Fabricius, Anthocoris nemorum (Linnaeus, Orius (Heterorius minutus (Linnaeus, Orius (Heterorius nigerWolff (Anthocoridae, Campylomma verbasci (Mayer-Dür, Deraeocoris (Deraeocorisruber(Linnaeusand Deraeocoris(Knightocarsuslutescens (Schilling(Miridae],Neuroptera[Chrysopa pallens Rambur,Chrysoperla carnea(Stephens,Chrysopa sp.(Chrysopidae], and Coleoptera [Coccinella septempunctata Linnaeus, Adalia bipunctata Linnaeus, Adalia decempunctata(Linnaeus, Hippodamia tredecimpunctata (Linnaeus,Hippodamia variegata(Goeze,Propylea quatuordecimpunctata (Linnaeus, Calvia (Anisocalvia quatuordecimguttata(Linnaeus(Coccinellidae, Cantharis rustica Fallén, Rhagonycha fulva (Scopoli and Rh. testacea(Linnaeus (Cantharidae]. Of the predators determined, 12 species were registered for the first time as predators of C. pyri in Serbia, while C. rustica, Rhagonycha fulva and Rh.testacea have so far been known neither in Serbia nor in the world as predators of pear suckers.

Does being attractive always help? Positive and negative effects of attractiveness on social decision making.

Science.gov (United States)

Agthe, Maria; Spörrle, Matthias; Maner, Jon K

2011-08-01

Previous studies of organizational decision making demonstrate an abundance of positive biases directed toward highly attractive individuals. The current research, in contrast, suggests that when the person being evaluated is of the same sex as the evaluator, attractiveness hurts, rather than helps. Three experiments assessing evaluations of potential job candidates (Studies 1 and 3) and university applicants (Study 2) demonstrated positive biases toward highly attractive other-sex targets but negative biases toward highly attractive same-sex targets. This pattern was mediated by variability in participants' desire to interact with versus avoid the target individual (Studies 1 and 2) and was moderated by participants' level of self-esteem (Study 3); the derogation of attractive same-sex targets was not observed among people with high self-esteem. Findings demonstrate an important exception to the positive effects of attractiveness in organizational settings and suggest that negative responses to attractive same-sex targets stem from perceptions of self-threat.

Modeling Environmental Influences in the Psyllaephagus bliteus (Hymenoptera: Encyrtidae)-Glycaspis brimblecombei (Hemiptera: Aphalaridae) Parasitoid-Host System.

Science.gov (United States)

Margiotta, M; Bella, S; Buffa, F; Caleca, V; Floris, I; Giorno, V; Lo Verde, G; Rapisarda, C; Sasso, R; Suma, P; Tortorici, F; Laudonia, S

2017-04-01

Glycaspis brimblecombei Moore (Hemiptera: Aphalaridae) is an invasive psyllid introduced into the Mediterranean area, where it affects several species of Eucalyptus. Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) is a specialized parasitoid of this psyllid that was accidentally introduced into Italy in 2011. We developed a model of this host-parasitoid system that accounts for the influence of environmental conditions on the G. brimblecombei population dynamics and P. bliteus parasitism rates in the natural ecosystem. The Lotka-Volterra-based model predicts non-constant host growth and parasitoid mortality rates in association with variation in environmental conditions. The model was tested by analyzing sampling data collected in Naples in 2011 (before the parasitoid was present) and defining several environmental patterns, termed Temperature-Rain or T-R patterns, which correspond to the host growth rate. A mean value of the host growth rate was assigned to each T-R pattern, as well as a variation of the parasitoid mortality rate based on temperature thresholds. The proposed model was applied in simulation tests related to T-R patterns carried out with a data series sampled between June 2014 and July 2015 in five Italian sites located in Campania, Lazio, Sicily, and Sardinia regions. The simulation results showed that the proposed model provides an accurate approximation of population trends, although oscillation details may not be apparent. Results predict a 64% reduction in G. brimblecombei population density owing to P. bliteus parasitoid activity. Our results are discussed with respect to features of the host-parasitoid interaction that could be exploited in future biological control programs. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Habitat selection of a parasitoid mediated by volatiles informing on host and intraguild predator densities

DEFF Research Database (Denmark)

Cotes, Belén; Rännbäck, Linda Marie; Björkman, Maria

2015-01-01

both a parasitoid and its host, parasitoids may reduce the risk of intraguild predation (IGP) by avoiding such patches. In this study, we examined whether the presence of the entomopathogenic fungi Metarhizium brunneum and Beauveria bassiana in soil habitats of a root herbivore, Delia radicum, affects...

PERBANDINGAN KEANEKARAGAMAN HYMENOPTERA PARASITOID PADA AGROEKOSISTEM KEDELAI DENGAN APLIKASI DAN TANPA APLIKASI INSEKTISIDA

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Hendrival Hendrival

2017-04-01

Full Text Available Abstrak Sistem pengelolaan tanaman kedelai dengan penggunaan insektisida sintetik yang intensif akan menurunkan keanekaragaman jenis Hymenoptera parasitoid. Penelitian bertujuan untuk memban-dingkan keanekaragaman Hymenoptera parasitoid pada agroekosistem kedelai dengan dan tanpa aplikasi insektisida sintetik. Pengumpulan data serangga menggunakan perangkap dari jaring serangga dan nampan kuning. Hasil penelitian menunjukkan bahwa indeks keanekaragaman jenis pada fase pertumbuhan vegetatif dan generatif kedelai dengan aplikasi insektisida lebih rendah dibandingkan dengan yang tanpa aplikasi insektisida, yang keduanya tergolong sedang. Indeks kemerataan jenis pada fase pertumbuhan vegetatif dan generatif dari kedua agroekosistem kedelai tergolong tinggi. Indeks kekayaan jenis pada fase vegetatif dari agroekosistem kedelai dengan aplikasi insektisida tergolong rendah (0<2,3955≤2,5, sedangkan pada fase generatif tergolong sedang (0<3,6118≤4. Indeks kekayaan jenis pada fase vegetatif (0<2,6229≤4 dan generatif (0<3,8287≤4 dari agroekosistem kedelai tanpa aplikasi insektisida tergolong sedang. Komunitas Hymenoptera parasitoid pada agroekosistem kedelai tanpa aplikasi insektisida memiliki kemiripan lebih rendah daripada yang dengan aplikasi insektisida. Aplikasi insektisida mempengaruhi indeks kekayaan jenis pada fase generatif dan kemiripan komunitasnya, yaitu nilainya lebih rendah daripada yang tanpa insektisida. Abstract The management system of soybean agroecosystem with an intensive use of synthetic insecticides will reduce the diversity of parasitoid Hymenoptera species. The study aimed to compare the diversity of the parasitoids in soybean agroecosystem with and without insecticide application. The collection of the parasitoid used insect net and yellow tray. The results showed that the diversity index of the parasitoids during vegetative and generative growth of the soybean with the insecticide application was lower than the one without

Hymenopteran parasitoids associated with the banana-skipper Erionota thrax L. (Insecta: Lepidoptera, Hesperiidae in Java, Indonesia

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ERNIWATI

2011-04-01

Full Text Available Erniwati, Ubaidillah R (2011 Hymenopteran parasitoids associated with the banana-skipper Erionota thrax L. (Insecta: Lepidoptera, Hesperiidae in Java, Indonesia. Biodiversitas 12: 76-85. Hymenopteran parasitoids of banana-skipper Erionota thrax L. (Insecta: Lepidoptera, Hesperiidae from Java, Indonesia are reviewed and an illustrated key to 12 species is presented to include Theronia zebra zebra, Xanthopimpla gamsura, Casinaria sp., Charops sp., Cotesia (Apanteles erionotae, Brachymeria lasus, B. thracis, Ooencyrtus pallidipes, Anastatus sp., Pediobius erionotae, Agiommatus sumatraensis and Sympiesis sp. The surveys of the natural enemies of the banana-skipper were conducted in 1990-2006 in several localities in Java. The aim of this study was to assess the native natural enemies of E. thrax, especially the parasitic Hymenoptera. Infested eggs, larvae and pupae of E. thrax were collected and reared in the laboratory. Emerging parasitoids were preserved in both dry mounting and in 80% alcohol for the species identification. Members of families Braconidae, Ichneumonidae, Encyrtidae, Pteromalidae, Chalcididae, Eupelmidae and Eulophidae were recorded as parasitoids of the banana skipper E. thrax from Java, Indonesia. Species distribution and alternative hosts of the parasitoids are presented.

Host location by ichneumonid parasitoids is associated with nest dimensions of the host bee species.

Science.gov (United States)

Flores-Prado, L; Niemeyer, H M

2012-08-01

Parasitoid fitness depends on the ability of females to locate a host. In some species of Ichneumonoidea, female parasitoids detect potential hosts through vibratory cues emanating from them or through vibrational sounding produced by antennal tapping on the substrate. In this study, we (1) describe host location behaviors in Grotea gayi Spinola (Hymenoptera: Ichneumonidae) and Labena sp. on nests of Manuelia postica Spinola (Hymenoptera: Apidae), (2) compare nest dimensions between parasitized and unparasitized nests, (3) correlate the length of M. postica nests with the number of immature individuals developing, and (4) establish the relative proportion of parasitized nests along the breeding period of M. postica. Based on our results, we propose that these parasitoids use vibrational sounding as a host location mechanism and that they are able to assess host nest dimensions and choose those which may provide them with a higher fitness. Finally, we discuss an ancestral host-parasitoid relationship between Manuelia and ichneumonid species.

Genomic and karyotypic variation in Drosophila parasitoids (Hymenoptera, Cynipoidea, Figitidae

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Vladimir Gokhman

2011-08-01

Full Text Available Drosophila melanogaster Meigen, 1830 has served as a model insect for over a century. Sequencing of the 11 additional Drosophila Fallen, 1823 species marks substantial progress in comparative genomics of this genus. By comparison, practically nothing is known about the genome size or genome sequences of parasitic wasps of Drosophila. Here, we present the first comparative analysis of genome size and karyotype structures of Drosophila parasitoids of the Leptopilina Förster, 1869 and Ganaspis Förster, 1869 species. The gametic genome size of Ganaspis xanthopoda (Ashmead, 1896 is larger than those of the three Leptopilina species studied. The genome sizes of all parasitic wasps studied here are also larger than those known for all Drosophila species. Surprisingly, genome sizes of these Drosophila parasitoids exceed the average value known for all previously studied Hymenoptera. The haploid chromosome number of both Leptopilina heterotoma (Thomson, 1862 and L. victoriae Nordlander, 1980 is ten. A chromosomal fusion appears to have produced a distinct karyotype for L. boulardi (Barbotin, Carton et Keiner-Pillault, 1979 (n = 9, whose genome size is smaller than that of wasps of the L. heterotoma clade. Like L. boulardi, the haploid chromosome number for G. xanthopoda is also nine. Our studies reveal a positive, but non linear, correlation between the genome size and total chromosome length in Drosophila parasitoids. These Drosophila parasitoids differ widely in their host range, and utilize different infection strategies to overcome host defense. Their comparative genomics, in relation to their exceptionally well-characterized hosts, will prove to be valuable for understanding the molecular basis of the host-parasite arms race and how such mechanisms shape the genetic structures of insect communities.

The effect of floral resources on parasitoid and host longevity

DEFF Research Database (Denmark)

Sigsgaard, Lene; Betzer, Cathrine; Naulin, Cyril

2013-01-01

The strawberry tortricid, Acleris comariana Lienig and Zeller(Lepidoptera: Tortricidae)is an important pest in Danish strawberry production. Its most common parasitoid is Copidosoma aretas (Walker) (Hymenoptera: Chalcidoidea: Encyrtidae). To identify selective flowering plants that could be used...... to increase functional biodiversity, the longevity of C. aretas and its host A. comariana was assessed on 5 flowering species: buckwheat, Fagopyrum esculentum Moench (Caryophyllales: Polygonaceae); borage, Borago officinalis L. (Boraginaceae); strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae...... buckwheat also increased longevity of A. comariana, its longevity and survival on buckwheat, borage, and strawberry was not significantly different, so buckwheat was chosen for field experiments. A. comariana densities in the 3 fields with sown buckwheat flower strips were 0.5, 4.0, and 8.3 larvae per m per...

Functional and evolutionary insights from the genomes of three parasitoid Nasonia species

DEFF Research Database (Denmark)

Werren, John H; Richards, Stephen; Desjardins, Christopher A

2010-01-01

We report here genome sequences and comparative analyses of three closely related parasitoid wasps: Nasonia vitripennis, N. giraulti, and N. longicornis. Parasitoids are important regulators of arthropod populations, including major agricultural pests and disease vectors, and Nasonia is an emerging...... of genes involved in nuclear-mitochondrial interactions that are implicated in speciation. Newly developed genome resources advance Nasonia for genetic research, accelerate mapping and cloning of quantitative trait loci, and will ultimately provide tools and knowledge for further increasing the utility...

Feeding status of the parasitoid Diadegma semiclausum affects biological control of Plutella xylostella: a simulation study

NARCIS (Netherlands)

Hemerik, L.

2007-01-01

Life history characteristics of the diamondback moth (DBM), Plutella xylostella, a worldwide pest on cruciferous crops, and its important natural enemy, the parasitoid Diadegma semiclausum have intensely been studied. In addition, the searching behaviour of the parasitoid and the role of foraging

Chemical Cues in Tritrophic Interaction on Biocontrol of Insect Pest

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Nurindah Nurindah

2017-03-01

Full Text Available Tritrophic interaction among host plant-herbivore-parasitoid involves chemical cues. The infested plant by herbivores has been reacted to produce volatiles which is a cue used by the herbivore parasitoids for host location. These volatiles can be developed to enhance natural control of insect pests, especially by optimally use of parasitoids. Egg parasitoids are biocontrol agents that play an important role in natural control of herbivores. This research used a tritrophic interaction model of rice plant-brown plant hopper (BPH-egg parasitoid of BPH. Research on analysis of chemical cues in tritrophic interactions was aimed to identify volatiles that are used by the parasitoid to find its host. The volatiles that effectively affect the parasitoid orientation behavior could be developed into a parasitoid attractant. Extraction of volatiles as the egg parasitoid cues was done using soxhlet, and identification of the volatiles using Gas Chromatography-Mass Spectrometry (GC-MS. Bioassay of the volatiles on the BPH parasitoid orientation behavior was performed using Y-tube olfactometry. The volatiles that are used for host location cues by the parasitoid affect the parasitoid orientation behavior by showing the preference of the parasitoid females to the odor of volatile. Volatiles extracted from BPH-egg-infested plants and uninfested plants contain alcohol, hydrocarbon, and ester compounds. Based on the difference of the compound composition of both extractions, five compounds of long-chain hydrocarbon, both branched and unsaturated compounds are the main volatile components which caused positive orientation behavior of the egg parasitoid. The egg parasitoids showed positive behavior orientation toward the volatiles extracted from BPH-egg-infested plant. Those hydrocarbon compounds are potential materials to be developed into bio attractants of BPH egg parasitoid.

Quality of different aphids as hosts of the parasitoid Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae, Aphidiinae); Qualidade de diferentes especies de pulgoes como hospedeiros do parasitoide Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae, Aphidiinae)

Energy Technology Data Exchange (ETDEWEB)

Silva, Robson J.; Bueno, Vanda H.P. [Universidade Federal de Lavras, MG (Brazil). Dept. de Entomologia]. E-mail: vhpbueno@ufla.br; Sampaio, Marcus V.[Universidade Federal de Uberlandia (UFU), MG (Brazil). Inst. de Ciencias Agrarias]. E-mail: mvsampaio@iciag.ufu.br

2008-03-15

Lysiphlebus testaceipes (Cresson) has a broad aphid host range; however the quality of these preys may interfere in its biological feature. This study aimed to evaluate the quality of three Macrosiphini, Brevicoryne brassicae (L.), Lipaphis erysimi (Kaltenbach) and Myzus persicae (Sulzer), and three Aphidini Schizaphis graminum (Rondani) Rhopalosiphum maidis (Fitch) and Aphis gossypii Glover as hosts to L. testaceipes and to determine the relation possible of host preference, of size and quality of the host. The tests were carried out in climatic chamber at 25 {+-} 1 deg C, RH 70 {+-} 10% and 12h photophase. The parasitoid did not oviposite in B. brassicae and L. erysimi, while the other species were nutritionally suitable to the parasitoid. L. testaceipes showed preference for aphids from tribe Aphidini and these hosts presented better quality to the parasitoid when compared to Macrosiphini. Interactions among size, preference and quality between the Aphidini were found. L. testaceipes showed preference (parasitism rate 76.7%) for R. maidis, the bigger host (hind tibia with 0.281 mm). This host provided bigger size (hind tibia with 0.49 mm) and higher emergence rate (95.6%) to the parasitoid when compared to A. gossypii (parasitism rate of 55.7%). Also the smaller host A. gossypii (0.266 mm) provided smaller size hind tibia (0.45 mm) and higher mortality of the parasitoid (emergence rate 72.1%). However, the development time was shorter and the longevity was higher in A. gossypii (6.3 and 5.4 days, respectively) when compared to the host R. maidis (6.7 and 3.8 days, respectively), and not been related to host size. (author)

Disease-parasitoid relationships in natural populations of Lymantria dispar [Lep.: Lymantriidae] in the northeastern United States

Science.gov (United States)

R.C. Reardon; J.D. Podgwaite

1976-01-01

Immature Lymantria dispar L. were collected from 6 geographically distinct populations over 2 years to determine correlations between parasitoid and disease incidences. Incidence of the nuclear polyhedrosis virus disease (NPV) was found to be positively correlated with incidences of the parasitoids Apanteles melanoscelus (Ratzeburg...

Aphid parasitoids (Hymenoptera, Braconidae, Aphidiinae) from Thailand

Czech Academy of Sciences Publication Activity Database

Starý, Petr; Rakhshani, E.; Tomanović, Ž.; Kavallieratos, N. G.; Sharkey, M.

-, č. 2498 (2010), s. 47-52 ISSN 1175-5326 Grant - others:Ministry of Science of the Republic of Serbia(CS) 143006B; U. S. National Science Foundation(US) DEB 0542864 Institutional research plan: CEZ:AV0Z50070508 Keywords : aphids * parasitoids * biodiversity Subject RIV: EG - Zoology Impact factor: 0.853, year: 2010

A review of hymenopterous parasitoid guilds attacking Anastrepha spp. and Ceratitis capitata (Diptera: Tephritidae) in Argentina

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Ovruski, Sergio M.; Orono, Luis E.; Nunez-Campero, Segundo; Schliserman, Pablo; Albornoz-Medina, Patricia; Bezdjian, Laura P.; Nieuwenhove, Guido A. Van; Martin, Cristina B. [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Tucuman (Argentina). Planta Piloto de Procesos Industriales Microbiologicos y Biotecnologia. Div. Control Biologico de Plagas

2006-07-01

This study provides detailed information on the diversity, abundance, guilds, host plant and host fly ranges, distribution, and taxonomic status of hymenopterous parasitoid species associated with Ceratitis capitata (Wiedemann) and Anastrepha spp. (A. fraterculus (Wiedemann) and A. schultzi Blanchard) in Argentina. Moreover, the article also argues future needs regarding the use of some parasitoid species as an alternative tool in fruit fly management programs of the National Fruit Fly Control and Eradication Program (PROCEM-Argentina). Data used for this work were obtained from numerous old and recent published articles on fruit fly parasitoids in Argentina. (author)

A review of hymenopterous parasitoid guilds attacking Anastrepha spp. and Ceratitis capitata (Diptera: Tephritidae) in Argentina

International Nuclear Information System (INIS)

Ovruski, Sergio M.; Orono, Luis E.; Nunez-Campero, Segundo; Schliserman, Pablo; Albornoz-Medina, Patricia; Bezdjian, Laura P.; Nieuwenhove, Guido A. Van; Martin, Cristina B.

2006-01-01

This study provides detailed information on the diversity, abundance, guilds, host plant and host fly ranges, distribution, and taxonomic status of hymenopterous parasitoid species associated with Ceratitis capitata (Wiedemann) and Anastrepha spp. (A. fraterculus (Wiedemann) and A. schultzi Blanchard) in Argentina. Moreover, the article also argues future needs regarding the use of some parasitoid species as an alternative tool in fruit fly management programs of the National Fruit Fly Control and Eradication Program (PROCEM-Argentina). Data used for this work were obtained from numerous old and recent published articles on fruit fly parasitoids in Argentina. (author)

Susceptibility of the Parasitoid Phymastichus coffea LaSalle (Hymenoptera: Eulophidae) to Beauveria bassiana under laboratory conditions; Susceptibilidad del parasitoide Phymastichus coffea LaSalle (Hymenoptera:Eulophidae) a Beauveria bassiana en condiciones de laboratorio

Energy Technology Data Exchange (ETDEWEB)

Castillo, Alfredo; Gomez, Jaime; Infante, Francisco [El Colegio de la Frontera Sur (ECOSUR), Chiapas (Mexico). Dept. de Entomologia Tropical], e-mail: acastill@ecosur.mx, e-mail: jgomez@ecosur.mx, e-mail: finfante@ecosur.mx; Vega, Fernando E. [United States Department of Agriculture (USDA), Beltsville, MD (United States). Agricultural Research Service. Sustainable Perennial Crops Lab.], e-mail: fernando.vega@ars.usda.gov

2009-09-15

The coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae), is the most important coffee pest worldwide. Beauveria bassiana is a generalist entomopathogenic fungus widely used by coffee farmers to control this pest and Phymastichus coffea LaSalle (Hymenoptera: Eulophidae) is an African endo parasitoid of H. hampei adults, recently imported to several Latin American and Caribbean countries to aid in the coffee berry borer control. The objective of this study was to determine if B. bassiana is detrimental to P. coffea. The susceptibility of the parasitoid was evaluated in terms of adult survivorship, mean lethal concentration (LC{sub 50}), mean lethal time (LT{sub 50}), reproduction and immature mortality. The main effect of the fungus resulted in reduction of adult longevity and mortality of 100% for immature stages of this parasitoid. The LC{sub 50} for adults was 0.11% equivalent to 9.53 x 10{sup 7} conidia/ml of B. bassiana and a LT{sub 50} of 29.4 h, equivalent to reduction of 22% of its normal longevity as an adult. P. coffea was capable of disseminating spores of B. bassiana to non-infected H. hampei adults, which could indirectly cause the death of its own progeny. These results could be valuable when considering the use of both organisms in the field, especially in an integrated pest management program. (author)

Effects of volatiles from Maruca vitrata larvae and caterpillar-infested flowers of their host plant Vigna unguiculata on the foraging behavior of the parasitoid Apanteles taragamae

NARCIS (Netherlands)

Dannon, A.E.; Tamò, M.; Huis, van A.; Dicke, M.

2010-01-01

The parasitoid wasp Apanteles taragamae is a promising candidate for the biological control of the legume pod borer Maruca vitrata, which recently has been introduced into Benin. The effects of volatiles from cowpea and peabush flowers and Maruca vitrata larvae on host selection behavior of the

Hymenopterous parasitoids attacking Acanthiophilus helianthi Rossi (Diptera: Tephritidae pupae in Kohgiluyeh Safflower farms of Iran

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K. Saeidi

2016-12-01

Full Text Available The Safflower capsule fly (SCF, Acanthiophilus helianthi Rossi (Diptera: Tephritidae is the most destructive insect pest attacking the Safflower Carthamus tinctorius L. plant which are cultivated as an oil crop. It is mainly controlled through application of broad-spectrum insecticides, which can adversely affect safflower farms ecosystem and consequently human health. Since a first step in setting up an integrated pest management program is to assess the biological control agents within the ecosystem. Therefore, in this research work the pupal parasitoids of Safflower capsule fly a main insect pest attacking Safflower plants were identified. The impact of these parasitoids against this pest was evaluated on the varying pest generations and within different locations in Kohgiluyeh province during 2008-2009 seasons. Pupal parasitoid adults of SCF were recorded from fieldreared pupae, which had been collected from heavily infested small flower heads of the first generation as well from large flower heads of the second and third generations. Rate of parasitism on A. helianthi pupae was estimated as the number of parasitoids over the total count of parasitoids and flies. Ten hymenopterous species belonging to different families parasitizing insect pupae were screened as follows: Bracon hebetor (Spinola, 1808 and Bracon luteator (Spinola, 1808 (Braconidae; Isocolus tinctorious (Melika and Gharaei, 2006 (Cynipidae; Pronotalia carlinarum (Szelenyi and Erdos, 1951 (Eulophidae; Eurytoma acroptilae (Zerova, 1986 (Eurytomidae; Ormyrus orientalis (Walker, 1871 (Ormyridae; Colotrechnus viridis (Masi, 1921 and Pteromalus sp. (Walker, 1976 (Pteromalidae; and Antistrophoplex conthurnatus (Zerova, 2000 and Microdontomenus annulatus (Masi, 1899 (Torymidae. The average parasitization rate was 23±1 as revealed through the present study. The highest parasitization rate occurred during the first generation in all localities tested, as well as in years. Statistical

A two-component model of host–parasitoid interactions: determination of the size of inundative releases of parasitoids in biological pest contro

NARCIS (Netherlands)

Grasman, J.; Herwaarden, van O.A.; Hemerik, L.; Lenteren, van J.C.

2001-01-01

A two-component differential equation model is formulated for a host–parasitoid interaction. Transient dynamics and population crashes of this system are analysed using differential inequalities. Two different cases can be distinguished: either the intrinsic growth rate of the host population is

Clave dicotómica para especies parasitoides e hiperparasitoides (Hymenoptera de áfidos (Hemiptera: Aphididae de Costa Rica

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Daniel Zamora Mejías

2017-09-01

Full Text Available Los áfidos representan una problemática para muchas especies de plantas, debido a que son vectores de múltiples patógenos; el control biológico mediante el uso de parasitoides es una opción permanente de control de sus poblaciones. El objetivo de esta investigación fue elaborar una clave dicotómica para identificar parasitoides e hiperparasitoides de áfidos recolectados en Costa Rica. Se obtuvo desde el año 2008 hasta 2015 un total de 3009 parasitoides himenópteros de 25 especies de áfidos, de los cuales 2832 (94% se clasificaron como parasitoides primarios y 175 (6% como hiperparasitoides. Se elaboró una clave de identificación para nueve especies de parasitoides primarios Braconidae-Aphidiinae, Aphelinidae, Eulophidae y cinco familias de hiperparasitoides comprendidos en seis especies. Además, se incluye en la clave el género Quadrictonus (Aphidiinae, el cual se registró por primera vez para Costa Rica en este estudio.

Temperature-dependent development of the parasitoid Tachinaephagus zealandicus on five forensically important carrion fly species.

Science.gov (United States)

Voss, S C; Spafford, H; Dadour, I R

2010-06-01

The influences of temperature and host species on the development of the forensically important parasitoid Tachinaephagus zealandicus Ashmead (Hymenoptera: Encyrtidae) were studied at six constant temperatures in the range of 15-30 degrees C. T. zealandicus completed development successfully between 15 degrees C and 27 degrees C on five species of Calliphoridae, Calliphora albifrontalis Malloch, Calliphora dubia Macquart, Lucilia sericata Meigen, Chrysomya rufifacies Macquart and Chrysomya megacephala Fabricius. No adult parasitoids emerged from any of the host species reared at 30 degrees C. Temperature and host species significantly influenced development time, emergence success and progeny size. Development was significantly longer on Ch. megacephala and Ch. rufifacies at 18-24 degrees C and significantly longer on Ch. rufifacies and C. albifrontalis at 15 degrees C and 27 degrees C. Parasitoid emergence success was greatest at 21 degrees C, declined at the temperature extremes (15 degrees C and 27 degrees C) and was significantly lower on Ch. megacephala and Ch. rufifacies than on the three other host species. Progeny numbers per host pupa were highest at 21-24 degrees C, declined on either side of this temperature range and were significantly lower on L. sericata, Ch. rufifacies and Ch. megacephala than on either C. dubia or C. albifrontalis. An effect of host species on sex ratio was only observed at 27 degrees C, at which a higher proportion of T. zealandicus females emerged from Ch. megacephala and Ch. rufifacies than from the other host species. The thermal requirements for development (developmental thresholds, thermal constant, optimum temperature) of T. zealandicus in each host species were estimated using linear and non-linear models. Upper and lower developmental thresholds ranged between 29.90 degrees C and 31.73 degrees C, and 9.73 degrees C and 10.08 degrees C, respectively. The optimum temperature for development was estimated at between 25

Potential use of F1 sterility and the parasitoid, Cotesia plutellae, to control diamondback moth, Plutella xylostella, in Myanmar

International Nuclear Information System (INIS)

Maung, N.

2002-01-01

Diamondback moth (DBM), Plutella xylostella males irradiated with 100 Gy and larval parasitoids (Cotesia plutellae) were studied for their potential to control DBM in cabbage fields of Nyaung-Le-Bin Township, Bago Division. The following treatments were evaluated as control tactics: release of irradiated male DBM, augmentative release of parasitoids, and combined release of irradiated male DBM and parasitoids. These treatments reduced the larval population of feral DBM. (author)

Toxicity of organic supplies for the egg parasitoid Telenomus podisi

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Débora Mello da Silva

2014-01-01

Full Text Available Toxicity (dosage per hectare of: 1 Baculovirus anticarsia 140x109 cpi; 2 Bacillus thuringiensis 16.8g; 3 Azadirachtin-A, azadirachtin-B, nimbina and salamina 9.6 ppm; 4 Rotenoids 4 liters; 5 Nitrogen 1.3%, phosphorus 3.0% and total organic carbon 8.0% 3 liters; 6 Sodium silicate 2% 4 liters; 7 Copper 7% + calcium 3.3% 1.8 liters; 8 Sulfur 20% + quicklime 10% 1.8 liters; 9 Chlorpyrifos 384g; 10 Distilled H2O (control were evaluated for pupae and adults of Telenomus podisi. Treatments from 1 to 8 were in general harmless (class 1 to both pupae and adults of T. podisi. Among them, only treatment 5 and 7 presented slightly toxic to the parasitoid with a reduction in parasitism 5 days after F1 parasitoid emergence. Differently, the chlorpyrifos was classified as slightly harmful (class 2 or moderately harmful (class 3. Therefore, the use of the tested organic agricultural supplies in the production of organic soybean is viable, without impairing the natural biological control allowed by this egg parasitoid. Chlorpyrifos use, on the other hand, is not allowed in organic soybean, but even on convention crop production, could whenever possible, be replaced by other products more compatible with T. podisi preservation.

Effects of solute--solvent attractive forces on hydrophobic correlations

International Nuclear Information System (INIS)

Pratt, L.R.; Chandler, D.

1980-01-01

A theory is presented for the effect of slowly varying attractive forces on correlations between nonpolar solutes in dilute aqueous solution. We find that hydrophobic correlations are sensitive to relatively long range slowly varying interactions. Thus, it is possible to make qualitative changes in these correlations by introducing small changes in the attractive forces. Several model calculations are presented to illustrate these facts. The contributions of the Lennard-Jones attractive forces to the computer simulation results of Pangali, Rao, and Berne are calculated. For this case it is found that the potential of mean force between spherical nonpolar solutes is hardly affected by inclusion of attractive forces. However, the osmotic second virial coefficient is dominated by the contributions of the attractive forces. For spherical solutes which provide a reasonable model for the methane molecule, inclusion of attractive forces produces a qualitative change in the methane--methane potential of mean force. The connection between these effects of slowly varying attractive forces and the enthalpic part of Ben-Naim's deltaA/sup H/I is discussed

Do biopesticides affect the demographic traits of a parasitoid wasp and its biocontrol services through sublethal effects?

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Antonio Biondi

Full Text Available Pesticide risk assessments are usually based on short-term acute toxicity tests, while longer-term population dynamic related traits, critical to the success of biological control and Integrated Pest Management (IPM programs, are often overlooked. This is increasingly important with respect to new biopesticides that frequently cause no short-term acute effects, but that can induce multiple physiological and behavioral sublethal effects, leading to a decrease in population growth and ecosystem services. In this study we assessed the lethal and sublethal effects of six biopesticides [abamectin, azadirachtin, Bacillus thuringiensis, borax plus citrus oil (Prev-Am®, emamectin benzoate, and spinosad], used in tomato crops to control the invasive pest Tuta absoluta (Lepidoptera: Gelechiidae, on adults and pupae of the parasitoid Bracon nigricans (Hymenoptera: Braconidae. Data on female survival and production of female offspring were used to calculate population growth indexes as a measure of population recovery after pesticide exposure. Spinosad caused 100% and 80% mortality in exposed adults (even 10 d after the treatment and pupae, respectively. Although most of the biopesticides had low levels of acute toxicity, multiple sublethal effects were observed. The biocontrol activity of both females that survived 1-h and 10-d old residues, and females that emerged from topically treated pupae was significantly affected by the application of the neurotoxic insecticides emamectin benzoate and abamectin. Furthermore, very low B. nigricans demographic growth indices were estimated for these two insecticides, indicating potential local extinction of the wasp populations. Among the tested products, Bt proved to be the safest for B. nigricans adults and pupae. Our findings emphasize that acute toxicity assessment alone cannot fully predict the actual impact of pesticides on non-target parasitoids. Thus, sublethal effects related to the species specific life

The Effect of Expected Value on Attraction Effect Preference Reversals.

Science.gov (United States)

Farmer, George D; Warren, Paul A; El-Deredy, Wael; Howes, Andrew

2017-10-01

The attraction effect shows that adding a third alternative to a choice set can alter preference between the original two options. For over 30 years, this simple demonstration of context dependence has been taken as strong evidence against a class of parsimonious value-maximising models that evaluate alternatives independently from one another. Significantly, however, in previous demonstrations of the attraction effect alternatives are approximately equally valuable, so there was little consequence to the decision maker irrespective of which alternative was selected. Here we vary the difference in expected value between alternatives and provide the first demonstration that, although extinguished with large differences, this theoretically important effect persists when choice between alternatives has a consequence. We use this result to clarify the implications of the attraction effect, arguing that although it robustly violates the assumptions of value-maximising models, it does not eliminate the possibility that human decision making is optimal. © 2016 The Authors Journal of Behavioral Decision Making Published by John Wiley & Sons Ltd.

Parasitoid dan Parasitisasi Plutella xylostella (L. (Lepidoptera: Yponomeutidae di Sumatera Selatan

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SITI HERLINDA

2005-12-01

Full Text Available Surveys from May 2003 to January 2004 in South Sumatera were conducted to determine parasitoid attacking Plutella xylostella (L. and to estimate P. xylostella parasitization by the parasitoids. The eggs and the larvae of P. xylostella were collected from brassicaceous crops, i.e. mustard, Indian mustard, and cabbage. Six parasitoids found were Trichogrammatoidea cojuangcoi Nagaraja (Hymenoptera: Trichogrammatidae, Cotesia plutellae (Kurdj. (Hymenoptera: Braconidae, Diadegma semiclausum Hellen (Hymenoptera: Ichneumonidae, Oomyzus sokolowskii (Kurdj. (Hymenoptera: Eulophidae, Tetrastichus (Hymenoptera: Eulophidae, and a ceraphronid wasp (unidentified species. Trichogrammatoidea cojuangcoi parasitized P. xylostella eggs, however, the others parasitized the larvae except the ceraphronid wasp. In South Sumatera, the ceraphronid wasp was reported for the first time parasitizing D. semiclausum pupae, and its parasitization reached 6.2%. Oomyzus sokolowskii and Tetrastichus were found in this area for the first time, as well. In the highland, D. semiclausum was the most abundant compared to the others where its parasitization reached 79.2%. In the lowland P. xylostella larvae was mainly attacked by C. plutellae with the parasitization reaching 64.9% In the dry and rainy seasons, the parasitization was mainly exerted by T. cojuangcoi (77.0% and D. semiclausum (79.2%.

The effectiveness of habitat modification schemes for enhancing beneficial insects: Assessing the importance of trap cropping management approach

Science.gov (United States)

Trisnawati, Indah; Azis, Abdul

2017-06-01

Many farms in regions of intensive crop production lack the habitats that historically provided resources to beneficial insects, and this lack has compromised the ability of farmers to rely on natural enemies for pest control. One of the strategies to boost populations of existing or naturally occurring beneficial insects is to supply them with appropriate habitat and alternative food sources, such as diversifying trap crop systems and plant populations in or around fields include perennials and flowering plants. Trap cropping using insectary plant that attracts beneficial insects as natural enemies, especially flowering plants, made for provision of habitat for predators or parasitoids that are useful for biological control. Perimeter trap cropping (PTC) is a method of integrated pest management in which the main crop is surrounded with a perimeter trap crop that is more attractive to pests. We observed PTC habitat modification and conventionaly-managed tobacco farms in Purwosari Village, Pasuruan (East Java) to evaluate the effectiveness of habitat modification management prescription (perimeter trap crop using flowering plant Crotalaria juncea) on agroecosystem natural enemies. Field tests were conducted in natural enemies (predator and parasitoid) abundance dynamic and diversity on tobacco field in Purwoasri, Pasuruan. Yellow pan trap, sweep net and hand collecting methods were applied in each 10 days during tobacco growth stage (vegetative, generative until reproductive/harvesting. The results showed that application perimeter trap crop with C. juncea in tobacco fields able to help arthropod conservation of natural enemies on all tobacco growth stages. These results were evidenced the increase in abundance of predators and parasitoids and the increased value of the Diversity Index (H') and Evenness Index (EH) in all tobacco growth phases. Composition of predator and parasitoid in the habitat modification field were more diverse than in the conventional field

Parasitoids of the endangered leafcutter ant Atta robusta Borgmeier in urban and natural areas

Directory of Open Access Journals (Sweden)

Diego S. Gomes

2013-09-01

Full Text Available Parasitoids of the endangered leafcutter ant Atta robusta Borgmeier in urban and natural areas. Hosts of parasitoids in urban areas may suffer from a double threat of habitat destruction by urbanization and parasitism pressure. Moreover, the parasitoids themselves might be at risk if they are specialists. Here, we studied whether Atta robusta (Hymenoptera, Formicidae, which is on the red list of Brazilian threatened species, suffers from higher parasitism pressure in an urban area compared to a natural one. In addition, we determined whether their specialist parasitoids, Eibesfeldtphora breviloba and Myrmosicarius exrobusta (Diptera, Phoridae, are in risk and evaluated whether they are influenced by habitat structure, temperature, humidity, ant traffic, and time of the day. The study was carried out in an urban park and in a natural protected area in the city of Rio de Janeiro. In each site we chose an open area and a closed area (forest and sampled nine nests in each area. We found that parasitism pressure was similar in urban and natural areas, with the same two parasitoid species present in both areas. The main difference was related to habitat structure, since M. exrobusta was mainly present in open areas while E. breviloba was almost exclusively found in closed areas. Myrmosicarius exrobusta was not present during the hottest midday times, and its abundance was negatively correlated to vapor pressure deficit. These results suggest that green areas can be an important component in efforts to conserve diversity in urban areas. However, the complexity of the habitats in those areas is a fundamental issue in designing urban parks.

