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Michael R. Strand - One of the best experts on this subject based on the ideXlab platform.

  • Cross-protection experiments with parasitoids in the genus Microplitis (Hymenoptera: Braconidae) suggest a high level of specificity in their associated bracoviruses
    Journal of insect physiology, 2003
    Co-Authors: K. Kadash, Jeffrey A. Harvey, Michael R. Strand
    Abstract:

    The immunological and developmental effects of bracoviruses (BVs) from three parasitoids in the genus Microplitis (Braconidae: Microgastrinae) were compared in the hosts Pseudoplusia includens and Heliothis virescens (Lepidoptera: Noctuidae). Southern blotting experiments indicated that viral DNAs from Microplitis demolitor bracovirus (MdBV) cross-hybridized with viral DNAs from Microplitis croceipes bracovirus (McBV) and Microplitis mediator bracovirus (MmBV) under conditions of high stringency. Injection of calyx fluid plus venom from each parasitoid species dose-dependently delayed development of P. includens and H. virescens. Each virus also inhibited pupation of P. includens but not H. virescens. In situ hybridization experiments indicated that MdBV and McBV persistently infect hemocytes in both hosts while MmBV persistently infects hemocytes in P. includens but not H. virescens. While MdBV infection induced a loss of adhesion by most plasmatocytes, McBV and MmBV infection induced a loss of adhesion in less than 50% of cells. Cross-protection experiments indicated that calyx fluid plus venom from one species usually protected progeny of another species from encapsulation but did not always promote successful development.

  • Plasmatocyte spreading peptide does not induce Microplitis demolitor polydnavirus-infected plasmatocytes to spread on foreign surfaces.
    Archives of insect biochemistry and physiology, 1999
    Co-Authors: Michael R. Strand, Kevin C. Clark, Elisabeth M.m. Gardiner
    Abstract:

    Capsule formation by the moth Pseudopulsia includens requires that plasmatocytes change from being nonadhesive cells in circulation to strongly adhesive cells capable of attaching to the foreign target and one another. This change in adhesive state is induced by Plasmatocyte Spreading Peptide (PSP1); a 23 amino acid peptide isolated from P. includens plasma. Plasmatocytes from hosts parasitized by Microplitis demolitor remain in a nonadhesive state after infection by Microplitis demolitor polydnavirus (MdPDV). This alteration in plasmatocyte function prevents P. includens from encapsulating the developing parasitoid. In the current study, we examined whether MdPDV infection eliminates PSP1-responsive plasmatocytes from circulation or disrupts the ability of PSP1 to induce adhesion and spreading of plasmatocytes to foreign surfaces. In vivo experiments revealed that infection of P. includens by MdPDV induced an increase in the total number of hemocytes in circulation but reduced the proportion of hemocytes in circulation that were plasmatocytes. However, plasmatocytes normally capable of responding to PSP1 were not eliminated from circulation. Both in vivo and in vitro experiments indicated that plasmatocytes inoculated with MdPDV lost the capacity to respond to PSP1 4–6 h post-infection. Infection of P. includens with MdPDV reduced expression levels of prepro-PSP1 mRNA in hemocytes but did not appear to alter expression levels in fat body. Arch. Insect Biochem. Physiol. 40:41–52, 1999. © 1999 Wiley-Liss, Inc.

  • A limited role in parasitism for Microplitis demolitor polydnavirus.
    Journal of insect physiology, 1998
    Co-Authors: Dominique Trudeau, Michael R. Strand
    Abstract:

    Spodoptera frugiperda larvae stung by Microplitis demolitor undergo physiological alterations characteristic of parasitism. However, despite these physiological modifications, parasitized S. frugiperda larvae never yield adult wasps. Our original hypothesis that unsuccessful parasitism was due to a transcriptionally inactive polydnavirus proved untrue. Microplitis demolitor polydnavirus (MdPDV) successfully infected and expressed, albeit transiently, in S. frugiperda hemocytes. MdPDV expression was most abundant in the first three days of parasitism, then sharply declined on Day 4 post-parasitization and continued to decline for the remainder of the study. During the period of MdPDV expression, S. frugiperda hemocytes were non-adherent, incapable of spreading in vitro and did not encapsulate M. demolitor eggs in vivo. Concurrent with diminishing viral expresssion, S. frugiperda hemocytes regained their ability to adhere and spread in vitro and encapsulated M. demolitor eggs in vivo. Although MdPDV disrupted S. frugiperda's encapsulation response for the first three days post-parasitization, M. demolitor was unable to develop in this noctuid species. Failure to develop was independant of viral activity, all M. demolitor eggs oviposited in S. frugiperda larvae failed to complete embryogenesis and died within 24 hour of oviposition. S. frugiperda larvae infected with MdPDV exhibited alterations in development very similar to other lepidopterans that are permissive hosts for M. demolitor. In addition, MdPDV DNA persisted in Spodoptera frugiperda hemocytes in the absence of viral expression.

