Systematics and biology of Cotesia typhae sp. n. (Hymenoptera, Braconidae, Microgastrinae), a potential biological control agent against the noctuid Mediterranean corn borer, Sesamia nonagrioides

Cellular dynamics of host - parasitoid interactions: Insights from the encapsulation process in a partially resistant host

Cotesia typhae is an eastern African endoparasitoid braconid wasp that targets the larval stage of the lepidopteran stem borer, Sesamia nonagrioides, a maize crop pest in Europe. The French host population is partially resistant to the Makindu strain of the wasp, allowing its development in only 40% of the cases. Resistant larvae can encapsulate the parasitoid and survive the infection. This interaction provides a very interesting frame for investigating the impact of parasitism on host cellular resistance. We characterized the parasitoid ovolarval development in a permissive host and studied the encapsulation process in a resistant host by dissection and histological sectioning compared to that of inert chromatography beads. We measured the total hemocyte count in parasitized and bead-injected larvae over time to monitor the magnitude of the immune reaction. Our results show that parasitism of resistant hosts delayed encapsulation but did not affect immune abilities towards inert beads. Moreover, while bead injection increased total hemocyte count, it remained constant in resistant and permissive larvae. We conclude that while Cotesia spp virulence factors are known to impair the host immune system, our results suggest that passive evasion could also occur.

Name game conundrum: identical specific epithets in Microgastrinae (Hymenoptera, Braconidae)

It is a privilege to recognize a new species and immortalize it with a name. Taxonomists may use etymologies recalling the sampling locality, habitat, species morphology, people (actor, writer, singer, politician, scientist), culture (customs, beliefs), fictional characters (gods, demons, cartoons), brands, ancient names, and others. Naming a species is a creative act that allows scientists to express their love for nature. By drawing on personal and cultural associations, species names are often imbued with far greater meaning than one might initially assume. Unconventional names for species can be an effective way to capture the imagination of the public and make the species memorable. In other words, species names can be both meaningful and whimsical. The central focus of this study was to pinpoint species in the subfamily Microgastrinae that share the same specific epithet that often creates confusion regarding which species is being referred to. The findings showed that 153 specific epithets were repeated representing 340 species in 52 genera, while the remaining 2,823 species have unique epithets. Three of the five categories proposed accommodate the majority of the etymologies: people (42%), morphology (27%), and geography (15%) whereas the categories of other (9%) and biology (7%) achieve the least representation. Approximately 95% of the same specific epithets had a single clear meaning, while for the remaining 5%, it was not possible to trace etymology. The study revealed that the average length of specific epithets was 9.01 letters, the longest contains 18 (eliethcantillanoae) while the shortest four (eros and erro). Additionally, most identical specific epithets were repeated two times (85.25% of the occurrences), although three (12.82%), five, six, and even nine (each one with 0.64%) repetitions were also found. Finally, a list of recommendations for taxonomists when faced with the task of naming a new species is provided.

Hot and cold waves decrease sperm production and bias sex ratio in the parasitoid wasp Cotesia typhae (Hymenoptera, Braconidae)

Parasitoid wasps are haplodiploid, meaning that sperm stored by egg laying females are only used to produce daughters. Thus, the sex ratio of the offspring depends on the availability of sperm after mating. In these insects, males are sensitive to temperature at the pupal stage. This stress leads to subfertility due to a drastic reduction in the number of sperm produced and transferred to females. Experiments were conducted under controlled conditions on the parasitoid wasp Cotesia typhae (Hymenoptera, Braconidae), a natural enemy of the invading pest Sesamia nonagrioides (Lepidoptera, Noctuidae). At 25-27 °C, sperm production was measured for 7 days, and found to reach a plateau at the third day of adult life. It leads to a final amount around 25,000 sperm per male. A male can successfully inseminate at least 10 females, producing predominantly female offspring. Sperm production decreased significantly after 1 day of pupal exposure to heat at 34 or 36 °C and 7 days of cold at 0, 5 or 10 °C. This highlights that both cold and heat are stressful. After mating with one male treated at 10 or 34 °C, females store fewer sperm than the control, and produce fewer daughters. The sex ratio of the offspring is male biased when males experienced temperature stresses during development, like other parasitoid wasps. In the field, C. typhae populations would be affected by heat and cold, at least at the pupal stage. This lowers overwintering risk in case this biological agent was introduced in Europe. This risk is both economical, as companies seek to establish costly continuous production to sell beneficial insects, and ecological as the introduced population would not settle in the ecosystem. Lastly, the transport and storage of this insect of agronomic interest would need to consider temperature variations to ensure successful application.