Acute Toxicity of Fresh and Aged Residues of Pesticides to the Parasitoid Tamarixia radiata and to the HLB-Bacteria Vector Diaphorina citri.

Science.gov (United States)

Beloti, V H; Alves, G R; Moral, R A; Demétrio, C G B; Yamamoto, P T

2018-06-01

One method for controlling the Asian citrus psyllid (ACP) Diaphorina citri Kuwayama, the vector of the putative causal agent of Huanglongbing, uses the parasitoid Tamarixia radiata (Waterston). However, the general intensive use of insecticides has reduced the numbers of this parasitoid. This study evaluated the effect of the residual action of 24 insecticides on T. radiata and also determined the differential toxicity of insecticides to D. citri and T. radiata, using three bioassays. In the first, when adults of the parasitoid were exposed to residues of the 24 insecticides, ten were considered short-life (class 1), six slightly persistent (class 2), five moderately persistent (class 3), and three insecticides were considered persistent (class 4), under the IOBC/WPRS classification system. The second bioassay evaluated the sublethal concentrations of the persistent insecticides (formetanate, dimethoate, spinosad). Increasing the concentrations of the insecticides increased the number that were classified as persistent. In the third bioassay, evaluation of the differential toxicity of eight insecticides to the ACP and the parasitoid showed that chlorpyrifos and bifenthrin were more harmful to T. radiata. Therefore, these two insecticides are not recommended for application at the time of parasitoid release. Cypermethrin, imidacloprid, and dimethoate caused higher mortality of D. citri and are most often recommended in IPM programs. The choice of an insecticide for the control of citrus pests must be made with care, aiming to preserve the natural enemies in the ecosystem, and thereby contribute to the success of biological control.

The influence of flower morphology and nectar quality on the longevity of a parasitoid biological control agent

NARCIS (Netherlands)

Vattala, H.D.; Wratten, S.D.; Phillips, C.B.; Wäckers, F.L.

2006-01-01

Conservation biological control aims to enhance the efficacy of arthropod biological control agents, such as parasitoids, partly by providing them with access to floral nectar. However, the suitability of a flower species for providing nectar to a parasitoid is dependent on the morphologies of the

Host Plants Affect the Foraging Success of Two Parasitoids that Attack Light Brown Apple Moth Epiphyas postvittana (Walker (Lepidoptera: Tortricidae.

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Yi Feng

Full Text Available The light brown apple moth, Epiphyas postvittana is a key pest of wine grapes in Australia. Two parasitoids, Dolichogenidea tasmanica and Therophilus unimaculatus, attack the larval stage of this pest. D. tasmanica is dominant in vineyards, whereas T. unimaculatus is mainly active in native vegetation. We sought to understand why they differ in their use of habitats. Plants are a major component of habitats of parasitoids, and herbivore-infested plants influence parasitoid foraging efficiency by their architecture and emission of volatile chemicals. We investigated how different plant species infested by E. postvittana could affect the foraging success of the two parasitoid species in both laboratory and field experiments. Four common host-plant species were selected for this study. In paired-choice experiments to determine the innate foraging preferences for plants, both parasitoid species showed differences in innate search preferences among plant species. The plant preference of D. tasmanica was altered by oviposition experience with hosts that were feeding on other plant species. In a behavioral assay, the two parasitoid species allocated their times engaged in various types of behavior differently when foraging on different plant species. For both parasitoids, parasitism on Hardenbergia violacea was the highest of the four plant species. Significantly more larvae dropped from Myoporum insulare when attacked than from the other three host-plant species, which indicates that parasitism is also affected by interactions between plants and host insects. In vineyards, parasitism by D. tasmanica was significantly lower on M. insulare than on the other three host-plant species, but the parasitism rates were similar among the other three plant species. Our results indicate that plants play a role in the habitat preferences of these two parasitoid species by influencing their foraging behavior, and are likely to contribute to their distributions

Innate Host Habitat Preference in the Parasitoid Diachasmimorpha longicaudata: Functional Significance and Modifications through Learning.

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Diego F Segura

Full Text Available Parasitoids searching for polyphagous herbivores can find their hosts in a variety of habitats. Under this scenario, chemical cues from the host habitat (not related to the host represent poor indicators of host location. Hence, it is unlikely that naïve females show a strong response to host habitat cues, which would become important only if the parasitoids learn to associate such cues to the host presence. This concept does not consider that habitats can vary in profitability or host nutritional quality, which according to the optimal foraging theory and the preference-performance hypothesis (respectively could shape the way in which parasitoids make use of chemical cues from the host habitat. We assessed innate preference in the fruit fly parasitoid Diachasmimorpha longicaudata among chemical cues from four host habitats (apple, fig, orange and peach using a Y-tube olfactometer. Contrary to what was predicted, we found a hierarchic pattern of preference. The parasitism rate realized on these fruit species and the weight of the host correlates positively, to some extent, with the preference pattern, whereas preference did not correlate with survival and fecundity of the progeny. As expected for a parasitoid foraging for generalist hosts, habitat preference changed markedly depending on their previous experience and the abundance of hosts. These findings suggest that the pattern of preference for host habitats is attributable to differences in encounter rate and host quality. Host habitat preference seems to be, however, quite plastic and easily modified according to the information obtained during foraging.

The Effects of Physical Attractiveness and Anxiety on Heterosexual Attraction Over a Series of Five Encounters

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Mathes, Eugene W.

1975-01-01

The "information availability model" of heterosexual attraction was tested by having subjects go on a series of five encounters. It was found that both physical attractiveness and the personality variable, anxiety, had early and continuous effects on liking. It was concluded the model is an inadequate explanation of heterosexual…

Effects of molasses grass, Melinis minutiflora volatiles on the foraging behavior of the cereal stemborer parasitoid, Cotesia sesamiae

NARCIS (Netherlands)

Gohole, L.S.; Overholt, W.A.; Khan, Z.R.; Pickett, J.A.; Vet, L.E.M.

2003-01-01

Olfactory responses of the cereal stemborer parasitoid Cotesia sesamiae to volatiles emitted by gramineous host and nonhost plants of the stemborers were studied in a Y-tube olfactometer. The host plants were maize (Zea mays) and sorghum (Sorghum bicolor), while the nonhost plant was molasses grass

Effects of molasses grass, Melinis minutiflora volatiles on the foraging behavior of the cereal stemborer parasitoid, Cotesia sesamiae

NARCIS (Netherlands)

Gohole, L.S.; Overholt, W.A.; Khan, Z.U.; Pickett, J.A.; Vet, L.E.M.

2003-01-01

Olfactory responses of the cereal stemborer parasitoid Cotesia sesamiae to volatiles emitted by gramineous host and nonhost plants of the stemborers were studied in a Y-tube olfactometer. The host plants were maize (Zea mays) and sorghum ( Sorghum bicolor), while the nonhost plant was molasses grass

Induced parasitoid attraction by Arabidopsis thaliana : involvement of the octadecanoid and the salicylic acid pathway

NARCIS (Netherlands)

Poecke, van M.P.; Dicke, M.

2002-01-01

Plants can use indirect defence mechanisms to protect themselves against herbivorous insects. An example of such an indirect defence mechanism is the emission of volatiles by plants induced by herbivore feeding. These volatiles can attract the natural enemies of these herbivores, for example,

The herbivore-induced plant volatile methyl salicylate negatively affects attraction of the parasitoid Diadegma semiclausum

NARCIS (Netherlands)

Snoeren, T.A.L.; Mumm, R.; Poelman, E.H.; Yang, Y.; Pichersky, E.; Dicke, M.

2010-01-01

The indirect defense mechanisms of plants comprise the production of herbivore-induced plant volatiles that can attract natural enemies of plant attackers. One of the often emitted compounds after herbivory is methyl salicylate (MeSA). Here, we studied the importance of this caterpillar-induced

Asociaciones áfido-parasitoide (Hemiptera: Aphididae; Hymenoptera: Braconidae, Aphidiinae en cultivos hortícolas orgánicos en Los Cardales, Buenos Aires, Argentina Aphid-parasitoid associations (Hemiptera: Aphididae; Hymenoptera: Braconidae, Aphidiinae on organic vegetable crops in Los Cardales, Buenos Aires, Argentina

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Andrea V. Andorno

2007-07-01

Full Text Available Diez especies de áfidos (Hemiptera: Aphididae se hallaron parasitados por siete especies de parasitoides (Hymenoptera: Braconidae, Aphidiinae en cultivos hortícolas orgánicos. Myzus persicae (Sulzer fue el áfido más frecuentemente encontrado sobre una amplia variedad de cultivos, y con mayor diversidad de parasitoides asociados. Aphidius colemani Viereck fue el afidiino más usual, que ataca varias especies de áfidos. Ocho asociaciones tritróficas, involucrando Aphidius matricariae Haliday, han sido registradas por primera vez para la Argentina.Ten aphid species (Hemiptera: Aphididae were found parasitized by seven aphid parasitoid species (Hymenoptera: Braconidae, Aphidiinae on organic vegetable crops. Myzus persicae (Sulzer was the most frequent aphid found on a wide variety of crops, with the largest parasitoid diversity associated. Aphidius colemani Viereck was the most frequent aphidiine attacking several species of aphids. Eight tritrophic associations involving Aphidius matricariae Haliday are reported for the first time for Argentina.

Species diversity and activity of parasitoids of the sweetpotato ...

African Journals Online (AJOL)

The species range, activity and relative abundance of parasitoids attacking the sweetpotato butterfly, Acraea acerata Hew. (Lepidoptera: Nymphalidae) in Uganda was investigated. Samples of eggs and larvae of the sweetpotato butterfly were collected from some of the major sweetpotato growing districts of Uganda to ...

Aphid parasitoid (Hymenoptera:Braconidae: Aphidiinae) in wetland habitats in western Palearctic: key and associated aphid parasitoid guilds

Czech Academy of Sciences Publication Activity Database

Tomanović, Ž.; Starý, Petr; Kavallieratos, N. G.; Gagić, V.; Plećaš, M.; Janković, M.; Rakhshani, E.; Ćetković, A.; Petrović, A.

2012-01-01

Roč. 48, 1-2 (2012), s. 189-198 ISSN 0037-9271 Grant - others:The Ministry of Science and Technological Development of the Republic of Serbia(RS) 043001 Institutional research plan: CEZ:AV0Z50070508 Keywords : aphid parasitoids * tritrophic interactions * wetlands Subject RIV: EH - Ecology, Behaviour Impact factor: 0.529, year: 2012 http://zoologie.umh.ac.be/asef/pdf/2012_48_01_02/full/Tomanovic_et_al_2012_ASEF_48_1_2_189_198_full.pdf

Producción masiva y simultánea de machos de Ceratitis capitata (Diptera: Tephritidae y parasitoides Dichasmimorpha longicaudata (Hymenoptera: Braconidae Massive and simultaneous production of Ceratitis capitata (Diptera: Tephritidae males and Diachasmimorpha longicaudata (Hymenoptera: Braconidae parasitoids

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Silvia N. López

2006-12-01

Full Text Available En la línea de sexado genético «Cast191» las hembras de Ceratitis capitata son homocigotas para el gen slow , lo que reduce su velocidad de desarrollo; los machos son heterocigotas y muestran una velocidad de desarrollo normal. Esta característica permitió producir, con Cast191, machos estériles por un lado, y parasitoides criados sobre las larvas remanentes por el otro. Nuestro objetivo con este trabajo fue producir ambos insumos simultáneamente y a una escala mayor que hasta ahora. Además, bajo estas condiciones, y en un intento por aumentar la separación entre sexos, se aplicó a las larvas del primer estadío un pulso de 15º C, durante 1 ó 2 días, luego del cual se las mantuvo a 20º C ó 25º C, hasta que entraron al estado de pupa, luego se mantuvo todo el material a 25º C. La mejor separación de sexos, lograda con el tratamiento a 20º C sin pulso de frío, se usó para comparar la calidad del parasitoide Diachasmimorpha longicaudata, criado sobre las larvas obtenidas tras la separación de los machos, con aquellos criados sobre la línea salvaje. Para ello, este tratamiento de separación fue aplicado en la cría de la mosca, y el material remanente de dieta con larvas fue expuesto al parasitoide. La tasa de parasitismo obtenida fue semejante a la hallada sobre la línea salvaje, y la tasa sexual de la F 1 del parasitoide presentó un sesgo hacia las hembras aún mayor. Se discute la factibilidad de utilizar la línea Cast191 de C. Capitata, para la producción a mayor escala de machos de mosca y para la cría masiva del parasitoide D. longicaudata.In the genetic sexing strain «Cast191», the females of Ceratitis capitata are homozygous for the mutation slow , slowing down their rate of development, and the males are heterozygous, having a normal rate of development. This feature made Cast191 capable of producing sterile males, on one hand, and parasitoids that are reared on the remaining larvae, on the other. The

Parasitoid and Parasitization of Plutella xylostella (L. (Lepidoptera: Yponomeutidae in South Sumatera

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SITI HERLINDA

2005-12-01

Full Text Available Surveys from May 2003 to January 2004 in South Sumatera were conducted to determine parasitoid attacking Plutella xylostella (L. and to estimate P. xylostella parasitization by the parasitoids. The eggs and the larvae of P. xylostella were collected from brassicaceous crops, i.e. mustard, Indian mustard, and cabbage. Six parasitoids found were Trichogrammatoidea cojuangcoi Nagaraja (Hymenoptera: Trichogrammatidae, Cotesia plutellae (Kurdj. (Hymenoptera: Braconidae, Diadegma semiclausum Hellen (Hymenoptera: Ichneumonidae, Oomyzus sokolowskii (Kurdj. (Hymenoptera: Eulophidae, Tetrastichus (Hymenoptera: Eulophidae, and a ceraphronid wasp (unidentified species. Trichogrammatoidea cojuangcoi parasitized P. xylostella eggs, however, the others parasitized the larvae except the ceraphronid wasp. In South Sumatera, the ceraphronid wasp was reported for the first time parasitizing D. semiclausum pupae, and its parasitization reached 6.2%. Oomyzus sokolowskii and Tetrastichus were found in this area for the first time, as well. In the highland, D. semiclausum was the most abundant compared to the others where its parasitization reached 79.2%. In the lowland P. xylostella larvae was mainly attacked by C. plutellae with the parasitization reaching 64.9%. In the dry and rainy seasons, the parasitization was mainly exerted by T. cojuangcoi (77.0% and D. semiclausum (79.2%.

Nuclear magnetic resonance microscopy of the development of the parasitoid wasp Venturia canescens within its host moth Plodia interpunctella.

Science.gov (United States)

Chudek, J A; Crook, A M; Hubbard, S F; Hunter, G

1996-01-01

Nuclear magnetic resonance microscopy was used to image the parasitoid wasp Venturia canescens (Hymenoptera: Ichneumonidae) within larval and pupal instars of its host, the Indian meal moth, Plodia interpunctella (Lepidoptera: Pyralidae). The images were obtained using gradient-echo and chemical shift selective pulse sequences and clearly showed the location and shapes of the parasitoid as it developed from the L1 larva to a pupal stage within the host. The digestive, nervous, and tracheal systems of the host were identified and changes were observed as the host underwent metamorphosis. Destruction of the host tissues by the parasitoid was visible. It was found that the parasitoid first ate the fat body and digestive system of the host, allowing the host to continue to grow, and only progressed to the vital organs when its own development had neared pupation.

Analysis of Genetic Variation across the Encapsidated Genome of Microplitis demolitor Bracovirus in Parasitoid Wasps.

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Gaelen R Burke

Full Text Available Insect parasitoids must complete part of their life cycle within or on another insect, ultimately resulting in the death of the host insect. One group of parasitoid wasps, the 'microgastroid complex' (Hymenoptera: Braconidae, engage in an association with beneficial symbiotic viruses that are essential for successful parasitism of hosts. These viruses, known as Bracoviruses, persist in an integrated form in the wasp genome, and activate to replicate in wasp ovaries during development to ultimately be delivered into host insects during parasitism. The lethal nature of host-parasitoid interactions, combined with the involvement of viruses in mediating these interactions, has led to the hypothesis that Bracoviruses are engaged in an arms race with hosts, resulting in recurrent adaptation in viral (and host genes. Deep sequencing was employed to characterize sequence variation across the encapsidated Bracovirus genome within laboratory and field populations of the parasitoid wasp species Microplitis demolitor. Contrary to expectations, there was a paucity of evidence for positive directional selection among virulence genes, which generally exhibited signatures of purifying selection. These data suggest that the dynamics of host-parasite interactions may not result in recurrent rounds of adaptation, and that adaptation may be more variable in time than previously expected.

The landscape context of cereal aphid–parasitoid interactions

Science.gov (United States)

Thies, Carsten; Roschewitz, Indra; Tscharntke, Teja

2005-01-01

Analyses at multiple spatial scales may show how important ecosystem services such as biological control are determined by processes acting on the landscape scale. We examined cereal aphid–parasitoid interactions in wheat fields in agricultural landscapes differing in structural complexity (32–100% arable land). Complex landscapes were associated with increased aphid mortality resulting from parasitism, but also with higher aphid colonization, thereby counterbalancing possible biological control by parasitoids and lastly resulting in similar aphid densities across landscapes. Thus, undisturbed perennial habitats appeared to enhance both pests and natural enemies. Analyses at multiple spatial scales (landscape sectors of 0.5–6 km diameter) showed that correlations between parasitism and percentage of arable land were significant at scales of 0.5–2 km, whereas aphid densities responded to percentage of arable land at scales of 1–6 km diameter. Hence, the higher trophic level populations appeared to be determined by smaller landscape sectors owing to dispersal limitation, showing the ‘functional spatial scale’ for species-specific landscape management. PMID:15695212

Heat stress affects male reproduction in a parasitoid wasp.

Science.gov (United States)

Nguyen, Thanh Manh; Bressac, Christophe; Chevrier, Claude

2013-03-01

In insects, reproductive success and survival are affected by temperature. Reproduction is more sensitive than other physiological traits. While the effects of heat stress on females are well known, the effects on males are less clear. Hymenopteran parasitoids are valuable for studying the consequences of heat stress on male reproduction. In these species, through arrhenotoquous parthenogenesis, the sex ratio of the offspring is directly dependent on the sperm stock acquired by females during copulation. In the lab, heat temperature treatments (32-44°C) were applied for 3 days in the pupal stage of Anisopteromalus calandrae males, and development was completed at 30°C. Three different effects were observed depending on the temperature: mortality above 42°C, sterility of emerging males at 40°C, and sub-fertility at 38°C. This sub-fertility is characterized by a dramatic decrease in male sperm supplies, of up to 7% compared to control males. In the course of ageing, the sperm stock of sub-fertile males increases but never reaches the level of control males. Survival was significantly higher in control (30°C) males than those treated at 38°C. Male mating ability was similar whatever the treatment (control and 38°C), but females mated with 38°C-treated males stored 100 times less sperm on average than those mated with control males. The offspring sex ratio of females mated with 38°C-treated males was strongly male biased. The physiological mechanisms are as yet unknown. The relationship between temperature, sperm stock and sex ratio should be taken into account in the management of parasitoids for integrated pest management. Copyright © 2012 Elsevier Ltd. All rights reserved.

Revisiting the Red Effect on Attractiveness and Sexual Receptivity

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Leonard S. Peperkoorn

2016-10-01

Full Text Available Color-in-context theory is the first theoretical framework for understanding color effects in human mate preferences, arguing that red clothing enhances attractiveness ratings. Here we present three empirical studies failing to support this prediction. We aimed to extend the current literature by differentiating color effects by temporal context (short-term vs. long-term mating. Experiment 1 involved Dutch participants rating a woman in red, white, and black on (sexual attractiveness. Experiment 2 replicated the first experiment with an American sample. In the final experiment, we aimed to replicate a study that did find evidence of a red effect, using a substantially larger sample size. The results from each of the three studies (totaling N = 830 men fail to support the red effect. We discuss the implications of our results and avenues for future research on red effects and attractiveness.

The Effect of Physical Attractiveness of Models on Advertising Effectiveness for Male and Female Adolescents

Science.gov (United States)

Tsai, Chia-Ching; Chang, Chih-Hsiang

2007-01-01

This study investigates the effect of advertising with physically attractive models on male and female adolescents. The findings suggest that highly attractive models are less effective than those who are normally attractive. Implications of social comparison are discussed.

Beyond initial attraction: physical attractiveness in newlywed marriage.

Science.gov (United States)

McNulty, James K; Neff, Lisa A; Karney, Benjamin R

2008-02-01

Physical appearance plays a crucial role in shaping new relationships, but does it continue to affect established relationships, such as marriage? In the current study, the authors examined how observer ratings of each spouse's facial attractiveness and the difference between those ratings were associated with (a) observations of social support behavior and (b) reports of marital satisfaction. In contrast to the robust and almost universally positive effects of levels of attractiveness on new relationships, the only association between levels of attractiveness and the outcomes of these marriages was that attractive husbands were less satisfied. Further, in contrast to the importance of matched attractiveness to new relationships, similarity in attractiveness was unrelated to spouses' satisfaction and behavior. Instead, the relative difference between partners' levels of attractiveness appeared to be most important in predicting marital behavior, such that both spouses behaved more positively in relationships in which wives were more attractive than their husbands, but they behaved more negatively in relationships in which husbands were more attractive than their wives. These results highlight the importance of dyadic examinations of the effects of spouses' qualities on their marriages.

Long-distance assessment of patch profitability through volatile infochemicals by the parasitoids Cotesia glomerata and C. rubecula (Hymenoptera: Braconidae).

NARCIS (Netherlands)

Geervliet, J.B.F.; Ariens, S.; Dicke, M.; Vet, L.E.M.

1998-01-01

Using two closely related larval parasitoids (Cotesiaspp.) ofPieriscaterpillars we tested the hypothesis that parasitoids are capable of assessing patch profitability from a distance by showing differential responses to odors from plants infested with different host densities. We furthermore tested

Relationship between oviposition, virulence gene expression and parasitism success in Cotesia typhae nov. sp. parasitoid strains.

Science.gov (United States)

Benoist, R; Chantre, C; Capdevielle-Dulac, C; Bodet, M; Mougel, F; Calatayud, P A; Dupas, S; Huguet, E; Jeannette, R; Obonyo, J; Odorico, C; Silvain, J F; Le Ru, B; Kaiser, L

2017-12-01

Studying mechanisms that drive host adaptation in parasitoids is crucial for the efficient use of parasitoids in biocontrol programs. Cotesia typhae nov. sp. (Fernández-Triana) (Hymenoptera: Braconidae) is a newly described parasitoid of the Mediterranean corn borer Sesamia nonagrioides (Lefebvre) (Lepidoptera: Noctuidae). Braconidae are known for their domesticated bracovirus, which is injected with eggs in the host larva to overcome its resistance. In this context, we compared reproductive success traits of four Kenyan strains of C. typhae on a French and a Kenyan populations of its host. Differences were found between the four strains and the two most contrasted ones were studied more thoroughly on the French host population. Parasitoid offspring size was correlated with parasitism success and the expression of bracovirus virulence genes (CrV1 and Cystatin) in the host larva after parasitism. Hybrids between these two parasitoid strains showed phenotype and gene expression profiles similar to the most successful parental strain, suggesting the involvement of dominant alleles in the reproductive traits. Ovary dissections revealed that the most successful strain injected more eggs in a single host larva than the less successful one, despite an equal initial ovocyte number in ovaries. It can be expected that the amount of viral particles increase with the number of eggs injected. The ability to bypass the resistance of the allopatric host may in consequence be related to the oviposition behaviour (eggs allocation). The influence of the number of injected eggs on parasitism success and on virulence gene expression was evaluated by oviposition interruption experiments.

Rapid establishment of a regular distribution of adult tropical Drosophila parasitoids in a multi-patch environment by patch defence behaviour.

Science.gov (United States)

de Jong, Peter W; Hemerik, Lia; Gort, Gerrit; van Alphen, Jacques J M

2011-01-01

Females of the larval parasitoid of Drosophila, Asobara citri, from sub-Saharan Africa, defend patches with hosts by fighting and chasing conspecific females upon encounter. Females of the closely related, palearctic species Asobara tabida do not defend patches and often search simultaneously in the same patch. The effect of patch defence by A. citri females on their distribution in a multi-patch environment was investigated, and their distributions were compared with those of A. tabida. For both species 20 females were released from two release-points in replicate experiments. Females of A. citri quickly reached a regular distribution across 16 patches, with a small variance/mean ratio per patch. Conversely, A. tabida females initially showed a clumped distribution, and after gradual dispersion, a more Poisson-like distribution across patches resulted (variance/mean ratio was closer to 1 and higher than for A. citri). The dispersion of A. tabida was most probably an effect of exploitation: these parasitoids increasingly made shorter visits to already exploited patches. We briefly discuss hypotheses on the adaptive significance of patch defence behaviour or its absence in the light of differences in the natural history of both parasitoid species, notably the spatial distribution of their hosts.

Effects of Instructor Attractiveness on Learning.

Science.gov (United States)

Westfall, Richard; Millar, Murray; Walsh, Mandy

2016-01-01

Although a considerable body of research has examined the impact of student attractiveness on instructors, little attention has been given to the influence of instructor attractiveness on students. This study tested the hypothesis that persons would perform significantly better on a learning task when they perceived their instructor to be high in physical attractiveness. To test the hypothesis, participants listened to an audio lecture while viewing a photograph of instructor. The photograph depicted either a physically attractive instructor or a less attractive instructor. Following the lecture, participants completed a forced choice recognition task covering material from the lecture. Consistent with the predictions; attractive instructors were associated with more learning. Finally, we replicated previous findings demonstrating the role attractiveness plays in person perception.

Extending the Similarity-Attraction Effect : The effects of When-Similarity in mediated communication

NARCIS (Netherlands)

Kaptein, M.C.; Castaneda, D.; Fernandez, N.; Nass, C.

2014-01-01

The feeling of connectedness experienced in computer-mediated relationships can be explained by the similarity-attraction effect (SAE). Though SAE is well established in psychology, the effects of some types of similarity have not yet been explored. In 2 studies, we demonstrate similarity-attraction

Susceptibility of the Parasitoid Phymastichus coffea LaSalle (Hymenoptera: Eulophidae) to Beauveria bassiana under laboratory conditions

International Nuclear Information System (INIS)

Castillo, Alfredo; Gomez, Jaime; Infante, Francisco; Vega, Fernando E.

2009-01-01

The coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae), is the most important coffee pest worldwide. Beauveria bassiana is a generalist entomopathogenic fungus widely used by coffee farmers to control this pest and Phymastichus coffea LaSalle (Hymenoptera: Eulophidae) is an African endo parasitoid of H. hampei adults, recently imported to several Latin American and Caribbean countries to aid in the coffee berry borer control. The objective of this study was to determine if B. bassiana is detrimental to P. coffea. The susceptibility of the parasitoid was evaluated in terms of adult survivorship, mean lethal concentration (LC 50 ), mean lethal time (LT 50 ), reproduction and immature mortality. The main effect of the fungus resulted in reduction of adult longevity and mortality of 100% for immature stages of this parasitoid. The LC 50 for adults was 0.11% equivalent to 9.53 x 10 7 conidia/ml of B. bassiana and a LT 50 of 29.4 h, equivalent to reduction of 22% of its normal longevity as an adult. P. coffea was capable of disseminating spores of B. bassiana to non-infected H. hampei adults, which could indirectly cause the death of its own progeny. These results could be valuable when considering the use of both organisms in the field, especially in an integrated pest management program. (author)

Developing Cotton IPM by Conserving Parasitoids and Predators of The Main Pest

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Nurindah Nurindah

2015-09-01

Full Text Available On early development of intensive cotton program, insect pests were considered as an important aspect in cotton cultivation, so that it needed to be scheduled sprays. The frequency of sprays was 7 times used 12L of chemical insecticides per hectare per season. Development of cotton IPM was emphasized on non-chemical control methods through optimally utilize natural enemies of the cotton main pests (Amrasca biguttulla (IshidaHelicoverpa armigera (Hübner. Conservation of parasitoids and predators by providing the environment that support their population development is an act of supporting the natural enemies as an effective biotic mortality factor of the insect pests. The conservation could be done by improving the plant matter and cultivation techniques that include the use of resistant variety to leafhopper, intercropping cotton with secondary food plants, mulch utilization, using action threshold that considered the presence of natural enemies, and application of botanical insecticides, if needed. Conservation of parasitoids and predators in cotton IPM could control the insect pests without any insecticide spray in obtaining the production of cotton seed. As such, the use of IPM method would increase farmers’ income.

Diet quality can play a critical role in defense efficacy against parasitoids and pathogens in the Glanville fritillary (Melitaea cinxia).

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Laurentz, Minna; Reudler, Joanneke H; Mappes, Johanna; Friman, Ville; Ikonen, Suvi; Lindstedt, Carita

2012-01-01

Numerous herbivorous insect species sequester noxious chemicals from host plants that effectively defend against predators, and against parasitoids and pathogens. Sequestration of these chemicals may be expensive and involve a trade off with other fitness traits. Here, we tested this hypothesis. We reared Glanville fritillary butterfly (Melitaea cinxia L.) larvae on plant diets containing low- and high-levels of iridoid glycosides (IGs) (mainly aucubin and catalpol) and tested: 1) whether IGs affect the herbivore's defense against parasitoids (measured as encapsulation rate) and bacterial pathogens (measured as herbivore survival); 2) whether parasitoid and bacterial defenses interact; and 3) whether sequestration of the plant's defense chemicals incurs any life history costs. Encapsulation rates were stronger when there were higher percentages of catalpol in the diet. Implanted individuals had greater amounts of IGs in their bodies as adults. This suggests that parasitized individuals may sequester more IGs, increase their feeding rate after parasitism, or that there is a trade off between detoxification efficiency and encapsulation rate. Larval survival after bacterial infection was influenced by diet, but probably not by diet IG content, as changes in survival did not correlate linearly with the levels of IGs in the diet. However, M. cinxia larvae with good encapsulation abilities were better defended against bacteria. We did not find any life history costs of diet IG concentration for larvae. These results suggest that the sequestering of plant defense chemicals can help herbivorous insects to defend against parasitoids.

Interspecific competition between Diadegma semiclausum Hellen and Diadegma mollipla (Holmgren), parasitoids of the diamondback moth, Plutella xylostella (L), feeding on a new host plant.

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Rossbach, A; Löhr, B; Vidal, S

2008-04-01

Interspecific competition between an introduced parasitoid species aimed at controlling a herbivorous pest species and a native parasitoid parasitising the same host may influence the success of classical biological control programmes. In Kenya, interspecific competition between an introduced and a local parasitoid on two diamondback moth populations (DBM, Plutella xylostella) was investigated on two different host plants. We tested simultaneous and delayed competition of the local parasitoid Diadegma mollipla Holmgren and its exotic congenus D. semiclausum Hellen on a newly aquired DBM host plant (snowpea) in the laboratory. Under simultaneous competition, D. mollipla produced more progeny than D. semiclausum on snowpea. A head start of D. Mollipla, of four and eight hours before its congenus was introduced, resulted in a similar number of progeny of both species. In delayed competition (time intervals of 24 h, 48 h and 72 h), progeny production was similar for both parasitoids when the time interval was 24 h, irrespective of which species parasitized first. More progeny was produced by the species which attacked first, when the time interval was greater than 24 h, although it was only significant at 72 h. Competitive abilites of both parasitoids on the new host plant differed largely between laboratory and semi-field conditions. The influence of two host plants (snowpea and cabbage) on competition was studied in the greenhouse with different host and parasitoid densities. Parasitism levels of D. semiclausum were significantly higher than those of D. mollipla, regardless of host plant, host and parasitoid densities, but progeny production of D. mollipla on snowpea was still slightly higher than on cabbage. As compared to the confinement of parasitoids and larvae to small containers, D. mollipla parasitized very few larvae in the cages. Competitive ability of the two parasitoid species tested was influenced both by the density of the searching females and by

Dietary sugars and proline influence biological parameters of adult Trissolcus grandis, an egg parasitoid of Sunn pest, Eurygaster integriceps

NARCIS (Netherlands)

Hajirajabi, Nafiseh; Fazel, Morteza Movahedi; Harvey, Jeffrey A.; Arbab, Abbass; Asgari, Shahriar

Parasitoids are important natural enemies that are used in the biological control of insect herbivore pests. The egg parasitoid Trissolcus grandis Thompson (Hym. Scelionidae) is a major enemy of the Sunn pest, Eurygaster integriceps Puton (Hem. Scutelleridae), which in turn is one of the most

Parasitoids associated with the black scale Saissetia oleae(Olivier (Hemiptera: Coccidae in olive trees in Minas Gerais State, Brazil

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Ernesto Prado

2015-10-01

Full Text Available Black scale, Saissetia oleae (Olivier (Hemiptera: Coccidae is an important pest of olive trees (Olea europaea L. that requires the use insecticides for its control. Parasitoids are important regulating agents of this pest, but currently, no information on its complex of natural enemies and their impact on black scale in Brazilian conditions exists. This study focused on identifying parasitoid wasps that were associated with the black scale on olive trees to establish their relative abundance and rate of parasitism. Samplings were maintained in an olive orchard located in Maria da Fe, south of the state of Minas Gerais, Brazil, and infested branches were stored in emergence containers to recover parasitoids. Another group was kept in Flanders batteries to evaluate the rate of parasitism in approximately 100 scales. Sixteen parasitoid species were collected during the sampling period, and the most common species were Coccophagus caridei (Brèthes (Hymenoptera: Aphelinidae, Diversinervus elegans Silvestri (Hymenoptera: Encyrtidae, and Mesopeltita truncatipennis (Waterston (Hymenoptera: Pteromalidae, the latter of which was most abundant and frequent. Parasitism ranged from 3 to 31% with peaks in summer and autumn. This level could be considered insufficient to hold the black scale under the economic injury level; however, these parasitoids should be preserved for contributions to population regulation.

The Attraction Effect Modulates Reward Prediction Errors and Intertemporal Choices.

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Gluth, Sebastian; Hotaling, Jared M; Rieskamp, Jörg

2017-01-11

Classical economic theory contends that the utility of a choice option should be independent of other options. This view is challenged by the attraction effect, in which the relative preference between two options is altered by the addition of a third, asymmetrically dominated option. Here, we leveraged the attraction effect in the context of intertemporal choices to test whether both decisions and reward prediction errors (RPE) in the absence of choice violate the independence of irrelevant alternatives principle. We first demonstrate that intertemporal decision making is prone to the attraction effect in humans. In an independent group of participants, we then investigated how this affects the neural and behavioral valuation of outcomes using a novel intertemporal lottery task and fMRI. Participants' behavioral responses (i.e., satisfaction ratings) were modulated systematically by the attraction effect and this modulation was correlated across participants with the respective change of the RPE signal in the nucleus accumbens. Furthermore, we show that, because exponential and hyperbolic discounting models are unable to account for the attraction effect, recently proposed sequential sampling models might be more appropriate to describe intertemporal choices. Our findings demonstrate for the first time that the attraction effect modulates subjective valuation even in the absence of choice. The findings also challenge the prospect of using neuroscientific methods to measure utility in a context-free manner and have important implications for theories of reinforcement learning and delay discounting. Many theories of value-based decision making assume that people first assess the attractiveness of each option independently of each other and then pick the option with the highest subjective value. The attraction effect, however, shows that adding a new option to a choice set can change the relative value of the existing options, which is a violation of the independence

Effects on microhymenopteran progeny of different host exposure periods (Chrysomya megacephala, Calliphoridae to the parasitoid wasp Nasonia vitripennis (Hymenoptera: Pteromalidae

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Renata da Silva Mello

2010-02-01

Full Text Available To test the assumption that exposure of the host to parasitoid for long periods could provoke superparasitism, the aim of this work was to test the consequences on the immature development time, productivity of parasitoids per pupa, sex ratio and rate of parasitism of Nasonia vitripennis bred in Chrysomya megacephala pupae. Each individual pupa was placed in a glass tube with one parasitoid female for 24, 48, 72 and 96 h period of exposure, under controlled laboratory conditions. Twenty replicates of each period were performed. ANOVA with a 5% significance level was applied. The 72 h exposure caused the immature development time to increase. The mean parasitoids emergence per pupa did not vary significantly with the time of exposure. There were a significantly higher number of females than males and a trend in sex ratio deviation towards the females in all of the treatments. An increase in the number of unviable pupae rates were observed with increased exposure time.Para testar a hipótese que longos períodos de exposição do hospedeiro ao parasitóide podem ocasionar o superparasitismo, o presente estudo teve como objetivo testar as conseqüências sobre o tempo de desenvolvimento do imaturo, a produtividade de parasitóides, razão sexual e taxa de parasitismo de Nasonia vitripennis criadas em pupas de Chrysomya megacephala. Cada pupa foi individualizada e alocada em um tudo de ensaio com uma fêmea de N. vitripennis por 24, 48, 72 ou 96 h, sob condições laboratoriais controladas. Foram realizadas 20 réplicas para cada período de exposição. ANOVA com significância de 5 % foi aplicada. A exposição de 72 h causou um aumento no tempo desenvolvimento. A média de emergência de parasitóides não variou significativamente entre os tempos de exposição. Houve um número significativamente maior de fêmeas e uma tendência ao desvio da razão sexual para fêmeas em todos os tratamentos. Foi verificado um aumento no número de pupas invi

Eco-toxicological risk and impact of pesticides on important parasitoids of cabbage butterflies in cruciferous ecosystem.

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Firake, D M; Thubru, D P; Behere, G T

2017-02-01

Eco-toxicological risk and impact of pesticides was estimated on three important parasitoids of butterflies viz., Hyposoter ebeninus, Cotesia glomerata and Pteromalus puparum. Four commonly used pesticides were evaluated using standard protocol (of IOBC/WPRS-group). In laboratory tests, the survival of the female wasps decreased significantly on fresh contact and ingestion of deltamethrin, spinosad and azadirachtin; whereas Bacillus thuringiensis var kurstaki (Btk) was found harmless pesticide. Under semi-field conditions, parasitoid mortality decreased significantly on fresh contact with the pesticides. Although, at 72 h after treatment, spinosad and deltamethrin were found harmful (Class-IV) and azadirachtin was moderately harmful (Class-III), whereas Btk was harmless (Class-I). Furthermore, 15-day-old residues of pesticides (except deltamethrin) were harmless to all parasitoid species under semi-field conditions. Notably, adult emergence and pupal duration in pesticide-treated cocoons were not significantly affected; however, their survival decreased after emergence except in Btk. The contact and oral toxicity trends of the pesticides were almost similar for three species of parasitoid females and pupae; however little variability was observed in toxicity to the host caterpillars parasitized by H. ebeninus (HCPHE) and C. glomerata (HCPCG). In semi-field tests, fresh residues of all the pesticides were harmful to HCPHE and HCPCG. However, action of Btk was slightly delayed and toxicity was rather low for HCPCG. In 15-day-old residues, deltamethrin and azadirachtin were slightly harmful to the parasitized caterpillars, whereas those of Btk and spinosad were harmless. Since, Btk appeared to be safe for parasitoids; it could be used for managing cabbage butterflies in brassicaceous crops. Copyright © 2016 Elsevier Ltd. All rights reserved.

