The flavonoid rutin is recognized as playing an important role in the protection of plants against lepidopterans. Bioassays with this compound are generally carried out using artificial diets. Proteins of high energy value, such as casein, are important ingredients of insect artificial diets as a source of essential amino acids. However, such proteins can generally increase the allelochemical activity. Our objective was to evaluate the effects of rutin on larvae of the velvetbean caterpillar Anticarsia gemmatalis Hübner by incorporating this allelochemical into diets with different concentrations of casein. Three casein concentrations (0, 7 g, or 14 g) combined with none, 0.65%, or 1.30% of rutin were added to the rearing diet and offered to the larvae from hatching to pupation. Rutin negatively affected larval development, the amount of food consumed, and pupal weight of A. gemmatalis. These negative effects were clearly seen in insects fed on diets with 7 g of casein to which any concentration of rutin was added. The effects of rutin when added to the diets without casein were stronger than in diets containing a suitable amount of casein (14 g). The greater negative effects of rutin in diets containing suboptimal concentrations of casein indicate that casein can increase the effects of rutin only when the diets are nutritionally unsuitable for insect development.

Diferentes técnicas de conservação de ovos foram avaliadas, sob condições de baixa temperatura, visando a multiplicação do parasitóide de ovos de percevejos Trissolcus basalis (Woll.) (Hymenoptera: Scelionidae). Massas de ovos frescos de Nezara viridula (L.) foram armazenadas, por 12 meses, em nitrogênio líquido (-196ºC), embaladas em papel alumínio, em tubos de microcentrífuga ("eppendorf") e em sacos plásticos duplos vedados a vácuo (500 ovos/técnica/mês). A cada 30 dias, 10 massas de ovos, conservadas sob as diferentes modalidades, foram retiradas, descongeladas imediatamente e submetidas ao parasitismo por T. basalis. Ovos do percevejo verde, estocados a -196ºC, apresentaram condições de conservação e viabilidade para o desenvolvimento de T. basalis, constatando-se elevados índices de parasitismo e emergência nos ovos armazenados sob as três diferentes técnicas. Os ovos conservados em papel alumínio (95,4%), em tubos (92,3%) ou a vácuo (93,7%) apresentaram parasitismo estatísticamente igual aquele verificado em ovos frescos (97,3%). A viabilidade dos ovos, expressa pela taxa de emergência dos adultos do parasitóide, indica que as três técnicas estudadas proporcionaram excelentes condições de desenvolvimento e emergência de T. basalis, não havendo diferenças significativas quando comparadas a ovos frescos. Ao longo do período total de armazenamento (12 meses), não houve redução no número de fêmeas geradas por postura, embora tenham ocorrido flutuações na razão sexual, para alguns períodos. Os resultados obtidos viabilizam a conservação dos ovos do percevejo verde, e posterior multiplicação do parasitóide T.basalis, por um período duas vezes mais longo ao que hoje é conhecido e utilizado.

Different egg conservation techniques were assessed under low temperature conditions to multiply the parasitoid of stink bug eggs Trissolcus basalis (Woll.) (Hymenoptera:Scelionidae). Masses of fresh Nezara viridula (L.) eggs were stored for 12 months in liquid nitrogen (-196ºC), wrapped in aluminum foil, in microcentrifuge tubes ("eppendorf") or in vacuum sealed double plastic bags (500 eggs/technique/month). Every 30 days, 10 egg masses from each of the different storage techniques, were taken out, thawed immediately and subjected to parasitism by T. basalis. Green stink bug eggs, stored at -196ºC presented conservation conditions and viability for T. basalis development, with high parasitism rates and emergence in the eggs stored under the three different techniques. Parasitism of eggs stored wrapped in aluminum foil (95.4%), in tubes (92.3%), and under vacuum (93.7%) were statistically equal to parasitism in fresh eggs (97.3%). Egg viability, expressed by the rate of emergence of adult parasitoids, indicates that the three techniques studied provided excellent T. basalis development and emergence conditions with no significant differences when compared with fresh eggs. Throughout the total storage period (12 months) there was no reduction in the number of females hatched, although there were fluctuations in the sexual ratio for some periods. These results make green stink bug egg conservation, and later multiplication of the parasitoid T. basalis possible for a period twice as long as that known and used today.