Investigating bracovirus chromosomal integration and inheritance in lepidopteran host and nontarget species

Bracoviruses (BVs) are domesticated viruses found in braconid parasitoid wasp genomes. They are composed of domesticated genes from a nudivrius, coding viral particles in which wasp DNA circles are packaged. BVs are viewed as possible vectors of horizontal transfer of genetic material (HT) from wasp to their hosts because they are injected, together with wasp eggs, by female wasps into their host larvae, and because they undergo massive chromosomal integration in multiple host tissues. Here, we show that chromosomal integrations of the Cotesia typhae BV (CtBV) persist up to the adult stage in individuals of its natural host, Sesamia nonagrioides, that survived parasitism. However, while reproducing host adults can bear an average of nearly two CtBV integrations per haploid genome, we were unable to retrieve any of these integrations in 500 of their offspring using Illumina sequencing. This suggests either that host gametes are less targeted by CtBVs than somatic cells or that gametes bearing BV integrations are nonfunctional. We further show that CtBV can massively integrate into the chromosomes of other lepidopteran species that are not normally targeted by the wasp in the wild, including one which is divergent by at least 100 million years from the natural host. Cell entry and chromosomal integration of BVs are thus unlikely to be major factors shaping wasp host range. Together, our results shed new light on the conditions under which BV-mediated wasp-to-host HT may occur and provide information that may be helpful to evaluate the potential risks of uncontrolled HT associated with the use of parasitoid wasps as biocontrol agents.

Cotesiacassina sp. nov. from southwestern Colombia: a new gregarious microgastrine wasp (Hymenoptera, Braconidae) reared from the pest species Opsiphanescassina Felder & Felder (Lepidoptera, Nymphalidae) feeding on Elaeis oil palm trees (Arecaceae)

A new species of microgastrine wasp, Cotesiacassina Salgado-Neto, Vásquez & Whitfield, sp. nov., is described from southwestern Colombia in Tumaco, Nariño. This species is a koinobiont gregarious larval endoparasitoid, and spins a common mass of cocoons underneath the host caterpillars of Opsiphanescassina (Felder & Felder) (Lepidoptera, Nymphalidae), feeding on oil palm trees (interspecific hybrid Elaeisoleifera × E.guineensis) (Arecaceae). While superficially similar, both morphologically and biologically, to C.invirae Salgado-Neto & Whitfield from southern Brazil, the two species are distinct based on DNA barcodes, host species, geographical range and morphological characters.

Genome-Wide Patterns of Bracovirus Chromosomal Integration into Multiple Host Tissues during Parasitism

Bracoviruses are domesticated viruses found in parasitic wasp genomes. They are composed of genes of nudiviral origin that are involved in particle production and proviral segments containing virulence genes that are necessary for parasitism success. During particle production, proviral segments are amplified and individually packaged as DNA circles in nucleocapsids. These particles are injected by parasitic wasps into host larvae together with their eggs. Bracovirus circles of two wasp species were reported to undergo chromosomal integration in parasitized host hemocytes, through a conserved sequence named the host integration motif (HIM). Here, we used bulk Illumina sequencing to survey integrations of Cotesia typhae bracovirus circles in the DNA of its host, the maize corn borer (Sesamia nonagrioides), 7 days after parasitism. First, assembly and annotation of a high-quality genome for C. typhae enabled us to characterize 27 proviral segments clustered in proviral loci. Using these data, we characterized large numbers of chromosomal integrations (from 12 to 85 events per host haploid genome) for all 16 bracovirus circles containing a HIM. Integrations were found in four S. nonagrioides tissues and in the body of a caterpillar in which parasitism had failed. The 12 remaining circles do not integrate but are maintained at high levels in host tissues. Surprisingly, we found that HIM-mediated chromosomal integration in the wasp germ line has occurred accidentally at least six times during evolution. Overall, our study furthers our understanding of wasp-host genome interactions and supports HIM-mediated chromosomal integration as a possible mechanism of horizontal transfer from wasps to their hosts. IMPORTANCE Bracoviruses are endogenous domesticated viruses of parasitoid wasps that are injected together with wasp eggs into wasp host larvae during parasitism. Several studies have shown that some DNA circles packaged into bracovirus particles become integrated into host somatic genomes during parasitism, but the phenomenon has never been studied using nontargeted approaches. Here, we use bulk Illumina sequencing to systematically characterize and quantify bracovirus circle integrations that occur in four tissues of the Mediterranean corn borer (Sesamia nonagrioides) during parasitism by the Cotesia typhae wasp. Our analysis reveals that all circles containing a HIM integrate at substantial levels (from 12 to 85 integrations per host cell, in total) in all tissues, while other circles do not integrate. In addition to shedding new light on wasp-bracovirus-host interactions, our study supports HIM-mediated chromosomal integration of bracovirus as a possible source of wasp-to-host horizontal transfer, with long-term evolutionary consequences.