A. M. El‐minshawy - One of the best experts on this subject based on the ideXlab platform.

  • Effect of parasitism on digestion and development of Spodoptera littoralis (Boisd.) larvae
    Zeitschrift für Angewandte Entomologie, 2009
    Co-Authors: E. M. Hegazi, A. M. El‐minshawy, S. M. Hammad
    Abstract:

    The ratios of the total castor-oil leaves ingested by the Spodoptera littoralis larva parasitized by Microplitis rufiventris to that parasitized by Chelonus inanitus and that of the unparasitized one were 1: 1.7: 3.5, respectively. The unparasitized larva ingested excessive amounts of food than needed during the last days of its larval stage. M. rufiventris was more efficient than Ch. inanitus in controlling S. littoralis to the extent that the population of the succeeding generations of the host would be not only lowered, but also the leaf losses would be reduced. The number of moults subsequently to stinging the host lavae by parasitoids and the duration of instars of parasitized larvae were determined. Zusammenfassung Zur Wirkung der Parasitierung auf die Ernahrung und Entwicklung von Spodoptera littoralis (Boisd.) Zwischen S. littoralis-Larven, von Microplitis rufiventris parasitiert: von Chelonus inanitus parasitiert: nicht parasitiert, betrug das Verhaltnis der gefressenen Menge an Rizinusblattern 1: 1,7: 3,5. Damit wirken diese Parasiten (M. rufiventris starker als Ch. inanitus) nicht nur dadurch gunstig auf den Pflanzenbestand, das sie die Schadlingsdichte reduzieren, sondern auch dadurch, das die parasitierten Schadlinge die Kulturpflanze weniger schadigen. Weiterhin wurden die Zahl der Hautungen sowie die Dauer der Larvenentwicklung bei unparasitierten und parasitierten S. littoralis-Larven untersucht. Es ergab sich eine deutliche Abnahme der Hautungen sowie beim 4. Larvenstadium eine erhebliche Zunahme der Entwicklungsdauer parasitierter Larven.

  • Field and laboratory observations on the parasitoids of Spodoptera littoralis (Boisd.) (Lep.; Noctuidae) in Alexandria
    Journal of Applied Entomology, 2009
    Co-Authors: E. M. Hegazi, S. M. Hammad, A. M. El‐minshawy
    Abstract:

    During the cotton seasons of 1974 and 1975, a survey was carried out to examine the list of parasitoids of the cotton leafworm Spodoptera littoralis. Five parasitoids were found parasitising the immature stages of the pest. Four of them belonged to order Hymenoptera and the 5th was from order Diptera. Certain field and laboratory observations on Euplectrus laphygmae Ferr. (Hymen., Eulophidae), and Strobliomyia orbata Wield. (Dipt. Tachinidae) were recorded. The parasitoid Microplitis rufiventris Kok. (Hymen., Braconidae) proved to be an effective solitary larval parasitoid on S. littoralis in cotton fields in Egypt; it was more capable of tolerating the adverse conditions than its host. Zusammenfassung Freiland- und Laboruntersuchungen uber die Parasitoiden von Spodoptera littoralis (Boisd.) (Lep.; Noctuidae) in Alexandria Wahrend der Baumwollsaison 1974–1975 wurde das Spektrum der Parasitoiden der Baum-wolleule, S. littoralis, untersucht. Es wurden 5 Arten gefunden: 4 Hymenopteren und 1 Diptere. Freiland- und Laborbeobachtungen an Euplectrus laphygmae (Hymen., Eulophidae) und Strobliomyia orbata Wield. (Dipt., Tachinidae) wurden durchgefuhrt. Der Parasitoide Microplitis rufiventris Kok. (Hymen., Braconidae) erwies sich als wirksamster solitarer Larvenparasit der Baumwolleule in agypten. Er vertrug ungunstige Umwelt-faktoren besser als sein Wirt.

