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Pio Federico Roversi - One of the best experts on this subject based on the ideXlab platform.

  • pre release risk assessment of the egg parasitoid gryon pennsylvanicum for classical biological control of leptoglossus occidentalis
    Journal of Applied Entomology, 2014
    Co-Authors: Pio Federico Roversi, Paola Furlan, Sabbatini G Peverieri, Matteo Maltese, Ward Strong, Virgilio Caleca
    Abstract:

    Leptoglossus occidentalis Heidemann (Heteroptera: Coreidae) is a North American conifer seed pest that was accidentally introduced to Europe. In the Mediterranean area, it threatens the production of Pinus pinea Linnaeus seeds. The egg-parasitoid Gryon pennsylvanicum (Ashmead) (Hymenoptera: Platygastridae), the main natural enemy in the native range of L. occidentalis, was imported from British Columbia to Italy. Pre-release risk assessments were made under quarantine conditions by no-choice tests conducted with naive and experienced G. pennsylvanicum offering single eggs of target and non-target species for varying exposure times (1, 4, 48 h). G. pennsylvanicum successfully parasitized from 75% to 100% of the target host eggs. Only one female specimen of the egg-parasitoid emerged from a non-target egg (Gonocerus juniperi Herrich-Schaeffer, Heteroptera: Coreidae). Two dead female specimens were found, one inside an egg of Coreus marginatus (Linnaeus) (Heteroptera: Coreidae) and one in an egg of Camptopus lateralis (Germar) (Heteroptera: Alydidae). All three cases occurred at the longest oviposition exposure time. Results obtained with this conservative approach suggest that the risk to non-target species of releasing G. pennsylvanicum in Italy is low.

  • morphology of the male reproductive system and sperm ultrastructure of the egg parasitoid gryon pennsylvanicum ashmead hymenoptera platygastridae
    Arthropod Structure & Development, 2013
    Co-Authors: Francesco Paoli, Marco Gottardo, Romano Dallai, Pio Federico Roversi
    Abstract:

    Gryon pennsylvanicum is a platygastrid hymenopteran that has lately received increasing attention in Europe due to its possible use in biological control of the conifer seed bug pest Leptoglossus occidentalis. Here the male reproductive system and the spermatogenesis of this species, along with those of Gryon muscaeformis, are examined ultrastructurally for the first time. The male genital system is formed by a pair of testes, each containing only one follicle, a pair of accessory glands and deferent ducts connected to a single ejaculatory duct. All the stages of spermatogenesis are described in detail. Characteristic features of the Gryon spp. sperm, which are 100 μm long, are the presence of a polygonal nucleus, only one mitochondrial derivative, the occurrence of the centriole adjunct and a typical insect 9 + 9 + 2 flagellar axoneme. The single derivative, however, results from a process in which one of the two mitochondria is lost during spermiogenesis. Unlike in other insects, two centrioles occur in spermatids as a consequence of the ameiotic parthenogenesis. These characteristics stand as a valuable tool for phylogenetic inferences. Furthermore this study suggests a useful strategy for laboratory mass rearing.

  • host egg age of leptoglossus occidentalis heteroptera coreidae and parasitism by gryon pennsylvanicum hymenoptera platygastridae
    Journal of Economic Entomology, 2013
    Co-Authors: Giuseppino Sabbatini Peverieri, Paola Furlan, Daniele Benassai, Sarah Caradonna, W B Strong, Pio Federico Roversi
    Abstract:

    Leptoglossus occidentalis Heidemann (Heteroptera, Coreidae) is native to Western North America and is a serious pest for seed production of conifers. The pest was accidentally introduced into Europe in the 1990s. Since then, seed loss has been recorded in Pinus pinea (L.) forests, with a negative impact on the commercial production of pine nuts. Classical biological control of this pest in P. pinea stands is an attractive proposition. Previous work showed that the egg-parasitoid Gryon pennsylvanicum (Ashmead) (Hymenoptera, Platygastridae) had promising life history traits in laboratory studies using L. occidentalis eggs as host. In the present work, the effect of host egg age on parasitization rate was evaluated in the laboratory, using choice and no-choice tests. Host eggs ranged in age from < 24 h to within a day of hatching. Results showed that parasitization rate, juvenile survival rate, sex ratio, and longevity of female G. pennsylvanicum were not significantly affected by the age of the host eggs. However, egg-parasitoid development time was longer in older host eggs, and females were smaller than those that developed in younger host eggs. Parasitization behaviors (drumming, oviposition, and marking) were not affected by the age of the host. G. pennsylvanicum females tended to parasitize all available host eggs within a cluster before moving to a new cluster, without displaying a preferences for host egg age. The ability to exploit host eggs of any age class improves the prospect of successful classical biological control using this egg-parasitoid.

  • laboratory evaluation of gryon pennsylvanicum ashmead hymenoptera platygastridae as a biological control agent of leptoglossus occidentalis heidemann heteroptera coreidae
    Biological Control, 2012
    Co-Authors: Sabbatini G Peverieri, Paola Furlan, W B Strong, Sauro Simoni, Pio Federico Roversi
    Abstract:

    Abstract Leptoglossus occidentalis Heidemann (Heteroptera, Coreidae), the western conifer seed bug, is a serious conifer seed pest in North America; after its accidental introduction in Italy, it has spread to several European countries. In Central Italy, severe seed loss was recorded in stone pine forests ( Pinus pinea ). Classical biological control against L. occidentalis was evaluated by performing laboratory tests on Gryon pennsylvanicum (Ashmead), the most important hymenopteran egg parasitoid of the pest in North America, to acquire biological and demographical parameters. Tests were performed in climatic chambers using glass tubes to house specimens at 26 ± 1 °C, 75 ± 5% RH and 16:8 L:D and supplying honey drops as food for adults. G. pennsylvanicum reared on eggs of L. occidentalis has a high fecundity rate (144.55 eggs/female) and 90% of the total number of eggs are laid in the first two weeks of oviposition. Mean oviposition period is 23 days. Parasitoid females live a mean of 40 days, and longevity is higher in host deprived females. The intrinsic rate of increase ( r m ) was calculated to be 0.206. Mean sex ratio throughout a female’s life span was 70.42% females, though at the start of oviposition it was over 87% females. Adults survived only four days without honey as food, but up to 50 days with food; water did not influence longevity. Females lived significantly longer than males. Fecundity was negatively affected by duration of host deprivation, nevertheless, host-deprived females retained the ability to parasitize host eggs, and without a substantial sex ratio change in offspring. On the whole, G. pennsylvanicum shows potential for use in classical biological control against L. occidentalis . Several factors contribute to its suitability for biological control like high reproductive rate, high sex ratio, long-lived adults, and the ability to maintain reproductive potential during periods of host deprivation with a no substantial change in the sex ratio.

De Proft Michel - One of the best experts on this subject based on the ideXlab platform.

  • Comparative emergence phenology of the orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae) and its parasitoids (Hymenoptera: Pteromalidae and Platygastridae) under controlled conditions
    2015
    Co-Authors: Chavalle Sandrine, Buhl, Peter Neerup, Censier Florence, De Proft Michel
    Abstract:

    The orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is a wheat (Triticum aestivum L.) pest that can cause significant yield losses. Several hymenopterous parasitoids are known to attack S. mosellana. For the effective biological control of this pest by its parasitoids, the hostparasitoid synchrony is particularly important. The synchronization between the emergence of S. mosellana and its parasitoids was studied under controlled conditions with soils sampled from two locations. For both sites, three parasitoid species were identified: Macroglenes penetrans (Kirby) (Hymenoptera: Pteromalidae), Euxestonotus error (Fitch) (Hymenoptera: Platygastridae) and Platygaster tuberosula (Kieffer) (Hymenoptera: Platygastridae). The hypothesis that parasitoid emergence is triggered by the same rainfall that induces host emergence was tested by simulating three rainfall events, a week apart. The parasitoid M. penetrans emerged later than S. mosellana with a mean of 57 ± 7 DD (degree-days above 7 °C) for insects collected from Juprelle and 68 ± 10 DD for those from Veurne (i.e., 4-5 days after its host). M. penetrans was therefore closely synchronized with its host through the same inductive rainfall, but this was not the case for E. error or P. tuberosula. Depending on when the rainfall that triggered the emergence of S. mosellana occurred, E. error and P. tuberosula emerged either before or after their host. M. penetrans is a more effective biocontrol agent of S. mosellana compared to P. tuberosula and E. error. Greater knowledge about parasitoid emergence could lead to the better positioning of insecticide treatments against wheat midge that protect and conserve the parasitoid populations.Peer reviewe

