Toxoneuron nigriceps is a koinobiont larval endoparasitoid of the tobacco budworm, Heliothis virescens. No koinobiont parasitoid (which develop in active, growing hosts) has been reared completely in vitro. However, T. nigriceps has been partially reared in vitro, from egg stage through 2nd larval instar and from 2nd to 3rd larval instar. Despite reaching its final larval instar, T. nigriceps failed to develop past the larval stage. In the following study, two aspects of T. nigriceps development, post-egression tissue feeding and cocoon formation through pupation, were examined to determine why T. nigriceps failed to develop in vitro beyond the larval stage and how in vitro rearing might be improved to rear T. nigriceps to adulthood. The importance of post-egression feeding and the possibility of developing an artificial post-egression diet were examined by manipulating the post-egression feeding behavior of T. nigriceps. The tissues of pre- and post-tissue feeding T. nigriceps larvae were analyzed to investigate the macronutritional benefit of post-egression feeding. A preliminary artificial post-egression diet was tested, and the putative quality of T. nigriceps reared to adulthood using this diet was examined. The formation of subterranean pupation chambers by healthy and parasitized H. virescens larvae was examined to investigate potential behavioral manipulation by T. nigriceps during this process. Finally, the potential use of artificial pupation chambers by T. nigriceps was investigated. Post-egression feeding was determined to be a vital part of T. nigriceps development, contributing to both parasitoid size and survival to adulthood. A preliminary artificial post-egression diet was developed, which facilitated rearing of T. nigriceps from 3rd larval instar to adulthood. The dimensions and burial depth of chambers formed by parasitized H. virescens were significantly different from those of chambers formed by healthy H. virescens, suggesting that T. nigriceps manipulated host behavior during excavation. Toxoneuron nigriceps was able to use a number of common laboratory items as substitute pupation chambers during cocoon formation, and the merits of several artificial chambers were discussed. With provision of an adequate post-egression and artificial pupation chamber, in vitro rearing of T. nigriceps from the larval stage to adulthood may be possible.

Trichogramma atopovirilia Oatman & Platner, 1983, Trichogrammatoidea annulata De Santis, 1972 e Trichogramma bruni Nagaraja, 1983 são espécies que ocorrem naturalmente no Brasil, e assim como outras espécies de tricogramatídeos neotropicais apresentam potencial de utilização em programas de controle biológico. Todavia, para que essa estratégia seja implementada faz-se necessário um sistema eficiente de criação massal, baseando-se, principalmente, na escolha do hospedeiro adequado para multiplicação do parasitóide com qualidade. Normalmente são utilizados os hospedeiros alternativos Sitotroga cerealella (Olivier, 1819), Anagasta kuehniella (Zeller, 1879) e Corcyra cephalonica (Stainton, 1865); a produção destes hospedeiros é equivalente a mais de 70% dos custos de produção. Um sistema de criação que independa desses hospedeiros, como a criação in vitro, seria ideal para simplificar a linha de produção de parasitóides. Os objetivos deste trabalho foram: 1) selecionar o hospedeiro alternativo mais adequado para criação de T. atopovirilia, T. annulata e T. bruni, e avaliar os efeitos da criação destes parasitóides por sucessivas gerações, em suas características biológicas, incluindo capacidade de vôo e tabela de vida de fertilidade; 2) estudar a viabilidade da criação in vitro destas espécies de parasitóides. Concluiu-se que o hospedeiro alternativo afetou as características biológicas e a capacidade de vôo das espécies estudadas. Para T. atopovirilia, C. cephalonica e/ou A. kuehniella foram os hospedeiros alternativos mais adequados para sua criação, enquanto que para T. annulata e T. bruni C. cephalonica foi o hospedeiro preferencial. No entanto, com base na atividade de vôo, T. bruni não demonstrou potencial adaptativo ao longo das gerações avaliadas em nenhum dos 3 hospedeiros alternativos. As demais espécies apresentaram potencial adaptativo aos hospedeiros preferenciais. Com base em todos os parâmetros avaliados S. cerealella foi o pior hospedeiro para as 3 espécies de parasitóides estudadas. Foi possível a criação in vitro de T. atopovirilia, desde o parasitismo até a emergência dos adultos, numa dieta artificial composta de holotecidos pupais de Heliothis virescens Fabr. (65%), gema de ovo (18%), soro fetal bovino (8,5%), hidrolisado de lactoalbumina (8,5%) e anticontaminantes (0,3%). A dieta não permitiu o desenvolvimento de T. annulata e T. bruni. Os parasitóides criados in vitro apresentaram características semelhantes aos insetos criados in vivo, quando foram transferidos para o hospedeiro alternativo. / Trichogramma atopovirilia Oatman & Platner, 1983, Trichogrammatoidea annulata De Santis, 1972 and Trichogramma bruni Nagaraja, 1983 are species that occurs naturally in Brazil and just like other species of Neotropical trichogrammatid, they have potential for utilization in biological control programs. Therefore, for this strategy to be implemented, it is necessary to establish an efficient mass rearing system, based mainly on the choice of suitable hosts for multiplication of quality parasitoids. Frequently used factitious hosts are Sitotroga cerealella (Olivier, 1819), Anagasta kuehniella (Zeller, 1879) and Corcyra cephalonica (Stainton, 1865); the cost of production of these hosts is equivalent to more than 70% of the production costs. A rearing system which does not depend on these hosts such as in vitro production could be ideal to simplify production of parasitoids. The objectives of this work were to: 1) select the most suitable factitious host for rearing of T. atopovirilia, T. annulata and T. bruni, and evaluate the effect of rearing these parasitoids for successive generations on their biological characteristics including flight capacity and fertility life table and 2) study the viability of in vitro rearing of these parasitoids. It was concluded that factitious hosts affected biological characteristics and flight capacity of the studied species. For T. atopovirilia, C. cephalonica and/or A. kuehniella were the most suitable factitious hosts for its rearing, while for T. annulata and T. bruni, C. cephalonica was a preferential host. However, based on flight capacity, T. bruni did not demonstrate adaptive potential along the evaluated generations in all the 3 factitious hosts. The other species presented adaptive potential to their preferential hosts. Based on all the evaluated parameters, S. cerealella was the worst host for all the 3 parasitoid species studied. In vitro rearing of T. atopovirilia was possible from parasitism up to adult emergency on artificial diet consisting of holotissues of Heliothis virescens Fabr. (65%), egg york (18%), fetal bovine serum (8,5%), lactoalbumin hydrolysate (8,5%) and anti-contaminants (0,3%). The diet did not permit the development of T. annulata and T. bruni. The in vitro reared parasitoids presented similar characteristics to insects reared in vivo when they were transferred to factitious hosts.