Temperature-dependent functional response of Spalangia cameroni (Perkins) (Hymenoptera: Pteromalidae), a parasitoid of Stomoxys calcitrans (L.) (Diptera: Muscidae)

DEFF Research Database (Denmark)

Skovgård, Henrik; Nachman, Gösta

2015-01-01

The effects of host density, temperature, and burial depths on the functional response of the synovigenic parasitoid Spalangia cameroni (Perkins) attacking pupae of the stable fly Stomoxys calcitrans (L.) were examined. Five temperatures (15, 20, 25, 30, and 35 degrees C), six host densities (2, ...

Insects Can Count: Sensory Basis of Host Discrimination in Parasitoid Wasps Revealed.

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Sara Ruschioni

Full Text Available The solitary parasitoid Leptopilina heterotoma is one of the best studied organisms concerning the ecology, behaviour and physiology of host discrimination. Behavioural evidence shows that L. heterotoma uses its ovipositor to discriminate not only between parasitized and unparasitized Drosophila melanogaster larvae, but also to discriminate between hosts with different numbers of parasitoid eggs. The existing knowledge about how and when the parasitoid marks the host motivated us to unravel the chemosensory basis of host discrimination by L. heterotoma that allows it to choose the "best" host available. In this paper we report on electrophysiological recordings of multi-neural responses from the single taste sensillum on the tip of the unpaired ovipositor valve. We stimulated this sensillum with haemolymph of unparasitized, one-time-parasitized and two-times-parasitized Drosophila larvae. We demonstrate for the first time that quantitative characteristics of the neural responses to these haemolymph samples differed significantly, implying that host discrimination is encoded by taste receptor neurons in the multi-neuron coeloconic ovipositor sensillum. The activity of three of the six neurons present in the sensillum suffices for host discrimination and support the hypothesis that L. heterotoma females employ an ensemble code of parasitization status of the host.

Linking spatial processes to life-history evolution of insect parasitoids

NARCIS (Netherlands)

Hoffmeister, T.S.; Roitberg, B.D.; Vet, L.E.M.

2005-01-01

Understanding the evolutionary transition from solitary to group living in animals is a profound challenge to evolutionary ecologists. A special case is found in insect parasitoids, where a tolerant gregarious larval lifestyle evolved from an intolerant solitary ancestor. The conditions for this

Habitat eradication and cropland intensification may reduce parasitoid diversity and natural pest control services in annual crop fields

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Deborah K. Letourneau

2015-10-01

Full Text Available Abstract California’s central coast differs from many agricultural areas in the U.S., which feature large tracts of monoculture production fields and relatively simple landscapes. Known as the nations salad bowl, and producing up to 90% of U.S. production of lettuces, broccoli and Brussels sprouts, this region is a mosaic of fresh vegetable fields, coastal meadow, chaparral shrubs, riparian and woodland habitat. We tested for relationships between the percent cover of crops, riparian and other natural landscape vegetation and the species richness of parasitic wasps and flies foraging in crops, such as broccoli, kale and cauliflower, and interpreted our results with respect to the decrease in natural habitat and increase in cropland cover prompted by a local microbial contamination event in 2006. Our key results are that: (1 as cropland cover in the landscape increased, fewer species of parasitoids were captured in the crop field, (2 parasitoid richness overall was positively associated with the amount of riparian and other natural vegetation in the surrounding 500m, (3 different groups of parasitoids were associated with unique types of natural vegetation, and (4 parasitism rates of sentinel cabbage aphid and cabbage looper pests were correlated with landscape vegetation features according to which parasitoids caused the mortality. Although individual species of parasitoids may thrive in landscapes that are predominantly short season crops, the robust associations found in this study across specialist and generalist parasitoids and different taxa (tachinid flies, ichneumon wasps, braconid wasps shows that recent food safety practices targeting removal of natural vegetation around vegetable fields in an attempt to eliminate wildlife may harm natural enemy communities and reduce ecosystem services. We argue that enhancing biological diversity is a key goal for transforming agroecosystems for future productivity, sustainability and public health.

The spatial distribution of Hymenoptera parasitoids in a forest reserve in Central Amazonia, Manaus, AM, Brazil

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RB. Querino

Full Text Available Parasitoids are of great importance to forest ecosystems due to their ecological role in the regulation of the population of other insects. The species richness and abundance of parasitoids in the forest canopy and understory, both on the borders and in the interior of a tropical forest reserve in Central Amazonia were investigated. For a 12-month period, specimen collections were made every 15 days from suspended traps placed in the forest canopy and in the understory strata, both on the border and in the interior of forest areas. A total of 12,835 Hymenoptera parasitoids from 23 families were acquired. Braconidae, Diapriidae, Mymaridae, Eulophidae, and Scelionidae were the most represented in the area and strata samples. The results indicate that there were no significant differences in the species richness or abundance of Hymenoptera between the forest borders and the inner forest. The data does show that the presence of Hymenoptera is significantly greater in the understory in both the border and interior areas than in the canopy (vertical stratification. Aphelinidae and Ceraphronidae were significantly associated with the inner forest, while the other seven families with the border of the reserve. The abundance of Hymenoptera parasitoids presented seasonal variations during the year related to the rainy and dry seasons.

Evolutionary ecology of the interactions between aphids and their parasitoids.

Science.gov (United States)

Le Ralec, Anne; Anselme, Caroline; Outreman, Yannick; Poirié, Marylène; van Baaren, Joan; Le Lann, Cécile; van Alphen, Jacques J-M

2010-01-01

Many organisms, including entomopathogenous fungi, predators or parasites, use aphids as ressources. Parasites of aphids are mostly endoparasitoid insects, i.e. insects which lay eggs inside the body of an other insect which will die as a result of their development. In this article, we review the consequences of the numerous pecularities of aphid biology and ecology for their endoparasitoids, notably the Aphidiinae (Hymenoptera: Braconidae). We first examine the various mechanisms used by aphids for defence against these enemies. We then explore the strategies used by aphidiine parasitoids to exploit their aphid hosts. Finally, we consider the responses of both aphids and parasitoids to ecological constraints induced by seasonal cycles and to environmental variations linked to host plants and climate. The fundamental and applied interest of studying these organisms is discussed. Copyright 2010 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Expression of Early Immune-Response Genes in Lepidopteran Host are Suppressed by Venom From an Endoparasitoid, Pteromalus puparum

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The relationships between parasitoids and their insect hosts have attracted attention at two levels. First, the basic biology of host-parasitoid interactions is of fundamental interest. Second, parasitoids have tremendous potential as biological control agents in sustainable agriculture programs. Pt...

Judging attractiveness: Biases due to raters’ own attractiveness and intelligence

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Stacy Yen-Lin Sim

2015-12-01

Full Text Available Tennis and Dabbs (1975 reported that physically attractive males showed a positivity bias when rating the attractiveness of others. The opposite pattern was observed for females. We attempted to replicate and extend these findings by: (1 using self-assessed attractiveness rather than the experimentally derived attractiveness measure used in previous research, (2 using face-to-face interactions with targets as opposed to using photographs, and (3 examining the effect of another ego-involving attribute: intelligence. Consistent with previous research, attractiveness judgments made by men, but not women, correlated positively with their own self-perceived level of attractiveness (r = .51, p < .001. Attractiveness judgments made by women, but not men, correlated negatively with their intelligence (r = −.32, p = .001. Judgments of attractiveness are thus biased by a rater’s own attributes (e.g. attractiveness and intelligence, but these effects are not generalizable across men and women raters, and may be driven by different mechanisms.

Romantic Red: Testing the Characteristics of Color–Attraction Effects in a Novel Paradigm

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Lisa A. Williams

2017-04-01

Full Text Available The red-attraction effect refers to the finding that the color red enhances attractiveness ratings of targets, and is most robustly observed when males rate females. Three previously unexplored aspects of color-attraction effects were tested in a single experiment with a large sample size (N = 778. The effect of exposure to a color and the impact of pairing a color with a target were disentangled using a novel design. Moreover, we tested the proposition that color exerts its effects outside of awareness by examining the association of conscious awareness of color-target pairing with the red-attraction effect. Both prior exposure to red and pairing of red with a target influenced attractiveness ratings, but not always in the direction of increased attractiveness. Results also varied as a function of target and participant sex. However, when conscious awareness of target-color pairing was higher, results converged with the typically-observed red-attraction effect among males rating females.

Numerical relationships of the Solidago altissima stem gall insect-parasitoid guild food chain.

Science.gov (United States)

Abrahamson, Warren G; Armbruster, Paulette O; Maddox, G David

1983-06-01

The field site conditions (soil pH, soil moisture, soil nutrient availability, etc.) and abundances of Solidago altissima (often included in S. canadensis sensu lato), three S. altissima specific stem gall formers, and the parasitepredator guilds for two of the three gall insects were investigated. It was found that S. altissima is tolerant of a wide range of site conditions. Herbivore (stem gall insects) occurrences were positively correlated with plant occurrence, in a linear fashion. However, there was no disproportionate increase in stem gall insect densities with plant density as might be predicted by the resource concentration hypothesis. Parasitoid guilds were exploiting stem gall insect populations over a wide range of occurrence, but were under-utilizing fields of higher herbivore occurrences. Path analysis showed a high degree of predictability in the causal models, with all but 14% of the ball gall parasitoid guild and all but 43% of the elliptical gall parasitoid guild occurrences explained by the direct influences of stem gall insect occurrence and the indirect influences of goldenrod occurrence and site conditions. The numerical relations of this three trophic level system suggest a well-integrated and well-controlled food chain.

Effects of symmetry and familiarity on the attractiveness of human faces

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Mentus Tatjana

2016-01-01

Full Text Available The effects of both symmetry (perceptual factor and familiarity (cognitive factor on facial attractiveness were investigated. From the photographs of original slightly asymmetric faces, symmetric left-left (LL and right-right (RR versions were generated. Familiarity was induced in the learning block using the repetitive presentation of original faces. In the test block participants rated the attractiveness of original, previously seen (familiar faces, original, not previously seen faces, and both LL and RR versions of all faces. The analysis of variance showed main effects of symmetry. Post hoc tests revealed that asymmetric original faces were rated as more attractive than both LL and RR symmetric versions. Familiarity doesn’t have a significant main effect, but the symmetry-familiarity interaction was obtained. Additional post hoc tests indicated that facial attractiveness is positively associated with natural slight asymmetry rather than with perfect symmetry. Also, unfamiliar LL symmetric versions were rated as more attractive than familiar LL versions, whereas familiar RR versions were rated as more attractive than RR unfamiliar faces. These results suggested that symmetry (perceptual factor and familiarity (cognitive or memorial factor play differential roles in facial attractiveness, and indicate a relatively stronger effect of the perceptual compared to the cognitive factor. [Projekat Ministarstva nauke Republike Srbije, br. ON179018 i br. ON179033

[Interaction of Metarhizium anisopliae (Metsch.) Sorok., Beauveria bassiana (Bals.) Vuill. and the parasitoid Oomyzus sokolowskii (Kurdjumov) (Hymenoptera: Eulophidae) with larvae of diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae)].

Science.gov (United States)

dos Santos, Hugo J G; Marques, Edmilson J; Barros, Reginaldo; Gondim, Manoel G C

2006-01-01

Chemical insecticides are broadly applied to control diamondback moth, Plutella xylostella (L.). Diamondback moth is a major pest of cruciferous worldwide, and resistance of this pest to insecticide has been often reported. Thus, this research investigated the interactions among the fungi Metarhizium anisopliae (Metsch.) Sorok., Beauveria bassiana (Bals.) Vuill., and the larval-pupal parasitoid Oomyzus sokolowskii (Kurdjumov) before and after application of the fungi on DBM larvae offered to the parasitoid. The experiment was carried out at 26+/-l degreeC, 75+/- 5% RH and 12h photophase using a completely randomized design, with eight treatments with six replications each. The isolates E9 of M. anisopliae and ESALQ 447 of B. bassiana, were used at the concentration of 10(7) conidia ml(-1). The results showed that M. anisopliae and B. bassiana reduced the parasitism of P. xylostella by O. sokolowskii. Additive effects were found on the mortality of P. xylostella with the different combinations among the fungi and parasitoid, except for the treatment B. bassiana inoculated 24h before exposition of the larvae to O. sokolowskii. The isolates were more efficacious when applied after exposition of the larvae to the parasitoid. The efficiency of O. sokolowskii was negatively influenced by the presence of the fungi, mainly when the fungi were applied 24h before diamondback's larvae were exposed to the parasitoid. The association of the fungi with the parasitoid presents potential to be tested in field. The use of these natural enemies in the integrated management of P. xylostella may economically improve the cabbage productive system, especially for organic farming.

Biocontrol Potential of Lariophagus distinguendus (Hymenoptera: Pteromalidae) Against Sitophilus granarius (Coleoptera: Curculionidae) at Low Temperatures: Reproduction and Parasitoid-Induced Mortality

DEFF Research Database (Denmark)

Hansen, Lise Stengård

2007-01-01

Lariophagus distinguendus Förster (Hymenoptera: Pteromalidae) has been suggested as a biological control agent against the granary weevil, Sitophilus granarius (L.), in grain stores. Information on the effect of low temperatures prevailing in grain stores is necessary to be able to predict...... the potential of this parasitoid against S. granarius in temperate regions, where grain is cooled with ambient air to achieve safe storage conditions. The influence of constant temperatures of 16, 18, and 20°C on life table parameters and parasitoid-induced mortality (PIM) was investigated in the laboratory. L...... is quicker than that of its host, estimated from the literature; and it kills many hosts in addition to those used for reproduction....

[Dipteran parasitoidism on larvae of Caligo atreus (Lepidoptera: Nymphalidae) in Cartago, Costa Rica].

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Calvo, Renin

2004-12-01

Parasitoids on larvae of Caligo atreus were studied at the Estación de Biologia Tropical in Rio Macho, Cartago, Costa Rica. (1 600 masl), from March through July 2000. Fifth instar larvae of C. atreus were placed on Heliconia tortuosa Griggs var. Red Twist (Heliconiaceae) host plants at a mean temperature of 16.7 degrees C. The parasitoids obtained belong to an unidentified species of the genus Winthemia (Diptera: Tachinidae). Most flies emerge some 40 days after the eggs were laid (maximum 68 days). They make an orifice on the upper ventral part of the lepidopteran pupa. Winthemia is used commercially as biological control of cotton and banana.

Aphid parasitoids that occur on wheat crops of Northeast of the Parana State with recovery of Aphidius rhopalosiphi in BrazilParasitoides de pulgões-do-trigo que ocorrem no Norte do estado do Paraná e recaptura de Aphidius rhopalosiphi no Brasil

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Adriano Thibes Hoshino

2012-02-01

Full Text Available Aphids (Hemiptera: Aphididae are the main pest of wheat (Hemiptera: Aphididae in several countries. In Brazil, the Biological Control of Wheat Aphids released millions of aphid parasitoids (Hymenoptera: Braconidae and Aphelinidae on wheat fields and in the present moment the chemical control is rarely necessary. However, since the 80’s few studies was carried out to evaluate the species established in Brazil. For this reason, the aim of this study was to record the species of aphid parasitoids that occur in wheat in the northern region of Parana state, Brazil. Four commercial wheat fields were investigated in the agricultural years of 2008 and 2009. The aphid parasitoids were captured with traps (Moericke and Malaise and aphid mummified were collected. In total, six species of parasitoids were found, Aphidius colemani, A. uzbekistanicus, A. ervi, Aphidius rhopalosiphi, Diaeretiella rapae e Lysiphlebus testaceipes. These results contribute with the register of three exotic species in Parana, and confirm the establishment of A. rhopalosiphi in the country. We emphasize the need for further studies in other regions of the country, as other species introduced also need to have their establishment confirmed.Os pulgões (Hemiptera: Aphididae são pragas de extrema importância em cereais de inverno no mundo todo. No Brasil, o programa Controle Biológico de Pulgões do Trigo liberou milhões de parasitoides (Hymenoptera: Braconidae e Aphelinidae nas áreas tritícolas, reduzindo expressivamente a população da praga, e atualmente raramente o controle químico se faz necessário. Entretanto, desde a década de 80 poucos trabalhos de campo tem sido realizados para verificar as espécies efetivamente estabelecidas no País. Por esta razão, este estudo objetivou registrar as espécies de parasitoides de pulgões ocorrentes em lavouras de trigo na região Norte no Paraná. O trabalho foi realizado em quatro áreas comerciais de trigo, durante as safras

On the Nature of Clitics and Their Sensitivity to Number Attraction Effects.

Science.gov (United States)

Santesteban, Mikel; Zawiszewski, Adam; Erdocia, Kepa; Laka, Itziar

2017-01-01

Pronominal dependencies have been shown to be more resilient to attraction effects than subject-verb agreement. We use this phenomenon to investigate whether antecedent-clitic dependencies in Spanish are computed like agreement or like pronominal dependencies. In Experiment 1, an acceptability judgment self-paced reading task was used. Accuracy data yielded reliable attraction effects in both grammatical and ungrammatical sentences, only in singular (but not plural) clitics. Reading times did not show reliable attraction effects. In Experiment 2, we measured electrophysiological responses to violations, which elicited a biphasic frontal negativity-P600 pattern. Number attraction modulated the frontal negativity but not the amplitude of the P600 component. This differs from ERP findings on subject-verb agreement, since when the baseline matching condition obtained a biphasic pattern, attraction effects only modulated the P600, not the preceding negativity. We argue that these findings support cue-retrieval accounts of dependency resolution and further suggest that the sensitivity to attraction effects shown by clitics resembles more the computation of pronominal dependencies than that of agreement.

The Putative Son's Attractiveness Alters the Perceived Attractiveness of the Putative Father.

Science.gov (United States)

Prokop, Pavol

2015-08-01

A body of literature has investigated female mate choice in the pre-mating context (pre-mating sexual selection). Humans, however, are long-living mammals forming pair-bonds which sequentially produce offspring. Post-mating evaluations of a partner's attractiveness may thus significantly influence the reproductive success of men and women. I tested herein the theory that the attractiveness of putative sons provides extra information about the genetic quality of fathers, thereby influencing fathers' attractiveness across three studies. As predicted, facially attractive boys were more frequently attributed to attractive putative fathers and vice versa (Study 1). Furthermore, priming with an attractive putative son increased the attractiveness of the putative father with the reverse being true for unattractive putative sons. When putative fathers were presented as stepfathers, the effect of the boy's attractiveness on the stepfather's attractiveness was lower and less consistent (Study 2). This suggests that the presence of an attractive boy has the strongest effect on the perceived attractiveness of putative fathers rather than on non-fathers. The generalized effect of priming with beautiful non-human objects also exists, but its effect is much weaker compared with the effects of putative biological sons (Study 3). Overall, this study highlighted the importance of post-mating sexual selection in humans and suggests that the heritable attractive traits of men are also evaluated by females after mating and/or may be used by females in mate poaching.

Effects of Switching Behavior for the Attraction on Pedestrian Dynamics.

Science.gov (United States)

Kwak, Jaeyoung; Jo, Hang-Hyun; Luttinen, Tapio; Kosonen, Iisakki

2015-01-01

Walking is a fundamental activity of our daily life not only for moving to other places but also for interacting with surrounding environment. While walking on the streets, pedestrians can be aware of attractions like shopping windows. They can be influenced by the attractions and some of them might shift their attention towards the attractions, namely switching behavior. As a first step to incorporate the switching behavior, this study investigates collective effects of switching behavior for an attraction by developing a behavioral model. Numerical simulations exhibit different patterns of pedestrian behavior depending on the strength of the social influence and the average length of stay. When the social influence is strong along with a long length of stay, a saturated phase can be defined at which all the pedestrians have visited the attraction. If the social influence is not strong enough, an unsaturated phase appears where one can observe that some pedestrians head for the attraction while others walk in their desired direction. These collective patterns of pedestrian behavior are summarized in a phase diagram by comparing the number of pedestrians who visited the attraction to the number of passersby near the attraction. Measuring the marginal benefits with respect to the strength of the social influence and the average length of stay enables us to identify under what conditions enhancing these variables would be more effective. The findings from this study can be understood in the context of the pedestrian facility management, for instance, for retail stores.

Complex interactions envolving a gall midge Myrciamyia maricaensis Maia (Diptera, Cecidomyiidae, phytophagous modifiers and parasitoids

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Fernando Fortunato Faria Ferraz

2003-09-01

Full Text Available Myrciamyia maricaensis Maia, 1995 (Diptera, Cecidomyiidae induces a gall in lateral and apical shoots in the plant Myrcia lundiana Kiaersk (Myrtaceae which is used and modified by two eulophid wasps species. In both cases the gall former species suffer high rate of attack exceeding the importance of parasitoid species as mortality factors. In this study these interactions are described and their effects as mortality of gall former. The intensity of occurrence of the two eulophid species as modifiers and of microhymenopteran parasitoids, and the relative importance of these species as mortality agents of the M. maricaensis larvae is compared. This comparison reveals that two modifiers species found in the gall tissue modification causing the death of the M. maricaensis larva and it is a more important factor of mortality than the cecidomyiid larva parasitism. The fluctuation of the number of each type of gall along the year was monitored in the research field and confirmed in numerical and in synchronic terms of occurrence of the galls; the importance of the species of the gall modifier eulophids, particularly one of these species, as factors of mortality of the M. maricaensis larvae and justified our comparing the relationship between these species and M. maricaensis as similar to the parasitoid-host relationship. The gall shape modification by one of the eulophids allows the occurrence of other inquiline insect species, what means that this gall modification becomes it more heterogeneous and allows the increase of the species richness to the system.

Extending the Similarity-Attraction Effect: The Effects of When-Similarity in Computer-Mediated Communication

NARCIS (Netherlands)

Kaptein, M.C.; Castaneda, D.; Fernandez, N.; Nass, C.

2014-01-01

The feeling of connectedness experienced in computer-mediated relationships can be explained by the similarity-attraction effect (SAE). Though SAE is well established in psychology, the effects of some types of similarity have not yet been explored. In 2 studies, we demonstrate similarity-attraction

Biological parameters and thermal requirements of the parasitoid Praon volucre (Hymenoptera: Braconidae) with Macrosiphum euphorbiae (Hemiptera: Aphididae) as host

NARCIS (Netherlands)

Conti, De B.F.; Bueno, V.H.P.; Sampaio, M.V.; Lenteren, van J.C.

2011-01-01

The effect of temperature on the biology of Praon volucre (Haliday, 1833) (Hymenoptera: Braconidae) in Macrosiphum euphorbiae (Thomas, 1878) (Hemiptera: Aphididae) hosts was studied and the thermal requirements of the parasitoid were determined. Experiments were carried out at 16, 19, 22, 25, and 28

Honey and honey-based sugars partially affect reproductive trade-offs in parasitoids exhibiting different life-history and reproductive strategies

NARCIS (Netherlands)

Harvey, Jeffrey A.; Essens, Tijl A.; Las, Rutger A.; Veen, van Cindy; Visser, B.; Ellers, J.; Heinen, R.; Gols, R.

2017-01-01

Adult dietary regimes in insects may affect egg production, fecundity and ultimately fitness. This is especially relevant in parasitoid wasps where many species serve as important biological control agents of agricultural pests. Here, we tested the effect of honey and sugar diets on daily fecundity

Variation in the diversity and richness of parasitoid wasps based on sampling effort.

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Saunders, Thomas E; Ward, Darren F

2018-01-01

Parasitoid wasps are a mega-diverse, ecologically dominant, but poorly studied component of global biodiversity. In order to maximise the efficiency and reduce the cost of their collection, the application of optimal sampling techniques is necessary. Two sites in Auckland, New Zealand were sampled intensively to determine the relationship between sampling effort and observed species richness of parasitoid wasps from the family Ichneumonidae. Twenty traps were deployed at each site at three different times over the austral summer period, resulting in a total sampling effort of 840 Malaise-trap-days. Rarefaction techniques and non-parametric estimators were used to predict species richness and to evaluate the variation and completeness of sampling. Despite an intensive Malaise-trapping regime over the summer period, no asymptote of species richness was reached. At best, sampling captured two-thirds of parasitoid wasp species present. The estimated total number of species present depended on the month of sampling and the statistical estimator used. Consequently, the use of fewer traps would have caught only a small proportion of all species (one trap 7-21%; two traps 13-32%), and many traps contributed little to the overall number of individuals caught. However, variation in the catch of individual Malaise traps was not explained by seasonal turnover of species, vegetation or environmental conditions surrounding the trap, or distance of traps to one another. Overall the results demonstrate that even with an intense sampling effort the community is incompletely sampled. The use of only a few traps and/or for very short periods severely limits the estimates of richness because (i) fewer individuals are caught leading to a greater number of singletons; and (ii) the considerable variation of individual traps means some traps will contribute few or no individuals. Understanding how sampling effort affects the richness and diversity of parasitoid wasps is a useful

Urban land use decouples plant-herbivore-parasitoid interactions at multiple spatial scales.

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Amanda E Nelson

Full Text Available Intense urban and agricultural development alters habitats, increases fragmentation, and may decouple trophic interactions if plants or animals cannot disperse to needed resources. Specialist insects represent a substantial proportion of global biodiversity and their fidelity to discrete microhabitats provides a powerful framework for investigating organismal responses to human land use. We sampled site occupancy and densities for two plant-herbivore-parasitoid systems from 250 sites across a 360 km2 urban/agricultural landscape to ask whether and how human development decouples interactions between trophic levels. We compared patterns of site occupancy, host plant density, herbivory and parasitism rates of insects at two trophic levels with respect to landcover at multiple spatial scales. Geospatial analyses were used to identify landcover characters predictive of insect distributions. We found that herbivorous insect densities were decoupled from host tree densities in urban landcover types at several spatial scales. This effect was amplified for the third trophic level in one of the two insect systems: despite being abundant regionally, a parasitoid species was absent from all urban/suburban landcover even where its herbivore host was common. Our results indicate that human land use patterns limit distributions of specialist insects. Dispersal constraints associated with urban built development are specifically implicated as a limiting factor.

Attraction Effects in Honorific Agreement in Korean.

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Kwon, Nayoung; Sturt, Patrick

2016-01-01

Previous studies have suggested that sentence processing is mediated by content-addressable direct retrieval processes (McElree, 2000; McElree et al., 2003). However, the memory retrieval processes may differ as a function of the type of dependency. For example, while many studies have reported facilitatory intrusion effects associated with a structurally illicit antecedent during the processing of subject-verb number or person agreement and negative polarity items (Pearlmutter et al., 1999; Xiang et al., 2009; Dillon et al., 2013), studies investigating reflexives have not found consistent evidence of intrusion effects (Parker et al., 2015; Sturt and Kwon, 2015; cf. Nicol and Swinney, 1989; Sturt, 2003). Similarly, the memory retrieval processes could be also sensitive to cross-linguistic differences (cf. Lago et al., 2015). We report one self-paced reading experiment and one eye-tracking experiment that examine the processing of subject-verb honorific agreement, a dependency that is different from those that have been studied to date, in Korean, a typologically different language from those previously studied. The overall results suggest that the retrieval processes underlying the processing of subject-verb honorific agreement in Korean are susceptible to facilitatory intrusion effects from a structurally illicit but feature-matching subject, with a pattern that is similar to subject-verb agreement in English. In addition, the attraction effect was not limited to the ungrammatical sentences but was also found in grammatical sentences. The clear attraction effect in the grammatical sentences suggest that the attraction effect does not solely arise as the result of an error-driven process (cf. Wagers et al., 2009), but is likely also to result from general mechanisms of retrieval processes of activating of potential items in memory (Vasishth et al., 2008).

Sugar in Moderation: Variable Sugar Diets Affect Short-Term Parasitoid Behavior

Science.gov (United States)

The biological control potential of parasitic wasps in the field is expected to increase with provisioning of sugar sources, which increase longevity and replenish carbohydrate reserves. Apanteles aristoteliae Viereck is an important parasitoid of Argyrotaenia franciscana (Walsingham), the orange to...

Close-range host searching behavior of the stemborer parasitoids Cotesia sesamiae and Dentichasmias busseolae: influence of a non-host-plant Melinis minutiflora

NARCIS (Netherlands)

Gohole, L.S.; Overholt, W.A.; Khan, Z.R.; Vet, L.E.M.

2005-01-01

Studies were conducted on the host searching behavior of the larval parasitoid Cotesia sesamiae (Cameron) (Hymenoptera: Braconidae) and the pupal parasitoid Dentichasmias busseolae Heinrich (Hymenoptera: Ichneumonidae), both of which attack lepidopteran (Crambidae, Noctuidae) cereal stemborers. The

Close-range host searching behavior of the stemborer parasitoids Cotesia sesamiae and Dentichasmias busseolae: Influence of a non-host plant Melinis minutiflora

NARCIS (Netherlands)

Gohole, L.S.; Overholt, W.A.; Khan, Z.U.; Vet, L.E.M.

2005-01-01

Studies were conducted on the host searching behavior of the larval parasitoid Cotesia sesamiae (Cameron) (Hymenoptera: Braconidae) and the pupal parasitoid Dentichasmias busseolae Heinrich (Hymenoptera: Ichneumonidae), both of which attack lepidopteran (Crambidae, Noctuidae) cereal stemborers. The

Effects of Switching Behavior for the Attraction on Pedestrian Dynamics.

Directory of Open Access Journals (Sweden)

Jaeyoung Kwak

Full Text Available Walking is a fundamental activity of our daily life not only for moving to other places but also for interacting with surrounding environment. While walking on the streets, pedestrians can be aware of attractions like shopping windows. They can be influenced by the attractions and some of them might shift their attention towards the attractions, namely switching behavior. As a first step to incorporate the switching behavior, this study investigates collective effects of switching behavior for an attraction by developing a behavioral model. Numerical simulations exhibit different patterns of pedestrian behavior depending on the strength of the social influence and the average length of stay. When the social influence is strong along with a long length of stay, a saturated phase can be defined at which all the pedestrians have visited the attraction. If the social influence is not strong enough, an unsaturated phase appears where one can observe that some pedestrians head for the attraction while others walk in their desired direction. These collective patterns of pedestrian behavior are summarized in a phase diagram by comparing the number of pedestrians who visited the attraction to the number of passersby near the attraction. Measuring the marginal benefits with respect to the strength of the social influence and the average length of stay enables us to identify under what conditions enhancing these variables would be more effective. The findings from this study can be understood in the context of the pedestrian facility management, for instance, for retail stores.

Determination of Opiinae parasitoids (Hymenoptera: Braconidae) associated with crop infesting Bactrocera spp. (Diptera: Tephritidae) using COI and Cyt b sequences

Science.gov (United States)

Shariff, Safiah; Yaakop, Salmah; Zain, Badrul Munir Md.

2013-11-01

Members of the Opiinae subfamily (Hymenoptera: Braconidae) are well known as important parasitoids of fruit fly larvae (Diptera: Tephritidae). They are widely used as biological control agents of fruit flies, especially the Bactrocera Macquart species that infest fruits. In this study, the larvae of fruit flies were collected from infested crops including star fruit, guava, wax apple and ridge gourd. The parasitized larvae were then reared under laboratory conditions until emergence of the adult parasitoids. Additionally, Malaise trap also was used to collect parasitoid species. The general concept of the multiplex PCR has been performed is to amplify two mitochondrial DNA markers, namely cytochrome oxidase subunit I (COI) and cytochrome b (Cyt b) simultaneously. Therefore, the lengthy process of reaction will be reduced. The status of the fruit fly species has also been confirmed by using COI marker on the early stage of the larvae. Maximum parsimony (MP) and Bayesian Inference (BI) were implemented to help and support the identification of Opiinae species. The result obtained from this study showed three parasitoid genera of the Opiinae viz. Fopius Wharton, Psyttalia Walker and Diachasmimorpha Viereck. Each genus has been determined by clustering together in a similar clade according to their infested crops. Therefore, accurate determination of parasitoids and the fruit fries species was highly useful and necessary for successful biological control of Bactrocera species.

Differences in memory dynamics between two closely related parasitoid wasp species

NARCIS (Netherlands)

Bleeker, M.A.K.; Smid, H.M.; Steidle, J.L.M.; Kruidhof, H.M.; van Loon, J.J.A.; Vet, L.E.M.

2006-01-01

The two closely related parasitoids Cotesia glomerata and C. rubecula (Hymenoptera: Braconidae) coexist in The Netherlands where they occupy slightly different niches. When searching for their caterpillar hosts, they use host plant odours that are released upon feeding by the caterpillars. The

The importance of phenology in studies of plant-herbivore-parasitoid interactions

NARCIS (Netherlands)

Fei, Minghui

2016-01-01

Thesis title: The importance of phenology in studies of plant-herbivore-parasitoid interactions Author: Minghui Fei Abstract As food resources of herbivorous insects, the quality and quantity of plants can directly affect the performance of herbivorous insects and indirectly affect

Effect of doses and of refuge on the insecticide selectivity to predators and parasitoids of soybean insect pests

International Nuclear Information System (INIS)

Corso, Ivan Carlos; Gazzoni, Decio Luiz; Nery, Manoel Eugenio

1999-01-01

A field experiment was conducted to evaluate seasonal effect of insecticides on predators and parasitoids of soybean insect pests. A randomized block design was used, with three replications, and the experiment was set up in the experimental station of the EMBRAPA-Centro Nacional de Pesquisa de Soja, located at Londrina, PR, Brazil. Treatments consisted of insecticide application to control the velvet bean caterpillar (1/21/1993) or the stink bug complex (3/4/1993). Insect population was sampled through the shock technique, consisting of an application of a broad spectrum insecticide over the plants to be sampled, being the insects collected on cloths placed on the ground, and transferred to the laboratory to be identified and counted. Statistical analysis revealed no differences on the populations of species of predators, diptera or himenoptera as a group. No effects of pest resurgence or secondary pest outbreaks were also observed. (author)

Metagenomic analysis of microbial community of a parasitoid wasp Megaphragma amalphitanum

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A.V. Nedoluzhko

2017-03-01

Full Text Available The vast majority of multicellular organisms coexist with bacterial symbionts that may play various roles during their life cycle. Parasitoid wasp Megaphragma amalphitanum (Hymenoptera: Trichogrammatidae belongs to the smallest known insects whose size is comparable with some bacteria. Using 16S rRNA gene sequencing and Whole Genome Sequencing (WGS, we described microbiota diversity for this arthropod and its potential impact on their lifecycle. Metagenomic sequences were deposited to SRA database which is available at NCBI with accession number SRX2363723 and SRX2363724. We found that small body size and limited lifespan do not lead to a significant reduction of bacterial symbionts diversity. At the same time, we show here a specific feature of microbiota composition in M. amalphitanum – the absence of the Rickettsiaceae family representatives that are known to cause sex-ratio distortion in arthropods and well represented in other populations of parasitoid wasps.

A Study on Effectiveness of Search Keyword Advertising to Attract Tourists Online

OpenAIRE

山本, 真嗣

2015-01-01

Regional tourism is currently receiving a great deal of attention, but the methodology for effectively attracting visitors is still developing. To effectively attract tourists, several factors that affect travelers’ destination decisions must be examined. In this study, I conducted a survey on attracting tourists online and measured the effect. I displayed ads on search results of keywords related to regional tourism, such as“ tourism Noto,”“ Noto tourism,” and“ Nanao tourism,” and used these...

The effects of facial adiposity on attractiveness and perceived leadership ability.

Science.gov (United States)

Re, Daniel E; Perrett, David I

2014-01-01

Facial attractiveness has a positive influence on electoral success both in experimental paradigms and in the real world. One parameter that influences facial attractiveness and social judgements is facial adiposity (a facial correlate to body mass index, BMI). Overweight people have high facial adiposity and are perceived to be less attractive and lower in leadership ability. Here, we used an interactive design in order to assess whether the most attractive level of facial adiposity is also perceived as most leader-like. We found that participants reduced facial adiposity more to maximize attractiveness than to maximize perceived leadership ability. These results indicate that facial appearance impacts leadership judgements beyond the effects of attractiveness. We suggest that the disparity between optimal facial adiposity in attractiveness and leadership judgements stems from social trends that have produced thin ideals for attractiveness, while leadership judgements are associated with perception of physical dominance.

THE EFFECT OF TRANSPORTATION INFRASTRUCTURE ONFOREIGN DIRECT INVESTMENT ATTRACTION IN IRAN

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Manijeh Taghilou Barzelaghi

2012-07-01

Full Text Available Weak transportation infrastructure in developing countries, e.g. Iran, presents abig obstacle to foreign direct investment attraction. One way of increasing theflow of foreign direct investment into a country is decreasing the production coststhrough expanding facilities as well as employing higher technology level. Thus,transportation cost usually is high in these countries and industries are oftenconcentrated in regions with more improved transportation system. The presentstudy aimed to investigate the effect of transportation infrastructure in Iran onforeign direct investment attraction. Hence, the researchers employed JohansenJuselius econometrics method to quantify the short run and long run effect oftransportation infrastructure, trade intensity, and market size on foreign directinvestment attraction during 1974-2007. The results emerging from the presentstudy indicated that transportationinfrastructure did not affect foreign directinvestment attraction in short run, but in long run, it had positive and significanteffect on foreign direct investment attraction.

The Effect of Attractiveness on Recognition Memory when Women Look at Female Faces

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Kana Kuraguchi

2011-05-01

Full Text Available In previous studies, the relationship between facial attractiveness and memory has been inconsistent. We investigated the effect of facial attractiveness on recognition memory in terms of gender and judgment contents. Both female and male facial images were judged for their attractiveness and personal character, and incidental memory was tested later. Recognition performance was shown as d' and analyzed with 2 (participant's gender x 2 (condition of attractiveness ANOVA. The interaction was significant for female faces but not for male faces. It is, therefore, suggested that the difference of gender affects the recognition memory concerning facial attractiveness. In particular, attractiveness of female faces had different effects for female participants when compared to other combinations. As a control, the interaction for female faces was not significant when the task was to judge the physical features such as the size of eyes and the angle of mouth. In sum, unattractive faces were better recognized than attractive faces in general except for the case when women judged attractiveness of female faces. These results suggest that there may be an effect of attention to attractiveness on recognition memory that is particularly strong when women look at female faces.