Draft nuclear genome and complete mitogenome of the Mediterranean corn borer, Sesamia nonagrioides, a major pest of maize

The Mediterranean corn borer (Sesamia nonagrioides, Noctuidae, Lepidoptera) is a major pest of maize in Europe and Africa. Here, we report an assembly of the nuclear and mitochondrial genome of a pool of inbred males and females third-instar larvae, based on short- and long-read sequencing. The complete mitochondrial genome is 15,330 bp and contains all expected 13 and 24 protein-coding and RNA genes, respectively. The nuclear assembly is 1021 Mb, composed of 2553 scaffolds and it has an N50 of 1105 kb. It is more than twice larger than that of all Noctuidae species sequenced to date, mainly due to a higher repeat content. A total of 17,230 protein-coding genes were predicted, including 15,776 with InterPro domains. We provide detailed annotation of genes involved in sex determination (doublesex, insulin-like growth factor 2 mRNA-binding protein, and P-element somatic inhibitor) and of alpha-amylase genes possibly involved in interaction with parasitoid wasps. We found no evidence of recent horizontal transfer of bracovirus genes from parasitoid wasps. These genome assemblies provide a solid molecular basis to study insect genome evolution and to further develop biocontrol strategies against S. nonagrioides.

Toxicological risk assessment of some commonly used insecticides on Cotesia flavipes, a larval parasitoid of the spotted stem borer Chilo partellus

Cotesia flavipes Cameron is an important larval parasitoid exploited for the control of the spotted stem borer, Chilo partellus (Swinhoe). Several studies have evaluated the toxic effects of insecticides on C. partellus, however, little is known about non-target effects of insecticides on this parasitoid, when used to control C. partellus. This laboratory study evaluated the lethal and sublethal effects of twelve insecticides on C. flavipes. Residual toxicity tests showed that organophosphates (chlorpyrifos, triazophos and profenofos) exhibited highest contact toxicity to C. flavipes adults with a LC₅₀ range from 0.63 to 1.05 mg a.i/l, while neonicotinoids (nitenpyram, acetamiprid and imidacloprid) were less toxic to C. flavipes with a LC₅₀ range from 1.27 to 139.48 mg a.i/l. Sugar-insecticide feeding bioassays showed that organophosphates, pyrethroids (cypermethrin, bifenthrin and lambda-cyhalothrin) and carbamates (thiodicarb, carbaryl and methomyl) were highly toxic to C. flavipes adults and caused 100% mortality at 48 h of exposure, while imidacloprid caused 66% mortality at 48 h of exposure. Risk quotient analysis showed that among all tested insecticides, imidacloprid and acetamiprid were less toxic to C. flavipes adults with a risk quotient value of 0.88 and 1.6, respectively. Furthermore, exposure of immature C. flavipes through their host bodies significantly decreased the parasitism rate at their F₁ and F₂ generations. Risk quotient analysis of insecticides indicated that imidacloprid and acetamiprid were the least toxic to C. flavipes. This study provides important information that will be used in incorporating the most suitable insecticides in integrated pest management programs with reduced negative impacts on non-target beneficial arthropods.