  • Effect of temperature and host age on the progeny production and sex ratio of Microplitis rufiventris Kok. (Hym., Braconidae).
    Journal of Applied Entomology, 2009
    Co-Authors: A. M. El‐minshawy, Esmat M. Hegazi
    Abstract:

    When the females of Microplitis rufiventris were returned from the parasitism container to the vial where their males were placed, they immediately took a honey meal which indicated that they needed a meal after parasitism. The preoviposition period of M. rufiventris was so short that parasitism could begin within few hours after emergence. The mated females of M. rufiventris produced offspring of both sexes, demonstrating that this species exhibited facultative parthenogensis or arrhenotoky. The oviposition capacity varied according to the insectary conditions. The higher oviposition capacity occurred when adults maintained at 22°C and introduced for parasitization at 27°C. Zusammenfassung Uber die Wirkung von Temperatur und Wirtsalter auf Reproduktion und Geschlechterverhaltnis von Microplitis rufiventris Kok. (Hym.; Braconidae) Wenn Weibchen von M. rufiventris aus dem Parasitierungsgefas zu den Mannchen zuruckgesetzt wurden, nahmen sie sofort eine Honigmahlzeit auf, die sie offensichtlich nach jeder Parasitierung benotigen. Die Praovipositionsperiode von M. rufiventris war so kurz, das die Parasitierung innerhalb weniger Stunden nach dem Schlupfen begann. Die begatteten Weibchen von M. rufiventris brachten Nachkommen beider Geschlechter hervor und zeigten damit, das bei dieser Schlupfwespenart fakultative Parthenogenese und Arrhenotokie auftreten. Die Eiablage und Kapazitat variierte entsprechend den Zuchtverhaltnissen. Die hochste Eizahl wurde festgestellt, wenn die Adulten bei 22°C ihre Wirte parasitierten.

Daniel H Janzen - One of the best experts on this subject based on the ideXlab platform.

  • museum für naturkunde Revision of the genera Microplitis and Snellenius (Hymenoptera, Braconidae, Microgastrinae) from Area de Conservacion Guanacaste, Costa Rica, with a key to all species previously described
    2016
    Co-Authors: From Mesoamerica, James B Whitfield, Robert R. Kula, Winnie Hallwachs, Jose L. Fern, Alex M. Smith, Daniel H Janzen
    Abstract:

    The genera Microplitis and Snellenius (Hymenoptera: Braconidae, Microgastrinae) from Area de Conservacion Guanacaste (ACG), Costa Rica, are revised. A total of 28 new species are described: 23 of Snellenius (the first record for Mesoamerica) and five of Microplitis. A key is provided to all new species and five species of Microplitis previous-ly described from Mesoamerica. In ACG, all Microplitis were reared exclusively from Sphingidae, while all Snellenius were reared from Noctuoidea (Noctuidae and Erebidae). All of the wasp species with known host records are unambiguously specialists, parasitiz-ing one or a few related hosts. Biological information (wasp cocoon and caterpillar hosts) in the Neotropical region seems to differ from similar data reported in previous works for the Oriental region-but more studies on the world fauna are needed. Although the distinction between these two genera has been controversial, we consider that the avail-able evidence, although not conclusive, suggests that these two genera are best kept as separate (based on the presence of at least a partial epicnemial carina in Snellenius, which is absent in Microplitis). The following 28 species, all authored by Fernández-Triana &

  • Revision of the genera Microplitis and Snellenius (Hymenoptera, Braconidae, Microgastrinae) from Area de Conservacion Guanacaste, Costa Rica, with a key to all species previously described from Mesoamerica
    Deutsche Entomologische Zeitschrift, 2015
    Co-Authors: Jose Fernandez-triana, James B Whitfield, M. Alex Smith, Robert R. Kula, Winnie Hallwachs, Daniel H Janzen
    Abstract:

