The diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a cosmopolitan pest that causes leaf-area reduction in Brassicaceae plants. DBM populations have significant genetic variability that manifests in different feeding preferences and reproductive behaviors across generations. We evaluated the influence of Brassicaceae cultivars on biological and behavioral parameters across 18 generations of DBM populations that were separated and held on three varieties of Brassicaceae: Brassica oleracea var. acephala (kale), Brassica oleracea var. italica (broccoli), and Brassica oleracea var. capitata (cabbage). P, F6, F12, and F18 generations were evaluated, and biological aspects of young adulthood and fertility parameters of adults held on each host plant were examined over multiple generations. Additionally, larvae and adults were subjected to dual-choice and multiple-choice (feeding and oviposition) between cultivars, over generations. The results indicated that larvae of P. xylostella consumed greater quantities of kale and broccoli cultivars, on average (4.05 cm2), than cabbage (2.7 cm2). The number of eggs per female in F18 generation was 1.95 and 2.17 times higher than those in the parental (P) generation, when reared on kale and cabbage. The population reared exclusively on kale had higher net population growth rate (R0), intrinsic rate (rm), finite rate (λ) and generation time (T) than that reared on broccoli and cabbage. Last generations evaluated, the larval stage reared on cabbage showed feeding preference (F18) and oviposition preference (F12 and F18) for cabbage. Thus, we note the existence of learning, characterized as pre-imaginal conditioning to cabbage cultivars, over various DBM generations.

O objetivo deste estudo foi avaliar a resposta funcional de Orius insidiosus que predaram ninfas de terceiro e quarto instar de Aphis gossypii criadas em variedades de algodão transgênico e convencional. Cinquenta fêmeas de O. insidiosus de 12-24h foram individualizadas por tratamento em placas de Petri. Diferentes densidades de A. gossypii (2, 4, 8, 16 e 32 ninfas por placa) foram testadas usando cada variedade de algodão. O número de presas consumidas foi avaliado durante 12h. Foi realizada uma avaliação final com 24h. O tempo de manipulação (Th) e a taxa de ataque (a) foram 0,0697h e 1,1862h-1, respectivamente, para a variedade Buriti e 0,0713h e 0,3030h-1, respectivamente, para a variedade NuOPAL. O número médio de presas consumidas por O. insidiosus foi similar para ambas variedades com 24h e com maiores densidades; a taxa de ataque foi maior com pulgões criados em Buriti do que criados em NuOPAL.

The objective of this study was to evaluate the functional response of Orius insidiosus preying on the third and fourth instars of Aphis gossypii nymphs that were reared on transgenic NuOPAL (Bollgard I Event 531) and conventional Buriti cotton varieties. Fifty O. insidiosus female bugs aged 12-24h were distributed into five different Petri dishes with different densities of A. gossypii (2, 4, 8, 16, and 32 nymphs per plate) for each cotton variety. The number of prey consumed was evaluated over the course of 12h, with a final assessment at 24h. The handling times (Th) and attack rates (a) were 0.0697h and 1.1862h-1, respectively, for the Buriti variety and 0.0713h and 0.3030h-1, respectively, for the NuOPAL variety. The average number of prey consumed by O. insidiosus was similar for both varieties at 24h and at higher densities; the attack rate was higher for the Buriti-reared aphid prey than for the NuOPAL-reared aphids.

O objetivo do trabalho foi avaliar diferentes dietas para lagartas de Diatraea saccharalis, com o intuito de obter informações sobre as características biológicas da praga e consequentemente avaliar a qualidade do parasitoide Cotesia flavipes, visando melhorar tecnicamente sua produção massal. Lagartas de 24 horas de idade foram transferidas para tubos (25 lagartas/tubo) contendo dieta artificial com levedura de cerveja e germe de trigo e outra somente com germe de trigo como fonte de proteína. Depois de aproximadamente 15 dias, as lagartas foram retiradas dos tubos e acondicionadas em placas com dieta, sendo observadas lagartas de D. saccharalis não parasitadas e parasitadas para avaliação das características biológicas de D. saccharalis e C. flavipes.nas diferentes dietas. Além da observação das características biológicas de D. saccharalis, foram realizadas medições nas lagartas de 15 dias de idade. Também, massas de pupas de C. flavipes.produzidas em biofábrica foram classificadas em três diferentes tamanhos, sendo pequenas (1,3 a 2,5 cm de comprimento), médias (2,5 a 3,5 cm de comprimento) e grandes (3,5 a 4,0 cm de comprimento). Após a emergência dos adultos foi realizado o parasitismo em lagartas de D. saccharalis, sendo observados o número de machos e fêmeas, tamanho da massa, razão sexual e número de pupas inviáveis. A dieta artificial que contém somente germe de trigo é a mais indicada para criação massal do hospedeiro D. saccharalis para produção em larga escala de C. flavipes. Massas de pupas classificadas como grandes possuem melhor qualidade em criações massais de C. flavipes.

The aim of this work was to evaluate different diets for Diatraea saccharalis larvae, obtaining information about the biological characteristics of the pest, and to evaluate the quality of Cotesia flavipes parasitoid, to improve mass rearing method. For the accomplishment of the experiment, 24 hour-old larvae were transferred to tubes (25 larvae/tube) containing artificial diets with yeast and wheat germ or just wheat germ as protein source. After approximately 15 days, the larvae were removed from tubes and placed in Petri dishes, being observed D. saccharalis larvae not parasitized and parasitized for evaluation of D. saccharalis and C. flavipes.biological characteristics. Biological characteristics of D. saccharalis were also evaluated in 15 day-old larvae. Pupae mass of C. flavipes.from mass rearing were classified in three different sizes separated in small (1.3 to 2.5 cm of length), moderate (2.5 to 3.5 cm of length) and large (3.5 to 4.0 cm of length) classes. After the adult emergency, the parasitism was evaluated in D. saccharalis larvae, being observed the number of males and females, size of pupae mass, sex ratio and number of unviable pupae. The artificial diet that contains wheat germ is the most suitable for D. saccharalis mass rearing and C. flavipes. Pupae mass of large size presents better quality of C. flavipes.