Quantitative trait loci involved in the reproductive success of a parasitoid wasp

Dissecting the genetic basis of intraspecific variations in life history traits is essential to understand their evolution, notably for potential biocontrol agents. Such variations are observed in the endoparasitoid Cotesia typhae (Hymenoptera: Braconidae), specialized on the pest Sesamia nonagrioides (Lepidoptera: Noctuidae). Previously, we identified two strains of C. typhae that differed significantly for life history traits on an allopatric host population. To investigate the genetic basis underlying these phenotypic differences, we used a quantitative trait locus (QTL) approach based on restriction site-associated DNA markers. The characteristic of C. typhae reproduction allowed us generating sisters sharing almost the same genetic content, named clonal sibship. Crosses between individuals from the two strains were performed to generate F2 and F8 recombinant CSS. The genotypes of 181 clonal sibships were determined as well as the phenotypes of the corresponding 4,000 females. Informative markers were then used to build a high-quality genetic map. These 465 markers spanned a total length of 1,300 cM and were organized in 10 linkage groups which corresponded to the number of C. typhae chromosomes. Three QTLs were detected for parasitism success and two for offspring number, while none were identified for sex ratio. The QTLs explained, respectively, 27.7% and 24.5% of the phenotypic variation observed. The gene content of the genomic intervals was investigated based on the genome of C. congregata and revealed 67 interesting candidates, as potentially involved in the studied traits, including components of the venom and of the symbiotic virus (bracovirus) shown to be necessary for parasitism success in related wasps.

Annotated and illustrated world checklist of Microgastrinae parasitoid wasps (Hymenoptera, Braconidae)