  • Comparative emergence phenology of the orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae) and its parasitoids (Hymenoptera: Pteromalidae and Platygastridae) under controlled conditions
    'Elsevier BV', 2015
    Co-Authors: Chavalle Sandrine, Buhl, Peter Neerup, Censier Florence, De Proft Michel
    Abstract:

    peer reviewedaudience: researcher, professionalThe orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is a wheat (Triticum aestivum L.) pest that can cause significant yield losses. Several hymenopterous parasitoids are known to attack S. mosellana. For the effective biological control of this pest by its parasitoids, the hostparasitoid synchrony is particularly important. The synchronization between the emergence of S. mosellana and its parasitoids was studied under controlled conditions with soils sampled from two locations. For both sites, three parasitoid species were identified: Macroglenes penetrans (Kirby) (Hymenoptera: Pteromalidae), Euxestonotus error (Fitch) (Hymenoptera: Platygastridae) and Platygaster tuberosula (Kieffer) (Hymenoptera: Platygastridae). The hypothesis that parasitoid emergence is triggered by the same rainfall that induces host emergence was tested by simulating three rainfall events, a week apart. The parasitoid M. penetrans emerged later than S. mosellana with a mean of 57 ± 7 DD (degree-days above 7 °C) for insects collected from Juprelle and 68 ± 10 DD for those from Veurne (i.e., 4-5 days after its host). M. penetrans was therefore closely synchronized with its host through the same inductive rainfall, but this was not the case for E. error or P. tuberosula. Depending on when the rainfall that triggered the emergence of S. mosellana occurred, E. error and P. tuberosula emerged either before or after their host. M. penetrans is a more effective biocontrol agent of S. mosellana compared to P. tuberosula and E. error. Greater knowledge about parasitoid emergence could lead to the better positioning of insecticide treatments against wheat midge that protect and conserve the parasitoid populations

Gérard Delvare - One of the best experts on this subject based on the ideXlab platform.

  • investigating biological control agents for controlling invasive populations of the mealybug pseudococcus comstocki in france
    PLOS ONE, 2016
    Co-Authors: Thibaut Malausa, Gérard Delvare, Mathilde Delaunay, Alexandre Fleisch, Geraldine Groussierbout, Sylvie Warot, Didier Crochard, Emilio Guerrieri, Giuseppina Pellizzari, Bora M Kaydan
    Abstract:

    Pseudococcus comstocki (Hemiptera: Pseudococcidae) is a mealybug species native to Eastern Asia and present as an invasive pest in northern Italy and southern France since the start of the century. It infests apple and pear trees, grapevines and some ornamental trees. Biocontrol programmes against this pest proved successful in central Asia and North America in the second half of the 20th century. In this study, we investigated possible biocontrol agents against P. comstocki, with the aim of developing a biocontrol programme in France. We carried out systematic DNA-barcoding at each step in the search for a specialist parasitoid. First we characterised the French target populations of P. comstocki. We then identified the parasitoids attacking P. comstocki in France. Finally, we searched for foreign mealybug populations identified a priori as P. comstocki and surveyed their hymenopteran parasitoids. Three mealybug species (P. comstocki, P. viburni and P. cryptus) were identified during the survey, together with at least 16 different parasitoid taxa. We selected candidate biological control agent populations for use against P. comstocki in France, from the species Allotropa burrelli (Hymenoptera: Platygastridae) and Acerophagus malinus (Hymenoptera: Encyrtidae). The coupling of molecular and morphological characterisation for both pests and natural enemies facilitated the programme development and the rejection of unsuitable or generalist parasitoids.