Identification and evaluation of a new entomopathogenic fungal strain against Riptortus pedestris (Hemiptera: Alydidae) and its two egg parasitoids

Science.gov (United States)

Lim, Un Taek

2018-01-01

A strain (ARP14) of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin was isolated from field-collected Riptortus pedestris (Fabricius) (Hemiptera: Alydidae). The lethal median concentration of the ARP14 strain was compared with that of a commercialized strain (GHA) of the same fungus against R. pedestris and its two egg parasitoids, Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) and Gryon japonicum (Ashmead) (Hymenoptera: Platygastridae). Mortality and mycosis rates were evaluated after exposure to five concentrations of the fungus, i.e., 1×109, 1×108, 1×107, 1×106, and 1×105 conidia/mL, using a glass scintillation vial as an exposure arena in 25.0 ± 0.5°C and 93.7 ± 2.9% RH. The lethal median concentrations (LC50) for 2nd and 4th instar nymphs, and adults of R. pedestris were not significantly different between the two strains of B. bassiana. However, the mycosis rate of ARP14 was 1.3 and 1.8 times higher than that of the GHA strain in 4th instar nymphs and adult females of R. pedestris, respectively, at the 1×108 conidia/mL concentration. More interestingly, the mycosis rates at 1×108 conidia/mL concentration in the parasitoids G. japonicum and O. nezarae were much lower in the ARP14 strain (15.0 and 0%) than in the GHA strain (73.3 and 66.0%), respectively, suggesting that the B. bassiana strain ARP14 is less virulent to these parasitoids than the commercially available strain. Our results suggest that B. bassiana ARP14 may be a potential new biopesticide against R. pedestris with fewer negative effects on beneficial parasitoids than currently available options. PMID:29664929

Cross-channel effects of vocal and physical attractiveness and their implications for interpersonal perception.

Science.gov (United States)

Zuckerman, M; Miyake, K; Hodgins, H S

1991-04-01

Judges' ratings of senders' vocal attractiveness from face-plus-voice (F+V) cues were influenced by senders' physical attractiveness, and ratings of senders' physical attractiveness from F+V cues were influenced by senders' vocal attractiveness. This occurred even when judges were warned not to pay attention to face when rating vocal attractiveness and not to pay attention to voice when rating physical attractiveness. Instructions to judge attractiveness without being told which channel to attend to resulted in ratings influenced by both vocal and physical attractiveness of senders. Because of cross-channel effects, F+V attractiveness ratings should be more highly related to F+V personality impressions than attractiveness ratings based on only face or only voice. The results supported this hypothesis. Implications of cross-channel effects for research on the attractiveness stereotype were discussed.

Life-history strategies in parasitoid wasps: a comparative analysis of 'ovigeny'

NARCIS (Netherlands)

Jervis, M.A.; Heimpel, G.E.; Ferns, P.N.; Harvey, J.A.; Kidd, N.A.C.

2001-01-01

1. Ecologists concerned with life-history strategies of parasitoid wasps have recently focused on interspecific variation in the fraction of the maximum potential lifetime egg complement that is mature when the female emerges into the environment. Species that have all of this complement mature upon

Semiochemical exploitation of host-associated cues by seven Melittobia parasitoid species

NARCIS (Netherlands)

González, Jorge M.; Camino, Dakota; Simon, Sabrina; Cusumano, Antonino

2018-01-01

Chemical compounds (infochemicals or semiochemicals) play an important role both in intra-specific and inter-specific communication. For example, chemical cues appear to play a key role in the host selection process adopted by insect parasitoids. In recent years significant advances have been made

First extensive characterization of the venom gland from an egg parasitoid

NARCIS (Netherlands)

Cusumano, Antonino; Duvic, Bernard; Jouan, Véronique; Ravallec, Marc; Legeai, Fabrice; Peri, Ezio; Colazza, Stefano; Volkoff, Anne Nathalie

2018-01-01

The venom gland is a ubiquitous organ in Hymenoptera. In insect parasitoids, the venom gland has been shown to have multiple functions including regulation of host immune response, host paralysis, host castration and developmental alteration. However, the role played by the venom gland has been

Effects of Temperature and Photoperiod on the Reproductive Biology and Diapause of Oobius agrili (Hymenoptera: Encyrtidae), an Egg Parasitoid of Emerald Ash Borer (Coleoptera: Buprestidae).

Science.gov (United States)

Hoban, J; Duan, J J; Hough-Goldstein, J

2016-04-25

Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae) is a solitary egg parasitoid of the invasive emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), and has been introduced to the United States for classical biological control. We characterized the weekly survivorship, fecundity, and diapause patterns of both diapaused and nondiapaused populations of O. agrili under four different temperature-photophase combinations: 30°C (warm) and 20°C (cold) temperatures with both long-day (16 h) and short-day (8 h) photophase. Results of this study showed that regardless of the length of photophase, parental parasitoids of both diapaused and nondiapaused O. agrili survived significantly longer at 20°C than at 30°C. Both populations also laid their eggs faster at 30°C compared with those at 20°C. Higher proportions of the progeny produced by both populations of O. agrili were induced into diapause by short-day (8 h) photophase, regardless of rearing temperature. In addition, the diapaused parasitoids in the short-day photophase treatment at both warm and cold temperatures produced increasing proportions of diapaused progeny over time, whereas no significant differences were observed in the proportions of diapaused progeny by the nondiapaused parasitoids over different sampling times. These findings suggest that O. agrili should be continuously reared under warm temperature and long-day photoperiod (to avoid diapause for increased reproduction). In addition, we recommend that diapaused adults be used for field releases in early summer when temperatures are still relatively low (∼20°C) and host eggs are available so that they can produce multiple generations prior to overwintering. Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is written by US Government employees and is in the public domain in the United States.

Reciprocal diversification in a complex plant-herbivore-parasitoid food web

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Bokma Folmer

2007-11-01

Full Text Available Abstract Background Plants, plant-feeding insects, and insect parasitoids form some of the most complex and species-rich food webs. According to the classic escape-and-radiate (EAR hypothesis, these hyperdiverse communities result from coevolutionary arms races consisting of successive cycles of enemy escape, radiation, and colonization by new enemy lineages. It has also been suggested that "enemy-free space" provided by novel host plants could promote host shifts by herbivores, and that parasitoids could similarly drive diversification of gall form in insects that induce galls on plants. Because these central coevolutionary hypotheses have never been tested in a phylogenetic framework, we combined phylogenetic information on willow-galling sawflies with data on their host plants, gall types, and enemy communities. Results We found that evolutionary shifts in host plant use and habitat have led to dramatic prunings of parasitoid communities, and that changes in gall phenotype can provide "enemy-free morphospace" for millions of years even in the absence of host plant shifts. Some parasites have nevertheless managed to colonize recently-evolved gall types, and this has apparently led to adaptive speciation in several enemy groups. However, having fewer enemies does not in itself increase speciation probabilities in individual sawfly lineages, partly because the high diversity of the enemy community facilitates compensatory attack by remaining parasite taxa. Conclusion Taken together, our results indicate that niche-dependent parasitism is a major force promoting ecological divergence in herbivorous insects, and that prey divergence can cause speciation in parasite lineages. However, the results also show that the EAR hypothesis is too simplistic for species-rich food webs: instead, diversification seems to be spurred by a continuous stepwise process, in which ecological and phenotypic shifts in prey lineages are followed by a lagged evolutionary

The Perceived Relationship between Physical Attractiveness and Social Influence Effectiveness.

Science.gov (United States)

Longo, Laura C.; Ashmore, Richard D.

The power of beauty has been contemplated by writers, poets, and philosophers for centuries. The link between the target physical attractiveness and perceived social influence effectiveness has not been directly and systematically investigated. The goal of this study was to assess whether physically attractive (versus unattractive) individuals are…

Mountain aphid and parasitoid guilds on Aconitum spp. in Europe

Czech Academy of Sciences Publication Activity Database

Havelka, Jan; Tomanović, Ž.; Kos, K.; Kavallieratos, N. G.; Janeček, J.; Pons, X.; Rakhshani, E.; Starý, Petr

2014-01-01

Roč. 67, č. 1 (2014), s. 57-61 ISSN 1721-8861 Grant - others:Ministry of Education, Science and Technological Development(RS) III43001 Institutional support: RVO:60077344 Keywords : aphis * Aphididae * parasitoids Subject RIV: EH - Ecology, Behaviour Impact factor: 1.494, year: 2014 http://www.bulletinofinsectology.org/pdfarticles/vol67-2014-057-061havelka.pdf

The Behavioural Abilities of Meteorus versicolor Wesm. and Rogas rossicus Kok. (Hymenoptera, Branconidae) Parasitoids of Tephrina arenacearia Den. Et Schiff. (Lepidoptera, Geometridae)

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KERIMOVA, Ilhama Gudrat Gizi

1998-01-01

This paper concerns with the behavioural abilities of Meteorus versicolor Wesm. and Rogas rossicus Kok. (Hymenoptera, Braconidae)-internal parasitoids of Thephrina arenacearia Den. et Schiff. (Lepidoptera, Geometridae) as well. Periods of development phases and searching, ovipositional and mating behaviour of both parasitoids have been investigated.

Selfish element maintains sex in natural populations of a parasitoid wasp.

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Stouthamer, R.; Tilborg, van M.; Jong, de J.H.; Nunney, L.; Luck, R.F.

2001-01-01

Genomic conflicts between heritable elements with different modes of inheritance are important in the maintenance of sex and in the evolution of sex ratio. Generally, we expect sexual populations to exhibit a 1:1 sex ratio. However, because of their biology, parasitoid wasps often exhibit a

Potential dependence of the effective attraction in doped C60

International Nuclear Information System (INIS)

Goff, W.E.; Phillips, P.

1992-01-01

In an effort to explain superconductivity in the alkali-doped C 60 , Chakravarty and Kivelson have proposed that there is a net effective electron attraction due to intramolecular Coulomb forces. The calculation makes use of a Hubbard model in which long-range interactions are absent. The authors show that this result strongly depends on the form of the electron-electron interaction and that for potentials with long-range interactions, e.g. an Ohno potential that interpolates between an on site energy and 1/r at large distances, they do not find an effective attraction. Reasonable screening does not significantly modify this result. This indicates that the electronic mechanism in the proposed form cannot be the primary source of an attractive interaction

Intraspecific competition: the role of lags between attack and death in host-parasitoid interactions.

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Cameron, T C; Metcalfe, D; Beckerman, A P; Sait, S M

2007-05-01

Many natural enemies do not immediately kill their host, and the lag this creates between attack and host death results in mixed populations of uninfected and infected hosts. Both competition and parasitism are known to be major structuring forces in ecological communities; however, surprisingly little is known about how the competitive nature of infected hosts could affect the survival and dynamics of remaining uninfected host populations. Using a laboratory system comprising the Indian meal moth, Plodia interpunctella, and a solitary koinobiont parasitoid, Venturia canescens, we address this question by conducting replicated competition experiments between the unparasitized and parasitized classes of host larvae. For varying proportions of parasitized host larvae and competitor densities, we consider the effects of competition within (intraclass) and between (interclass) unparasitized and parasitized larvae on the survival, development time, and size of adult moths and parasitoid wasps. The greatest effects were on survival: increased competitor densities reduced survival of both parasitized and unparasitized larvae. However, unparasitized larvae survival, but not parasitized larvae survival, was reduced by increasing interclass competition. To our knowledge, this is the first experimental demonstration of the competitive superiority of parasitized over unparasitized hosts for limiting resources. We discuss possible mechanisms for this phenomenon, why it may have evolved, and its possible influence on the stability of host-parasite dynamics.

Adaptation effects to attractiveness of face photographs and art portraits are domain-specific

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Hayn-Leichsenring, Gregor U.; Kloth, Nadine; Schweinberger, Stefan R.; Redies, Christoph

2013-01-01

We studied the neural coding of facial attractiveness by investigating effects of adaptation to attractive and unattractive human faces on the perceived attractiveness of veridical human face pictures (Experiment 1) and art portraits (Experiment 2). Experiment 1 revealed a clear pattern of contrastive aftereffects. Relative to a pre-adaptation baseline, the perceived attractiveness of faces was increased after adaptation to unattractive faces, and was decreased after adaptation to attractive faces. Experiment 2 revealed similar aftereffects when art portraits rather than face photographs were used as adaptors and test stimuli, suggesting that effects of adaptation to attractiveness are not restricted to facial photographs. Additionally, we found similar aftereffects in art portraits for beauty, another aesthetic feature that, unlike attractiveness, relates to the properties of the image (rather than to the face displayed). Importantly, Experiment 3 showed that aftereffects were abolished when adaptors were art portraits and face photographs were test stimuli. These results suggest that adaptation to facial attractiveness elicits aftereffects in the perception of subsequently presented faces, for both face photographs and art portraits, and that these effects do not cross image domains. PMID:24349690

Adaptation Effects to Attractiveness of Face Photographs and Art Portraits are Domain-Specific

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Gregor U. Hayn-Leichsenring

2013-08-01

Full Text Available We studied the neural coding of facial attractiveness by investigating effects of adaptation to attractive and unattractive human faces on the perceived attractiveness of veridical human face pictures (Experiment 1 and art portraits (Experiment 2. Experiment 1 revealed a clear pattern of contrastive aftereffects. Relative to a pre-adaptation baseline, the perceived attractiveness of faces was increased after adaptation to unattractive faces, and was decreased after adaptation to attractive faces. Experiment 2 revealed similar aftereffects when art portraits rather than face photographs were used as adaptors and test stimuli, suggesting that effects of adaptation to attractiveness are not restricted to facial photographs. Additionally, we found similar aftereffects in art portraits for beauty, another aesthetic feature that, unlike attractiveness, relates to the properties of the image (rather than to the face displayed. Importantly, Experiment 3 showed that aftereffects were abolished when adaptors were art portraits and face photographs were test stimuli. These results suggest that adaptation to facial attractiveness elicits aftereffects in the perception of subsequently presented faces, for both face photographs and art portraits, and that these effects do not cross image domains.

Ecosystem-Based Incorporation of Nectar-Producing Plants for Stink Bug Parasitoids

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Glynn Tillman

2017-06-01

Full Text Available Adult parasitoids of pest insects rely on floral resources for survival and reproduction, but can be food-deprived in intensively managed agricultural systems lacking these resources. Stink bugs are serious pests for crops in southwest Georgia. Provisioning nectar-producing plants for parasitoids of stink bugs potentially can enhance biocontrol of these pests. Knowledge of spatial and temporal availability and distribution of stink bugs in host plants is necessary for appropriate timing and placement of flowering plants in agroecosystems. Stink bugs move between closely associated host plants throughout the growing season in response to deteriorating suitability of their host plants. In peanut-cotton farmscapes, stink bugs develop in peanut, and subsequently the adults disperse into adjacent cotton. Parasitism of Nezara viridula (L. adults by Trichopoda pennipes (F. at the peanut-cotton interface was significantly higher in cotton with a strip of milkweed or buckwheat between the two crops than in cotton alone. Milkweed and buckwheat also provided nectar to a wide range of insect pollinators. Monarch butterflies fed on milkweed. When placed between peanut and cotton, a strip of soybean was an effective trap crop for cotton, reducing economic damage. Incorporation of buckwheat near soybean enhanced parasitism of Euschistus servus (Say eggs by Telenomus podisi Ashmead in cotton. In conclusion, nectar provision enhances biocontrol of stink bugs, acts together with other management tactics for stink bug control, and aids in conservation of natural enemies, insect pollinators, and the monarch butterfly.

Seletividade de diferentes agrotóxicos usados na cultura da soja ao parasitoide de ovos Telenomus remus Selectivity of different pesticides used in soybean to the eggs parasitoid Telenomus remus

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Eduardo Lima do Carmo

2009-11-01

Full Text Available A preservação dos agentes de controle biológico no agroecossistema é indispensável para o sucesso do manejo integrado de pragas. Entretanto, o controle químico de pragas ainda é indispensável em diversas culturas. Nesse contexto, a seletividade dos agrotóxicos aos inimigos naturais deve ser sempre considerada na escolha do melhor produto. Portanto, este estudo verificou o impacto causado por diferentes agrotóxicos na emergência do parasitoide de ovos Telenomus remus Nixon (Hymenoptera: Scelionidae, quando aplicados nas fases de larva e pupa (posturas de 100 a 150 ovos de Spodoptera frugiperda (J.E. Smith (Lepidoptera: Noctuidae seis e 10 dias após o parasitismo, respectivamente. Três ensaios, com 11 tratamentos e cinco repetições, foram conduzidos em laboratório com inseticidas, fungicidas e herbicidas, respectivamente. Cada ensaio foi conduzido com 10 tratamentos de agrotóxicos e água como testemunha seletiva. Todos os produtos fitossanitários foram testados nas doses utilizadas na cultura da soja. Ovos de S. frugiperda parasitados por T. remus foram imersos nos tratamentos por cinco segundos e, após secagem total, foram acondicionados em sacos plásticos até a emergência dos adultos dos parasitoides. A viabilidade do parasitismo foi avaliada, e a redução na emergência dos parasitoides foi classificada segundo as normas da International Organization for Biological Control (IOBC. Os resultados mostraram que os inseticidas do grupo dos reguladores de crescimento, como o flufenoxurom, diflubenzurom e metoxifenozido e também os inseticidas imidacloprido + beta-ciflutrina e acefato, foram seletivos às fases imaturas do parasitoide. Espinosade foi classificado como inócuo para larvas de T. remus. Gama-cialotrina foi levemente nocivo para larvas e inócuo para pupas. Bifentrina e clorpirifós foram, respectivamente, levemente nocivo e nocivo para ambas as fases de desenvolvimento de T. remus. Com relação aos herbicidas

Parasitoid Diaeretiella rapae (Hymenoptera: Braconidae) Adjusts Reproductive Strategy When Competing for Hosts.

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Kant, Rashmi; Minor, Maria A

2017-06-01

Parasitoid fitness depends on its ability to manipulate reproductive strategies when in competition. This study investigated the parasitism and sex allocation strategies of the parasitic wasp Diaeretiella rapae McIntosh at a range of host (Brevicoryne brassicae L.) and conspecific densities. The results suggest that D. rapae females adjust their progeny production and progeny sex ratio with changing competition. When foraging alone, female D. rapae parasitize larger number of B. brassicae nymphs when the number of available hosts is increased, but the overall proportion of parasitized hosts decreases with increase in host density. The proportion of female offspring also decreases with elevated host density. Increase in the number of female D. rapae foraging together increased total parasitism, but reduced relative contribution of each individual female. The number of female progeny decreased when multiple females competed for the same host. However, foraging experience in the presence of one or more conspecifics increased the parasitism rate and proportion of female progeny. Competing females were more active during oviposition and had shorter lives. The study suggests that both host and foundress (female parasitoid) densities have significant effect on progeny production, sex allocation, and longevity of foraging females. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Biology, life history, and laboratory rearing of Atanycolus cappaerti (Hymenoptera:Braconidae), a larval parasitoid of the invasive Emerald Ash Borer (Coleoptera: Buprestidae)

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Atanycolus cappaerti Marsh and Strazanac is a native North American parasitoid that has been found to parasitize the invasive emerald ash borer (EAB), Agrilus planipennis Fairmaire, which has killed millions of ash trees since it was first detected in Michigan. A native parasitoid like A. cappaerti...

Dinâmica populacional do parasitoide de ovos erythmelus tingitiphagus (hymenoptera: mymaridae em clone de seringueira, em Itiquira, MT Population dynamic of egg parasitoid erythmelus tingitiphagus (hymenoptera: mymaridae in rubber tree clone in Itiquira, Mato Grosso State, Brazil

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Rodrigo Souza Santos

2013-04-01

Full Text Available O percevejo-de-renda Leptopharsa heveae Drake & Poor (Hemiptera: Tingidae é uma das mais importantes pragas da heveicultura no Brasil, principalmente nas regiões Sudeste e Centro-Oeste. Devido ao seu hábito sugador, na face abaxial das folhas, esta praga leva à senescência precoce das mesmas e a reduções na produção de látex em até 30%. Dentre os inimigos naturais de L. heveae está o parasitoide de ovos Erythmelus tingitiphagus (Soares (Hymenoptera: Mymaridae, regulando suas populações em condições naturais. O objetivo deste estudo foi verificar a dinâmica populacional deste parasitoide, bem como correlacioná-la com os fatores meteorológicos temperatura e pluviosidade, em plantio comercial de seringueira do clone PB 217, em Itiquira, MT. Semanalmente foram coletadas quatro folhas maduras por árvore, no terço inferior da copa de 40 árvores, totalizando 160 folhas por amostragem, no período de agosto de 2006 a janeiro de 2007. Houve correlação positiva entre a dinâmica populacional e os fatores meteorológicos, sendo o pico populacional do parasitoide observado no mês de novembro e declinando até janeiro na área estudada.The lace bug Leptopharsa heveae Drake & Poor (Hemiptera: Tingidae is one of the most import heveiculture pests in Brazil, mainly in the southeast and central-west regions. Due to its sucking habit on the abaxial surface, this pest causes precocious senescence in leaves, and leads to the reduction in latex production in up to 30% of them. Among the natural enemies of L. heveae is the egg parasitoid Erythmelus tingitiphagus (Soares (Hymenoptera: Mymaridae, regulating populations of L. heveae in natural conditions. The objective of this work was to verify the population dynamics of this parasitoid, as well as to correlate it with meteorological factors such as temperature and rainfall, in a commercial plantation of rubber trees of the PB 217 clone, in Itiquira, in the Mato Grosso state, Brazil. Four

Alien dominance of the parasitoid wasp community along an elevation gradient on Hawai'i Island

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Peck, R.W.; Banko, P.C.; Schwarzfeld, M.; Euaparadorn, M.; Brinck, K.W.

2008-01-01

Through intentional and accidental introduction, more than 100 species of alien Ichneumonidae and Braconidae (Hymenoptera) have become established in the Hawaiian Islands. The extent to which these parasitoid wasps have penetrated native wet forests was investigated over a 1,765 m elevation gradient on windward Hawai'i Island. For >1 year, malaise traps were used to continuously monitor parasitoid abundance and species richness in nine sites over three elevations. A total of 18,996 individuals from 16 subfamilies were collected. Overall, the fauna was dominated by aliens, with 44 of 58 species foreign to the Hawaiian Islands. Ichneumonidae was dominant over Braconidae in terms of both diversity and abundance, comprising 67.5% of individuals and 69.0% of species collected. Parasitoid abundance and species richness varied significantly with elevation: abundance was greater at mid and high elevations compared to low elevation while species richness increased with increasing elevation, with all three elevations differing significantly from each other. Nine species purposely introduced to control pest insects were found, but one braconid, Meteorus laphygmae, comprised 98.0% of this assemblage, or 28.3% of the entire fauna. Endemic species, primarily within the genera Spolas and Enicospilus, were collected almost exclusively at mid- and high-elevation sites, where they made up 22.1% and 36.0% of the total catch, respectively. Overall, 75.9% of species and 96.0% of individuals are inferred to parasitize Lepidoptera larvae and pupae. Our results support previous data indicating that alien parasitoids have deeply penetrated native forest habitats and may have substantial impacts on Hawaiian ecosystems. ?? 2008 Springer Science+Business Media B.V.

Associative learning in two closely related parasitoid wasps: a neuroecological approach

NARCIS (Netherlands)

Bleeker, M.A.K.

2005-01-01

Insects are useful model organisms to study learning and memory. Their brains are less complex than vertebrate brains, but the basic mechanisms of learning and memory are similar in both taxa. In this thesis I study learning and subsequent memory formation in two parasitoid wasp species that differ

Evaluation of the host specificity of Spathius galinae (Hymenoptera: Braconidae), a larval parasitoid of the emerald ash borer (Coleoptera: Buprestidae) in Northeast Asia

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Host-specificity determination prior to the introduction of non-native natural enemies (predators and parasitoids) is a critical component of the risk assessment for modern classical biological control programs. In the present study, we assessed the host specificity of a newly described parasitoid,...

Physical attractiveness, issue agreement, and assimilation effects in candidate appraisal.

Science.gov (United States)

Schubert, James N; Curran, Margaret Ann; Strungaru, Carmen

2011-01-01

This study examines the cognitive and affective factors of candidate appraisal by manipulating candidate attractiveness and levels of issue agreement with voters. Drawing upon research in evolutionary psychology and cognitive neuroscience, this analysis proposes that automatic processing of physical appearance predisposes affective disposition toward more attractive candidates, thereby influencing cognitive processing of issue information. An experimental design presented attractive and unattractive candidates who were either liberal or conservative in a mock primary election. The data show strong partial effects for appearance on vote intention, an interaction between appearance and issue agreement, and a tendency for voters to assimilate the dissimilar views of attractive candidates. We argue that physical appearance is important in primary elections when the differences in issue positions and ideology between candidates is small.

Romantic Red: Testing the Characteristics of Color–Attraction Effects in a Novel Paradigm

OpenAIRE

Lisa A. Williams; Timothy P. Schofield; Thomas J. Whitford

2017-01-01

The red-attraction effect refers to the finding that the color red enhances attractiveness ratings of targets, and is most robustly observed when males rate females. Three previously unexplored aspects of color-attraction effects were tested in a single experiment with a large sample size (N = 778). The effect of exposure to a color and the impact of pairing a color with a target were disentangled using a novel design. Moreover, we tested the proposition that color exerts its effects outside ...

Gustatory response and longevity in Aphidius parasitoids and their hyperparasitoid Dendrocerus aphidum

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Goelen, Tim; Baets, Dieter; Kos, Martine; Paulussen, Caroline; Lenaerts, Marijke; Rediers, Hans; Wäckers, F.L.; Jacquemyn, Hans; Lievens, Bart

2018-01-01

Aphid parasitoids are commonly used in the biological control of aphids. However, their success in biological control largely depends on the availability of carbohydrate-rich food as an energy source for maintenance and reproduction. Therefore, as these resources have become rare in modern

Tracking the elusive history of diversification in plant-herbivorous insect-parasitoid food webs: insights from figs and fig wasps.

Science.gov (United States)

Kjellberg, Finn; Proffit, Magali

2016-02-01

The food webs consisting of plants, herbivorous insects and their insect parasitoids are a major component of terrestrial biodiversity. They play a central role in the functioning of all terrestrial ecosystems, and the number of species involved is mind-blowing (Nyman et al. 2015). Nevertheless, our understanding of the evolutionary and ecological determinants of their diversity is still in its infancy. In this issue of Molecular Ecology, Sutton et al. (2016) open a window into the comparative analysis of spatial genetic structuring in a set of comparable multitrophic models, involving highly species-specific interactions: figs and fig wasps. This is the first study to compare genetic structure using population genetics tools in a fig-pollinating wasp (Pleistodontes imperialis sp1) and its main parasitoid (Sycoscapter sp.A). The fig-pollinating wasp has a discontinuous spatial distribution that correlates with genetic differentiation, while the parasitoid bridges the discontinuity by parasitizing other pollinator species on the same host fig tree and presents basically no spatial genetic structure. The full implications of these results for our general understanding of plant-herbivorous insect-insect parasitoids diversification become apparent when envisioned within the framework of recent advances in fig and fig wasp biology. © 2016 John Wiley & Sons Ltd.

Metabolic and proteomic profiling of diapause in the aphid parasitoid Praon volucre.

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Hervé Colinet

Full Text Available BACKGROUND: Diapause, a condition of developmental arrest and metabolic depression exhibited by a wide range of animals is accompanied by complex physiological and biochemical changes that generally enhance environmental stress tolerance and synchronize reproduction. Even though some aspects of diapause have been well characterized, very little is known about the full range of molecular and biochemical modifications underlying diapause in non-model organisms. METHODOLOGY/PRINCIPAL FINDINGS: In this study we focused on the parasitic wasp, Praon volucre that exhibits a pupal diapause in response to environmental signals. System-wide metabolic changes occurring during diapause were investigated using GC-MS metabolic fingerprinting. Moreover, proteomic changes were studied in diapausing versus non-diapausing phenotypes using a combination of two-dimensional differential gel electrophoresis (2D-DIGE and mass spectrometry. We found a reduction of Krebs cycle intermediates which most likely resulted from the metabolic depression. Glycolysis was galvanized, probably to favor polyols biosynthesis. Diapausing parasitoids accumulated high levels of cryoprotective polyols, especially sorbitol. A large set of proteins were modulated during diapause and these were involved in various functions such as remodeling of cytoskeleton and cuticle, stress tolerance, protein turnover, lipid metabolism and various metabolic enzymes. CONCLUSIONS/SIGNIFICANCE: The results presented here provide some first clues about the molecular and biochemical events that characterize the diapause syndrome in aphid parasitoids. These data are useful for probing potential commonality of parasitoids diapause with other taxa and they will help creating a general understanding of diapause underpinnings and a background for future interpretations.

Study on the Hymenoptera parasitoid associated with Lepidoptera larvae in reforestation and agrosilvopastoral systems at Fazenda Canchim (Embrapa Pecuária Sudeste) São Carlos, SP, Brazil.

Science.gov (United States)

Pereira, A G; Silva, R B; Dias, M M; Penteado-Dias, A M

2015-11-01

The aim of this study was to characterize the local fauna of Hymenoptera parasitoids associated with Lepidoptera larvae in areas of reforestation and agrosilvopastoral systems at Fazenda Canchim (Embrapa Pecuária Sudeste, São Carlos, SP, Brazil). Lepidoptera larvae collected with entomological umbrella were kept in the laboratory until emergence of adults or their parasitoids. From those collected in the agrosilvopastoral system, emerged 267 specimens of hymenopteran parasitoids belonging to 16 genera: Braconidae, Agathidinae (Alabagrus), Braconinae (Bracon), Microgastrinae (Cotesia, Diolcogaster, Glyptapanteles, Pholetesor and Protapanteles), Orgilinae (Orgilus); Ichneumonidae, Campopleginae (Casinaria, Charops and Microcharops); Chalcididae, Chalcidinae (Brachymeria and Conura); Eulophidae, Entedoninae (Horismenus), Eulophinae (Elachertus and Euplectrus). From the Lepidoptera larvae collected in the reforestation, emerged 68 specimens of hymenopteran parasitoids, belonging to 8 genera: Chalcididae, Chalcidinae (Conura); Ichneumonidae, Pimplinae (Neotheronia), Campopleginae (Charops and Microcharops) and Braconidae, Microgastrinae (Apanteles, Diolcogaster, Distatrix, Glyptapanteles and Protapanteles). The results of this study suggest the occurrence of a wide variety of Hymenoptera parasitoids in the studied environments.

Study on the Hymenoptera parasitoid associated with Lepidoptera larvae in reforestation and agrosilvopastoral systems at Fazenda Canchim (Embrapa Pecuária Sudeste São Carlos, SP, Brazil

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A. G. Pereira

Full Text Available Abstract The aim of this study was to characterize the local fauna of Hymenoptera parasitoids associated with Lepidoptera larvae in areas of reforestation and agrosilvopastoral systems at Fazenda Canchim (Embrapa Pecuária Sudeste, São Carlos, SP, Brazil. Lepidoptera larvae collected with entomological umbrella were kept in the laboratory until emergence of adults or their parasitoids. From those collected in the agrosilvopastoral system, emerged 267 specimens of hymenopteran parasitoids belonging to 16 genera: Braconidae, Agathidinae (Alabagrus, Braconinae (Bracon, Microgastrinae (Cotesia, Diolcogaster, Glyptapanteles, Pholetesor and Protapanteles, Orgilinae (Orgilus; Ichneumonidae, Campopleginae (Casinaria, Charops and Microcharops; Chalcididae, Chalcidinae (Brachymeria and Conura; Eulophidae, Entedoninae (Horismenus, Eulophinae (Elachertus and Euplectrus. From the Lepidoptera larvae collected in the reforestation, emerged 68 specimens of hymenopteran parasitoids, belonging to 8 genera: Chalcididae, Chalcidinae (Conura; Ichneumonidae, Pimplinae (Neotheronia, Campopleginae (Charops and Microcharops and Braconidae, Microgastrinae (Apanteles, Diolcogaster, Distatrix, Glyptapanteles and Protapanteles. The results of this study suggest the occurrence of a wide variety of Hymenoptera parasitoids in the studied environments.

Study on the Hymenoptera parasitoid associated with Lepidoptera larvae in reforestation and agrosilvopastoral systems at Fazenda Canchim (Embrapa Pecuária Sudeste) São Carlos, SP, Brazil

OpenAIRE

Pereira,A. G.; Silva,R. B.; Dias,M. M.; Penteado-Dias,A. M.

2015-01-01

Abstract The aim of this study was to characterize the local fauna of Hymenoptera parasitoids associated with Lepidoptera larvae in areas of reforestation and agrosilvopastoral systems at Fazenda Canchim (Embrapa Pecuária Sudeste, São Carlos, SP, Brazil). Lepidoptera larvae collected with entomological umbrella were kept in the laboratory until emergence of adults or their parasitoids. From those collected in the agrosilvopastoral system, emerged 267 specimens of hymenopteran parasitoids belo...

The dipteran parasitoid Exorista bombycis induces pro- and anti-oxidative reactions in the silkworm Bombyx mori: Enzymatic and genetic analysis.

Science.gov (United States)

Makwana, Pooja; Pradeep, Appukuttan Nair R; Hungund, Shambhavi P; Ponnuvel, Kangayam M; Trivedy, Kanika

2017-02-01

Hymenopteran parasitoids inject various factors including polydnaviruses along with their eggs into their host insects that suppress host immunity reactions to the eggs and larvae. Less is known about the mechanisms evolved in dipteran parasitoids that suppress host immunity. Here we report that the dipteran, Exorista bombycis, parasitization leads to pro-oxidative reactions and activation of anti-oxidative enzymes in the silkworm Bombyx mori larva. We recorded increased activity of oxidase, superoxide dismutase, thioredoxin peroxidase, catalase, glutathione-S-transferase (GST), and peroxidases in the hemolymph plasma, hemocytes, and fat body collected from B. mori after E. bombycis parasitization. Microarray and qPCR showed differential expression of genes encoding pro- and anti-oxidant enzymes in the hemocytes. The significance of this work lies in increased understanding of dipteran parasitoid biology. © 2017 Wiley Periodicals, Inc.

The impact of resource limitation and the phenology of parasitoid attack on the duration of insect herbivore outbreaks.

Science.gov (United States)

Umbanhowar, James; Hastings, Alan

2002-11-01

Fluctuations in resource quality and quantity, and changes in mortality due to predators and parasites are thought to be of prime importance in the regular fluctuations of forest insects. We examine how food limitation and parasitoids with different phenologies of attack regulate the population cycles of insect hosts. Our analysis of the limit cycle of a model with a biologically realistic form of density dependence in the host yields two novel predictions. First, outbreaks will typically last for only 2 generations after parasitoids begin to reduce the host population below the maximum density. Second, host growth rate is important in determining cycle length only when parasitoids attack before the impacts of resource limitation affect the host. The robustness of these predictions are tested using a more general form of density dependence in the host, revealing that our predictions are valid as long as density dependence in the host is not too overcompensatory.

Impact of botanical pesticides derived from Melia azedarach and Azadirachta indica on the biology of two parasitoid species of the diamondback moth

NARCIS (Netherlands)

Charleston, D.S.; Kfir, R.; Dicke, M.; Vet, L.E.M.

2005-01-01

The effect of two botanical pesticides was tested on two species of parasitoids, Cotesia plutellae and Diadromus collaris. Aqueous leaf extracts from the syringa tree, Melia azedarach and commercial formulations from the neem tree, Azadirachta indica, Neemix 4.5 were investigated in the laboratory

Spatio-Temporal Dynamics of Viruses are Differentially Affected by Parasitoids Depending on the Mode of Transmission

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Elisa Viñuela

2012-11-01

Full Text Available Relationships between agents in multitrophic systems are complex and very specific. Insect-transmitted plant viruses are completely dependent on the behaviour and distribution patterns of their vectors. The presence of natural enemies may directly affect aphid behaviour and spread of plant viruses, as the escape response of aphids might cause a potential risk for virus dispersal. The spatio-temporal dynamics of Cucumber mosaic virus (CMV and Cucurbit aphid-borne yellows virus (CABYV, transmitted by Aphis gossypii in a non-persistent and persistent manner, respectively, were evaluated at short and long term in the presence and absence of the aphid parasitoid, Aphidius colemani. SADIE methodology was used to study the distribution patterns of both the virus and its vector, and their degree of association. Results suggested that parasitoids promoted aphid dispersion at short term, which enhanced CMV spread, though consequences of parasitism suggest potential benefits for disease control at long term. Furthermore, A. colemani significantly limited the spread and incidence of the persistent virus CABYV at long term. The impact of aphid parasitoids on the dispersal of plant viruses with different transmission modes is discussed.

A checklist of the species of Anastrepha with the families of their host plants and hymenopteran parasitoids in Brazil

International Nuclear Information System (INIS)

Zucchi, Roberto Antonio

2000-01-01

Many surveys on fruit flies have already been carried out by several researchers in Brazil while others are still going on. Most of these surveys were conducted in areas where no studies had been previously done. With these surveys, new species and new records of species were found in Brazil. Also, in this decade, several surveys on fruit fly braconid parasitoids were conducted. These data have been summarised recently, because of the great interest in the biological control of fruit flies in Brazil. Research on eucoilid fruit fly parasitoids have been largely neglected. However, taxonomic studies are being conducted on eucoilids associated with frugivorous flies (Tephritidae and Lonchaeidae) in Brazil. All the data on fruit flies, host plants and hymenopteran parasitoids are unfortunately scattered in the literature and frequently are only published as dissertations or congress abstracts which are not widely available. Even when submitted for publication, papers take a long time to come out in Brazil. Consequently, it is very difficult to get a list of the Anastrepha species in Brazil, or to determine which host plant species are associated with them. These data are of particular interest in the case of economically important species, especially those considered as quarantine pests. Therefore, such a list is very useful for regulatory entomologists and pest management programmes by listing the Anastrepha species in Brazil and their associated host plants and hymenopteran parasitoids. The objective of this paper is to gather some available records of the Anastrepha species, their host plants and hymenopteran parasitoids (Braconidae and Eucoilidae) published in Brazil. Due to the space limitation of this paper, only families of the host plants of the Anastrepha species are presented. In fact, this work is part of a research which deals with the preparation of a database for the Anastrepha species in Brazil

Relationship between Physical Attractiveness, Physical Effectiveness, and Self-Esteem: A Cross-Sectional Analysis among Adolescents.

Science.gov (United States)

Thornton, Bill; Ryckman, Richard M.

1991-01-01

Examined contributions of physical attractiveness and physical effectiveness to self-esteem among adolescents in grades 7, 9, and 11, and college freshmen. Both attractiveness and effectiveness were significantly related to self-esteem of males and females. Attractiveness and effectiveness did not appear to be differentially important to…

Parasitoid complex of the mealybug Oracella acuta (Lobdell) (Hemiptera: Pseudococcidae), in Georgia, USA

Science.gov (United States)

Jiang-Hua Sun; Stephen R. Clarke; Gary L. Debarr; C. Wayne Berisford

2004-01-01

The parasitoid complex of the mealybug Oracella acuta (Lobdell) was examined in two field populations in Georgia in 1995-96. Allotropa n. sp. and Zarhopalus debarri Sun were the primary endoparasitoids emerging from 0. acuta. Adult abundance varied seasonally, with Allotropa...

Physical Attractiveness: Interactive Effects of Counselor and Client on Counseling Processes.

Science.gov (United States)

Vargas, Alice M.; Borkowski, John G.