A checklist of world species of Microgastrinae parasitoid wasps (Hymenoptera: Braconidae) is provided. A total of 81 genera and 2,999 extant species are recognized as valid, including 36 nominal species that are currently considered as species inquirendae. Two genera are synonymized under Apanteles. Nine lectotypes are designated. A total of 318 new combinations, three new replacement names, three species name amendments, and seven species status revised are proposed. Additionally, three species names are treated as nomina dubia, and 52 species names are considered as unavailable names (including 14 as nomina nuda). A total of three extinct genera and 12 extinct species are also listed. Unlike in many previous treatments of the subfamily, tribal concepts are judged to be inadequate, so genera are listed alphabetically. Brief diagnoses of all Microgastrinae genera, as understood in this paper, are presented. Illustrations of all extant genera (at least one species per genus, usually more) are included to showcase morphological diversity. Primary types of Microgastrinae are deposited in 108 institutions worldwide, although 76% are concentrated in 17 collections. Localities of primary types, in 138 countries, are reported. Recorded species distributions are listed by biogeographical region and by country. Microgastrine wasps are recorded from all continents except Antarctica; specimens can be found in all major terrestrial ecosystems, from 82°N to 55°S, and from sea level up to at least 4,500 m a.s.l. The Oriental (46) and Neotropical (43) regions have the largest number of genera recorded, whereas the Palaearctic region (28) is the least diverse. Currently, the highest species richness is in the Palearctic region (827), due to more historical study there, followed by the Neotropical (768) and Oriental (752) regions, which are expected to be the most species rich. Based on ratios of Lepidoptera and Microgastrinae species from several areas, the actual world diversity of Microgastrinae is expected to be between 30,000–50,000 species; although these ratios were mostly based on data from temperate areas and thus must be treated with caution, the single tropical area included had a similar ratio to the temperate ones. Almost 45,000 specimens of Microgastrinae from 67 different genera (83% of microgastrine genera) have complete or partial DNA barcode sequences deposited in the Barcode of Life Data System; the DNA barcodes represent 3,545 putative species or Barcode Index Numbers (BINs), as estimated from the molecular data. Information on the number of sequences and BINs per genus are detailed in the checklist. Microgastrinae hosts are here considered to be restricted to Eulepidoptera, i.e., most of the Lepidoptera except for the four most basal superfamilies (Micropterigoidea, Eriocranioidea, Hepialoidea and Nepticuloidea), with all previous literature records of other insect orders and those primitive Lepidoptera lineages being considered incorrect. The following nomenclatural acts are proposed: 1) Two genera are synonymyzed under Apanteles: Cecidobracon Kieffer & Jörgensen, 1910, new synonym and Holcapanteles Cameron, 1905, new synonym; 2) Nine lectotype designations are made for Alphomelondisputabile (Ashmead, 1900), Alphomelonnigriceps (Ashmead, 1900), Cotesiasalebrosa (Marshall, 1885), Diolcogasterxanthaspis (Ashmead, 1900), Dolichogenideaononidis (Marshall, 1889), Glyptapantelesacraeae (Wilkinson, 1932), Glyptapantelesguyanensis (Cameron, 1911), Glyptapantelesmilitaris (Walsh, 1861), and Pseudapantelesannulicornis Ashmead, 1900; 3) Three new replacement names are a) Diolcogasteraurangabadensis Fernandez-Triana, replacing Diolcogasterindicus (Rao & Chalikwar, 1970) [nec Diolcogasterindicus (Wilkinson, 1927)], b) Dolichogenideaincystatae Fernandez-Triana, replacing Dolichogenidealobesia Liu & Chen, 2019 [nec Dolichogenidealobesia Fagan-Jeffries & Austin, 2019], and c) Microplitisvitobiasi Fernandez-Triana, replacing Microplitisvariicolor Tobias, 1964 [nec Microplitisvaricolor Viereck, 1917]; 4) Three names amended are Apantelesirenecarrilloae Fernandez-Triana, 2014, Cotesiaayerzai (Brèthes, 1920), and Cotesiariverai (Porter, 1916); 5) Seven species have their status revised: Cotesiaarctica (Thomson, 1895), Cotesiaokamotoi (Watanabe, 1921), Cotesiaukrainica (Tobias, 1986), Dolichogenideaappellator (Telenga, 1949), Dolichogenideamurinanae (Capek & Zwölfer, 1957), Hypomicrogasteracarnas Nixon, 1965, and Nyererianigricoxis (Wilkinson, 1932); 6) New combinations are given for 318 species: Alloplitiscongensis, Alloplitisdetractus, Apantelesasphondyliae, Apantelesbraziliensis, Apantelessulciscutis, Choerasaper, Choerasapollion, Choerasdaphne, Choerasfomes, Choerasgerontius, Choerashelle, Choerasirates, Choeraslibanius, Choeraslongiterebrus, Choerasloretta, Choerasrecusans, Choerassordidus, Choerasstenoterga, Choerassuperbus, Choerassylleptae, Choerasvacillatrix, Choerasvacillatropsis, Choerasvenilia, Cotesiaasavari, Cotesiabactriana, Cotesiabambeytripla, Cotesiaberberidis, Cotesiabhairavi, Cotesiabiezankoi, Cotesiabifida, Cotesiacaligophagus, Cotesiacheesmanae, Cotesiacompressithorax, Cotesiadelphinensis, Cotesiaeffrena, Cotesiaeuphobetri, Cotesiaelaeodes, Cotesiaendii, Cotesiaeuthaliae, Cotesiaexelastisae, Cotesiahiberniae, Cotesiahyperion, Cotesiahypopygialis, Cotesiahypsipylae, Cotesiajujubae, Cotesialesbiae, Cotesialevigaster, Cotesializeri, Cotesiamalevola, Cotesiamalshri, Cotesiamenezesi, Cotesiamuzaffarensis, Cotesianeptisis, Cotesianycteus, Cotesiaoeceticola, Cotesiaoppidicola, Cotesiaopsiphanis, Cotesiapachkuriae, Cotesiapaludicolae, Cotesiaparbhanii, Cotesiaparvicornis, Cotesiapratapae, Cotesiaprozorovi, Cotesiapterophoriphagus, Cotesiaradiarytensis, Cotesiarangii, Cotesiariverai, Cotesiaruficoxis, Cotesiasenegalensis, Cotesiaseyali, Cotesiasphenarchi, Cotesiasphingivora, Cotesiatransuta, Cotesiaturkestanica, Diolcogasterabengouroui, Diolcogasteragama, Diolcogasterambositrensis, Diolcogasteranandra, Diolcogasterannulata, Diolcogasterbambeyi, Diolcogasterbicolorina, Diolcogastercariniger, Diolcogastercincticornis, Diolcogastercingulata, Diolcogastercoronata, Diolcogastercoxalis, Diolcogasterdipika, Diolcogasterearina, Diolcogasterepectina, Diolcogasterepectinopsis, Diolcogastergrangeri, Diolcogasterheterocera, Diolcogasterhomocera, Diolcogasterindica, Diolcogasterinsularis, Diolcogasterkivuana, Diolcogastermediosulcata, Diolcogastermegaulax, Diolcogasterneglecta, Diolcogasternigromacula, Diolcogasterpalpicolor, Diolcogasterpersimilis, Diolcogasterplecopterae, Diolcogasterplutocongoensis, Diolcogasterpsilocnema, Diolcogasterrufithorax, Diolcogastersemirufa, Diolcogasterseyrigi, Diolcogastersubtorquata, Diolcogastersulcata, Diolcogastertorquatiger, Diolcogastertristiculus, Diolcogasterturneri, Diolcogastervulcana, Diolcogasterwittei, Distatrixanthedon, Distatrixcerales, Distatrixcuspidalis, Distatrixeuproctidis, Distatrixflava, Distatrixgeometrivora, Distatrixmaia, Distatrixtookei, Distatrixtermina, Distatrixsimulissima, Dolichogenideaagamedes, Dolichogenideaaluella, Dolichogenideaargiope, Dolichogenideaatreus, Dolichogenideabakeri, Dolichogenideabasiflava, Dolichogenideabersa, Dolichogenideabiplagae, Dolichogenideabisulcata, Dolichogenideacatonix, Dolichogenideachrysis, Dolichogenideacoffea, Dolichogenideacoretas, Dolichogenideacyane, Dolichogenideadiaphantus, Dolichogenideadiparopsidis, Dolichogenideadryas, Dolichogenideaearterus, Dolichogenideaensiger, Dolichogenideaeros, Dolichogenideaevadne, Dolichogenideafalcator, Dolichogenideagelechiidivoris, Dolichogenideagobica, Dolichogenideahyalinis, Dolichogenideairiarte, Dolichogenidealakhaensis, Dolichogenidealampe, Dolichogenidealaspeyresiella, Dolichogenidealatistigma, Dolichogenidealebene, Dolichogenidealucidinervis, Dolichogenideamalacosomae, Dolichogenideamaro, Dolichogenideamendosae, Dolichogenideamonticola, Dolichogenideanigra, Dolichogenideaolivierellae, Dolichogenideaparallelis, Dolichogenideapelopea, Dolichogenideapelops, Dolichogenideaphaenna, Dolichogenideapisenor, Dolichogenidearoepkei, Dolichogenideascabra, Dolichogenideastatius, Dolichogenideastenotelas, Dolichogenideastriata, Dolichogenideawittei, Exoryzaasotae, Exoryzabelippicola, Exoryzahylas, Exoryzamegagaster, Exoryzaoryzae, Glyptapantelesaggestus, Glyptapantelesagynus, Glyptapantelesaithos, Glyptapantelesamenophis, Glyptapantelesantarctiae, Glyptapantelesanubis, Glyptapantelesarginae, Glyptapantelesargus, Glyptapantelesatylana, Glyptapantelesbadgleyi, Glyptapantelesbataviensis, Glyptapantelesbistonis, Glyptapantelesborocerae, Glyptapantelescacao, Glyptapantelescadei, Glyptapantelescinyras, Glyptapanteleseryphanidis, Glyptapanteleseuproctisiphagus, Glyptapanteleseutelus, Glyptapantelesfabiae, Glyptapantelesfulvigaster, Glyptapantelesfuscinervis, Glyptapantelesgahinga, Glyptapantelesglobatus, Glyptapantelesglyphodes, Glyptapantelesguierae, Glyptapanteleshorus, Glyptapantelesintricatus, Glyptapanteleslamprosemae, Glyptapanteleslefevrei, Glyptapantelesleucotretae, Glyptapanteleslissopleurus, Glyptapantelesmadecassus, Glyptapantelesmarquesi, Glyptapantelesmelanotus, Glyptapantelesmelissus, Glyptapantelesmerope, Glyptapantelesnaromae, Glyptapantelesnepitae, Glyptapantelesnigrescens, Glyptapantelesninus, Glyptapantelesnkuli, Glyptapantelesparasundanus, Glyptapantelespenelope, Glyptapantelespenthocratus, Glyptapantelesphilippinensis, Glyptapantelesphilocampus, Glyptapantelesphoebe, Glyptapantelesphytometraduplus, Glyptapantelespropylae, Glyptapantelespuera, Glyptapantelesseydeli, Glyptapantelessiderion, Glyptapantelessimus, Glyptapantelesspeciosissimus, Glyptapantelesspilosomae, Glyptapantelessubpunctatus, Glyptapantelesthespis, Glyptapantelesthoseae, Glyptapantelesvenustus, Glyptapanteleswilkinsoni, Hypomicrogastersamarshalli, Iconellacajani, Iconelladetrectans, Iconellajason, Iconellalynceus, Iconellapyrene, Iconellatedanius, Illidopsazamgarhensis, Illidopslamprosemae, Illidopstrabea, Keylimepiestriatus, Microplitisadisurae, Microplitismexicanus, Neoclarkinellaariadne, Neoclarkinellacurvinervus, Neoclarkinellasundana, Nyereriaituriensis, Nyererianioro, Nyereriaproagynus, Nyereriataoi, Nyereriavallatae, Parapantelesaethiopicus, Parapantelesalternatus, Parapantelesaso, Parapantelesatellae, Parapantelesbagicha, Parapantelescleo, Parapantelescyclorhaphus, Parapantelesdemades, Parapantelesendymion, Parapantelesepiplemicidus, Parapantelesexpulsus, Parapantelesfallax, Parapantelesfolia, Parapantelesfurax, Parapanteleshemitheae, Parapanteleshyposidrae, Parapantelesindicus, Parapantelesjavensis, Parapantelesjhaverii, Parapantelesmaculipalpis, Parapantelesmaynei, Parapantelesneocajani, Parapantelesneohyblaeae, Parapantelesnydia, Parapantelesprosper, Parapantelesprosymna, Parapantelespunctatissimus, Parapantelesregalis, Parapantelessarpedon, Parapantelessartamus, Parapantelesscultena, Parapantelestransvaalensis, Parapantelesturri, Parapantelesxanthopholis, Pholetesoracutus, Pholetesorbrevivalvatus, Pholetesorextentus, Pholetesoringenuoides, Pholetesorkuwayamai, Promicrogasterapidanus, Promicrogasterbriareus, Promicrogasterconopiae, Promicrogasteremesa, Promicrogastergrandicula, Promicrogasterorsedice, Promicrogasterrepleta, Promicrogastertyphon, Sathonbekilyensis, Sathonflavofacialis, Sathonlaurae, Sathonmikeno, Sathonruandanus, Sathonrufotestaceus, Venanidesastydamia, Venanidesdemeter, Venanidesparmula, and Venanidessymmysta.