  • les parasites de diaprepes abbreviatus coleoptera curculionidae aux antilles francaises
    Bulletin de la Société entomologique de France, 1991
    Co-Authors: Johann Etienne, Gérard Delvare
    Abstract:

    Summary. — The egg parasitoids of citrus weevil Diaprepes abbreviatus in Guadeloupe and Martinique (FWI) are mentioned. Six species of Hymenoptera within three families ( Eulophidae : Aprostocetus gala , Aprostocetus haitiensis , Aprostocetus sp. , Baryscapus fennahi ; Trichogrammatidae : Ceratogramma etiennei and Platygastridae : Fidiobia citri ) are reported. The first five species are actually primary parasites of egg masses of Diaprepes abbreviatus but the host of the last species, F. citri, is not stated precisely. A few aspects of the biology of some of these parasites are given. A map of the general repartition of all the egg parasitoids of citrus weevils known in the Caribbean Region is given.

Odair Aparecido Fernandes - One of the best experts on this subject based on the ideXlab platform.

  • mortality dynamics of spodoptera frugiperda lepidoptera noctuidae immatures in maize
    PLOS ONE, 2015
    Co-Authors: Andrea C Varella, Alexandre Carlos Menezesnetto, Juliana Duarte De Souza Alonso, Daniel Ferreira Caixeta, Robert K D Peterson, Odair Aparecido Fernandes
    Abstract:

    We characterized the dynamics of mortality factors affecting immature developmental stages of the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae). Multiple decrement life tables for egg and early larval stages of S. frugiperda in maize (Zea mays L.) fields were developed with and without augmentative releases of Telenomus remus Nixon (Hymenoptera: Platygastridae) from 2009 to 2011. Total egg mortality ranged from 73 to 81% and the greatest egg mortality was due to inviability, dislodgement, and predation. Parasitoids did not cause significant mortality in egg or early larval stages and the releases of T. remus did not increase egg mortality. Greater than 95% of early larvae died from predation, drowning, and dislodgment by rainfall. Total mortality due to these factors was largely irreplaceable. Results indicate that a greater effect in reducing generational survival may be achieved by adding mortality to the early larval stage of S. frugiperda.

  • interspecific interaction between telenomus remus hymenoptera platygastridae and trichogramma pretiosum hymenoptera trichogrammatidae on spodoptera frugiperda lepidoptera noctuidae eggs
    Anais Da Academia Brasileira De Ciencias, 2012
    Co-Authors: Tatiana Rodrigues Carneiro, Odair Aparecido Fernandes
    Abstract:

    This work aimes to evaluate the interspecific interaction between Trichogramma pretiosum and Telenomus remus, two biological control agents of fall armyworm (Spodoptera frugiperda) eggs. Eggs of Spodoptera frugiperda previously parasitized by Telenomus remus were offered to Trichogramma pretiosum, and those parasitized by Trichogramma pretiosum were offered to Telenomus remus. The previously parasitized eggs were tested at different embryonic development stages for each parasitoid. In addition, to evaluate the competition between species, Spodoptera frugiperda eggs were offered to the parasitoids simultaneously. The behavior of the insects was recorded under a stereomicroscope. When Spodoptera frugiperda eggs were previously exposed to either parasitoid, there was no emergence of the other parasitoid. When the Telenomus remus and Trichogramma pretiosum females were placed together with Spodoptera frugiperda eggs, Telenomus remus had a greater parasitism rate. Except searching time, all Trichogramma pretiosum behaviors took a longer time than Telenomus remus behaviors. Thus, despite belonging to different families, each of these parasitoids is able to recognize host eggs previously parasitized by the other. So, this suggests that the recognition mechanism involved is not exclusively specific.

Liljesthröm, Gerardo Gustavo - One of the best experts on this subject based on the ideXlab platform.