    The genera Microplitis and Snellenius (Hymenoptera: Braconidae, Microgastrinae) from Area de Conservacion Guanacaste (ACG), Costa Rica, are revised. A total of 28 new species are described: 23 of Snellenius (the first record for Mesoamerica) and five of Microplitis. A key is provided to all new species and five species of Microplitis previously described from Mesoamerica. In ACG, all Microplitis were reared exclusively from Sphingidae, while all Snellenius were reared from Noctuoidea (Noctuidae and Erebidae). All of the wasp species with known host records are unambiguously specialists, parasitizing one or a few related hosts. Biological information (wasp cocoon and caterpillar hosts) in the Neotropical region seems to differ from similar data reported in previous works for the Oriental region -but more studies on the world fauna are needed. Although the distinction between these two genera has been controversial, we consider that the available evidence, although not conclusive, suggests that these two genera are best kept as separate (based on the presence of at least a partial epicnemial carina in Snellenius, which is absent in Microplitis). The following 28 species, all authored by Fernández-Triana & Whitfield, are described as species nova: Microplitis adrianguadamuzi, M. alexanderrojasi, M. francopupulini, M. hebertbakeri, M. jorgehernandezi, Snellenius billburgeri, S. bobdressleri, S. donstonei, S. felipechavarriai, S. gerardoherrerai, S. irenebakerae, S. isidrochaconi, S. johnkressi, S. jorgecampabadali, S. jorgegomezlauritoi, S. josesarukhani, S. kerrydresslerae, S. lucindamcdadeae, S. luisdiegogomezi, S. mariakuzminae, S. mariamartachavarriae, S. phildevriesi, S. quiricojimenezi, S. robertoespinozai, S. sandyknappae, S. velvaruddae, S. vickifunkae, S. warrenwagneri

  • host specificity and hyperparasitoids of three new costa rican species of Microplitis foerster hymenoptera braconidae microgastrinae parasitoids of sphingid caterpillars
    Journal of Hymenoptera Research, 2003
    Co-Authors: Daniel H Janzen, A K Walker, James B Whitfield, Gerard Delvare, I D Gauld
    Abstract:

    Three new species of parasitoid wasps (Braconidae: Microgastrinae) from Costa Rica are described: Microplitis espinachi Walker, n. sp.; Microplitis figueresi Walker, n. sp. and Microplitis marini Whitfield, n. sp. Two parasitoids of Sphingidae are redescribed for comparison with the three new species: Microplitis ceratomiae Riley and Microplitis chacoensis (Cameron) (=Microplitis ayerzai Brethes, New Synonymy). The ichneumonid wasp Acrolyta stroudi Gauld, n. sp., and the chalcidid wasp Conura convergea Delvare, n. sp. are also described; both are hyperparasitoids of prepupae in newly spun cocoons of M. espinachi and M. figueresi. The mesochorine ichneumonid hyperparasitoid Mesoschorus angustistigmatus Dasch, a hyperparasitoid of M. espinachi and M. espinachi larvae while still inside the caterpillar, is redescribed. The seasonal biology and host specificity of the Microplitis and associated hyperparasitoids is discussed in the context of the extensive caterpillar and parasitoid inventory data for the Area de Conservacion Guanacaste (ACG) in northwestern Costa Rica. M. espinachi is a dry forest parasitoid of Agrius cingulata, Sphinx merops and nine species of Manduca (all Sphingidae), all when in the most open and insolated habitats and on a variety of host plants; it does not search for other common species of Manduca or other Sphingidae in slightly shadier microhabitats a few meters away. The extremely similar M. figueresi parasitizes Erinnyis ello and Erinnyis crameri (Sphingidae) in slightly shadier older woody succession (only a few meters from the microhabitat occupied by M. espinachi), and conspicuously does not parasitize Erinnyis oenotris or the tens of other species of sphingid caterpillars in the same habitat. M. figueresi finds E. ello on seven different species of food plants, and E. crameri on two others (but does not parasitize E. crameri on an insolated third). Neither species of Microplitis extends from the ACG dry forest into the contiguous cloud forest or rain forest, even though their host caterpillars do. While E. ello is a common pest in commercial cassava plantations, M. figueresi does not appear to have followed this host into this highly insolated habitat. Both species are highly univoltine and pass the last two thirds of the rainy season and six-month dry season in an extremely tough silk cocoon in the litter. In the ACG, M. marini is a parasitoid of only Xylophanes tersa in very insolated low herbaceous vegetation in mid-elevation rainforest and lower elevation cloud forest, and does not parasitize at least 15 other species of Xylophanes in the adjacent forest understory. (Resume d'auteur)

Ted C J Turlings - One of the best experts on this subject based on the ideXlab platform.