Role of egg-laying behavior, virulence and local adaptation in a parasitoid's chances of reproducing in a new host

Understanding the ability of parasitoid insects to succeed in new host populations is a relevant question for biological control and adaptive mechanisms. Cotesia typhae is an African parasitoid specialized on the moth Sesamiae nonagrioides, also called the Mediterranean corn borer. Two Kenyan strains of C. typhae differ in their virulence against a new host population from France. We explored behavioral and physiological hypotheses about this differentiation. Cotesia genus belongs to a group of Hymenoptera in which females inject a domesticated virus in their host to overcome its resistance. Since viral particles are injected along with eggs and since the strain with the higher virulence injects more eggs, we hypothesized that virulence could be explained by the quantity of virus injected. To test this assumption, we measured the injected quantities of eggs and viral particles (estimated by viral DNA segments) of each parasitoid strain along several ovipositions, to vary these quantities. Unexpectedly, results showed that virulence against the French host was not correlated to the injected quantities of eggs or viral segments, indicating that virulence differentiation is explained by other causes. The virulence against the respective natural hosts of the two C. typhae strains was also measured, and results suggest that local adaptation to a more resistant natural host may explain the pre-adaptation of one strain to the new host population. We also identified a differentiation of oviposition strategy and subsequent offspring number between the parasitoid strains, which is important in a biocontrol perspective.