1983-01-01

Assessed how the physical attractiveness of counselors and clients interacted to build rapport in two experiments involving college students (N=128 and N=64). Results showed the counselor's physical attractiveness had a major impact on her perceived effectiveness and the client's expectation of success irrespective of the client's attractiveness…

Residual toxicity of insecticides used in Tunisian citrus orchards on the imported parasitoid Diachasmimorpha longicaudata (Hymenoptera: Braconidae: Implications for IPM program of Ceratitis capitata (Diptera: Tephritidae

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Ahlem Harbi

2017-12-01

Full Text Available Citrus agro-industry is globally harshened mainly by Ceratitis capitata (Wiedemann, the most worldwide destructive tephritid fruit fly species. Citrus agro-industry is one of the pillars of Tunisia economy, and by hence, harshened by this species. Tunisia has established an Integrated Pest Management (IPM programme against citrus pests, including C. capitata, that rely on the structured use of pesticides, on the application several trapping protocols, along with pilot-scale sterile insect technique program and, since 2013, with pilot-scale releases of the braconid parasitoid Diachasmimorpha longicaudata Ashmed (Hymenoptera: Braconidae. Insecticide side-effects on parasitoids and other natural enemies are being requested for a successful implementation of biological control within any IPM programme. However, these data are almost scarce for the braconid species D. longicaudata. To this end, we have determined the side-effects of malathion, methidathion, acetamiprid, azadiractin, abamectin, deltametrin+thiacloprid and spinosad, as the most popular insecticides used in Tunisia either as fresh residues or at several aged time points, on the parasitoid D. longicaudata according the IOBC pesticide harm-classification. IOBC classification evolution of residues over time had allowed determining the best combination of pesticide applications in a structured fashion with the viable releases of D. longicaudata for the control of C. capitata in Tunisian citrus agro-ecosystems.

Residual toxicity of insecticides used in Tunisian citrus orchards on the imported parasitoid Diachasmimorpha longicaudata (Hymenoptera: Braconidae): Implications for IPM program of Ceratitis capitata (Diptera: Tephritidae)

Energy Technology Data Exchange (ETDEWEB)

Harbi, A.; Abbes, K.; Sabater-Muñoz, B.; Beitia, F.; Chermiti, B.

2017-07-01

Citrus agro-industry is globally harshened mainly by Ceratitis capitata (Wiedemann), the most worldwide destructive tephritid fruit fly species. Citrus agro-industry is one of the pillars of Tunisia economy, and by hence, harshened by this species. Tunisia has established an Integrated Pest Management (IPM) programme against citrus pests, including C. capitata, that rely on the structured use of pesticides, on the application several trapping protocols, along with pilot-scale sterile insect technique program and, since 2013, with pilot-scale releases of the braconid parasitoid Diachasmimorpha longicaudata Ashmed (Hymenoptera: Braconidae). Insecticide side-effects on parasitoids and other natural enemies are being requested for a successful implementation of biological control within any IPM programme. However, these data are almost scarce for the braconid species D. longicaudata. To this end, we have determined the side-effects of malathion, methidathion, acetamiprid, azadiractin, abamectin, deltametrin+thiacloprid and spinosad, as the most popular insecticides used in Tunisia either as fresh residues or at several aged time points, on the parasitoid D. longicaudata according the IOBC pesticide harm-classification. IOBC classification evolution of residues over time had allowed determining the best combination of pesticide applications in a structured fashion with the viable releases of D. longicaudata for the control of C. capitata in Tunisian citrus agro-ecosystems.

KAPASITAS REPRODUKSI PARASITOID TELUR Trichogrammatoidea nana Zehntner (Hymenoptera:Trichogrammatidae

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- Sujak

2011-09-01

Full Text Available Trichogramma nana is one species of egg parasitoids that are polifag. insect pests that attack crops such as soybean pod borer and rice. Research conducted at the Laboratory of Entomology Research Institute for Tobacco and Fiber Crops Malang in March until June 2009 that aims to determine the reproductive capacity of T. nana on eggs  C. cephalonica. Reproductive capacity of T. nana allegedly using the net reproductive rate (Ro, estimatedtime of one generation (T, the capacity of population growth (r, and the rate of parasitoids per day (λ. T. nana were tested  came from the rice stem borer  eggs collected from the land in the district of East Java Beji Pasuruan. Eggs C.cephalonica which is used as the host is the result of breeding in the laboratory of Entomology Research Institute for Tobacco and Fiber Crops. The results showed that T. nana has greatpotential  as  biological agents.  Most  female  progeny  produced by adult females aged 1-2 days . On the first day produced 12 and 8 tails on the second day or 40% and 27% of the total of 30 females produced by a female during life.  Reproductive capacity of  T. nana on eggs C. cephalonica the net reproductive rate  Ro = 44.7, Capacity of population growth (r = 1.78,  parasitoid growth rate per day (λ=5.9, and mean - mean length of generation (T = 10, 9 days.

Effects of water-channel attractions on single-file water permeation through nanochannels

International Nuclear Information System (INIS)

Xu, Yousheng; Zheng, Youqu; Tian, Xingling; Lv, Mei; He, Bing; Deng, Maolin; Xiu, Peng; Tu, Yusong

2016-01-01

Single-file transportation of water across narrow nanochannels such as carbon nanotubes has attracted much attention in recent years. Such permeation can be greatly affected by the water-channel interactions; despite some progress, this issue has not been fully explored. Herein we use molecular dynamics simulations to investigate the effects of water-channel attractions on occupancy, translational (transportation) and orientational dynamics of water inside narrow single-walled carbon nanotubes (SWNTs). We use SWNTs as the model nanochannels and change the strength of water-nanotube attractions to mimic the changes in the hydrophobicity/polarity of the nanochannel. We investigate the dependence of water occupancy inside SWNTs on the water-channel attraction and identify the corresponding threshold values for drying states, wetting-drying transition states, and stably wetting states. As the strength of water-channel attractions increases, water flow increases rapidly first, and then decreases gradually; the maximal flow occurs in the case where the nanochannel is predominately filled with the 1D water wire but with a small fraction of ‘empty states’, indicating that appropriate empty-filling (drying-wetting) switching can promote water permeation. This maximal flow is unexpected, since in traditional view, the stable and tight hydrogen-bonding network of the water wire is the prerequisite for high permeability of water. The underlying mechanism is discussed from an energetic perspective. In addition, the effect of water-channel attractions on reorientational dynamics of the water wire is studied, and a negative correlation between the flipping frequency of water wire and the water-channel attraction is observed. The underlying mechanism is interpreted in term of the axial total dipole moment of inner water molecules. This work would help to better understand the effects of water-channel attractions on wetting properties of narrow nanochannels, and on single

Unconscious processing of facial attractiveness: invisible attractive faces orient visual attention.

Science.gov (United States)

Hung, Shao-Min; Nieh, Chih-Hsuan; Hsieh, Po-Jang

2016-11-16

Past research has proven human's extraordinary ability to extract information from a face in the blink of an eye, including its emotion, gaze direction, and attractiveness. However, it remains elusive whether facial attractiveness can be processed and influences our behaviors in the complete absence of conscious awareness. Here we demonstrate unconscious processing of facial attractiveness with three distinct approaches. In Experiment 1, the time taken for faces to break interocular suppression was measured. The results showed that attractive faces enjoyed the privilege of breaking suppression and reaching consciousness earlier. In Experiment 2, we further showed that attractive faces had lower visibility thresholds, again suggesting that facial attractiveness could be processed more easily to reach consciousness. Crucially, in Experiment 3, a significant decrease of accuracy on an orientation discrimination task subsequent to an invisible attractive face showed that attractive faces, albeit suppressed and invisible, still exerted an effect by orienting attention. Taken together, for the first time, we show that facial attractiveness can be processed in the complete absence of consciousness, and an unconscious attractive face is still capable of directing our attention.

Dirhinus giffardii (Hymenoptera: Chalcididae, parasitoid affecting Black Soldier Fly production systems in West Africa

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Emilie Devic

2015-12-01

Full Text Available Interest for insect farming is currently growing globally. Conditions in West Africa appear suitable for developing such farming systems that can benefit communities by improving livelihoods, food and feed security or sanitation. In Ghana and Mali, the Black Soldier Fly (Hermetia illucens Linnaeus, 1758 is being produced for waste recycling and animal feed. In a two stages process (egg and larvae production, egg production was hampered by a pupal parasitoid, Dirhinus giffardii Silvestri, 1913 (Hymenoptera: Chalcididae, which reduced future broodstock by almost 72%. This is the first time D. giffardii is reported as a parasitoid of H. illucens pupae and one of the first reports of parasitism in this commercially important fly species. The introduction of precautionary measures is highly recommended for the success of H. illucens production systems in West Africa.

Effect of Physical Attractiveness on Therapists' Initial Judgments of a Person's Self-concept

Science.gov (United States)

Hobfoll, Stevan E.; Penner, Louis A.

1978-01-01

Investigated effect of a person's physical attractiveness on a therapist's initial judgment of that person's self-concept. Videotapes and audiotapes were made of interviews with attractive and unattractive males and females. Physically attractive persons of both sexes were rated as having better self-concepts than unattractive persons. (Author)

Aphid-parasitoid community structure on genetically modified wheat.

Science.gov (United States)

von Burg, Simone; van Veen, Frank J F; Álvarez-Alfageme, Fernando; Romeis, Jörg

2011-06-23

Since the introduction of genetically modified (GM) plants, one of the main concerns has been their potential effect on non-target insects. Many studies have looked at GM plant effects on single non-target herbivore species or on simple herbivore-natural enemy food chains. Agro-ecosystems, however, are characterized by numerous insect species which are involved in complex interactions, forming food webs. In this study, we looked at transgenic disease-resistant wheat (Triticum aestivum) and its effect on aphid-parasitoid food webs. We hypothesized that the GM of the wheat lines directly or indirectly affect aphids and that these effects cascade up to change the structure of the associated food webs. Over 2 years, we studied different experimental wheat lines under semi-field conditions. We constructed quantitative food webs to compare their properties on GM lines with the properties on corresponding non-transgenic controls. We found significant effects of the different wheat lines on insect community structure up to the fourth trophic level. However, the observed effects were inconsistent between study years and the variation between wheat varieties was as big as between GM plants and their controls. This suggests that the impact of our powdery mildew-resistant GM wheat plants on food web structure may be negligible and potential ecological effects on non-target insects limited.

The effect of corporate image on the formation of customer attraction

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Reza Koohjani Gouji

2016-10-01

Full Text Available This paper examines the relationship of corporate image with customer attraction in Irancell Telecommunications Services Company in city of Ahvaz, Iran. The study uses a sample of 384 randomly selected people who use the firm’s services. Measuring tools for corporate image and customer attraction are an 18-item questionnaire of Rampersad (2001 [Rampersad, H. (2001. 75 painful questions about your customer satisfaction. the TQM Magazine, 13(5, 341-347.] and a 14-item questionnaire of Geib (2005 [Geib, M. (2005. Architecture for customer relationship management to attract and retain customers approaches in financial services, IEEE, Proceedings of the 38th Hawaii International Conference on System Sciences.], respectively. Results of regression analysis showed that there was a significant relationship between corporate image and attracting customers in Irancell firm. In addition, dimensions of corporate image including experience, character, competence, quality, differentiation, cost, technology, and culture and cognition increase customer attraction to the company. On the other hand, component of culture has the most effect on attracting customers in this firm.

Relationship of Physical Attractiveness to Students' Ratings of Teaching Effectiveness.

Science.gov (United States)

O'Reilly, Maria T.

1987-01-01

A study found that the physical attractiveness of a dental school teacher affected the student's opinion of teaching effectiveness, regardless of the student's sex, with effectiveness ratings correlating with pleasing appearance. (MSE)

Occurrence of the rare root aphid parasitoid, Aclitus obscuripennis (Hymenoptera: Braconidae: Aphidiinae) in Iran

Czech Academy of Sciences Publication Activity Database

Farahani, S.; Talebi, A. A.; Starý, Petr; Rakhshani, E.

2017-01-01

Roč. 72, č. 12 (2017), s. 1494-1498 ISSN 0006-3088 Institutional support: RVO:60077344 Keywords : Western Asia * new record * parasitoid wasps Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 0.759, year: 2016

Pathogenic fungi and parasitoids of aphids present in air captures of migratory alates in the low-latitude plateau of Yunnan, China.

Science.gov (United States)

Huang, Zhi-Hong; Feng, Ming-Guang; Chen, Xue-Xin; Liu, Shu-Sheng

2008-10-01

To survey fungal pathogens and parasitoids of aphids in the low-latitude plateau of Yunnan, southwest China, 3,553 migratory alates of Brevicoryne brassicae, Lipaphis erysimi, and Myzus persicae were attracted to a yellow-plus-plant trap from air during a full-year period and individually reared on cabbage leaves for 7-14 d at 18-22 degrees C and L:D 12:12. Among the trapped alates, 19.2% were killed by 10 species of aphid-pathogenic fungi after survival of 2.3 d (range, 1-7 d). Another 2.8% were mummified by the wasps Aphidius gifuensis, Diaeretella rapae, Ephedrus plagiator, and Aphelinus mali after survival of 4.9 d (range, 1-11 d). Most of the mycosed alates (77.8%) died from Entomophthorales predominated by Pandora neoaphidis (42.7%) and Zoophthora radicans (14.5%), followed by P. nouryi, Neozygites fresenii, Conidiobiolus spp., Entomophthora planchoniana, and Z. aphidis in decreasing frequencies. A mitosporic fungus, Lecanicillium lecanii, was found frequently in L. erysimi alates trapped in rainy season. However, B. brassicae alates captured in dry season were infected or parasitized very occasionally. The predeath fecundity of the infected or parasitized alates warranted successful colonization on plants, although greatly reduced, and was well shown by the fitted probability for a given fecundity per capita and the increasing mean size of their progeny colonies. Contagious transmission of the alate-borne mycosis in most of the colonies caused high progeny mortalities within 14 d. The results highlight for the first time the diversity of aphid pathogens and the spread of both pathogens and parasitoids with host dispersal flight in the low-latitude plateau.

Monitoring the establishment and flight phenology of egg and larval parasitoids of emerald ash borer (Coleoptera: Buprestidae) in Michigan, USA using sentinel eggs and larvae

Science.gov (United States)

Emerald ash borer (EAB), Agrilus planipennis Fairmaire, is an important invasive pest of ash (Fraxinus) trees in North America. Two larval parasitoids, Tetrastichus planipennisi Yang and Spathius agrili Yang, and one egg parasitoid, Oobius agrili Zhang and Huang, were introduced into the United Sta...

Parasitoids attacking emerald ash borers in western Pennsylvania and their potential use in biological control

Science.gov (United States)

J.J. Duan; R.W. Fuester; J. Wildonger; P.B. Taylor; S. Barth; S-E. Spichiger

2009-01-01

Current biological control programs against the emerald ash borer (EAB, Agrilus planipennis Fairmaire) have primarily focused on the introduction and releases of exotic parasitoids from China, home of the pest origin....

Evaluation of recovery and monitoring methods for parasitoids released against Emerald Ash Borer

Science.gov (United States)

The emerald ash borer (Agrilus planipennis Fairmaire, EAB) is an invasive insect pest, and the target of an extensive biological control campaign designed to mitigate EAB driven ash tree (Fraxinus spp.) mortality. Since 2007, environmental releases of three species of hymenopteran parasitoids of EA...

Checklist of Aphidiine parasitoids (Hymenoptera: Braconidae) and their host aphid associations in Iran

Czech Academy of Sciences Publication Activity Database

Barahoei, H.; Rakhshani, E.; Nader, E.; Starý, Petr; Kavallieratos, N. G.; Tomanović, Ž.; Mehrparvar, M.

2014-01-01

Roč. 3, č. 2 (2014), s. 199-232 ISSN 2251-9041 Grant - others:University of Zabol(IR) 89-9198; Ministry of Education, Science and Technological Development of the Republic of Serbia(IR) III43001 Institutional support: RVO:60077344 Keywords : fauna * aphid parasitoids * host association

Parasitoid complex of Stereonychus fraxini (De Geer) (Coleoptera, Curculionidae) in Serbia

Czech Academy of Sciences Publication Activity Database

Drekić, M.; Mihajlović, L. J.; Lozan, Aurel

2013-01-01

Roč. 65, č. 2 (2013), s. 733-737 ISSN 0354-4664 Grant - others:Ministry of Education and Science of the Republic of Serbia(RS) III 43002 Institutional support: RVO:60077344 Keywords : Stereonychus fraxini * parasitoids * Serbia Subject RIV: EH - Ecology, Behaviour Impact factor: 0.607, year: 2013 http://www.doiserbia.nb.rs/img/doi/0354-4664/2013/0354-46641302733D.pdf

Parallel and costly changes to cellular immunity underlie the evolution of parasitoid resistance in three Drosophila species.

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John E McGonigle

2017-10-01

Full Text Available A priority for biomedical research is to understand the causes of variation in susceptibility to infection. To investigate genetic variation in a model system, we used flies collected from single populations of three different species of Drosophila and artificially selected them for resistance to the parasitoid wasp Leptopilina boulardi, and found that survival rates increased 3 to 30 fold within 6 generations. Resistance in all three species involves a large increase in the number of the circulating hemocytes that kill parasitoids. However, the different species achieve this in different ways, with D. melanogaster moving sessile hemocytes into circulation while the other species simply produce more cells. Therefore, the convergent evolution of the immune phenotype has different developmental bases. These changes are costly, as resistant populations of all three species had greatly reduced larval survival. In all three species resistance is only costly when food is in short supply, and resistance was rapidly lost from D. melanogaster populations when food is restricted. Furthermore, evolving resistance to L. boulardi resulted in cross-resistance against other parasitoids. Therefore, whether a population evolves resistance will depend on ecological conditions including food availability and the presence of different parasite species.

Primeiro registro de Trichopria anastrephae, parasitoide de moscas-das-frutas, no Rio Grande do Sul First record of Trichopria anastrephae, parasitoid of fruit flies, in the Rio Grande do Sul State, Brazil

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Patrícia Postalli Cruz

2011-08-01

Full Text Available Existem poucas informações sobre as espécies nativas de himenópteros parasitoides de moscas-das-frutas da Região Neotropical, o que objetivou a realização do presente trabalho. Assim, coletas de goiaba (Psidium guajava L. foram realizadas de janeiro a março de 2009 na Área Experimental em Estudos de Produção Agroecológica (AEEPA da Universidade Federal de Pelotas, no município de Capão do Leão, Rio Grande do Sul. Os frutos foram levados ao laboratório, contados, pesados e acondicionados individualmente em potes plásticos contendo areia umedecida e telado na parte superior. Semanalmente, o substrato foi peneirado, os pupários recolhidos e acondicionados em placas de Petri com papel filtro umedecido com água destilada. Os pupários foram mantidos em sala climatizada (26±2°C, 60±10% de umidade relativa e 12h fotofase onde foram efetuadas observações semanais para verificar a emergência de moscas e/ou parasitoides e posterior identificação das espécies. Trichopria anastrephae Lima (Hymenoptera: Diapriidae foi obtida de pupários de Anastrepha fraterculus, com parasitismo de 5,8%.There is little information on native species of hymenopteran parasitoids of fruit flies from the Neotropical region. Collections of guava (Psidium guajava L. were conducted from January to March 2009 at the Experimental Area of Agroecological Production studies (AEEPA, Federal University of Pelotas, Capão do Leão, Rio Grande do Sul. Fruits were taken individually to the laboratory, counted, weighed and packaged in plastic pots containing moist sand and mesh on top. Weekly substrate was sieved, the pupae collected and placed in Petri dishes with filter paper moistened with distilled water. The pupae were placed in a room (26±2°C, 60±10% RH and 12h photophase where observations were made weekly to check the emergence of adult flies or parasitoids and subsequent species identification. Trichopria anastrephae Lima was obtained from Anastrepha

Particle attraction effects on the centrifugal casting and extrusion of alumina

International Nuclear Information System (INIS)

Schilling, C.H.; Bergstroem, L.; Ker, H.L.; Aksay, I.A.

1993-01-01

Interparticle attraction forces were empirically related to the centrifugal casting and extrusion behavior of flocculated alumina suspensions. Attractive forces were altered by two approaches: Salt flocculation, which entails regulating the electrical double-layer thickness through electrolyte additions; and screening of van der Waals attraction by steric interactions of surface-adsorbed fatty acids. Specimens produced by both compressibility at a critical maximum density that increased with decreasing interparticle attraction. Gradients in packing density during centrifugal casting were alleviated using both methods as long as spatial variations of the effective stress were within the low-compressibility range. We hypothesized that the reduced interparticle attraction in both methods may also raise the threshold packing density at which ductile-to-brittle transitions occur during plastic shear. Specimens prepared with oleic acid adlayers were highly plastic and easily extrudable at solids contents of up to 59 vol%, although salt-flocculated samples at 55 vol% density extruded at creeping flow rates that were insensitive to the applied pressure. Results suggested that particle rearrangement during shear, is a rate-limiting process, with an average relaxation time that is lowered by reducing interparticle attraction

Lack of phenotypic and evolutionary cross-resistance against parasitoids and pathogens in Drosophila melanogaster.

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Alex R Kraaijeveld

Full Text Available When organisms are attacked by multiple natural enemies, the evolution of a resistance mechanism to one natural enemy will be influenced by the degree of cross-resistance to another natural enemy. Cross-resistance can be positive, when a resistance mechanism against one natural enemy also offers resistance to another; or negative, in the form of a trade-off, when an increase in resistance against one natural enemy results in a decrease in resistance against another. Using Drosophila melanogaster, an important model system for the evolution of invertebrate immunity, we test for the existence of cross-resistance against parasites and pathogens, at both a phenotypic and evolutionary level.We used a field strain of D. melanogaster to test whether surviving parasitism by the parasitoid Asobara tabida has an effect on the resistance against Beauveria bassiana, an entomopathogenic fungus; and whether infection with the microsporidian Tubulinosema kingi has an effect on the resistance against A. tabida. We used lines selected for increased resistance to A. tabida to test whether increased parasitoid resistance has an effect on resistance against B. bassiana and T. kingi. We used lines selected for increased tolerance against B. bassiana to test whether increased fungal resistance has an effect on resistance against A. tabida.We found no positive cross-resistance or trade-offs in the resistance to parasites and pathogens. This is an important finding, given the use of D. melanogaster as a model system for the evolution of invertebrate immunity. The lack of any cross-resistance to parasites and pathogens, at both the phenotypic and the evolutionary level, suggests that evolution of resistance against one class of natural enemies is largely independent of evolution of resistance against the other.

Beneficial Insect Attraction to Milkweeds (Asclepias speciosa, Asclepias fascicularis in Washington State, USA

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David G. James

2016-06-01

Full Text Available Native plant and beneficial insect associations are relatively unstudied yet are important in native habitat restoration programs for improving and sustaining conservation biological control of arthropod pests in agricultural crops. Milkweeds (Asclepias spp. are currently the focus of restoration programs in the USA aimed at reversing a decline in populations of the milkweed-dependent monarch butterfly (Danaus plexippus; however, little is known of the benefits of these plants to other beneficial insects. Beneficial insects (predators, parasitoids, pollinators attracted to two milkweed species (Asclepias speciosa, Asclepias fascicularis in central Washington State, WA, USA were identified and counted on transparent sticky traps attached to blooms over five seasons. Combining all categories of beneficial insects, means of 128 and 126 insects per trap were recorded for A. speciosa and A. fascicularis, respectively. Predatory and parasitic flies dominated trap catches for A. speciosa while parasitic wasps were the most commonly trapped beneficial insects on A. fascicularis. Bees were trapped commonly on both species, especially A. speciosa with native bees trapped in significantly greater numbers than honey bees. Beneficial insect attraction to A. speciosa and A. fascicularis was substantial. Therefore, these plants are ideal candidates for habitat restoration, intended to enhance conservation biological control, and for pollinator conservation. In central Washington, milkweed restoration programs for enhancement of D. plexippus populations should also provide benefits for pest suppression and pollinator conservation.

Beneficial Insect Attraction to Milkweeds (Asclepias speciosa, Asclepias fascicularis) in Washington State, USA.

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James, David G; Seymour, Lorraine; Lauby, Gerry; Buckley, Katie

2016-06-29

Native plant and beneficial insect associations are relatively unstudied yet are important in native habitat restoration programs for improving and sustaining conservation biological control of arthropod pests in agricultural crops. Milkweeds (Asclepias spp.) are currently the focus of restoration programs in the USA aimed at reversing a decline in populations of the milkweed-dependent monarch butterfly (Danaus plexippus); however, little is known of the benefits of these plants to other beneficial insects. Beneficial insects (predators, parasitoids, pollinators) attracted to two milkweed species (Asclepias speciosa, Asclepias fascicularis) in central Washington State, WA, USA were identified and counted on transparent sticky traps attached to blooms over five seasons. Combining all categories of beneficial insects, means of 128 and 126 insects per trap were recorded for A. speciosa and A. fascicularis, respectively. Predatory and parasitic flies dominated trap catches for A. speciosa while parasitic wasps were the most commonly trapped beneficial insects on A. fascicularis. Bees were trapped commonly on both species, especially A. speciosa with native bees trapped in significantly greater numbers than honey bees. Beneficial insect attraction to A. speciosa and A. fascicularis was substantial. Therefore, these plants are ideal candidates for habitat restoration, intended to enhance conservation biological control, and for pollinator conservation. In central Washington, milkweed restoration programs for enhancement of D. plexippus populations should also provide benefits for pest suppression and pollinator conservation.

Differences in the reliance on cuticular hydrocarbons as sexual signaling and species discrimination cues in parasitoid wasps.

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Buellesbach, Jan; Vetter, Sebastian G; Schmitt, Thomas

2018-01-01

Cuticular hydrocarbons (CHC) have been documented to play crucial roles as species- and sex-specific cues in the chemical communication systems of a wide variety of insects. However, whether they are sufficient by themselves as the sole cue triggering sexual behavior as well as preference of con- over heterospecific mating partners is rarely assessed. We conducted behavioral assays in three representative species of parasitoid wasps (Hymenoptera: Pteromalidae) to determine their reliance on CHC as species-specific sexual signaling cues. We found a surprising degree of either unspecific or insufficient sexual signaling when CHC are singled out as recognition cues. Most strikingly, the cosmopolitan species Nasonia vitripennis , expected to experience enhanced selection pressure to discriminate against other co-occurring parasitoids, did not discriminate against CHC of a partially sympatric species from another genus, Trichomalopsis sarcophagae . Focusing on the latter species, in turn, it became apparent that CHC are even insufficient as the sole cue triggering conspecific sexual behavior, hinting at the requirement of additional, synergistic sexual cues particularly important in this species. Finally, in the phylogenetically and chemically most divergent species Muscidifurax uniraptor, we intriguingly found both CHC-based sexual signaling as well as species discrimination behavior intact although this species is naturally parthenogenetic with sexual reproduction only occurring under laboratory conditions. Our findings implicate a discrepancy in the reliance on and specificity of CHC as sexual cues in our tested parasitioid wasps. CHC profiles were not sufficient for unambiguous discrimination and preference behavior, as demonstrated by clear cross-attraction between some of our tested wasp genera. Moreover, we could show that only in T. sarcophagae , additional behavioral cues need to be present for triggering natural mating behavior, hinting at an interesting

Creating beauty: creativity compensates for low physical attractiveness when individuals assess the attractiveness of social and romantic partners.

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Watkins, Christopher D

2017-04-01

Although creativity is attractive in a potential mate, it is unclear (i) whether the effects of creativity on attractiveness generalize to other social contexts and (ii) whether creativity has equivalent effects on men's and women's attractiveness. As social knowledge of creativity may either enhance or 'offset' the appeal of social partners who differ in physical attractiveness, three repeated measures experiments were conducted to directly address these issues. Here, participants rated a series of face-text pairs for attractiveness on trials that differed in one of four combinations of facial attractiveness (attractive and less attractive) and creativity (creative and less creative), rating story-tellers in two experiments (short interpretations of an identical painting) and creative ideas in a further experiment (alternative uses for an everyday object). Regardless of the sex of the judge, creativity and facial attractiveness had independent effects on men's overall attractiveness (initial experiment) and, in further experiments, more substantial effects on the attractiveness of men with less attractive faces than men with attractive faces (when using a different measure of creativity) and specific effects on the attractiveness of individuals with less attractive faces (when using different face stimuli). Collectively, across three experiments, these findings suggest that creativity may compensate for putative cues to lower biological 'quality' and that the benefits of creativity to social groups more generally enhance attraction to creative men (in two experiments) and creative men and women (one experiment). More broadly, the data suggest that species can integrate knowledge of cognitive intelligence with visual cues to biological 'quality' to facilitate mate and/or ally choice.

Parasitoidism Rate and Life Table Parameters of Aphytis diaspidis (Howard (Hymenoptera: Aphelinidae and Hemiberlesia lataniae (Signoret (Hemiptera: Diaspididae Tasa de Parasitoidismo y Parámetros de Tabla de Vida de Aphytis diaspidis (Howard (Hymenoptera: Aphelinidae y Hemiberlesia lataniae (Signoret (Hemiptera: Diaspididae

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Dennis Navea O

2012-09-01

Full Text Available Latania scale, Hemiberlesia lataniae (Signoret, has become a major pest of avocado (Persea americana Mill. in Chile and has reached high populations in the fruit because of limited natural control. The objective of this study was to identify the biological parameters of the parasitoid Aphytis diaspidis (Howard as a control agent of latania scale. Postembryonic development, parasitoidism rate, and life table parameters of the parasitoid and scale were determined under laboratory conditions. Aphytis diaspidis postembryonic development and parasitoidism rate varied significantly when evaluated on distinct latania scale stages with the highest survival (56% occurring at the third scale stage, it also had the shortest development time between egg and adult (19.14 d and the highest parasitoidism rate (66%. The intrinsic growth rate (r m was higher for A. diaspidis (r m = 0.099 than latania scale (r m = 0.068. These laboratory results demonstrated that A. diaspidis is an effective parasitoid for decreasing H. lataniae populations, especially in the third stage.La escama latania, Hemiberlesia lataniae (Signoret, se ha transformado en Chile en una plaga de importancia primaria en palto (Persea americana Mill., donde alcanza altas poblaciones en la fruta debido al escaso control natural existente. El objetivo del presente estudio fue conocer parámetros biológicos del parasitoide Aphytis diaspidis (Howard, como agente de control de la escama latania. Es asi como se determinó en laboratorio el desarrollo postembrionario, tasa de parasitoidismo, y parámetros de tabla de vida del parasitoide y la escama. El desarrollo postembrionario y la tasa de parasitoidismo de A. diaspidis varió significativamente al ser evaluado sobre distintos estadios de la escama latania, alcanzando el mayor porcentaje de supervivencia (56% sobre el tercer estadio de la escama, asi como el menor tiempo de desarrollo entre huevo y adulto (19,14 d y la máxima tasa de

The effects of objectification on stereotypical perception and attractiveness of women and men

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Rollero Chiara

2016-01-01

Full Text Available Objectification has been found to have negative consequences on how women are perceived by others. However in an even more sexualized world being a sexual object has become a standard of physical attractiveness for women and objectification could foster a positive evaluation increasing attractiveness. Although Objectification Theory was originally grounded in women’s experiences, some research points to the promise of Objectification Theory for understanding men’s experiences as well. The aim of the paper was investigating the effects of objectification on gender stereotypes and perceived attractiveness. Two experimental studies were conducted. Study 1 (N=139 investigated the effects of objectification on female targets. Study 2 (N=146 investigated the effects on male targets. In both studies three dependent variables were considered: communality, agency, and attractiveness. Results of Study 1 revealed that objectified women were considered less communal and more attractive. Moreover, men perceived objectified women less agentic than the non-objectified ones, whereas women showed the opposite perception. Concerning men, objectification has a limited impact, as it interacted with participants’ gender only on communality: men considered objectified males more communal than the non-objectified ones, while women revealed the opposite perception.

Molecular Theory and the Effects of Solute Attractive Forces on Hydrophobic Interactions.

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Chaudhari, Mangesh I; Rempe, Susan B; Asthagiri, D; Tan, L; Pratt, L R

2016-03-03

The role of solute attractive forces on hydrophobic interactions is studied by coordinated development of theory and simulation results for Ar atoms in water. We present a concise derivation of the local molecular field (LMF) theory for the effects of solute attractive forces on hydrophobic interactions, a derivation that clarifies the close relation of LMF theory to the EXP approximation applied to this problem long ago. The simulation results show that change from purely repulsive atomic solute interactions to include realistic attractive interactions diminishes the strength of hydrophobic bonds. For the Ar-Ar rdfs considered pointwise, the numerical results for the effects of solute attractive forces on hydrophobic interactions are opposite in sign and larger in magnitude than predicted by LMF theory. That comparison is discussed from the point of view of quasichemical theory, and it is suggested that the first reason for this difference is the incomplete evaluation within LMF theory of the hydration energy of the Ar pair. With a recent suggestion for the system-size extrapolation of the required correlation function integrals, the Ar-Ar rdfs permit evaluation of osmotic second virial coefficients B2. Those B2's also show that incorporation of attractive interactions leads to more positive (repulsive) values. With attractive interactions in play, B2 can change from positive to negative values with increasing temperatures. This is consistent with the puzzling suggestions of decades ago that B2 ≈ 0 for intermediate cases of temperature or solute size. In all cases here, B2 becomes more attractive with increasing temperature.

Face inversion increases attractiveness.

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Leder, Helmut; Goller, Juergen; Forster, Michael; Schlageter, Lena; Paul, Matthew A

2017-07-01

Assessing facial attractiveness is a ubiquitous, inherent, and hard-wired phenomenon in everyday interactions. As such, it has highly adapted to the default way that faces are typically processed: viewing faces in upright orientation. By inverting faces, we can disrupt this default mode, and study how facial attractiveness is assessed. Faces, rotated at 90 (tilting to either side) and 180°, were rated on attractiveness and distinctiveness scales. For both orientations, we found that faces were rated more attractive and less distinctive than upright faces. Importantly, these effects were more pronounced for faces rated low in upright orientation, and smaller for highly attractive faces. In other words, the less attractive a face was, the more it gained in attractiveness by inversion or rotation. Based on these findings, we argue that facial attractiveness assessments might not rely on the presence of attractive facial characteristics, but on the absence of distinctive, unattractive characteristics. These unattractive characteristics are potentially weighed against an individual, attractive prototype in assessing facial attractiveness. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Effects of an attractive wall on the translocation of polymer under driving

International Nuclear Information System (INIS)

Cao Weiping; Wang Chao; Sun Lizhen; Luo Mengbo

2012-01-01

The effects of an attractive wall at the trans side on the translocation of an eight-site bond-fluctuation model (BFM) polymer through a pore in a membrane under driving are simulated by the dynamic Monte Carlo method. The attractive wall shows two contrary effects: its excluded volume effect reduces configuration entropy and thus hinders the translocation of the polymer, while its attraction decreases the energy and thus accelerates the translocation. At a critical polymer-wall interaction ε* ≈- 1, we find that the two effects compensate each other and the translocation time τ is roughly independent of the separation distance between the wall and the pore. The value ε* ≈- 1 is roughly equal to the critical adsorption point for the BFM polymer. Moreover, the value of the critical attraction is roughly independent of chain length N and chemical potential difference Δμ. At last, a scaling relation τ ∼ N α is observed for polymer translocation at a high value of NΔμ. Though the translocation time is highly dependent on the polymer-wall interaction and pore-wall separation distance, the exponent α is always about 1.30 ± 0.05 so long as NΔμ is large enough. (paper)

Selectivity of organic compounds to the egg parasitoid Telenomus remus Nixon (Hymenoptera: Plastygastridae

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Débora Mello da Silva

2016-02-01

Full Text Available The selectivity of insecticides, bio-protective mixtures, and biofertilizers used in organic soybean production was evaluated for adults and pupae of the egg parasitoid Telenomus remus Nixon (Hymenoptera: Platygastridae under laboratory conditions in accordance with protocols proposed by the International Organization for Biological Control (IOBC. The products sprayed (dosage/180L of water were: 1 Baculovírus anticarsia 140x109 cpi; 2 Bacillus thuringiensis 16.8g; 3 Azadirachtin-A, azadirachtin-B, nimbina and salamina 9.6 ppm; 4 Rotenoids 4 liters; 5 Nitrogen 1.3%, phosphorus 3.0% and total organic carbon 8.0% 3 liters; 6 Sodium silicate 2% 4 liters; 7 Copper 7% + calcium 3.3% 1.8 liters; 8 Sulfur 20% + quicklime 10% 1.8 liters; 9 Chlorpyrifos 384g (positive control; 10 Distilled H2O (negative control. The results of experiments using pupae indicate that the organic compounds were classified as harmless (Class 1, except for the copper 7% + calcium 3.3% and sulfur 20% + quicklime 10%, which were classified as slightly harmful (Class 2. The contact bioassay with adults showed that all products were classified as harmless (Class 1. Only chlorpyrifos (384g was classified as harmful (Class 4 for both stages of the parasitoid. However, the use of this product (chlorpyrifos is not permitted in organic farming, and even in conventional farming is recommended, where feasible, replacement of the product with one compatible with the preservation of T. remus in nature. Thus, the products tested and used in organic soybean production were considered compatible with the parasitoid eggs of T. remus.

Understanding talent attraction: The influence of financial rewards elements on perceived job attractiveness

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Anton Schlechter

2014-11-01

Full Text Available Orientation: In order to attract knowledge workers and maintain a competitive advantage,it is necessary for organisations to understand how knowledge workers are attracted todifferent types and levels of financial rewards. Research purpose: This research investigated a set of financial reward elements (remuneration, employee benefits and variable pay to determine whether knowledgeworkers perceived them as attractive inducements when considering a job or position. Motivation for the study: In South Africa there is a shortage of talent, largely due to highrates of emigration of scarce skills (human capital. Financial rewards or inducementsare necessary to attract talent and it is essential to assess which of these rewards are mostsuccessful in this regard. Method: A 23 full-factorial experimental design (field experiment was used. The threefinancial reward elements (remuneration, employee benefits and variable pay weremanipulated in a fictitious job advertisement (each at two levels. Eight (2 × 2 × 2 = 8 differentversions of a job advertisement were used as a stimulus to determine the effect of financialreward elements on perceived job attractiveness. A questionnaire was used to measure howparticipants perceived the attractiveness of the job. A convenience sampling approach wasused. Different organisations throughout South Africa, as well as corporate members of the South African Reward Association, were asked to participate in the study. Respondents (n = 169 were randomly assigned to the various experimental conditions (i.e. one of the eightadvertisements. Data were analysed using descriptive statistics. A full-factorial analysis ofvariance was used to investigate if significant main effects could be found. Main findings: Participants considered high levels of remuneration, the inclusion ofbenefits and variable pay to be significant job attraction factors within a reward package. Remuneration was found to have the largest main effect on job

Introduced and Native Parasitoid Wasps Associated With Larch Casebearer (Lepidoptera: Coleophoridae) in Western Larch

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M. Miller-Pierce; D. C. Shaw; A. Demarco; P. T. Oester

2015-01-01

The larch casebearer [Coleophora laricella (Hubner)], a non-native insect, continues to impact western larch (Larix occidentalis Nutt.) through defoliation events in the Pacific Northwest. Biological control programs starting in the 1960s released seven species of parasitoid wasps to control C. laricella...