  • Combined use of herbivore‐induced plant volatiles and sex pheromones for mate location in braconid parasitoids
    Plant cell & environment, 2016
    Co-Authors: Gaylord A. Desurmont, Thomas Degen, Luka Henryk, Guoxin Zhou, Diane Laplanche, Ted C J Turlings
    Abstract:

    Herbivore-induced plant volatiles (HIPVs) are important cues for female parasitic wasps to find hosts. Here, we investigated the possibility that HIPVs may also serve parasitoids as cues to locate mates. To test this, the odour preferences of four braconid wasps - the gregarious parasitoid Cotesia glomerata (L.) and the solitary parasitoids Cotesia marginiventris (Cresson), Microplitis rufiventris Kokujev and Microplitis mediator (Haliday) - were studied in olfactometers. Each species showed attraction to pheromones but in somewhat different ways. Males of the two Cotesia species were attracted to virgin females, whereas females of M. rufiventris were attracted to virgin males. Male and female M. mediator exhibited attraction to both sexes. Importantly, female and male wasps of all four species were strongly attracted by HIPVs, independent of mating status. In most cases, male wasps were also attracted to intact plants. The wasps preferred the combination of HIPVs and pheromones over plant odours alone, except M. mediator, which appears to mainly use HIPVs for mate location. We discuss the ecological contexts in which the combined use of pheromones and HIPVs by parasitoids can be expected. To our knowledge, this is the first study to show that braconid parasitoids use HIPVs and pheromones in combination to locate mates.

Guo-hua Huang - One of the best experts on this subject based on the ideXlab platform.

  • Identification of a novel virus in wasp -Microplitis similis bracovirus: a possible new species of Polydnaviridae
    2019
    Co-Authors: Yi-yi Ou-yang, Jing Peng, Shuang-qing Liu, Guo-hua Huang
    Abstract:

    Polydnaviruses, double-stranded DNA viruses with segmented genomes, have evolved as obligate endosymbionts of parasitoid, and plays a very important role in the life cycle of parasitoids. The PDV symbiotic with different endoparasites are often different. Here we completed the the six protein tyrosine phosphatases (PTPs) and six ankyrins sequence of a PDV which from Microplitis similis , by sequencing and compared the gene features of this PDV to those of other polydnaviruses. Phylogenetic analysis indicated that it was closely related to Microplitis demolitor  BV (MdBV) and Microplitis mediator  BV (MmBV), and this result was supported by nucleotide multiple sequence alignment. So a new species of PDV-MsBV was identified and characterized in Microplitis similis . It provides a new material for the co-evolution of biology. At the same time, the structure and function of these 12 proteins were predicted and analyzed. The results showed a new perspective on the study of PTPs and ankyrins protein family in PDVs, and provide the materials and foundations for analysizing the function of MsBV.

  • A Place to Grow? Host Choice and Larval Performance of Microplitis similis (Hymenoptera: Braconidae) in the Host Spodoptera litura (Lepidoptera: Noctuidae).
    Environmental entomology, 2017
    Co-Authors: Xu-yang Chen, Richard J. Hopkins, Yi-pei Zhao, Guo-hua Huang
    Abstract:

    Host selection is a key stage in the lifecycle of parasitoids, and is critical to both their function in control and to the maintenance of their population. The solitary endoparasitoid Microplitis similis (Hymenoptera: Braconidae) is a potential biological control agent of Spodoptera litura (F.) larvae (Lepidoptera: Noctuidae). In this study, we examined the preference M. similis exhibits for different instars of the host, host instar effects on parasitoid development, and the weight gain and food consumption of different instars of parasitized larvae. In no-choice tests, parasitization rates were highest in second- and early third-instar larvae, and no fourth- or fifth-instar hosts were parasitized. When provided with a choice of first- to late third-instar host larvae, M. similis preferred to parasitize early third-instar host larvae (41%) with a selection coefficient of 0.37. All morphometric features of wasp offspring increased with increasing age of the host at parasitization. A lower proportion of females emerged from first-instar larvae than any other instar. Parasitized S. litura larvae showed a pronounced reduction in food consumption and weight gain. Microplitis similis may have the potential to significantly suppress population growth and the damage caused by S. litura.