Trichogramma atopovirilia Oatman & Platner, 1983, Trichogrammatoidea annulata De Santis, 1972 e Trichogramma bruni Nagaraja, 1983 são espécies que ocorrem naturalmente no Brasil, e assim como outras espécies de tricogramatídeos neotropicais apresentam potencial de utilização em programas de controle biológico. Todavia, para que essa estratégia seja implementada faz-se necessário um sistema eficiente de criação massal, baseando-se, principalmente, na escolha do hospedeiro adequado para multiplicação do parasitóide com qualidade. Normalmente são utilizados os hospedeiros alternativos Sitotroga cerealella (Olivier, 1819), Anagasta kuehniella (Zeller, 1879) e Corcyra cephalonica (Stainton, 1865); a produção destes hospedeiros é equivalente a mais de 70% dos custos de produção. Um sistema de criação que independa desses hospedeiros, como a criação in vitro, seria ideal para simplificar a linha de produção de parasitóides. Os objetivos deste trabalho foram: 1) selecionar o hospedeiro alternativo mais adequado para criação de T. atopovirilia, T. annulata e T. bruni, e avaliar os efeitos da criação destes parasitóides por sucessivas gerações, em suas características biológicas, incluindo capacidade de vôo e tabela de vida de fertilidade; 2) estudar a viabilidade da criação in vitro destas espécies de parasitóides. Concluiu-se que o hospedeiro alternativo afetou as características biológicas e a capacidade de vôo das espécies estudadas. Para T. atopovirilia, C. cephalonica e/ou A. kuehniella foram os hospedeiros alternativos mais adequados para sua criação, enquanto que para T. annulata e T. bruni C. cephalonica foi o hospedeiro preferencial. No entanto, com base na atividade de vôo, T. bruni não demonstrou potencial adaptativo ao longo das gerações avaliadas em nenhum dos 3 hospedeiros alternativos. As demais espécies apresentaram potencial adaptativo aos hospedeiros preferenciais. Com base em todos os parâmetros avaliados S. cerealella foi o pior hospedeiro para as 3 espécies de parasitóides estudadas. Foi possível a criação in vitro de T. atopovirilia, desde o parasitismo até a emergência dos adultos, numa dieta artificial composta de holotecidos pupais de Heliothis virescens Fabr. (65%), gema de ovo (18%), soro fetal bovino (8,5%), hidrolisado de lactoalbumina (8,5%) e anticontaminantes (0,3%). A dieta não permitiu o desenvolvimento de T. annulata e T. bruni. Os parasitóides criados in vitro apresentaram características semelhantes aos insetos criados in vivo, quando foram transferidos para o hospedeiro alternativo. / Trichogramma atopovirilia Oatman & Platner, 1983, Trichogrammatoidea annulata De Santis, 1972 and Trichogramma bruni Nagaraja, 1983 are species that occurs naturally in Brazil and just like other species of Neotropical trichogrammatid, they have potential for utilization in biological control programs. Therefore, for this strategy to be implemented, it is necessary to establish an efficient mass rearing system, based mainly on the choice of suitable hosts for multiplication of quality parasitoids. Frequently used factitious hosts are Sitotroga cerealella (Olivier, 1819), Anagasta kuehniella (Zeller, 1879) and Corcyra cephalonica (Stainton, 1865); the cost of production of these hosts is equivalent to more than 70% of the production costs. A rearing system which does not depend on these hosts such as in vitro production could be ideal to simplify production of parasitoids. The objectives of this work were to: 1) select the most suitable factitious host for rearing of T. atopovirilia, T. annulata and T. bruni, and evaluate the effect of rearing these parasitoids for successive generations on their biological characteristics including flight capacity and fertility life table and 2) study the viability of in vitro rearing of these parasitoids. It was concluded that factitious hosts affected biological characteristics and flight capacity of the studied species. For T. atopovirilia, C. cephalonica and/or A. kuehniella were the most suitable factitious hosts for its rearing, while for T. annulata and T. bruni, C. cephalonica was a preferential host. However, based on flight capacity, T. bruni did not demonstrate adaptive potential along the evaluated generations in all the 3 factitious hosts. The other species presented adaptive potential to their preferential hosts. Based on all the evaluated parameters, S. cerealella was the worst host for all the 3 parasitoid species studied. In vitro rearing of T. atopovirilia was possible from parasitism up to adult emergency on artificial diet consisting of holotissues of Heliothis virescens Fabr. (65%), egg york (18%), fetal bovine serum (8,5%), lactoalbumin hydrolysate (8,5%) and anti-contaminants (0,3%). The diet did not permit the development of T. annulata and T. bruni. The in vitro reared parasitoids presented similar characteristics to insects reared in vivo when they were transferred to factitious hosts.