  • Searching ability of Telenomus podisi and Trissolcus urichi (Hymenoptera: Platygastridae), when searching for the host Piezodorus guildinii (Hemiptera: Pentatomidae)
    2020
    Co-Authors: Cingolani, María Fernanda, Barakat, María Candela, Liljesthröm, Gerardo Gustavo
    Abstract:

    Varios parasitoides explorando simultáneamente un hospedador pueden experimentar competencia entre los adultos (extrínseca) ó entre sus larvas dentro del hospedador (intrínseca). Un competidor intrínsecamente inferior coexistirá con otro intrínsecamente superior si localiza al hospedador más fácilmente. Piezodorus guildinii (Hemiptera: Pentatomidae) es una importante plaga de soja y sus principales enemigos naturales son los parasitoides oófagos Telenomus podisi y Trissolcus urichi (Hymenoptera: Platygastridae). Nuestro objetivo fue valuar la habilidad de estos parasitoides de localizar y parasitar al hospedador. No hubo diferencias en el manipuleo del hospedador por parte de estos parasitoides, y los dos tendrían similares habilidades de localización de hospedadores.Several parasitoids simultaneously exploring a host may experience competition between adults (extrinsic) or between their larvae within the host (intrinsic). An intrinsically inferior competitor will coexist with an intrinsically superior one if it locates the host more easily. Piezodorus guildinii (Hemiptera: Pentatomidae) is an important soybean pest and its main natural enemies are the oophagous parasitoids Telenomus podisi and Trissolcus urichi (Hymenoptera: Platygastridae). Our objective was to evaluate the ability of these parasitoids to locate and parasitize hosts. There were no differences in host manipulation between these parasitoids, and both would have similar host location abilities.Centro de Estudios Parasitológicos y de Vectore

  • Parasitismo de huevos de Piezodorus guildinii y Nezara viridula (Hemiptera: Pentatomidae) en soja, alfalfa y trébol rojo
    2020
    Co-Authors: Cingolani, María Fernanda, Greco, Nancy Mabel, Liljesthröm, Gerardo Gustavo
    Abstract:

    Piezodorus guildinii Westwood y Nezara viridula (L.) (Hemiptera: Pentatomidae) son importantes plagas en soja. P. guildinii causa mayores daños y es menos susceptible a los insecticidas. Los parasitoides oófagos de N. viridula fueron ampliamente estudiados, pero poco se conoce sobre los de P. guildinii. Se muestreó alfalfa, soja y trébol rojo durante varias temporadas para caracterizar la abundancia de ambas chinches, identificar sus parasitoides y estimar el impacto de los mismos. Telenomus podisi (Ashmead), Trissolcus urichi (Crawford) y Trissolcus basalis (Wollaston) (Hymenoptera: Platygastridae) emergieron de P. guildinii, mientras que solo T. basalis (Wollaston) (Hymenoptera: Platygastridae) emergió de N. viridula. Las proporciones de huevos (impacto del parasitoide) y de posturas parasitadas, y el número de huevos parasitados/número total de huevos de las posturas parasitadas, fueron similares para alfalfa y soja. En trébol rojo no se registró parasitismo. El impacto del parasitoide fue menor durante las temporadas secas. Si bien el parasitismo de P. guildinii por T. urichi a campo fue poco significativo, los antecedentes de la bibliografía indican que su desempeño en el laboratorio sobre este hospedador es muy bueno. T. urichi podría ser un potencial agente de control biológico de P. guildinii, principalmente en situaciones de mayor abundancia de la chinche.Piezodorus guildinii Westwood and Nezara viridula (L.) (Hemiptera: Pentatomidae) are important soybean pests. P. guildinii causes more injury and is less susceptible to insecticides compared to N. viridula. N. viridula egg parasitoids are well studied; however, little is known about parasitoids of P. guildinii. Alfalfa, soybean and red clover were sampled during several seasons to characterize the abundance of both stink bugs, to determine their egg parasitoids, and to estimate parasitoids impact. In the field, Telenomus podisi (Ashmead),Trissolcus urichi (Crawford) and Trissolcus basalis (Wollaston) (Hymenoptera: Platygastridae) emerged from P. guildinii, while only T. basalis (Wollaston) (Hymenoptera: Platygastridae) emerged from N. viridula. The proportions of parasitized eggs (i. e., the parasitoid impact) and egg masses, as well as the number of parasitized eggs/total number of eggs of the parasitized egg masses, were similar for alfalfa and soybean. Parasitism was not observed in red pclover. Parasitoid impact was lower during the dry growing seasons. Although P. guildinii field parasitism by T. urichi was less significant, laboratory experiments from the bibliography indicate that this wasp species performs well on this host. Trissolcus urichi would be an important biological control agent against P. guildinii, principally when the stink bug is more abundant.Centro de Estudios Parasitológicos y de Vectore