Pre-pupation behaviour of the aphid parasitoid Aphidius ervi (Haliday) and its consequences for pre-imaginal learning

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Gutiérrez-Ibáñez, Cristián; Villagra, Cristian A.; Niemeyer, Hermann M.

2007-07-01

Olfactory learning may occur at different stages of insect ontogeny. In parasitoid wasps, it has been mostly shown at adult emergence, whilst it remains controversial at pre-imaginal stages. We followed larval growth of the parasitoid wasp, Aphidius ervi Haliday, inside the host aphid, Acyrthosiphom pisum Harris, and characterised in detail the behaviour of third instar larvae. We found that just before cocoon spinning begins, the third instar larva bites a hole through the ventral side of the mummified aphid exoskeleton. We then evaluated whether this period of exposure to the external environment represented a sensitive stage for olfactory learning. In our first experiment, the third instar larvae were allowed to spin their cocoon on the host plant ( Vicia faba L.) surface or on a plastic plate covering the portion of the host plant exposed to the ventral opening. Recently emerged adults of the first group showed a preference for plant volatiles in a glass Y-olfactometer, whereas no preference was found in adults of the second group. In a second experiment, during the period in which the aphid carcass remains open or is being sealed by cocoon spinning, third instar larvae were exposed for 24 h to either vanilla odours or water vapours as control. In this experiment, half of the parasitoid larvae were later excised from the mummy to avoid further exposure to vanilla. Adult parasitoids exposed to vanilla during the larval ventral opening of the mummy showed a significant preference for vanilla odours in the olfactometer, regardless of excision from the mummy. The larval behaviour described and the results of the manipulations performed are discussed as evidences for the acquisition of olfactory memory during the larval stage and its persistence through metamorphosis.

Multiplex PCR in determination of Opiinae parasitoids of fruit flies, Bactrocera sp., infesting star fruit and guava.

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Shariff, S; Ibrahim, N J; Md-Zain, B M; Idris, A B; Suhana, Y; Roff, M N; Yaakop, S

2014-01-23

Malaysia is a tropical country that produces commercial fruits, including star fruits, Averrhoa carambola L. (Oxalidales: Oxalidaceae), and guavas, Psidium guajava L. (Myrtales: Myrtaceae). There is a high demand for these fruits, and they are planted for both local consumption and export purposes. Unfortunately, there has been a gradual reduction of these fruits, which has been shown to be related to fruit fly infestation, especially from the Bactrocera species. Most parasitic wasps (Hymenoptera: Braconidae: Opiinae) are known as parasitoids of fruit fly larvae. In this study, star fruits and guavas infested by fruit fry larvae were collected from the Malaysian Agricultural Research and Development Institute. The parasitized larvae were reared under laboratory conditions until the emergence of adult parasitoids. Multiplex PCR was performed to determine the braconid species using two mitochondrial DNA markers, namely cytochrome oxidase subunit I and cytochrome b. Two benefits of using multiplex PCR are the targeted bands can be amplified simultaneously using the same reaction and the identification process of the braconid species can be done accurately and rapidly. The species of fruit flies were confirmed using the COI marker. The results obtained from our study show that Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae), Fopius arisanus (Sonan), and Pysttalia incisi (Silvestri) were parasitoids associated with Bactrocera carambolae (Drew and Hancock) (Diptera: Tephritidae) infested star fruits. Fopius arisanus was also the parasitoid associated with Bactrocera papayae (Drew and Hancock) infested guavas. Maximum parsimony was been constructed in Opiinae species to compare tree resolution between these two genes in differentiating among closely related species. The confirmation of the relationship between braconids and fruit fly species is very important, recognized as preliminary data, and highly necessary in biological control programs. This is an

Biological Control of Tephritid Fruit Flies in Argentina: Historical Review, Current Status, and Future Trends for Developing a Parasitoid Mass-Release Program.

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Ovruski, Sergio M; Schliserman, Pablo

2012-09-14

In Argentina there are two tephritid fruit fly species of major economic and quarantine importance: the exotic Ceratitis capitata that originated from Southeast Africa and the native Anastrepha fraterculus. In recent years, the use of fruit fly parasitoids as biocontrol agents has received renewed attention. This increasing interest has recently led to the establishment of a program for the mass rearing of five million Diachasmimorpha longicaudata parasitoids per week in the BioPlanta San Juan facility, San Juan, Argentina. The first augmentative releases of D. longicaudata in Argentina are currently occurring on commercial fig crops in rural areas of San Juan as part of an integrated fruit fly management program on an area-wide basis. In this context, research is ongoing to assess the suitability of indigenous parasitoid species for successful mass rearing on larvae of either C. capitata or A. fraterculus. The purpose of this article is to provide a historical overview of the biological control of the fruit fly in Argentina, report on the strategies currently used in Argentina, present information on native parasitoids as potential biocontrol agents, and discuss the establishment of a long-term fruit fly biological control program, including augmentative and conservation modalities, in Argentina's various fruit growing regions.

Biological Control of Tephritid Fruit Flies in Argentina: Historical Review, Current Status, and Future Trends for Developing a Parasitoid Mass-Release Program

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Sergio M. Ovruski

2012-09-01

Full Text Available In Argentina there are two tephritid fruit fly species of major economic and quarantine importance: the exotic Ceratitis capitata that originated from Southeast Africa and the native Anastrepha fraterculus. In recent years, the use of fruit fly parasitoids as biocontrol agents has received renewed attention. This increasing interest has recently led to the establishment of a program for the mass rearing of five million Diachasmimorpha longicaudata parasitoids per week in the BioPlanta San Juan facility, San Juan, Argentina. The first augmentative releases of D. longicaudata in Argentina are currently occurring on commercial fig crops in rural areas of San Juan as part of an integrated fruit fly management program on an area-wide basis. In this context, research is ongoing to assess the suitability of indigenous parasitoid species for successful mass rearing on larvae of either C. capitata or A. fraterculus. The purpose of this article is to provide a historical overview of the biological control of the fruit fly in Argentina, report on the strategies currently used in Argentina, present information on native parasitoids as potential biocontrol agents, and discuss the establishment of a long-term fruit fly biological control program, including augmentative and conservation modalities, in Argentina’s various fruit growing regions.

The Role of Lipid Competition for Endosymbiont-Mediated Protection against Parasitoid Wasps in Drosophila

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Juan C. Paredes

2016-07-01

Full Text Available Insects commonly harbor facultative bacterial endosymbionts, such as Wolbachia and Spiroplasma species, that are vertically transmitted from mothers to their offspring. These endosymbiontic bacteria increase their propagation by manipulating host reproduction or by protecting their hosts against natural enemies. While an increasing number of studies have reported endosymbiont-mediated protection, little is known about the mechanisms underlying this protection. Here, we analyze the mechanisms underlying protection from parasitoid wasps in Drosophila melanogaster mediated by its facultative endosymbiont Spiroplasma poulsonii. Our results indicate that S. poulsonii exerts protection against two distantly related wasp species, Leptopilina boulardi and Asobara tabida. S. poulsonii-mediated protection against parasitoid wasps takes place at the pupal stage and is not associated with an increased cellular immune response. In this work, we provide three important observations that support the notion that S. poulsonii bacteria and wasp larvae compete for host lipids and that this competition underlies symbiont-mediated protection. First, lipid quantification shows that both S. poulsonii and parasitoid wasps deplete D. melanogaster hemolymph lipids. Second, the depletion of hemolymphatic lipids using the Lpp RNA interference (Lpp RNAi construct reduces wasp success in larvae that are not infected with S. poulsonii and blocks S. poulsonii growth. Third, we show that the growth of S. poulsonii bacteria is not affected by the presence of the wasps, indicating that when S. poulsonii is present, larval wasps will develop in a lipid-depleted environment. We propose that competition for host lipids may be relevant to endosymbiont-mediated protection in other systems and could explain the broad spectrum of protection provided.

Parasitoid inventarisation of European corn borer (Ostrinia nubilalis Hübner, 1796 and options for its biological control in Slovenia

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Jaka RAZINGER

2016-04-01

Full Text Available European corn borer (Ostrinia nubilalis (ECB is an important maize pest in central and northern Europe. Presently it is controlled by insecticides or biological agents such as Trichogramma brassicae in several European countries, excluding Slovenia, where the pest’s pressure is highly variable and no appropriate mechanization is available. Lessening the dependence on chemical pesticides is an integral part of the European Union’s agenda for agriculture. Mass release of Trichogramma spp. could be seen as a promising alternative for ECB control in countries with a highly fluctuating ECB pressure and no mechanization for insecticide applications. However, no records of naturally occurring hymenopteran parasitoids of ECB exist in Slovenia. To address this important under-researched topic and provide the expert basis for potential introduction of ECB egg parasitoids in Slovene maize production, a systematic inventarisation programme of ECB parasitoids was launched in 2010. Additionally, ECB flight was monitored in 2011 and 2012 at two locations in Slovenia: Jablje and Rakičan. In both locations two ECB generations  were observed. ECB was fist observed at the end of May in Rakičan. During the five years of the systematic survey we discovered two ECB parasitoid species. ECB egg masses were parasitized by Trichogramma brassicae, whereas ECB pupae were parasitized by Tycherus nigridens, with 6 or 7 % parasitation rate, respectively. T. nigridens represents a new taxon report for Slovenia. We conclude that there is a strong need for undertaking systematic surveys of natural enemies of agricultural pests.

Recruiting nurses through social media: Effects on employer brand and attractiveness.

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Carpentier, Marieke; Van Hoye, Greet; Stockman, Sara; Schollaert, Eveline; Van Theemsche, Bart; Jacobs, Gerd

2017-11-01

To investigate whether and how nurses' exposure to a hospital's profile on social media affects their perceptions of the hospital's brand and attractiveness as an employer. Since in many places across the globe hospitals are struggling with nursing shortages, competition is rising to be perceived as an attractive employer by this target group. Organizations are increasingly using social media for recruitment, however, little is known about its effects on potential applicants' perceptions of the organization as an employer. We thus examine whether these effects occur and rely on the media richness theory to explain the mechanisms at play. A between-subjects experimental design was applied. Three conditions were used: a control group, one condition that required visiting the Facebook page of a hospital and one condition that required visiting the LinkedIn page. The focal organization was an existing Belgian hospital which had a LinkedIn and a Facebook page. An online questionnaire was sent to nursing students and employed nurses over 5 months in 2015-2016. Nurses' exposure to the hospital's Facebook or LinkedIn page had a significant positive effect on a majority of the employer brand dimensions, both instrumental and symbolic. In addition, nurses who visited the Facebook page felt more attracted to working at the hospital. Most of these effects were mediated by social presence. Nurses' perceptions of employers can be positively influenced by seeing a hospital's social media page. Hospitals can thus employ social media to improve their employer brand image and attractiveness. © 2017 John Wiley & Sons Ltd.

Development of microsatellite markers and estimation of inbreeding frequency in the parasitoid wasp Melittobia

NARCIS (Netherlands)

Abe, Jun; Pannebakker, Bart A.

2017-01-01

The parasitoid wasp Melittobia is an important insect for basic and applied biology. Specifically, their extremely female-biased sex ratios, which contrast to the prediction of pre-existing theories, are needed to be explained from the aspect of evolutionary biology. In this study, using

How to behave? : evolution of host-handling behaviour in the whitefly parasitoid Encarsia formosa

NARCIS (Netherlands)

Burger, J.M.S.

2002-01-01

The main aim of evolutionary ecology is to explain the adaptation of form, function and behaviour of organisms to their environment. In this thesis, I studied host-handling behaviour of the whitefly parasitoid Encarsia formosa form such an evolutionary point of view.

Impact of Abamectin on Anagrus nilaparvatae, An Egg Parasitoid of Nilaparvata lugens

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Edi Eko Sasmito

2017-12-01

Full Text Available Anagrus nilaparvatae (Hymenoptera: Mymaridae is an egg parasitoid potential for controlling the major pests on rice, the brown planthopper (Nilaparvata lugens [Hemiptera: Delphacidae].Abamectin is one of insecticides registered for N. lugens. The research was aimed to investigate the impact of contact application of abamectin on the parasitism level of A. nilaparvatae under laboratory conditions. Adults of A. nilaparvatae and the first instars as well as adults of N. lugens were exposed to the residue of abamection inside the test tube. A. nilaparvatae was much more susceptible to abamectin compared to N. lugens. Application of abamectin at the recommended concentration (22.78 ppm for 30 min caused 100% mortality, and it reduced to 85% when the concentration was decreased to 0.36 ppm. In contrast, the mortality for the first instar of N. lugens was only 15% at 22.78 and no mortality at 0.36 ppm. No N. lugens adults died even when they were exposed to 22.78 ppm. Furthermore, the parasitism test was conducted using 38 days after planting of IR-64 rice variety. Those plants were infested with 50 females of N. lugens for 2 days. A. nilaparvatae were exposed by contact to 0.02, 0.23, and 2.28 ppm of abamectin. The survivors were released to the rice plant containing eggs of N. lugens. Contact application of abamectin reduced parasitism level of A. nilaparvatae as much as 86.34, 70.01, and 28.43% with concentrations of 2.28 ppm, 0.23 and 0.02 ppm, respectively. In addition, the number of parasitoids emerged decreased with increasing concentration of abamectin. These results suggest that abamectin could be detrimental to A. nilaparvatae due to direct mortality, reduced the parasitism level, and decreased the number of progeny produced.   Intisari Anagrus nilaparvatae (Hymenoptera: Mymaridae merupakan salah satu parasitoid telur yang berpotensi untuk mengendalikan hama utama tanaman padi, wereng batang padi cokelat (Nilaparvata lugens [Hemiptera

Assessing risks of pesticides targeting lepidopteran pests in cruciferous ecosystems to eggs parasitoid, Trichogramma brassicae (Bezdenko

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D.P. Thubru

2018-05-01

Full Text Available Lethal and sub lethal effects of fresh and old residues of azadirachtin, spinosad, Bacillus thuringiensis var. kurstaki (Bt var. k, and deltamethrin, were evaluated at their recommended field doses against adult and immature stages of Trichogramma brassicae under in vitro conditions. The experiments were carried out at the Entomology section of Division of Crop Protection, ICAR Research Complex for NEH region, Umiam, Meghalaya, in 2012–2013. The effects of different pesticides were determined by bioassays using the residual film method, the diet contamination method, the pupal dip method and the topical application technique. The four pesticides were found harmful to adult T. brassicae after ingestion, however surface contact bioassays revealed that Bt var. k was the least toxic pesticide. Except Bt var. k, other three pesticides were found harmful also to the immature stages of T. brassicae and significantly affected parasitism potential, adult emergence, longevity of adults, and sex ratio of the progeny. Deltamethrin and azadirachtin were the most harmful, even after 15 days of application. Spinosad was found to be relatively safe to T. brassicae after 15 days of application. As Bt appeared to be the least toxic pesticide for T. brassicae, it could be used for the management of severe infestations of lepidopteran pests in cruciferous ecosystems.If essential, spinosad may be used 15 days after parasitoid release, thus minimizing the chances of parasitoid exposure. Keywords: Azadirachtin, Bacillus thuringiensis, Deltamethrin, Spinosad

Effect of potential attraction term on surface tension of ionic liquids

Science.gov (United States)

Vaziri, N.; Khordad, R.; Rezaei, G.

2018-03-01

In this work, we have studied the effect of attraction term of molecular potential on surface tension of ionic liquids (ILs). For this purpose, we have introduced two different potential models to obtain analytical expressions for the surface tension of ILs. The introduced potential models have different attraction terms. The obtained surface tensions in this work have been compared with other theoretical methods and also experimental data. Using the calculated surface tension, the sound velocity is also estimated. We have studied the structural effects on the surface tensions of imidazolium-based ionic liquids. It is found that the cation alkyl chain length and the anion size play important roles to the surface tension of the selected ionic liquids. The calculated surface tensions show a good harmony with experimental data. It is clear that the attraction term of molecular potential has an important role on surface tension and sound velocity of our system.

Evaluación de algunos insecticidas para el control de la «polilla del tomate», Tuta absoluta (Lepidoptera: Gelechiidae y su efecto residual sobre el parasitoide Trichogrammatoidea bactrae (Hymenoptera: Trichogrammatidae Efficacy of insecticides against the «tomato moth», Tuta absoluta (Lepidoptera: Gelechiidae and their residual effects on the parasitoid Trichogrammatoidea bactrae (Hymenoptera: Trichogrammatidae

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María B. Riquelme Virgala

2006-12-01

Full Text Available La «polilla del tomate», Tuta absoluta (Meyrick, es una plaga clave de este cultivo en Argentina. Su manejo integrado debería incluir una selección de productos fitosanitarios que sean eficaces para su control y, al mismo tiempo, selectivos respecto de sus enemigos naturales. El objetivo de este trabajo fue evaluar la capacidad de control de los insecticidas triflumurón, clorfenapir, abamectin y una cepa experimental de Bacillus thuringiensis (Bt sobre la plaga, y el poder residual de los mismos sobre Trichogrammatoidea bactrae Nagaraja. Se registró la mortalidad de la polilla cada cuatro días, desde la aplicación hasta la emergencia de los adultos. El efecto sobre el parasitoide, se evaluó a través del número de huevos parasitados por hembra expuesta durante 48 horas a folíolos tratados, y su mortalidad luego de 1, 3, 7, 14 y 30 días de la pulverización. Todos los productos ocasionaron una mortalidad de T. absoluta mayor al 65% después de 12 días de aplicados. El Bt fue el único insecticida que no afectó la supervivencia y el parasitismo de T. bactrae . Estos resultados aportan información de interés para la selección de plaguicidas, a emplearse en programas de manejo integrado.The «tomato moth», Tuta absoluta (Meyrick is one of the key pests of tomato crops in Argentina. The compatible use of chemical and biological control is the main purpose of integrated pest management. Selective pesticides that can be successfully used to control pest without adverse side effects on natural enemies are highly required. The aim of this work was to evaluate the efficacy of control of T. absoluta and the residual effect on the oophagous parasitoid, Trichogrammatoidea bactrae Nagaraja of the following insecticides: triflumuron, abamectin, chlorfenapyr, and an experimental strain of Bacillus thuringiensis (Bt. Mortality of T. absoluta was evaluated every 4 days from pesticide spraying until adult emergency. The effect of pesticides on

The role of contact chemoreception in the host location process of an egg parasitoid

NARCIS (Netherlands)

Iacovone, Alessia; French, Alice Sarah; Tellier, Frédérique; Cusumano, Antonino; Clément, Gilles; Gaertner, Cyril; Conti, Eric; Salerno, Gianandrea; Marion-Poll, Frédéric

2016-01-01

Taste allows insects to detect palatable or toxic foods, identify a mate, and select appropriate oviposition sites. The gustatory system strongly contributes to the survival and reproductive success of many species, yet it is rarely studied in insect parasitoids. In order to locate and assess a

Reproduction now or later: optimal host-handling strategies in the whitefly parasitoid Encarsia formosa

NARCIS (Netherlands)

Burger, J.M.S.; Hemerik, L.; Lenteren, van J.C.; Vet, L.E.M.

2004-01-01

We developed a dynamic state variable model for studying optimal host-handling strategies in the whitefly parasitoid Encarsia formosa Gahan (Hymenoptera: Aphelinidae). We assumed that (a) the function of host feeding is to gain nutrients that can be matured into eggs, (b) oogenesis is continuous and

Apomictic parthenogenesis in a parasitoid wasp Meteorus pulchricornis, uncommon in the haplodiploid order Hymenoptera.

Science.gov (United States)

Tsutsui, Y; Maeto, K; Hamaguchi, K; Isaki, Y; Takami, Y; Naito, T; Miura, K

2014-06-01

Although apomixis is the most common form of parthenogenesis in diplodiploid arthropods, it is uncommon in the haplodiploid insect order Hymenoptera. We found a new type of spontaneous apomixis in the Hymenoptera, completely lacking meiosis and the expulsion of polar bodies in egg maturation division, on the thelytokous strain of a parasitoid wasp Meteorus pulchricornis (Wesmael) (Braconidae, Euphorinae) on pest lepidopteran larvae Spodoptera litura (Fabricius) (Noctuidae). The absence of the meiotic process was consistent with a non-segregation pattern in the offspring of heterozygous females, and no positive evidence was obtained for the induction of thelytoky by any bacterial symbionts. We discuss the conditions that enable the occurrence of such rare cases of apomictic thelytoky in the Hymenoptera, suggesting the significance of fixed heterosis caused by hybridization or polyploidization, symbiosis with bacterial agents, and occasional sex. Our finding will encourage further genetic studies on parasitoid wasps to use asexual lines more wisely for biological control.

Age-Differential Effects of Job Characteristics on Job Attraction: A Policy-Capturing Study.

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Zacher, Hannes; Dirkers, Bodil T; Korek, Sabine; Hughes, Brenda

2017-01-01

Based on an integration of job design and lifespan developmental theories, Truxillo et al. (2012) proposed that job characteristics interact with employee age in predicting important work outcomes. Using an experimental policy-capturing design, we investigated age-differential effects of four core job characteristics (i.e., job autonomy, task variety, task significance, and feedback from the job) on job attraction (i.e., individuals' rating of job attractiveness). Eighty-two employees between 19 and 65 years ( M age = 41, SD = 14) indicated their job attraction for each of 40 hypothetical job descriptions in which the four job characteristics were systematically manipulated (in total, participants provided 3,280 ratings). Results of multilevel analyses showed that the positive effects of task variety, task significance, and feedback from the job were stronger for younger compared to older employees, whereas we did not find significant age-differential effects of job autonomy on job attraction. These findings are only partially consistent with propositions of Truxillo et al.'s (2012) lifespan perspective on job design.

Biological control of olive fruit fly (Diptera: Tephritidae) by releases of Psyttalia cf. concolor (Hymenoptera: Braconidae) in California, parasitoid longevity in presence of the host, and host status of Walnut Husk Fly

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Yokoyama, Victoria Y., E-mail: vyokoyama@fresno.ars.usda.go [U.S. Department of Agriculture (USDA/ARS/SJVASC), Parlier, CA (United States). Agricultural Research Service. Subtropical Horticulture Research Station; Rendon, Pedro A., E-mail: prendon@aphisguate.co [U.S. Department of Agriculture (USDA/APHIS), Guatemala City (Guatemala). Center for Plant Health Science and Technology. Animal and Plant Health Inspection.; Sivinski, John, E-mail: jsivinski@gainesville.usda.ufl.ed [U.S. Department of Agriculture (USDA/ARS/CMAVE), Gainesville, FL (United States). Agricultural Research Service. Center for Medical, Agricultural and Veterinary Entomology

2006-07-01

The larval parasitoid, Psyttalia cf. concolor, collected from tephritids infesting coffee in Kenya and reared on Mediterranean fruit fly, Ceratitis capitata Weidemann, in Guatemala by USDA-APHIS, PPQ, was imported into California for biological control of olive fruit fly, Bactrocera oleae (Gmelin), in olives, Olea europaea. Free releases of the parasitoids were made in olive trees infested with olive fruit fly at a coastal and inland valley location during the fall and early winter of 2005. The relative humidity during the releases was significantly higher at the coastal location. Mean percentage parasitism ranged from 0.5 to 4 and 1.5 to 30 at the coastal and inland valley locations respectively, based on same season recovery of the F1 generation. One parasitoid was found in infested olives in the next crop of the following year in San Jose. Survival of the parasitoid in the greenhouse in the presence of olive fruit fly infested olives was not significantly different than in the presence of non-infested olives. The greatest number of progeny was produced from female parasitoids that were 12-16 d old. In laboratory tests, a few individuals of the parasitoid successfully completed one life cycle in walnut husk fly, Rhagoletis completa Cresson, infested English walnuts, Juglans regia L. (author)

Biological control of olive fruit fly (Diptera: Tephritidae) by releases of Psyttalia cf. concolor (Hymenoptera: Braconidae) in California, parasitoid longevity in presence of the host, and host status of Walnut Husk Fly

International Nuclear Information System (INIS)

Yokoyama, Victoria Y.; Rendon, Pedro A.; Sivinski, John

2006-01-01

The larval parasitoid, Psyttalia cf. concolor, collected from tephritids infesting coffee in Kenya and reared on Mediterranean fruit fly, Ceratitis capitata Weidemann, in Guatemala by USDA-APHIS, PPQ, was imported into California for biological control of olive fruit fly, Bactrocera oleae (Gmelin), in olives, Olea europaea. Free releases of the parasitoids were made in olive trees infested with olive fruit fly at a coastal and inland valley location during the fall and early winter of 2005. The relative humidity during the releases was significantly higher at the coastal location. Mean percentage parasitism ranged from 0.5 to 4 and 1.5 to 30 at the coastal and inland valley locations respectively, based on same season recovery of the F1 generation. One parasitoid was found in infested olives in the next crop of the following year in San Jose. Survival of the parasitoid in the greenhouse in the presence of olive fruit fly infested olives was not significantly different than in the presence of non-infested olives. The greatest number of progeny was produced from female parasitoids that were 12-16 d old. In laboratory tests, a few individuals of the parasitoid successfully completed one life cycle in walnut husk fly, Rhagoletis completa Cresson, infested English walnuts, Juglans regia L. (author)

Red is Romantic, but Only for Feminine Females: Sexual Dimorphism Moderates Red Effect on Sexual Attraction

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Fangfang Wen

2014-10-01

Full Text Available Previous researchers have documented that the color red enhances one's sexual attraction to the opposite sex. The current study further examined the moderating role of sexual dimorphism in red effects. The results indicated that red enhanced men's sexual attraction to women with more feminine facial characteristics but had no effect on ratings of perceived general attractiveness. Red clothing also had a marginally significant effect on men's sexual attractiveness. In addition, regardless of sexual dimorphism cues, male participants rated women with red as warmer and more competent. The underlying mechanisms of the red effect, the limitations of the current study, and suggestions for future directions are discussed.

Toxicity risk of insecticides to the insect egg parasitoid Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae).

Science.gov (United States)

Wang, Yanhua; Wu, Changxing; Cang, Tao; Yang, Lizhi; Yu, Weihua; Zhao, Xueping; Wang, Qiang; Cai, Leiming

2014-03-01

Natural populations of Trichogramma evanescens contribute to the control of lepidopterous pests. The toxic effects of insecticides have been extensively reported on trichogrammatids, but are largely unknown on T. evanescens. In this study, the toxicities of seven classes of chemicals against the parasitoid were investigated. Among these classes, organophosphates and carbamates exhibited the highest levels of intrinsic toxicity, with LC50 values ranging from 0.025 (0.023-0.028) to 2.20 (1.71-3.09) and from 0.040 (0.032-0.053) to 1.84 (1.53-2.30) mg AI L(-1) respectively. Among the phenylpyrazoles, only ethiprole can be considered to be less toxic in the group. Avermectins, pyrethroids and neonicotinoids were less toxic, with LC50 values ranging from 1.29 to 2.57, from 2.26 to 14.03 and from 1.12 to 239.1 mg AI L(-1) respectively. In contrast, insect growth regulators (IGRs) showed the lowest toxicity to the parasitoid, with LC50 values ranging from 3383 (2406-5499) to 5650 (4228-8579) mg AI L(-1) . The results of risk quotient analysis indicated that neonicotinoids, avermectins, pyrethroids and IGRs were less hazardous, but phenylpyrazoles (except for ethiprole), organophosphates and carbamates were slightly to moderately or dangerously toxic to T. evanescens. The present results provide informative data for implementing biological and chemical control strategies in integrated pest management of lepidopterans. © 2013 Society of Chemical Industry.

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.

Object attraction effects during subject-verb agreement in Persian.

Science.gov (United States)

Feiz, Aazam; Cowles, Wind

2018-04-01

Subject-verb agreement provides insight into how grammatical and semantic features interact during sentence production, and prior studies have found attraction errors when an intervening local noun is grammatically part of the subject. Two major types of theories have emerged from these studies: control based and competition-based. The current study used an subject-object-verb language with optional subject-verb agreement, Persian, to test the competition-based hypothesis that intervening object nouns may also cause attraction effects, even though objects are not part of the syntactic relationship between the subject and verb. Our results, which did not require speakers to make grammatical errors, show that objects can be attractors for agreement, but this effect appears to be dependent on the type of plural marker on the object. These results support competition-based theories of agreement production, in which agreement may be influenced by attractors that are outside the scope of the subject-verb relationship.

Use of pupal parasitoids as biological control agents of filth flies on equine facilities

Science.gov (United States)

House flies, Musca domestica L., and stable flies, Stomoxys calcitrans (L.), (Diptera: Muscidae), are common pests on horse farms. The use of pupal parasitoids as biological control agents for filth flies is becoming more popular on equine facilities; however, there is a lack of information on the e...

Reproduction now or later: optimal host-hanling strategies in the whitefly parasitoid Encarsia formosa

NARCIS (Netherlands)

Burger, J.S.M.; Hemerik, L.; Van Lenteren, J.C.; Vet, L.E.M.

2004-01-01

We developed a dynamic state variable model for studying optimal host-handling strategies in the whitefly parasitoid Encarsia formosa Gahan (Hymenoptera: Aphelinidae). We assumed that (a) the function of host feeding is to gain nutrients that can be matured into eggs, (b) oögenesis is continuous and

Social dynamics in emergency evacuations: Disentangling crowd's attraction and repulsion effects

Science.gov (United States)

Haghani, Milad; Sarvi, Majid

2017-06-01

The social dynamics of crowds in emergency escape scenarios have been conventionally modelled as the net effect of virtual forces exerted by the crowd on each individual (as self-driven particles), with the magnitude of the influence formulated as decreasing functions of inter-individual distances and the direction of effect assumed to be transitioning from repulsion to attraction by distance. Here, we revisit this conventional assumption using laboratory experimental data. We show based on robust econometric hypothesis-testing methods that individuals' perception of other escapees differs based on whether those individuals are jamming around exit destinations or are on the move towards the destinations. Also, for moving crowds, it differs based on whether the escape destination chosen by the moving flow is visible or invisible to the individual. The presence of crowd jams around a destination, also the movement of crowd flows towards visible destinations are both perceived on average as repulsion (or disutility) effects (with the former showing significantly larger magnitude than the latter). The movement of crowd flows towards an invisible destination, however, is on average perceived as attraction (or utility) effect. Yet, further hypothesis testing showed that neither of those effects in isolation determines adequately whether an individual would merge with or diverge from the crowd. Rather, the social interaction factors act (at significant levels) in conjunction with the physical factors of the environments (including spatial distances to exit destinations and destinations' visibility). In brief, our finding disentangles the conditions under which individuals are more likely to show mass behaviour from the situations where they are more likely to break from the herd. It identifies two factors that moderate the perception of social interactions, ;crowds' jam/movement status; and ;environmental setup;. Our results particularly challenge the taxonomy of

Parasitoidism of Chalcidid wasps (Hymenoptera, Chalcididae on Philornis sp. (Diptera, Muscidae

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M. S. Couri

Full Text Available Philornis Meinert larvae are known as parasites of birds, with coprophagous, semi-hematophagous or hematophagous habits. Biological data of the larvae of the fifty described species are still scarcely known. Here we describe some aspects of the parasitism of a species of Philornis on Thalurania glaucopis Gmelin (Trochilidae and record two species of Chalcididae (Hymenoptera parasitoids, Conura annulifera (Walker, 1864 and Brachymeria podagrica (Fabricius, 1787, reared from Philornis puparia.

Functional response and life history parameters of Apanteles taragamae, a larval parasitoid of Maruca vitrata

NARCIS (Netherlands)

Dannon, A.E.; Tamò, M.; Huis, van A.; Dicke, M.

2010-01-01

The legume pod borer Maruca vitrata Fabricius (Lepidoptera: Crambidae) is a serious pest of cowpea in West-Africa. The parasitoid Apanteles taragamae Viereck (Hymenoptera: Braconidae) that originates from Taiwan is a potential candidate for biological control of M. vitrata. We investigated under

Aphid parasitoids sampled by Malaise traps in the National parks of Thailand (Hymenoptera, Braconidae, Aphidiinae)

Czech Academy of Sciences Publication Activity Database

Starý, Petr; Sharkey, M.; Hutacharern, C.

2008-01-01

Roč. 41, 1-2 (2008), s. 37-43 ISSN 0049-3589 Grant - others:Framework of Research Funded by the NSF grant(US) DEB 0542864 Institutional research plan: CEZ:AV0Z50070508 Keywords : aphids * parasitoids * biodiversity Subject RIV: EH - Ecology, Behaviour

Ailing voters advance attractive congressional candidates.

Science.gov (United States)

Zebrowitz, Leslie A; Franklin, Robert G; Palumbo, Rocco

2015-01-06

Among many benefits of facial attractiveness, there is evidence that more attractive politicians are more likely to be elected. Recent research found this effect to be most pronounced in congressional districts with high disease threat-a result attributed to an adaptive disease avoidance mechanism, whereby the association of low attractiveness with poor health is particularly worrisome to voters who feel vulnerable to disease. We provided a more direct test of this explanation by examining the effects of individuals' own health and age. Supporting a disease avoidance mechanism, less healthy participants showed a stronger preference for more attractive contenders in U.S. Senate races than their healthier peers, and this effect was stronger for older participants, who were generally less healthy than younger participants. Stronger effects of health for older participants partly reflected the absence of positive bias toward attractive candidates among the healthiest, suggesting that healthy older adults may be unconcerned about disease threat or sufficiently wise to ignore attractiveness.

Parasitization of commercially available parasitoid species against the lettuce aphid, Nasonovia ribisnigri (Hemiptera: Aphididae).

Science.gov (United States)

Shrestha, G; Skovgård, H; Enkegaard, A

2014-12-01

The lettuce aphid, Nasonovia ribisnigri (Mosley), is an economically important pest of lettuce worldwide. Little documentation exists for the control efficacy of aphid parasitoids against N. ribisnigri. This laboratory study evaluated three commercially available parasitoid species: Aphidius colemani (Viereck), Lysiphlebus testaceipes (Cresson), and Aphelinus abdominalis (Dalman) for their mortality impact on N. ribisnigri. The green peach aphid Myzus persicae (Sulzer) was included as a reference aphid. The study showed that A. abdominalis successfully parasitized 39 and 13% of the offered N. ribisnigri and M. persicae, respectively, within a 24-h exposure period. In contrast, none of the lettuce aphids exposed to Ap. colemani or L. testaceipes were successfully parasitized, whereas 60 and 3.5% of M. persicae, respectively, were successfully parasitized within a 6-h exposure period. Lettuce aphid mortality due to incomplete parasitization was 26 and 31% when exposed to Ap. colemani and L. testaceipes, respectively, with corresponding values for M. persicae being 5 and 10%, respectively. Mortality as a result of incomplete parasitization when aphids were exposed to A. abdominalis was low for both aphid species. The total mortality inflicted by A. abdominalis within a 24-h exposure period was 51% for the lettuce aphids and significantly less (19%) for green peach aphids. In contrast, Ap. colemani inflicted a higher mortality in M. persicae (65%) compared with N. ribisnigri (26%) within a 6-h exposure period. L. testaceipes caused a greater mortality in N. ribisnigri as compared with M. persicae. This study concludes that A. abdominalis has the potential to be used against N. ribisnigri in inoculative biocontrol programs as compared with the other parasitoid species based on successful parasitization.

Aphids and their parasitoids (Hym., Braconidae: Aphidiinae) asociated with medicinal plants in Iran

Czech Academy of Sciences Publication Activity Database

Talebi, A. A.; Rakhshani, E.; Fathipour, Y.; Starý, Petr; Tomanović, Ž.; Rajabi-Mazhar, N.

2009-01-01

Roč. 3, č. 2 (2009), s. 205-219 ISSN 1995-0748 R&D Projects: GA AV ČR IBS5007102 Grant - others:University of Zabol(IR) No. 86-19; The Serbian Ministry of Science(CS) 143006 Institutional research plan: CEZ:AV0Z50070508 Keywords : medicinal plants * aphid parasitoids * Aphidiinae Subject RIV: EH - Ecology, Behaviour

New species and a review of aphid parasitoids of Madagascar (Hym., Braconidae, Aphidiinae)

Czech Academy of Sciences Publication Activity Database

Starý, Petr

2005-01-01

Roč. 37, č. 2 (2005), s. 1711-1718 ISSN 0253-116X R&D Projects: GA AV ČR(CZ) IBS5007102 Grant - others:National Science Foundation(US) DEB-0072713; National Science Foundation(US) DEB-0344731 Institutional research plan: CEZ:AV0Z50070508 Keywords : aphids * parasitoids * sub - Saharan Africa Sub ject RIV: EG - Zoology

Effect of Inhomogeneity on s-wave Superconductivity in the Attractive Hubbard Model

Energy Technology Data Exchange (ETDEWEB)

Aryanpour, K. A. [University of California, Davis; Dagotto, Elbio R [ORNL; Mayr, Matthias [Max-Planck-Institut fur Feskorperforschung, Stuttgart, Germany; Paiva, T. [Universidade Federal do Rio de Janeiro, Brazil; Pickett, W. E. [University of California, Davis; Scalettar, Richard T [ORNL

2006-01-01

Inhomogeneous s-wave superconductivity is studied in the two-dimensional, square lattice attractive Hubbard Hamiltonian using the Bogoliubov-de Gennes BdG mean field approximation. We find that at weak coupling, and for densities mainly below half-filling, an inhomogeneous interaction in which the on-site interaction Ui takes on two values, Ui=0, 2U results in a larger zero temperature pairing amplitude, and that the superconducting Tc can also be significantly increased, relative to a uniform system with Ui=U on all sites. These effects are observed for stripe, checkerboard, and even random patterns of the attractive centers, suggesting that the pattern of inhomogeneity is unimportant. Monte Carlo calculations which reintroduce some of the fluctuations neglected within the BdG approach see the same effect, both for the attractive Hubbard model and a Hamiltonian with d-wave pairing symmetry.

Tooth color: effects on judgments of attractiveness and age.

Science.gov (United States)

Grosofsky, Alexis; Adkins, Sarah; Bastholm, Robert; Meyer, Leif; Krueger, Lisa; Meyer, Joshua; Torma, Peter

2003-02-01

Tooth whitening has become a very popular procedure. Advertisements for whitening products imply that whiter teeth are more attractive than yellower teeth. We tested this idea empirically by manipulating the tooth color of pictures of male and female targets. Participants' ratings of attractiveness were not influenced by tooth color. Exp. 2 yielded a negative correlation between attractiveness and age ratings: targets judged to be older were rated as less attractive. Unless whiter teeth help in some other way, e.g., improved self-esteem or confidence, it seems that tooth whitening procedures or products are not associated with increased attractiveness to others.

The role of atomic level steric effects and attractive forces in protein folding.