  • Cold-storage of Piezodorus guildinii (Hemiptera: Pentatomidae) eggs for rearing Telenomus podisi (Hymenoptera: Platygastridae)
    2020
    Co-Authors: Cingolani, María Fernanda, Greco, Nancy Mabel, Liljesthröm, Gerardo Gustavo
    Abstract:

    Piezodorus guildinii (Hemiptera: Pentatomidae) is an important soybean pest, and one of its main natural enemies is Telenomus podisi (Hymenoptera: Platygastridae). Rearing of the parasitoid is constrained by the hosts' egg quality, which deteriorates after few generations in laboratory, therefore, cold-stored host eggs utilization could be a useful tool for augmentative biological control. Thus, the objective was to evaluate the quality of P. guildinii cold-stored eggs, on the performance of parental and F1 generation of T. podisi. Hosteggs 24 hour old were stored at -18°C for one (N= 53), two (N= 28) or three months (N= 29), and approximately 40 host eggs were offered to a T. podisi female per treatment, for 48 hours. The control treatment consisted of 24-hour-old non-frozen host eggs, obtained and kept at 24°C (N= 55). Parental generation parasitism and progeny´s emergence on frozen eggs was significantly lower than on non-frozen eggs, even for the shorter storage period. Male proportion and preimaginal development time of the progeny increased with freezing period. However, parasitism proportion caused by adults of F1, and emergence, male proportion, and preimaginal development time of F2 were not affected. Although the performance of T. podisi on frozen P. guildinii eggs was significantly lower than on nonfrozen ones, host eggs storage for up to two months allowed obtaining a parasitism rate of 40% with a high emergence rate. This could be helpful enough to maintain mass rearings, mainly during the host hibernation period, and to enhance field parasitism when host is scarce.Centro de Estudios Parasitológicos y de Vectore

  • Multiparasitism of Piezodorus guildinii eggs by Telenomus podisi and Trissolcus urichi
    'Springer Science and Business Media LLC', 2013
    Co-Authors: Cingolani, María Fernanda, Greco, Nancy Mabel, Liljesthröm, Gerardo Gustavo
    Abstract:

    Multiparasitism involves competition between larvae inside the host. Telenomus podisi (Ashmead) and Trissolcus urichi (Crawford) (Hymenoptera: Platygastridae) are solitary egg parasitoids of Piezodorus guildinii Westwood (Hemiptera: Pentatomidae), an important soybean pest. Egg masses partially parasitized by one species were offered to females of the other species. Both species attacked randomly unparasitized and parasitized hosts. Emergence from multiparasitized eggs was greater for T. urichi than for T. podisi, although it was lower than emergence from eggs parasitized by T. urichi alone. Emergence of each species was independent of the order in which they parasitized and of time elapsed between ovipositions. Progeny sex ratio obtained from multiparasitized and from parasitized eggs were similar for both parasitoids. Our results suggest that T. urichi is a better intrinsic competitor than T. podisi for P. guildinii eggs. In the field, however, T. podisi was the dominant species, and T. urichi could be using other pentatomid eggs as resource.Fil: Cingolani, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Estudios Parasitológicos y de Vectores (i); Argentina. Universidad Nacional de La Plata; ArgentinaFil: Greco, Nancy Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Estudios Parasitológicos y de Vectores (i); Argentina. Universidad Nacional de La Plata; ArgentinaFil: Liljesthrom, Gerardo Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Estudios Parasitológicos y de Vectores (i); Argentina. Universidad Nacional de La Plata; Argentin