Science.gov (United States)

Lammert, Heiko; Wolynes, Peter G; Onuchic, José N

2012-02-01

Protein folding into tertiary structures is controlled by an interplay of attractive contact interactions and steric effects. We investigate the balance between these contributions using structure-based models using an all-atom representation of the structure combined with a coarse-grained contact potential. Tertiary contact interactions between atoms are collected into a single broad attractive well between the C(β) atoms between each residue pair in a native contact. Through the width of these contact potentials we control their tolerance for deviations from the ideal structure and the spatial range of attractive interactions. In the compact native state dominant packing constraints limit the effects of a coarse-grained contact potential. During folding, however, the broad attractive potentials allow an early collapse that starts before the native local structure is completely adopted. As a consequence the folding transition is broadened and the free energy barrier is decreased. Eventually two-state folding behavior is lost completely for systems with very broad attractive potentials. The stabilization of native-like residue interactions in non-perfect geometries early in the folding process frequently leads to structural traps. Global mirror images are a notable example. These traps are penalized by the details of the repulsive interactions only after further collapse. Successful folding to the native state requires simultaneous guidance from both attractive and repulsive interactions. Copyright © 2011 Wiley Periodicals, Inc.

Interactions between Bacillus thuringiensis and parasitoids of late-instar larvae of the spruce budworm (Lepidoptera: Tortricidae)

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Schoenmaker, A.; Cusson, M.; Frankenhuyzen, van K.

2001-01-01

We investigated interactions between Bacillus thuringiensis Berliner var. kurstaki and parasitoids that attack late instars of the eastern spruce budworm, Choristoneura fumiferana (Clemens). In a petri-dish arena, females of Tranosema rostrale rostrale (Brishke) (Hymenoptera: Ichneumonidae) were

A compound produced by fruigivorous Tephritidae (Diptera) larvae promotes oviposition behavior by the biological control agent Diachasmimorpha longicaudata (Hymenoptera: Braconidae).

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Stuhl, Charles; Sivinski, John; Teal, Peter; Paranhos, Beatriz; Aluja, Martin

2011-06-01

Tephritid fruit fly parasitoids use fruit-derived chemical cues and the vibrations that result from larval movements to locate hosts sequestered inside fruit. However, compounds produced by the larvae themselves have not been previously described nor their significance to parasitoid foraging determined. We collected the volatiles from four species of tropical and subtropical Tephritidae: Anastrepha suspensa (Loew), Bactrocera dorsalis Hendel, Bactrocera cucurbitae Coquillett, and Ceratitis capitata (Wiedemann), representing two subfamilies (Dacinae and Trypetinae). Para-ethylacetophenone, an analog of a known tephritid parasitoid attractant, was a major constituent of all four, and was not associated with larvae of another acalypterate fly, Drosophila melanogaster Meigen, or with the calypterate Musca domestica L. It also was present in volatiles from whole, A. suspensa infested fruits of Eugenia uniflora (L.). Para-ethylacetophenone was not necessarily produced as a direct consequence of fruit consumption because it also was detected from larvae that developed in two artificial diets and in spent diets subsequent to larval development. Sensillae on both the antennae and ovipositor of the opiine braconid fruit fly parasitoid, Diachasmimorpha longicaudata (Ashmead) responded to the para-ethylacetophenone in larval volatiles and as a synthetic. Although a potential cue to foraging parasitoids, para-ethylacetophenone showed no long range (>1m) attractiveness to the adult female parasitoid, but did stimulate ovipositor-insertion and oviposition into both a natural (fruit) and an artificial (parafilm) substrate. Thus it may prove useful in colonizing and mass-rearing opine fruit fly parasitoids.

Physical attractiveness biases in ratings of employment suitability: tracking down the "beauty is beastly" effect.

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Johnson, Stefanie K; Podratz, Kenneth E; Dipboye, Robert L; Gibbons, Ellie

2010-01-01

The "what is beautiful is good" heuristic suggests that physically attractive persons benefit from their attractiveness in a large range of situations, including perceptions of employment suitability. Conversely, the "beauty is beastly" effect suggests that attractiveness can be detrimental to women in certain employment contexts, although these findings have been less consistent than those for the "what is beautiful is good" effect. The current research seeks to uncover situations in which beauty might be detrimental for female applicants. In two studies, we found that attractiveness can be detrimental for women applying for masculine sex-typed jobs for which physical appearance is perceived as unimportant.

The effect of meat consumption on body odor attractiveness.

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Havlicek, Jan; Lenochova, Pavlina

2006-10-01

Axillary body odor is individually specific and potentially a rich source of information about its producer. Odor individuality partly results from genetic individuality, but the influence of ecological factors such as eating habits are another main source of odor variability. However, we know very little about how particular dietary components shape our body odor. Here we tested the effect of red meat consumption on body odor attractiveness. We used a balanced within-subject experimental design. Seventeen male odor donors were on "meat" or "nonmeat" diet for 2 weeks wearing axillary pads to collect body odor during the final 24 h of the diet. Fresh odor samples were assessed for their pleasantness, attractiveness, masculinity, and intensity by 30 women not using hormonal contraceptives. We repeated the same procedure a month later with the same odor donors, each on the opposite diet than before. Results of repeated measures analysis of variance showed that the odor of donors when on the nonmeat diet was judged as significantly more attractive, more pleasant, and less intense. This suggests that red meat consumption has a negative impact on perceived body odor hedonicity.

Platigástridos (Hymenoptera: Platygastridae parasitoides de Pentatomidae en Córdoba. Caracterización de las masas de huevos parasitoidizadas y aspectos biológicos

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Norma LA PORTA

2013-01-01

Full Text Available Se caracterizan las masas de huevos parasitoidizadas de pentatómidos per - tenecientes a cinco especies, cuatro fitófagas y una depredadora. Además, se analizan aspectos biológicos de esas oviposturas (abundancia y parasitoidismo y de sus para - sitoides (proporción sexual y emergencia: cinco especies de microhimenópteros plati - gástridos pertenecientes a los géneros Trissolcus Ashmead, Telenomus Haliday y Gryon Haliday . El análisis de las masas de huevos de pentatómidos en el campo apor ta indi - cadores exomorfológicos para determinar si están o no parasitoidizadas y, en algunos casos, conocer la especie de parasitoide emergente. Los altos niveles de parasitoidismo registrados en ambos sitios muestreados –Marcos Juárez y zona periurbana de Córdoba, sugieren que los parasitoides oófagos inciden de manera importante en las poblaciones de hemípteros presentes en el cultivo de soja. Las especies parasitoides mostraron una proporción de sexos marcadamente sesgada hacia las hembras, con un comportamiento similar respecto a cada huésped con el que interactuaron. Los porcentajes de emergencia resultaron más variables dependiendo de la especie parasitoide, del huésped y del sitio. El multiparasitoidismo fue registrado en todas las especies con excepción de Nezara viridula L. Telenomus podisi Ashmead fue el parasitoide común en las combinaciones observadas, resultando T. podisi-Trissolcus urichi Crawford la más frecuente.

Genetics of female functional virginity in the Parthenogenesis-Wolbachia infected parasitoid wasp Telenomus nawai (Hymenoptera: Scelionidae)

NARCIS (Netherlands)

Jeong, G.S.; Stouthamer, R.

2005-01-01

A lepidopteran egg parasitoid species Telenomus nawai consists of two distinct populations with different reproductive modes. One is a completely thelytokous population consisting of females only, whereas the other displays arrhenotokous reproduction where fertilized eggs develop into diploid

Interactions among the effects of head orientation, emotional expression, and physical attractiveness on face preferences.

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Main, Julie C; DeBruine, Lisa M; Little, Anthony C; Jones, Benedict C

2010-01-01

Previous studies have shown that preferences for direct versus averted gaze are modulated by emotional expressions and physical attractiveness. For example, preferences for direct gaze are stronger when judging happy or physically attractive faces than when judging disgusted or physically unattractive faces. Here we show that preferences for front versus three-quarter views of faces, in which gaze direction was always congruent with head orientation, are also modulated by emotional expressions and physical attractiveness; participants demonstrated preferences for front views of faces over three-quarter views of faces when judging the attractiveness of happy, physically attractive individuals, but not when judging the attractiveness of relatively unattractive individuals or those with disgusted expressions. Moreover, further analyses indicated that these interactions did not simply reflect differential perceptions of the intensity of the emotional expressions shown in each condition. Collectively, these findings present novel evidence that the effect of the direction of the attention of others on attractiveness judgments is modulated by cues to the physical attractiveness and emotional state of the depicted individual, potentially reflecting psychological adaptations for efficient allocation of social effort. These data also present the first behavioural evidence that the effect of the direction of the attention of others on attractiveness judgments reflects viewer-referenced, rather than face-referenced, coding and/or processing of gaze direction.

A review of insect parasitoids associated with Lobesia botrana (Denis & Schiffermüller, 1775) in Italy. 1. DipteraTachinidae and HymenopteraBraconidae (Lepidoptera, Tortricidae).

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Scaramozzino, Pier Luigi; Loni, Augusto; Lucchi, Andrea

2017-01-01

This paper is aimed to summarize the information available on the parasitoid complex of the European Grapevine Moth (EGVM), Lobesia botrana (Denis & Schiffermüller, 1775) (Lepidoptera Tortricidae) in Italy. The list is the result of the consultation of a vast bibliography published in Italy for almost two hundred years, from 1828 to date. This allowed the clarification and correction of misunderstandings and mistakes on the taxonomic position of each species listed. In Italy the complex of parasitoids detected on EGVM includes approximately 90 species belonging to ten families of Hymenoptera (Braconidae, Ichneumonidae, Chalcididae, Eulophidae, Eupelmidae, Eurytomidae, Pteromalidae, Torymidae, Trichogrammatidae, and Bethylidae) and one family of Diptera (Tachinidae). This paper deals with EGVM parasitoids of the families Tachinidae (Diptera) and Braconidae (Hymenoptera). Only two species of Tachinidae are associated to EGVM larvae in Italy, Actia pilipennis (Fallen) and Phytomyptera nigrina (Meigen), whereas the record of Eurysthaea scutellaris (Robineau-Desvoidy) is doubtful. Moreover, 21 species of Braconidae are reported to live on EGVM, but, unfortunately, eight of them were identified only at generic level. Bracon mellitor Say has been incorrectly listed among the parasitoids of Lobesia botrana . Records concerning Ascogaster rufidens Wesmael, Meteorus sp., Microgaster rufipes Nees, and Microplitis tuberculifer (Wesmael) are uncertain.

A review of insect parasitoids associated with Lobesia botrana (Denis & Schiffermüller, 1775 in Italy. 1. Diptera Tachinidae and Hymenoptera Braconidae (Lepidoptera, Tortricidae

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Pier Luigi Scaramozzino

2017-01-01

Full Text Available This paper is aimed to summarize the information available on the parasitoid complex of the European Grapevine Moth (EGVM, Lobesia botrana (Denis & Schiffermüller, 1775 (Lepidoptera Tortricidae in Italy. The list is the result of the consultation of a vast bibliography published in Italy for almost two hundred years, from 1828 to date. This allowed the clarification and correction of misunderstandings and mistakes on the taxonomic position of each species listed. In Italy the complex of parasitoids detected on EGVM includes approximately 90 species belonging to ten families of Hymenoptera (Braconidae, Ichneumonidae, Chalcididae, Eulophidae, Eupelmidae, Eurytomidae, Pteromalidae, Torymidae, Trichogrammatidae, and Bethylidae and one family of Diptera (Tachinidae. This paper deals with EGVM parasitoids of the families Tachinidae (Diptera and Braconidae (Hymenoptera. Only two species of Tachinidae are associated to EGVM larvae in Italy, Actia pilipennis (Fallen and Phytomyptera nigrina (Meigen, whereas the record of Eurysthaea scutellaris (Robineau-Desvoidy is doubtful. Moreover, 21 species of Braconidae are reported to live on EGVM, but, unfortunately, eight of them were identified only at generic level. Bracon mellitor Say has been incorrectly listed among the parasitoids of L. botrana. Records concerning Ascogaster rufidens Wesmael, Meteorus sp., Microgaster rufipes Nees, and Microplitis tuberculifer (Wesmael are uncertain.

Influence of age and diet on the performance of Cephalonomia stephanoderis (Hymenoptera, Bethylidae a parasitoid of the coffee berry borer, Hypothenemus hampei (Coleoptera, Curculionidae

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Jaime Gómez

2012-03-01

Full Text Available The importance of age and feeding on the performance of Cephalonomia stephanoderis (Hymenoptera, Bethylidae, a parasitoid of the coffee berry borer, Hypothenemus hampei (Coleoptera, Curculionidae was investigated in the laboratory. Groups of female parasitoids were subject to the following treatments: a group fed during one, five and ten days after emergence of adults with coffee borer larvae; another group fed only with honey solution during five days after emergence; and as a control, a third group was kept without food for five days. At the end of each treatment, survivorship, parasitoid activity (walking and flying capacity in an arena, search capacity for finding coffee borer-infested berries, host feeding and oviposition (on immature hosts, were assessed. Unfed females showed a significant decrease in survivorship compared to individuals that were fed. The type of meal (insects or honey did not significantly influence parasitoid activity, search and oviposition capacities. Females fed with honey solution significantly consumed less immature coffee borers. Younger females (one day old walked and flew out of the arena significantly faster than older ones (5 and 10 days old. Implications of these results are discussed on the performance of C. stephanoderis as a biological control agent of the coffee berry borer.

Populations of predators and parasitoids of Bemisia tabaci (Hemiptera: Aleyrodidae) after the application of eight biorational insecticides in vegetable crops.

Science.gov (United States)

Simmons, Alvin M; Shaaban, Abd-Rabou

2011-08-01

The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is an important pest of vegetables and many other crops worldwide. Eight biorational insecticides (based on oil, plant derivatives, insect growth regulator and fungus) were evaluated in the field for their influence on populations of six natural enemies of B. tabaci. Natural populations of two predators [Chrysoperla carnea Stephen (Neuroptera: Chrysopidae) and Orius spp. (Hemiptera: Anthocoridae)] and two genera of parasitoids [Encarsia spp. and Eretmocerus spp. (Hymenoptera: Aphelinidae)] were evaluated in eggplant (Solanum melongena L.). Also, augmented field populations of three predators [C. carnea, Coccinella undecimpunctata L. (Coleoptera: Coccinellidae) and Macrolophus caliginosus (Wagner) (Hemiptera: Miridae)] were evaluated in cabbage (Brassica oleracea var. capitata L.), cucumber (Cucumis sativus L.) and squash (Cucurbita pepo L.). Regardless of natural enemy or crop, jojoba oil, Biovar and Neemix had the least effect on abundance of the natural enemies in comparison with the other insecticides during a 14 day evaluation period. Conversely, Admiral, KZ oil, Mesrona oil, Mesrona oil + sulfur and natural oil had a high detrimental effect on abundance of the natural enemies. These results demonstrate the differential effects of biorational insecticides for whitefly control on predators and parasitoids in the field. This article is a US Government work and is in the public domain in the USA. Published 2011 by John Wiley & Sons, Ltd.

Sexy Mouth Odour? Male Oral Gland Pheromone in the Grain Beetle Parasitoid Lariophagus distinguendus (Förster) (Hymenoptera: Pteromalidae).

Science.gov (United States)

König, Kerstin; Seeger, Lucy; Steidle, Johannes L M

2015-01-01

Throughout the animal kingdom, sexual pheromones are used for the attraction of mates and as courtship signals but also enable sexual isolation between species. In the parasitic wasp Lariophagus distinguendus, male courtship behaviour consisting of wing fanning, antennal stroking of the female antenna, and head nodding stimulates female receptivity leading to copulation. Recently L. distinguendus was reported to consist of two different lineages, which are sexually isolated because males fail to elicit receptivity in foreign females. It is unclear, however, which part of the courtship behaviour triggers female receptivity and therefore could be a mechanism causing sexual isolation. Here we show that in L. distinguendus a nonvolatile male oral pheromone is essential to release the female receptivity signal. In contrast, male wing fanning and antennal contact play a minor role. Additionally, the composition of the oral pheromone depends on the developmental host and females learn the composition upon emergence from the host substrate. These results will enable more detailed work on oral sexual pheromones to answer the question of how they are involved in the speciation process of L. distinguendus and other parasitoid species, for a better understanding of the huge biodiversity in this group.

Sexy Mouth Odour? Male Oral Gland Pheromone in the Grain Beetle Parasitoid Lariophagus distinguendus (Förster (Hymenoptera: Pteromalidae

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Kerstin König

2015-01-01

Full Text Available Throughout the animal kingdom, sexual pheromones are used for the attraction of mates and as courtship signals but also enable sexual isolation between species. In the parasitic wasp Lariophagus distinguendus, male courtship behaviour consisting of wing fanning, antennal stroking of the female antenna, and head nodding stimulates female receptivity leading to copulation. Recently L. distinguendus was reported to consist of two different lineages, which are sexually isolated because males fail to elicit receptivity in foreign females. It is unclear, however, which part of the courtship behaviour triggers female receptivity and therefore could be a mechanism causing sexual isolation. Here we show that in L. distinguendus a nonvolatile male oral pheromone is essential to release the female receptivity signal. In contrast, male wing fanning and antennal contact play a minor role. Additionally, the composition of the oral pheromone depends on the developmental host and females learn the composition upon emergence from the host substrate. These results will enable more detailed work on oral sexual pheromones to answer the question of how they are involved in the speciation process of L. distinguendus and other parasitoid species, for a better understanding of the huge biodiversity in this group.

Physical Attractiveness and Counseling Skills.

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Vargas, Alice M.; Borkowski, John G.

1982-01-01

Searched for interaction between quality of counseling skills (presence or absence of empathy, genuineness, and positive regard) and physical attractiveness as determinants of counseling effectiveness. Attractiveness influenced perceived effectiveness of counselor's skill. Analyses of expectancy data revealed that only with good skills did…

Increase of acceptability period of Musca domestic l., 1758 (diptera: muscidae) pupae, irradiated by gamma radiation as host of the pupal parasitoid Spalangia endius, Walker, 1839 (hymenoptera: pteromalidae)

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Itepan, Natanael M., E-mail: nmitepan@ifsp.edu.br [Instituto Federal de Sao Paulo (IFSP), Piracicaba, SP (Brazil); Itepan, Sara E.D.Z., E-mail: sarazenitepan@ig.com.br [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia Ciencias e Letras; Arthur, Valter, E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

2013-07-01

This experiment was carried out in Biological Control of Domestic Fly 'Eduardo Hiroshi Mizumoto' Laboratory at Entomology and Acarology Department (LEA/ESALQ/USP) and in Food Irradiation and Radioentomology Laboratory (LIARE/CENA/USP). The gamma radiation source used was a Co-60 irradiator model Gammabeam-650 of the Atomic Energy of Canada Ltd. whose activity in the beginning of the experiments was 9.8x10{sup 13} Bq. (2,644 Ci). The lots of pupae of Musca domestic L., 1758 and the parasitoid Spalangia endius Walker, 1839 had been kept in acclimatized room with 25 ± 2 deg C of temperature and 70 ± 5% of relative humidity. This experiment was designed to investigate if the non-viabilization M. domestic pupae, using gamma radiation, could build up the acceptability period as host of the pupal parasitoid S. endius. At these age intervals, the dose to prevent adult emergence was 25, 220, 360 and 520 Gy respectively. The 1, 2, 3 and 4 days old pupae were irradiated (dose rate: 1,510 Gy/hr) and exposed to the parasitoid S. endius at a proportion of one female parasitoid to five housefly pupae, during different periods after the irradiation. The results allow us to conclude that irradiation increase the acceptability period of the housefly pupae by the parasitoid. The best age to irradiate the housefly pupae was one day. (author)

Increase of acceptability period of Musca domestic l., 1758 (diptera: muscidae) pupae, irradiated by gamma radiation as host of the pupal parasitoid Spalangia endius, Walker, 1839 (hymenoptera: pteromalidae)

International Nuclear Information System (INIS)

Itepan, Natanael M.; Itepan, Sara E.D.Z.

2013-01-01

This experiment was carried out in Biological Control of Domestic Fly 'Eduardo Hiroshi Mizumoto' Laboratory at Entomology and Acarology Department (LEA/ESALQ/USP) and in Food Irradiation and Radioentomology Laboratory (LIARE/CENA/USP). The gamma radiation source used was a Co-60 irradiator model Gammabeam-650 of the Atomic Energy of Canada Ltd. whose activity in the beginning of the experiments was 9.8x10 13 Bq. (2,644 Ci). The lots of pupae of Musca domestic L., 1758 and the parasitoid Spalangia endius Walker, 1839 had been kept in acclimatized room with 25 ± 2 deg C of temperature and 70 ± 5% of relative humidity. This experiment was designed to investigate if the non-viabilization M. domestic pupae, using gamma radiation, could build up the acceptability period as host of the pupal parasitoid S. endius. At these age intervals, the dose to prevent adult emergence was 25, 220, 360 and 520 Gy respectively. The 1, 2, 3 and 4 days old pupae were irradiated (dose rate: 1,510 Gy/hr) and exposed to the parasitoid S. endius at a proportion of one female parasitoid to five housefly pupae, during different periods after the irradiation. The results allow us to conclude that irradiation increase the acceptability period of the housefly pupae by the parasitoid. The best age to irradiate the housefly pupae was one day. (author)

Distributional patterns of fall armyworm parasitoids in a corn field and pasture field in Florida

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An assessment of parasitoids and their selective patterns among Spodoptera frugiperda corn and rice host strains was performed from August 2008-August 2010 in a corn crop and a grass pasture in northern Florida under different seasonal conditions (spring and fall). Sentinel larvae from our laborator...

Brood size and sex ratio in response to host quality and wasp traits in the gregarious parasitoid Oomyzus sokolowskii (Hymenoptera: Eulophidae

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Xianwei Li

2017-01-01

Full Text Available This laboratory study investigated whether the larval-pupal parasitoid Oomyzus sokolowskii females adjust their brood size and sex ratio in response to body size and stage of Plutella xylostella larval hosts, as well as to their own body size and the order of oviposition. These factors were analyzed using multiple regression with simultaneous entry of them and their two-way interactions. Parasitoids brood size tended to increase with host body size at parasitism when the 4th instar larval host was attacked, but did not change when the 2nd and 3rd instar larvae were attacked. Parasitoids did not vary in brood size according to their body size, but decreased with their bouts of oviposition on a linear trend from 10 offspring adults emerged per host in the first bout of oviposition down to eight in the third. Parasitoid offspring sex ratio did not change with host instar, host body weight, wasp body size, and oviposition bout. Proportions of male offspring per brood were from 11% to 13% from attacking the 2nd to 4th instar larvae and from 13% to 16% across three successive bouts of oviposition, with a large variation for smaller host larvae and wasps. When fewer than 12 offspring were emerged from a host, one male was most frequently produced; when more than 12 offspring were emerged, two or more males were produced. Our study suggests that O. sokolowskii females may optimize their clutch size in response to body size of mature P. xylostella larvae, and their sex allocation in response to clutch size.

The use of F1 sterility and parasitoids for population suppression of lepidopteran pests of crucifers in Indonesia

International Nuclear Information System (INIS)

Singgih Sutrisno Apu

2002-01-01

We report on the population suppression of diamondback moth (DBM) Plutella xylostella (L.) (Lepidoptera: Plutellidae) and cabbage webworm (CWW) Crocidolomia binotalis Z. (Lepidoptera: Pyralidae) using releases of irradiated (200 Gy) substerile moths. The impact of substerile DBM was studied in field-cages and moths were released at a 9:1 treated:untreated ratio. Our results show that releasing F 1 substerile male and female DBM resulted in a high level of sterility (73.03% and 73.30% in the F 1 and F 2 generations, respectively) in the untreated population, while the release of only F 1 males induced a lower level of sterility (55.40% and 56.44% in the F 1 and F 2 generations, respectively). When substerile moths were released once per generation, the level of sterility was 44.78% in the F 1 and 68.01% in the F 2 generations. The effect of releasing substerile males only, females only, and substerile male and female CWW on the untreated population were studied in the laboratory. Percent egg hatch was 22.17% for male only releases. For female and mixed sex releases these percentages were 28.50% and 24.75%, respectively. For DBM, some studies combined releases of substerile DBM with releases of the parasitoid Diadegma semiclausum (H) (Hymenoptera: Ichneumonidae) in field-plots. Pupal viability in the F 1 generation in the area that received both parasitoids and substerile DBM was 32.5%. The effect on pupal viability when only a single tactic was used was lower than when both tactics were combined. The release of substerile males only gave a pupal viability of 57.5% and releases of the parasitoid D. semiclausum resulted in 81% pupal viability. When substerile DBM were released into a small isolated forested area in Malang, East Java, the average number of moths caught per week at the release area from June to October 1996 was about 89.42% of that found in the untreated control area. When population fluctuations of wild DBM were followed for 12 months, the lowest

Biología de Eretmocerus mundus (Hymenoptera: Aphelinidae, parasitoide del complejo Bemisia tabaci (Homoptera: Aleyrodidae, en condiciones de laboratorio Biology of Eretmocerus mundus (Hymenoptera: Aphelinidae, parasitoid of Bemisia tabaci complex (Homoptera: Aleyrodidae under laboratory conditions

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Yerlin Chacón Castro

2010-06-01

Full Text Available La estimación de los atributos biológicos de un enemigo natural, previa a su empleo en el campo, constituye un aspecto de importancia en todo proyecto de control biológico. El objetivo de este trabajo fue evaluar los principales parámetros biológicos de Eretmocerus mundus Mercet, parasitoide de Bemisia tabaci (Gennadius, bajo condiciones de laboratorio.La emergencia del adulto, longevidad y fecundidad de la hembra, proporción sexual de la descendencia, tasa intrínseca de crecimiento poblacional (r m, tasa neta de reproducción (Ro y tiempo generacional (T; se estimaron mediante la técnica de tabla de vida y fecundidad, utilizando el pimiento (Capsicum annuum L. y el tomate (Solanum lycopersicum L. como plantas hospederas. Los resultados obtenidos en pimiento y tomate fueron respectivamente: supervivencia pupal: 86.86 ± 1.94 y 83,45 ± 2,13%; longevidad de la hembra: 18,19 ± 1,61 y 17,00 ± 0,92 días; proporción sexual: 0,34 ± 0,06 y 0,47 ± 0,05 hembras/(machos + hembras; l x50: 21 y 18 días; r m: 0,226 ± 0,061 y 0,228 ± 0,057 ninfas parasitadas/hembra/día; Ro: 189,71 ± 24,25 y 154,65 ± 17,58 ninfas parasitadas/hembra; T: 25,88 ± 0,42 y 24,03 ± 0,34 días. Los resultados obtenidos son una contribución al conocimiento de la población local del parasitoide y su posible papel como agente de control biológico de B. tabaci.The estimation of biological attributes of natural enemies prior to its use in the field is an important tool in a biological control program. The objective of the present paper was to evaluate the main biological parameters of Eretmocerus mundus Mercet, a parasitoid of Bemisia tabaci (Gennadius, under controlled laboratory conditions. Parasitoid survival, female longevity, fecundity, sex rate, intrinsic rate of natural increase (r m, net reproductive rate (Ro and generational time (T were studied using life tables, with pepper (Capsicum annuum L. and tomato (Solanum lycopersicum L. as host plants. Results

A review of aphid parasitoids and their associations in Algeria (Hymenoptera: Braconidae: Aphidiinae; Hemiptera: Aphidoidea)

Czech Academy of Sciences Publication Activity Database

Laamari, M.; Chaouche, S. T.; Halimi, C. W.; Benferhat, S.; Abbes, S. B.; Khenissa, N.; Starý, Petr

2012-01-01

Roč. 20, č. 1 (2012), s. 161-170 ISSN 1021-3589 Institutional research plan: CEZ:AV0Z50070508 Keywords : parasitoids * Diuraphis noxia * Lysiphlebus testaceipes Subject RIV: EH - Ecology, Behaviour Impact factor: 0.969, year: 2012 http://www.bioone.org/doi/pdf/10.4001/003.020.0120

Tritrophic choice experiments with Bt plants, the diamondback moth (Plutella xylostella) and the parasitoid Cotesia plutellae

NARCIS (Netherlands)

Schuler, T.H.; Potting, R.P.J.; Denholm, I.; Clark, S.J.; Clark, A.J.; Stewart, C.N.; Poppy, G.M.

2003-01-01

Parasitoids are important natural enemies of many pest species and are used extensively in biological and integrated control programmes. Crop plants transformed to express toxin genes derived from Bacillus thuringiensis (Bt) provide high levels of resistance to certain pest species, which is likely

Convergent development of a parasitoid wasp on three host species with differing mass and growth potential

NARCIS (Netherlands)

Harvey, J.A.; Molina, A.C.; Bezemer, T.M.; Malcicka, M.

2015-01-01

Koinobiont parasitoids develop in hosts that continue feeding and growing during the course of parasitism. Here, we compared development of a solitary koinobiont endoparasitoid, Meteorus pulchricornis Westmael (Hymenoptera: Braconidae), in second (L2) and fourth (L4) instars of three host species

Effects of Humor Production, Humor Receptivity, and Physical Attractiveness on Partner Desirability

Directory of Open Access Journals (Sweden)

Michelle Tornquist

2015-10-01

Full Text Available This study examined women’s and men’s preferences for humor production and humor receptivity in long-term and short-term relationships, and how these factors interact with physical attractiveness to influence desirability. Undergraduates viewed photographs of the opposite sex individuals who were high or low in physical attractiveness, along with vignettes varying in humor production and receptivity. Participants rated physical attractiveness and desirability for long-term and short-term relationships. The main findings were that individuals desired partners who were high in humor production and receptivity, though the effects were particularly pronounced for women judging long-term relationships. Moreover, humor production was more important than receptivity for women’s ratings of male desirability. Notably, we also found that ratings of physical attractiveness were influenced by the humor conditions. These results are discussed in terms of the fitness indicator, interest indicator, and encryption hypotheses of the evolutionary functions of humor.

40 CFR 180.1101 - Parasitic (parasitoid) and predatory insects; exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... insects; exemption from the requirement of a tolerance. 180.1101 Section 180.1101 Protection of... predatory insects; exemption from the requirement of a tolerance. Parasitic (parasitoid) and predatory insects are exempted from the requirement of a tolerance for residues when they are used in accordance...

Nectar exploitation by herbivores and their parasitoids is a function of flower species and relative humidity

NARCIS (Netherlands)

Winkler, K.; Wäckers, F.L.; Kaufman, L.V.; Larraz, V.; Lenteren, van J.C.

2009-01-01

In conservation biological control, diversification of the agro ecosystem with flowering vegetation is seen as an important tool to support the broad range of predators and parasitoids that require nectar and pollen sources to survive and reproduce. In order to identify flowering plants that provide

Attracting International Hotels

DEFF Research Database (Denmark)

Assaf, A. George; Josiassen, Alexander; Agbola, Frank Wogbe

2015-01-01

With the increased international competition facing hotel chains, it is essential that the next destination they enter is the most attractive option possible. The host destinations too have a keen interest in strategically positioning themselves in order to attract international hotels since...... their presence has several positive effects. Using, for the first time, actual on-location data we investigate the factors that matter most for international hotels when selecting host destinations. Specifically, we identify 23 factors that make a destination an attractive (or unattractive) location...... for international hotels. We then rank these. The results show that welcomeness, infrastructure, and crime rate are the three most important factors that influence the location of international hotels in host destinations....

Experimental Effects and Individual Differences in Linear Mixed Models: Estimating the Relationship between Spatial, Object, and Attraction Effects in Visual Attention

Science.gov (United States)

Kliegl, Reinhold; Wei, Ping; Dambacher, Michael; Yan, Ming; Zhou, Xiaolin

2011-01-01

Linear mixed models (LMMs) provide a still underused methodological perspective on combining experimental and individual-differences research. Here we illustrate this approach with two-rectangle cueing in visual attention (Egly et al., 1994). We replicated previous experimental cue-validity effects relating to a spatial shift of attention within an object (spatial effect), to attention switch between objects (object effect), and to the attraction of attention toward the display centroid (attraction effect), also taking into account the design-inherent imbalance of valid and other trials. We simultaneously estimated variance/covariance components of subject-related random effects for these spatial, object, and attraction effects in addition to their mean reaction times (RTs). The spatial effect showed a strong positive correlation with mean RT and a strong negative correlation with the attraction effect. The analysis of individual differences suggests that slow subjects engage attention more strongly at the cued location than fast subjects. We compare this joint LMM analysis of experimental effects and associated subject-related variances and correlations with two frequently used alternative statistical procedures. PMID:21833292

Liquid drops attract or repel by the inverted Cheerios effect.

Science.gov (United States)

Karpitschka, Stefan; Pandey, Anupam; Lubbers, Luuk A; Weijs, Joost H; Botto, Lorenzo; Das, Siddhartha; Andreotti, Bruno; Snoeijer, Jacco H

2016-07-05

Solid particles floating at a liquid interface exhibit a long-ranged attraction mediated by surface tension. In the absence of bulk elasticity, this is the dominant lateral interaction of mechanical origin. Here, we show that an analogous long-range interaction occurs between adjacent droplets on solid substrates, which crucially relies on a combination of capillarity and bulk elasticity. We experimentally observe the interaction between droplets on soft gels and provide a theoretical framework that quantitatively predicts the interaction force between the droplets. Remarkably, we find that, although on thick substrates the interaction is purely attractive and leads to drop-drop coalescence, for relatively thin substrates a short-range repulsion occurs, which prevents the two drops from coming into direct contact. This versatile interaction is the liquid-on-solid analog of the "Cheerios effect." The effect will strongly influence the condensation and coarsening of drops on soft polymer films, and has potential implications for colloidal assembly and mechanobiology.

Body Odors of Parasitized Caterpillars Give Away the Presence of Parasitoid Larvae to Their Primary Hyperparasitoid Enemies

NARCIS (Netherlands)

Zhu, Feng; Weldegergis, Berhane T.; Lhie, Boris; Harvey, Jeffrey A.; Dicke, Marcel; Poelman, Erik H.

2014-01-01

Foraging success of parasitoids depends on the utilization of reliable information on the presence of their often, inconspicuous hosts. These parasitic wasps use herbivore-induced plant volatiles (HIPVs) that provide reliable cues on host presence. However, host searching of hyperparasitoids, a

Body odors of parasitized caterpillars give away the presence of parasitoid larvae to their primary hyperparasitoid enemies

NARCIS (Netherlands)

Zhu, F.; Weldegergis, B.T.; Lhie, B.; Harvey, J.A.; Dicke, M.; Poelman, E.H.

2014-01-01

Foraging success of parasitoids depends on the utilization of reliable information on the presence of their often, inconspicuous hosts. These parasitic wasps use herbivore-induced plant volatiles (HIPVs) that provide reliable cues on host presence. However, host searching of hyperparasitoids, a

Geographical distribution and genetic relatedness of sympatrical thelytokous and arrhenotokous populations of the parasitoid Venturia canescens (Hymenoptera)

NARCIS (Netherlands)

Schneider, M.V.; Beukeboom, L.W.; Driessen, G.; Lapchin, L.; Bernstein, C.; Alphen, J.J.M. van

2002-01-01

Theory predicts that asexual reproduction has a competitive advantage over sexual reproduction because of the twofold cost of producing males. Few systems are suitable for directly testing this prediction. In the solitary parasitoid wasp Venturia canescens both arrhenotokously (sexual) and

Understanding biological control of greenhouse whitefly with the parasitoid Encarsia formosa : from individual behaviour to population dynamics

NARCIS (Netherlands)

Roermund, van H.J.W.

1995-01-01

The greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Homoptera, Aleyrodidae), is a very common, highly polyphagous pest insect all over the world. Biological control of whiteflies with the parasitoid Encarsia formosa Gahan (Hymenoptera, Aphelinidae) was already applied in the 1920s in

Suitability of new and old association hosts for the development of selected microgastrine parasitoids of gramineous stemborers

NARCIS (Netherlands)

Ngi-Song, A.J.; Overholt, W.A.; Smith, J.W.; Vinson, S.B.

1999-01-01

The present study examined the acceptability and suitability of Old World stemborers (Chilo partellus and C. orichalcociliellus) for the development of New World parasitoids (Apanteles deplanatus and A. minator) and New World stemborers (Diatraea saccharalis and D. grandiosella) for the development

Comparative AFLP reveals paternal sex ratio chromosome specific DNA sequences in the parasitoid wasp Trichogramma kaykai

NARCIS (Netherlands)

Vugt, van J.J.F.A.; Hulst, van der R.G.M.; Pruijssers, A.; Verbaarschot, P.G.H.; Stouthamer, R.; Jong, de H.

2009-01-01

The parasitoid wasp Trichogramma kaykai with a haplo-diploid sex determination has a B chromosome called the paternal sex ratio (PSR) chromosome that confers paternal genome loss during early embryogenesis, resulting in male offspring. So far, it is not well known whether the PSR chromosome has

The parasitoids of the African white rice borer, Maliarpha separatella Ragonot (Lepidoptera: Pyralidae)

OpenAIRE

Polaszek, A.; Fitton, M.G.; Bianchi, G.; Huddleston, T.

2017-01-01

A key is provided for the recognition of the hymenopterous parasitoids of the African white rice borer, Maliarpha separatella Ragonot, a pest of rice in Africa and Madagascar. Five species are described as new: Braconidae: Chelonus maudae Huddleston, Rhacanotus carinafus Polaszek; Ichneumonidae: Prisfomerus bullis Fitton, Prisfomerus caris Fitton, Venturia jordanae Fitton. The following synonyms are proposed: Goniozus indicus Muesebeck, G. natalensis Gordh and G. procerae Risbec are synonymiz...

Sweet attraction: sugarcane pollen-associated volatiles attract gravid Anopheles arabiensis.

Science.gov (United States)

Wondwosen, Betelehem; Birgersson, Göran; Tekie, Habte; Torto, Baldwyn; Ignell, Rickard; Hill, Sharon R

2018-02-21

Anopheles arabiensis is a key vector for the transmission of human malaria in sub-Saharan Africa. Over the past 10,000 years, humans have successfully cultivated grasses and altered the landscape, creating An. arabiensis favourable environments that contain excellent habitats for both larvae and adults. Sugarcane is the most expanding agricultural system in sub-Saharan Africa, and is linked to the increased threat of malaria in rural communities. The prolific production and wind dispersal of sugarcane pollen, together with standing pools of water, often provide, as a result of irrigation, a nutrient-rich environment for the offspring of gravid malaria mosquitoes. In the present study, sugarcane pollen-associated volatiles from two cultivars are shown to attract gravid An. arabiensis in a still air two-port olfactometer and stimulate egg laying in an oviposition bioassay. Through combined gas chromatography and electroantennographic detection, as well as combined gas chromatography and mass spectrometric analyses, we identified the bioactive volatiles and generated a synthetic blend that reproduced the full behavioural repertoire of gravid mosquitoes in the Y-tube assay. Two subtractive odour blends, when compared with the full blend, were significantly more attractive. These three and four-component subtractive blends share the compounds (1R)-(+)-α-pinene, nonanal and benzaldehyde, of which, (1R)-(+)-α-pinene and nonanal are found in the attractive odour blends from rice plants and maize pollen. In pairwise comparisons, the rice synthetic odour blend was more attractive to gravid mosquitoes than either of the pollen blends, whereas the pollen blends did not differ in attraction. The attraction of gravid females to sugarcane pollen volatiles demonstrated in this study, together with the previously found grass-associated volatiles, raise the potential of developing a bioactive chimeric blend to attract gravid malaria mosquitoes. This is discussed in relation to

Asymmetric total synthesis of a putative sex pheromone component from the parasitoid wasp Trichogramma turkestanica

NARCIS (Netherlands)

Geerdink, Danny; Buter, Jeffrey; van Beek, Teris A.; Minnaard, Adriaan J.

2014-01-01

Virgin females of the parasitoid wasp Trichogramma turkestanica produce minute amounts of a sex pheromone, the identity of which has not been fully established. The enantioselective synthesis of a putative component of this pheromone, (6S,8S,10S)-4,6,8,10-tetramethyltrideca-2E,4E-dien-1-ol (2), is

Lethal and behavioral effects of selected novel pesticides on adults of Trichogramma pretiosum (Hymenoptera: Trichogrammatidae).

Science.gov (United States)

Khan, Muhammad Ashraf; Khan, Hizbullah; Ruberson, John R

2015-12-01

Growing demand for reduced chemical inputs in agricultural systems requires more effective integration of biological control with pesticides. The egg parasitoid Trichogramma pretiosum Riley is an important natural enemy of lepidopteran pests, used in biological control. In an investigation of the interaction of T. pretiosum and pesticides, we studied the acute toxicity of 19 pesticides (insecticides, miticides, fungicides and herbicides) to adult parasitoids and the behavioral effects of 11 pesticides on foraging parasitoid females, including host antennation, stinging and host feeding. At recommended field doses, fipronil, dinotefuran, spinetoram, tolfenpyrad and abamectin induced nearly 100% adult mortality within 24 h of exposure to treated cotton leaves by comparison with controls. Acetamiprid was also toxic, but significantly less so than the former materials. The other pesticides had no significant toxic effects. Only glufosinate ammonium exhibited increased toxicity among the non-toxic materials when increased two- or fourfold over recommended rates. The foraging behavior of parasitoids was affected only by tolfenpyrad among the materials tested. Most novel pesticides, except for several insecticides, exhibited little to no acute toxicity to the parasitoid. Parasitoid foraging behavior was only affected by tolfenpyrad, indicating that parasitoids could successfully forage on eggs treated with most pesticides evaluated. Therefore, many of these pesticides may have good compatibility with Trichogramma. © 2015 Society of Chemical Industry.

Influence of adult nutrition on the relationship between body size and reproductive parameters in a parasitoid wasp

NARCIS (Netherlands)

Bezemer, T.M.; Harvey, J.A.; Mills, N.J.

2005-01-01

1. An important constraint upon life-history evolution in parasitoids is the limit imposed by body size on allocation of limited metabolic resources to different fitness-related physiological functions such as reproduction and survival. 2. The influence of adult nutrition on reproductive and

Herbivore-induced volatile production by Arabidopsis thaliana leads to attraction of the parasitoid Cotesia rubecula: chemical, behavioral, and gene-expression analysis

NARCIS (Netherlands)

Poecke, R.M.P.; Posthumus, M.A.; Dicke, M.

2001-01-01

Many plant species defend themselves against herbivorous insects indirectly by producing volatiles in response to herbivory. These volatiles attract carnivorous enemies of the herbivores. Research on the model plant Arabidopsis thaliana (L.) Heynh. has contributed considerably to the unraveling of

Reproductive and developmental biology of the emerald ash borer parasitoid Spathius galinae (Hymenoptera: Braconidae) as affected by temperature

Science.gov (United States)

Emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) is an invasive pest of serious concern in North America. To complement ongoing biological control efforts, Spathius galinae Belokobylskij and Strazenac (Hymenoptera: Braconidae), a recently-described specialist parasitoid of ...

Life inside a gall: closeness does not favour horizontal transmission of Rickettsia between a gall wasp and its parasitoid.

Science.gov (United States)

Gualtieri, Liberata; Nugnes, Francesco; Nappo, Anna G; Gebiola, Marco; Bernardo, Umberto

2017-07-01

The incidence of horizontal transmission as a route for spreading symbiont infections is still being debated, but a common view is that horizontal transfers require intimate between-species relationships. Here we study a system that meets ideal requirements for horizontal transmission: the gall wasp Leptocybe invasa and its parasitoid Quadrastichus mendeli (Hymenoptera: Eulophidae). These wasps belong to the same subfamily, spend most of their lives inside the same minute gall and are both infected by Rickettsia, a maternally inherited endosymbiotic bacteria that infects several arthropods, sometimes manipulating their reproduction, like inducing thelytokous parthenogenesis in L. invasa. Despite intimate contact, close phylogenetic relationship and the parasitoid's host specificity, we show that host and parasitoid do not share the same Rickettsia. We provide indirect evidence that Rickettsia infecting Q. mendeli may be inducing thelytokous parthenogenesis, as the symbiont is densely present in the reproductive apparatus and is vertically transmitted. Phylogenetic analyses based on 16S and gltA placed this symbiont in the leech group. The confirmed and presumed parthenogenesis-inducing Rickettsia discovered so far only infect eulophid wasps, and belong to three different groups, suggesting multiple independent evolution of the parthenogenesis inducing phenotype. We also show some degree of cospeciation between Rickettsia and their eulophid hosts. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Antipsychotics and physical attractiveness.

Science.gov (United States)

Seeman, Mary V

2011-10-01

Antipsychotics are effective in treating the symptoms of schizophrenia, but they may induce adverse effects, some of which-those that impact negatively on physical appearance-have not been sufficiently discussed in the psychiatric literature. Through a narrative review, to catalog antipsychotic side effects that interfere with physical attractiveness and to suggest ways of addressing them. PubMed databases were searched for information on the association between "antipsychotic side effects" and "attractiveness" using those two search phrases plus the following terms: "weight," "teeth," "skin," "hair," "eyes," "gait," "voice," "odor." Data from relevant qualitative and quantitative articles were considered, contextualized, and summarized. Antipsychotics, as a group, increase weight and may lead to dry mouth and bad breath, cataracts, hirsutism, acne, and voice changes; they may disturb symmetry of gait and heighten the risk for tics and spasms and incontinence, potentially undermining a person's attractiveness. Clinicians need to be aware of the impact of therapeutic drugs on appearance and how important this issue is to patients. Early in treatment, they need to plan preventive and therapeutic strategies.

Diversidad de avispas parasitoides en un sistema silvopastoril orgánico de producción ganadera de Colombia

Directory of Open Access Journals (Sweden)

L. López

2013-01-01

Full Text Available En el sistema silvopastoril de la Reserva Natural El Hatico (Rneh en El Cerrito, Valle (Colombia, las legumbres del algarrobo (Prosopis juliflora, se utilizan como alimento para bovinos. Sin embargo, desde 2006, la polilla Eccopsis galapagana (Lepidoptera: Tortricidae, afecta el follaje y la producción de legumbres. Motivados por el brote poblacional de esta polilla, se propuso identificar las especies de parasitoides, su distribución, su densidad y relacionarlas con el hábitat y el daño del insecto sobre P. juliflora. Se capturaron himenópteros, utilizando platos amarillos ubicados en 24 árboles de algarrobo escogidos al azar, en cuatro lotes dentro del sistema silvopastoril y al interior del bosque adyacente (control. Se midió el porcentaje de herbivoría, por E. galapagana; la cobertura del dosel de cada árbol muestreado, la temperatura y se determinó la composición vegetal de cada lote. De un total de 1,376 parasitoides -pertenecientes a siete superfamilias, 18 familias y 42 morfoespecies- el 71% se identificó hasta género. La superfamilia más representativa fue Chalcidoidea, y Encyrtidae la familia más abundante. Se encontró una relación positiva entre composición, cobertura vegetal y abundancia de parasitoides; pero esto no se tradujo en una disminución de los porcentajes de herbivoría por la polilla.

Fruit flies (Diptera, Tephritidae and their parasitoids on cultivated and wild hosts in the Cerrado-Pantanal ecotone in Mato Grosso do Sul, Brazil

Directory of Open Access Journals (Sweden)

Tiago Ledesma Taira

2013-09-01

Full Text Available Fruit flies (Diptera, Tephritidae and their parasitoids on cultivated and wild hosts in the Cerrado-Pantanal ecotone in Mato Grosso do Sul, Brazil. Information on frugivorous flies in cultivated or wild host plants and their parasitoids in the Cerrado-Pantanal ecotone in Aquidauana, Mato Grosso do Sul is presented and discussed. Fruit fly samples were collected weekly in specific fruit trees, and McPhail® traps were installed in the same trees for a period of two years. The fruit flies infested ripe and unripe fruits of Averrhoa carambola L., Schoepfia sp., Psidium guajava L. and Pouteria torta (Mart. Radlk and mature fruits of Anacardium occidentale L. and Inga laurina (Sw. Willd. Nineteen fruit fly species were obtained with the combination of sampling methods (collecting fruits and trapping, nine of them obtained with both methods, five found only in fruits and five only in traps. This is the first record of Anastrepha striata Schiner in a species of Sapotaceae, as well as for A. castanea Norrbom and A. daciformes Bezzi in Schoepfia sp. (Olacaceae, and for A. distincta Greene in fruits of P. guajava in the state of Mato Grosso do Sul. Fruit collections simultaneously associated with capture of fruit flies by McPhail traps in the same host plants are essential to understand the diversity of fruit flies and their relationship with hosts and parasitoids. Species of Braconidae and Pteromalidae were recovered, where Doryctobracon areolatus (Szépligeti was the most abundant parasitoid in larvae of tephritids infesting both cultivated and wild host fruits.

Anastrepha species (Diptera: Tephritidae, their host plants and parasitoids (Hymenoptera in the state of Roraima, Brazil: state of the art

Directory of Open Access Journals (Sweden)

Alberto Luiz Marsaro Júnior

2017-02-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2017v30n1p13 The aim of this review was to update the available information on Anastrepha species in the state of Roraima, Brazil, with emphasis on distribution, host plants and parasitoids. In total, 25 species of Anastrepha and 27 host plant species have been recorded to date in Roraima. Anastrepha striata and A. obliqua are widely distributed in the state. Anastrepha obliqua is the most polyphagous species, where it is associated with 13 hosts. Six species of parasitoids of Anastrepha have been reported in Roraima. Of these, Doryctobracon areolatus is the most abundant and has been associated with the largest number of Anastrepha species.

Revisiting the Red Effect on Attractiveness and Sexual Receptivity: No effect of the color red on human mate preferences

OpenAIRE

Peperkoorn, Leonard; Roberts, S. Craig; Pollet, Thomas

2016-01-01

Color-in-context theory is the first theoretical framework for understanding color effects in human mate preferences, arguing that red clothing enhances attractiveness ratings. Here we present three empirical studies failing to support this prediction. We aimed to extend the current literature by differentiating color effects by temporal context (short-term vs. long-term mating). Experiment 1 involved Dutch participants rating a woman in red, white, and black on (sexual) attractiveness. Exper...

Effect of Leg-to-Body Ratio on Body Shape Attractiveness.

Science.gov (United States)

Kiire, Satoru

2016-05-01

Recent studies have examined various aspects of human physical attractiveness. Attractiveness is considered an evolved psychological mechanism acquired via natural selection because an attractive body reflects an individual's health and fertility. The length of the legs is an often-emphasized aspect of attractiveness and has been investigated using the leg-to-body ratio (LBR), which reflects nutritional status of the infant, health status, fecundity, and other factors that are predictive of physical fitness. However, previous studies of leg length and physical fitness have produced mixed results. The present study investigated the relationship between LBR, defined as the height to perineum divided by total height, and perceived attractiveness. Three-dimensional stimuli (11 male and 11 female) were constructed with various LBR features. Each stimulus was rated by 40 women and 40 men in Japan on a 7-point scale. The results showed that the values closest to the average LBRs were rated as the most attractive. Furthermore, by fitting a quadratic curve on the relationship between attractiveness and LBR, an inverted U-shaped curve with the peak located at the average LBR was observed. In addition, high LBR values were rated as more attractive in females, whereas the opposite was true for males. These results suggest that average LBR is indicative of good health and good reproductive potential, whereas more extreme values are avoided because they could be indicative of diseases and other maladaptive conditions.

Nectar-providing plants enhance the energetic state of herbivores as well as their parasitoids under field conditions

NARCIS (Netherlands)

Winkler, K.; Wackers, F.; Pinto, D.M.

2009-01-01

1. The use of flowering vegetation has been widely advocated as a strategy for providing parasitoids and predators with nectar and pollen. However, their herbivorous hosts and prey may exploit floral food sources as well. 2. Previous laboratory studies have shown that not all flower species are

Differing success of defense strategies in two parasitoid wasps in protecting their pupae against a secondary hyperparasitoid

NARCIS (Netherlands)

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

2011-01-01

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

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

NARCIS (Netherlands)

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

2011-01-01

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

Vitex agnus castus and Euphorbia characias ssp. wulfenii as reservoirs of aphid parasitoids (Hymenoptera: Braconidae: Aphidiinae)

Czech Academy of Sciences Publication Activity Database

Kavallieratos, N. G.; Tomanovic, Ž.; Starý, Petr; Emmanouel, N. E.

2008-01-01

Roč. 91, č. 2 (2008), s. 179-191 ISSN 0015-4040 Grant - others:The Ministry of Science nad Environment Protection of the Republic of Serbia(CS) 143006B Institutional research plan: CEZ:AV0Z50070508 Keywords : aphids * parasitoids * reservoirs Subject RIV: EH - Ecology, Behaviour Impact factor: 0.886, year: 2008

Sexual dimorphism in the parasitoid wasps Aphidius balcanicus, Aphidius rosae, and Aphidius urticae (Hymenoptera: Braconidae: Aphidiinae)

Czech Academy of Sciences Publication Activity Database

Petrović, A.; Tomanović, Ž.; Kavallieratos, N. G.; Mitrovski Bogdanović, A.; Starý, Petr; Ivanović, A.

2014-01-01

Roč. 107, č. 5 (2014), s. 1027-1032 ISSN 0013-8746 Grant - others:The Ministry of Education, Science and Technological Development of the Republic of Serbia(RS) 43001 Institutional support: RVO:60077344 Keywords : geometric morphometric * parasitoid wasp * sexual size dimorphism Subject RIV: EA - Cell Biology Impact factor: 1.190, year: 2014

Quantum Statistics: Is there an effective fermion repulsion or boson attraction?

OpenAIRE

Mullin, W. J.; Blaylock, G.

2003-01-01

Physicists often claim that there is an effective repulsion between fermions, implied by the Pauli principle, and a corresponding effective attraction between bosons. We examine the origins of such exchange force ideas, the validity for them, and the areas where they are highly misleading. We propose that future explanations of quantum statistics should avoid the idea of a effective force completely and replace it with more appropriate physical insights, some of which are suggested here.

Life-history parameters of Encarsia formosa, Eretmocerus eremicus and E. Mundus, aphelinid parasitoids of Bemisia argentifolii (Hemiptera: Aleyrodidae)

NARCIS (Netherlands)

Qiu, Y.T.; Lenteren, van J.C.; Drost, Y.C.; Posthuma-Doodeman, J.A.M.

2004-01-01

Life-history parameters (juvenile development time, adult longevity, host instar preference and rate of parasitism) offour parasitoids of Bemisia argentifolii (two strains of Encarsia formosa (D and B), Eretmocerus eremicus and Eretmocerus mundus) Were Studied in the laboratory. At 15degreesC

Chemical investigations of volatile kairomones produced by Hyphantria cunea (Drury), a host of the parasitoid Chouioia cunea Yang.

Science.gov (United States)

Zhu, G; Pan, L; Zhao, Y; Zhang, X; Wang, F; Yu, Y; Fan, W; Liu, Q; Zhang, S; Li, M

2017-04-01

In tritrophic 'plants-herbivores-natural enemies' systems, there are relatively few reports concerning the role(s) of kairomones in pupal parasitism. Chouioia cunea Yang (Hymenoptera: Eulophidae), an endoparasitic chalcid wasp, parasitizes pupae of the fall webworm (Hyphantria cunea Drury). The role of host-related kairomones was investigated using electroantennogram (EAG) and behavioral techniques. Chemicals from some host stages (pupae) and host by-products (frass), induced arrestment behavior of female parasitoids, while chemicals from prepupae, were inactive. Gas chromatography-mass spectrometry analysis of volatiles collected from pupae, frass and prepupae using solid-phase microextration revealed seven compounds with carbon chain lengths ranging from C4 to C20. All of the chemicals elicited significant EAG responses in C. cunea. Y-tube olfactometer bioassays demonstrated a significant positive response of mated female C. cunea to 1-dodecene. These data provide a better understanding of the host location mechanisms of pupal parasitoid.

FRUIT FLIES (DIPTERA: TEPHRITIDAE AND THEIR PARASITOIDS ASSOCIATED WITH DIFFERENT HOG PLUM GENOTYPES IN TERESINA, PIAUÍ

Directory of Open Access Journals (Sweden)

LEONARDO DA SILVA SOUSA

2017-10-01

Full Text Available ABSTRACT The aim of this work was to identify and quantify the infestation of fruit fly species and their parasitoids, associated with 20 hog plum genotypes (Spondias mombin L. in a commercial orchard in Teresina, Piauí, Brazil. The survey was conducted by fruit sampling and monitoring through traps stocked with bait food, in the period from January to December 2012. Overall, 6560 fruits were collected (79.58 kg, resulting in 23059 pupae, of which 10080 fruit flies of the genus Anastrepha and 4984 braconid parasitoids emerged. Anastrepha obliqua species was the predominant with 99.92%. F16P13 and F11P10 genotypes had the highest infestation indexes and F15P11 and F04P01 genotypes, the lowest. The main parasitoids collected were Opius bellus (77.65%, Doryctobracon areolatus (19.88% and Utetes anastrephae (2.47%. The average parasitism rate among genotypes was of 30.46%. In traps, a total of 1434 fruit flies were collected, whose species were: A. obliqua (97.6%, A. serpentina (1.4%, A. fraterculus (0.4%, A. striata (0.4%, A. dissimilis (0.1%, A. pseudoparallela (0.1%. Anastrepha obliqua species was predominant in the area, based on faunistic analysis. The infestation index in the orchard was relevant for five months (January-May, coinciding with the period of availability of hog plum fruits, reaching the highest peak in March (2.86 FAT. There was a significant negative correlation between number of fruit flies in the orchard and the average air temperature, and a significant positive correlation with rainfall and relative humidity. However, the main factor that influenced the observed infestation index in the hog plum orchard was fruit availability.

Survival and development of a stored-product pest, Sitophilus zeamais (Coleoptera: Curculionidae), and its natural enemy, the parasitoid Lariophagus distinguendus (Hymenoptera. Pteromalidae), on transgenic Bt maize

DEFF Research Database (Denmark)

Hansen, Lise S.; Lövei, Gabor L; Székács, András

2013-01-01

Background The effect of transgenic maize (Zea mays L.) containing a lepidopteran-specific Bt toxin on a stored-product pest, Sitophilus zeamais Motschulsky, and its parasitoid, Lariophagus distinguendus Förster, was examined in the laboratory to test the impact of transgenic maize on stored...

Fluids with highly directional attractive forces. III. Multiple attraction sites

International Nuclear Information System (INIS)

Wertheim, M.S.

1986-01-01

The authors derive a reformulation of statistical thermodynamics for fluids of molecules which interact by highly directional attraction. The molecular model consists of a repulsive core and several sites of very short-ranged attraction. The authors explore the relationship between graph cancellation in the fugacity expansion and three types of steric incompatibility between repulsive and attractive interactions involving several molecules. The steric effects are used to best advantage in a limited regrouping of bonds. This controls the density parameters which appear when articulation points are eliminated in the graphical representation. Each density parameter is a singlet density for a species consisting of molecules with a specified set of sites bonded. The densities satisfy subsidiary conditions of internal consistency. These conditions are equivalent to a minimization of the Helmholtz free energy A. Graphical expressions for A and for the pressure are derived. Analogs of the s-particle direct correlation functions and of the Ornstein-Zernike equation are found

Biology and Behavior of Spathius agrili, a Parasitoid of the Emerald Ash Borer, Agrilus planipennis, in China

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Yang, Zhong-Qi; Wang, Xiao-Yi; Gould, Juli R.; Reardon, Richard C.; Zhang, Yi-Nan; Liu, Gui-Jun; Liu, En-Shan

2010-01-01

Spathius agrili Yang (Hymenoptera: Braconidae) is a gregarious larval ectoparasitoid of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) and is a recently described species. Both pest and parasitoid are native to China. In Tianjin City, China, S. agrili typically exhibited 3–4 generations per year, overwintering as a prepupa in a cocoon inside the host gallery. The multiple generations of S. agrili overlapped with its host, as did the emergence dates of the overwintering generation. From a single host, 1–18 S. agrili successfully developed to the adult stage (average 8.4), but in all cases the host was killed. The sex ratio (female: male) of the parasitoid adults emerging from field-collected cocoons was 2:1, whereas the sex ratio of parasitoids reared from field collected eggs and larvae was greater than 3:1. On average, adult females lived 29.1 d, and males lived 23.6 d when fed with 20% honey solution, significantly longer than without a nutritional supplement. Sexual reproduction is the normal mode of reproduction, but in the laboratory females did reproduce parthenogenetically, producing only males. The average fecundity was 23.3 eggs per female in the laboratory. S. agrili developed through five larval instars, and the larvae fed gregariously on the host hemolymph. The generation time from egg to adult wasp was 27–28 d at 22–26°C. Natural parasitism rates were as high as 60%, and in October they reached over 90% in some stands. This study showed that S. agrili is a promising agent for biocontrol of A. planipennis. PMID:20569125

Biology of Blepyrus clavicornis (Compere (Hymenoptera: Encyrtidae, a parasitoid of Pseudococcus viburni (Signoret (Hemiptera: Pseudococcidae

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Vitor Pacheco da Silva

Full Text Available Abstract Encyrtids (Hymenoptera: Encyrtidae are the most important and diverse group of natural enemies of mealybugs (Hemiptera: Pseudococcidae. Blepyrus clavicornis (Compere is the most common parasitoid associated with Pseudococcus viburni (Signoret in the Serra Gaúcha region, Brazil. We conducted laboratory studies to assess the development time, sex ratio, adult longevity, host stage selection for parasitism, and effect of food on the longevity of adult females of B. clavicornis. The experiments were conducted in a climate chamber at 25 ± 1 °C, 70 ± 10% RH and 12:12 L:D photoperiod. The solitary parasitoid B. clavicornis parasitized third-instar and adult female stages of P. viburni. The development time was more than 30 days (31.75 ± 0.38 for females and 30.02 ± 0.34 for males when B. clavicornis laid eggs in adult mealybug females, and 35 days (36.50 ± 0.50 for females and 34.24 ± 0.43 for males on third-instar mealybug nymphs. The wasps did not survive longer than four days when they were fed only water, while females survived for about 30 days when fed with honey. The lifespan of females is about 20 days longer than the lifespan of males. Although B. clavicornis can provide significant natural control, reducing the number of individuals in the next generation by parasitizing advanced mealybug instars, we consider it unpromising for use in applied biological-control programs. Furthermore, the predominance of males in the progeny observed here suggests that P. viburni may not be the most suitable or preferred host for B. clavicornis.

Romantic attraction and adolescent smoking trajectories.

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Pollard, Michael S; Tucker, Joan S; Green, Harold D; Kennedy, David P; Go, Myong-Hyun

2011-12-01

Research on sexual orientation and substance use has established that lesbian, gay, and bisexual (LGB) individuals are more likely to smoke than heterosexuals. This analysis furthers the examination of smoking behaviors across sexual orientation groups by describing how same- and opposite-sex romantic attraction, and changes in romantic attraction, are associated with distinct six-year developmental trajectories of smoking. The National Longitudinal Study of Adolescent Health dataset is used to test our hypotheses. Multinomial logistic regressions predicting smoking trajectory membership as a function of romantic attraction were separately estimated for men and women. Romantic attraction effects were found only for women. The change from self-reported heterosexual attraction to lesbian or bisexual attraction was more predictive of higher smoking trajectories than was a consistent lesbian or bisexual attraction, with potentially important differences between the smoking patterns of these two groups. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effects of Physical Attractiveness on Evaluation of Vocal Performance.

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Wapnick, Joel; Darrow, Alice Ann; Kovacs, Jolan; Dalrymple, Lucinda

1997-01-01

Studies whether physical attractiveness of singers affects judges' ratings of their vocal performances. Reveals that physical attractiveness does impact evaluation, that male raters were more severe than female raters, and that the rating of undergraduate majors versus graduate students and professors combined were not differently affected by…

Subtle effect of Xenos vesparum (Xenidae, Strepsiptera) on the reproductive apparatus of its male host: Parasite or parasitoid?

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Beani, L; Marchini, D; Cappa, F; Petrocelli, I; Gottardo, M; Manfredini, F; Giusti, F; Dallai, R

2017-08-01

Parasitic castration is an adaptive strategy where parasites usurp the hosts' reproductive physiology to complete their life cycle. The alterations in the host traits vary in their magnitude, from subtle changes in the host morpho-physiology and behaviour to the production of complex aberrant phenotypes, which often depend on the host gender. The strepsipteran macroparasite Xenos vesparum induces dramatic behavioural and physiological changes in its female host, the paper wasp Polistes dominula, while its effect on the male phenotype is largely unknown. In this study we investigated how a single X. vesparum parasite influences the functional morphology of P. dominula male reproductive apparatus. We performed morphometry and ultrastructure characterization of corpora allata, testes, seminal vesicles and accessory glands in parasitized and unparasitized males, and also in young and old males to control for the effect of age on the natural deterioration of these organs. Our results show that age significantly affects the development of male reproductive apparatus. A low parasite load - one parasite per host is the common prevalence in the field - has only a marginal impact on the reproductive morphology of P. dominula males, affecting quantitatively but not qualitatively the protein content of male accessory glands. Thus, in male P. dominula wasps, X. vesparum appears to behave as a true "parasite", in clear opposition to the role of "parasitoid" that it takes in female hosts where castration causes the reproductive death. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nuevos registros de especies del género Eretmocerus (Hymenoptera: Aphelinidae, parasitoides de Trialeurodes vaporariorum y el complejo Bemisia tabaci (Hemiptera: Aleyrodidae en Argentina New records of species of the genus Eretmocerus (Hymenoptera: Aphelinidae, parasitoids of Trialeurodes vaporariorum and Bemisia tabaci complex (Hemiptera: Aleyrodidae in Argentina

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Silvia N. López

2008-06-01

Full Text Available El objetivo de este trabajo es dar a conocer nuevos registros y distribuciones de las especies del género Eretmocerus Haldeman, parasitoides de las dos especies de mosca blanca que tienen mayor importancia económica en cultivos hortícolas y ornamentales en Argentina. Una especie de Eretmocerus Haldeman fue hallada parasitando a Trialeurodes vaporariorum (Westwood en Santa Fe y Buenos Aires; por sus caracteres morfológicos, se encuentra en el grupo californicus, cercana a corni Haldeman, podría tratarse de una nueva especie. Asimismo, se amplía la distribución geográfica de Eretmocerus mundus Mercet, enemigo natural del complejo Bemisia tabaci (Gennadius, a las provincias de San Juan y Buenos Aires.The objective of this paper is to report new records of species of the genus Eretmocerus Haldeman, parasitoids of the most important whitefly pest species in vegetables and ornamental crops in Argentina. One species was found parasitizing Trialeurodes vaporariorum (Westwood in Santa Fe and Buenos Aires provinces and it is grouped into californicus group near corni Haldeman, due to its morphological characters. It could be a new species. The known distribution of Eretmocerus mundus Mercet, a parasitoid of Bemisia tabaci (Gennadius, is enlarged to include the provinces of San Juan and Buenos Aires of Argentina.

Consequences of Beauty: Effects of Rater Sex and Sexual Orientation on the Visual Exploration and Evaluation of Attractiveness in Real World Scenes

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Aleksandra eMitrovic

2016-03-01

Full Text Available One of the key behavioral effects of attractiveness is increased visual attention to attractive people. This effect is often explained in terms of evolutionary adaptations, such as attractiveness being an indicator of good health. Other factors could influence this effect. In the present study, we explored the modulating role of sexual orientation on the effects of attractiveness on exploratory visual behavior. Heterosexual and homosexual men and women viewed natural-looking scenes that depicted either two women or two men who varied systematically in levels of attractiveness (based on a pre-study. Participants’ eye movements and attractiveness ratings towards the faces of the depicted people were recorded. The results showed that although attractiveness had the largest influence on participants’ behaviors, participants’ sexual orientations strongly modulated the effects. With the exception of homosexual women, all participant groups looked longer and more often at attractive faces that corresponded with their sexual orientations. Interestingly, heterosexual and homosexual men and homosexual women looked longer and more often at the less attractive face of their non-preferred sex than the less attractive face of their preferred sex, evidence that less attractive faces of the preferred sex might have an aversive character. These findings provide evidence for the important role that sexual orientation plays in guiding visual exploratory behavior and evaluations of the attractiveness of others.

Antagonistic Interactions between the African Weaver Ant Oecophylla longinoda and the Parasitoid Anagyrus pseudococci Potentially Limits Suppression of the Invasive Mealybug Rastrococcus iceryoides

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Chrysantus M. Tanga

2015-12-01

Full Text Available The ant Oecophylla longinoda Latreille forms a trophobiotic relationship with the invasive mealybug Rastrococus iceryoides Green and promotes the latter’s infestations to unacceptable levels in the presence of their natural enemies. In this regard, the antagonistic interactions between the ant and the parasitoid Anagyrus pseudococci Girault were assessed under laboratory conditions. The percentage of parasitism of R. iceryoides by A. pseudococci was significantly higher on “ant-excluded” treatments (86.6% ± 1.27% compared to “ant-tended” treatments (51.4% ± 4.13%. The low female-biased sex-ratio observed in the “ant-tended” treatment can be attributed to ants’ interference during the oviposition phase, which disrupted parasitoids’ ability to fertilize eggs. The mean foraging time, host handling time and number of successful oviposition in “ant-excluded” treatment were significantly higher compared to “ant-tended” treatments. When ant workers were allowed access to sterilized sand grains, mummified and unmummified R. iceryoides, they selectively removed the mummified mealybugs, indicating that they recognized the mummies as potential foods (1.2 ± 0.46 to 7.8 ± 1.17 mummies at 10 min intervals for 2 h. Percentage emergence from mummified R. iceryoides removed by the ants was significantly lower compared to emergence from mummies not exposed to ants. Although, host seeking parasitoids frequently evaded attacks, some were killed by the foraging ant workers (2.0 ± 0.38 to 6.0 ± 0.88 at 10 min intervals for 2 h. These results suggest for the first time that the presence of O. longinoda has a detrimental effect on the abundance, reproductive success and possibly oviposition strategy of female parasitoids, which might be a delimiting factor in field conditions if both natural enemies are to be recommended for use within the same agro-ecosystem.

Effect of attractive interactions between polymers on the effective force acting between colloids immersed in a polymer system: Analytic liquid-state theory.

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Chervanyov, A I

2016-12-28

By making use of the polymer reference interaction site model, we analytically study the effect of attractive interactions between polymers on the effective forces acting between colloids immersed in a polymer system. The performed theoretical analysis has no restrictions with respect to the polymer density and relative sizes of the colloids and polymers. The polymer mediated (PM) potential acting between colloids is shown to significantly depend on the strength and range of the polymer-polymer interactions. In the nano-particle limit, where the colloid radius is much smaller than the polymer gyration radius, the presence of attractive polymer-polymer interactions causes only quantitative changes to the PM potential. In the opposite limit of relatively large colloids, the polymer-polymer interactions revert the sign of the total effective force acting between colloids so that this force becomes attractive at sufficiently large polymer densities. With the objective to study an intricate interplay between the attractive PM forces and steric repulsion in different polymer density regimes, we calculate the second virial coefficient B of the total effective potential acting between colloids. The dependence of B on the polymer density is discussed in detail, revealing several novel features of the PM interactions caused by the presence of attractive polymer-polymer interactions.

The Effect of Attractiveness on Food Sharing Preferences in Human Mating Markets

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Michael Stirrat

2011-01-01

Full Text Available The current study explored how physical attractiveness affects food sharing by studying payment preferences for hypothetical romantic dinner dates (a hypothetical mating market. We analyzed payment preferences, self-rated attractiveness, and rated attractiveness for hypothetical dates in 416 participants. We hypothesized that (1 men would be more likely to prefer to pay than would women, (2 attractive individuals of both sexes would be less willing to pay, and (3 preferences to enter an exchange would be influenced by the attractiveness of prospective partners such that (3a men would prefer to pay for attractive women, and (3b women would prefer to be paid for by attractive men. All hypotheses were supported by our results. Individuals with higher self-rated attractiveness were more likely to prefer that their date would pay for the meal, and we found clear sex differences in how the attractiveness of potential dates affected payment preferences. Male participants preferred to pay for dates that had higher facial attractiveness, while female participants preferred that attractive men would pay. Individuals show condition dependent financial preferences consistent with the provisioning hypothesis in this mating market that are adaptive to evaluations of their own quality and that of prospective partners.

Attractive celebrity and peer images on Instagram: Effect on women's mood and body image.

Science.gov (United States)

Brown, Zoe; Tiggemann, Marika

2016-12-01

A large body of research has documented that exposure to images of thin fashion models contributes to women's body dissatisfaction. The present study aimed to experimentally investigate the impact of attractive celebrity and peer images on women's body image. Participants were 138 female undergraduate students who were randomly assigned to view either a set of celebrity images, a set of equally attractive unknown peer images, or a control set of travel images. All images were sourced from public Instagram profiles. Results showed that exposure to celebrity and peer images increased negative mood and body dissatisfaction relative to travel images, with no significant difference between celebrity and peer images. This effect was mediated by state appearance comparison. In addition, celebrity worship moderated an increased effect of celebrity images on body dissatisfaction. It was concluded that exposure to attractive celebrity and peer images can be detrimental to women's body image. Copyright © 2016 Elsevier Ltd. All rights reserved.

Attractive Casimir effect in an infrared modified gluon bag model

International Nuclear Information System (INIS)

Oxman, L.E.; Amaral, R.L.P.G.; Svaiter, N.F.

2005-01-01

In this work, we are motivated by previous attempts to derive the vacuum contribution to the bag energy in terms of familiar Casimir energy calculations for spherical geometries. A simple infrared modified model is introduced which allows studying the effects of the analytic structure as well as the geometry in a clear manner. In this context, we show that if a class of infrared vanishing effective gluon propagators is considered, then the renormalized vacuum energy for a spherical bag is attractive, as required by the bag model to adjust hadron spectroscopy

VOCs-Mediated Location of Olive Fly Larvae by the Braconid Parasitoid Psyttalia concolor: A Multivariate Comparison among VOC Bouquets from Three Olive Cultivars

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Giulia Giunti

2016-01-01

Full Text Available Herbivorous activity induces plant indirect defenses, as the emission of herbivorous-induced plant volatiles (HIPVs, which could be used by parasitoids for host location. Psyttalia concolor is a larval pupal endoparasitoid, attacking a number of tephritid flies including B. oleae. In this research, we investigated the olfactory cues routing host location behavior of P. concolor towards B. oleae larvae infesting three different olive cultivars. VOCs from infested and healthy fruits were identified using GC-MS analyses. In two-choice behavioral assays, P. concolor females preferred infested olive cues, which also evoked ovipositional probing by female wasps. GC-MS analysis showed qualitative and quantitative differences among volatiles emitted by infested and healthy olives. Volatile emissions were peculiar for each cultivar analyzed. Two putative HIPVs were detected in infested fruits, regardless of the cultivar, the monoterpene (E-β-ocimene, and the sesquiterpene (E-E-α-farnesene. Our study adds basic knowledge to the behavioral ecology of P. concolor. From an applied point of view, the field application of the above-mentioned VOCs may help to enhance effectiveness of biological control programs and parasitoid mass-rearing techniques.

Abridged life tables for Cephalonomia stephanoderis and Prorops nasuta (Hymenoptera: Bethylidae) Parasitoids of Hypothenemus hampei (Coleoptera: Scolytidae) reared on artificial diet

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Biological aspects and demographic parameters of Cephalonomia stephanoderis Betrem (Hymenoptera: Bethylidae) and Prorops nasuta Waterston (Hymenoptera: Bethylidae) parasitoids of the coffee berry borer (CBB), Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae) were investigated usi...

The effect of attractions on the structure of fused sphere chains confined between surfaces

International Nuclear Information System (INIS)

Patra, C.N.; Yethiraj, A.; Curro, J.G.

1999-01-01

The effect of attractive interactions on the behavior of polymers between surfaces is studied using Monte Carlo simulations. The molecules are modeled as fused sphere freely rotating chains with fixed bond lengths and bond angles; wall endash fluid and fluid endash fluid site endash site interaction potentials are of the hard sphere plus Yukawa form. For athermal chains the density at the surface (relative to the bulk) is depleted at low densities and enhanced at high densities. The introduction of a fluid endash fluid attraction causes a reduction of site density at the surface, and an introduction of a wall endash fluid attraction causes an enhancement of site density at the surface, compared to when these interactions are absent. When the wall endash fluid and fluid endash fluid attractions are of comparable strength, however, the depletion mechanism due to the fluid endash fluid attraction dominates. The center of mass profiles show the same trends as the site density profiles. Near the surface, the parallel and the perpendicular components of chain dimensions are different, which is explained in terms of a reorientation of chains. copyright 1999 American Institute of Physics. thinsp

Federal tax effects on the financial attractiveness of renewable versus conventional power plants

International Nuclear Information System (INIS)

Hill, L.J.; Hadley, S.W.

1995-01-01

In this paper, we examine the effects of federal tax laws on the financial attractiveness of seven renewable and four conventional electric power generating technologies adopted by investor owned utilities (IOUs) and non-utility electricity generators (NUGs). The results show that federal income tax laws applicable to renewable generating technologies generally provide very attractive financial incentives for the adoption of these technologies by IOUs and NUGs. If an IOU and NUG is subject to the alternative minimum tax, however, it may not be able to take full advantage of these financial incentives. (author)

Susceptibility of two hymenopteran parasitoids of Agrilus planipennis (Coleoptera: Buprestidae) to the entomopathogenic fungus Beauveria bassiana (Ascomycota: Hypocreales)

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Kimberly M Dean; John D. Vandenberg; Michael H. Griggs; Leah S. Bauer; Melissa K. Fierke

2012-01-01

Emerald ash borer (EAB), Agrilus planipennis Fairmaire, native to Asia, is killing ash trees (Fraxinus spp.) across 15 states and southeastern Canada. Integrated pest management using biological control is the only viable long-term approach for controlling the spread of EAB outside of host resistance. Three hymenopteran parasitoids...

Moscas frugívoras e seus parasitoides nos municípios de Pelotas e Capão do Leão, Rio Grande do Sul, Brasil Frugivorous flies and their parasitoids in the cities of Pelotas and Capão do Leão, Rio Grande do Sul, Brazil

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