A produção do vírus de poliedrose nuclear (VPN) de Anticarsia gemmatalis Hübner em laboratório foi avaliada para lagartas de 1,0, 1,5, 2,0 e 2,5 cm inoculadas com duas doses do vírus (10(6) e 10(7) corpos poliédricos de inclusão-CPI/ml), pulverizadas sobre a dieta artificial do inseto. As larvas inoculadas com 2,0 cm, na maior dose, proporcionaram os maiores rendimentos na produção do VPN. No entanto, as perdas foram elevadas (42,4% a 64,0%), devido ao canibalismo, mortes por outras causas e sobrevivência à infecção. Num outro experimento foram utilizadas duas doses do VPN (1,0 x 10(7) e 4,0 x 10(7) CPI/ml), três densidades de lagartas/copo (25, 20 e 15), inoculadas no início do 4° instar (I4L); final do 4° instar (F4L); inicio do 5° instar (I5L) e final do 5° instar (F5L). A maior produção do VPN ocorreu para I5L, com 25 lagartas por copo, em ambas as doses, com uma eficiência em tomo de 90%, a despeito da diminuição do número de CPI/lagarta e o aumento do canibalismo com o incremento na densidade de lagartas/copo.
The laboratory production of Anticarsia gemmatalis Hübner nuclear polyhedrosis virus (AgNPV) was evaluated for larvae inoculated at 1.0, 1.5, 2.0, and 2.5 cm and with two NPV dosages, 10(6) and 10(7) polyhedron inclusion bodies (PIB)/ml, sprayed on the insect diet surface. A fixed population of 25 larvae/300-ml cup was used. Highest virus yield was achieved for larvae inoculated with ca. 2.0 cm at the higher NPV dosage. Losses of NPV-inoculated larvae ranged from 42.4% to 64%, due to high incidence of canibalism, death by other causes, and pupation. In another experiment, larvae were inoculated with two NPV dosages (1.0 x 10(7) and 4.0 x 10(7) PIB/ml), using 25,20, and 15 larvae/cup at the beginning of 4th instar (B4L); end of 4th instar (E4L); beginning of 5th instar (B5L); and end of 5th instar (E5L). Highest NPV production was attained for B5L at 25 larvae/cup, for both dosages, with a production efficiency of ca 90%, in spite of a decrease in PIB/larva and an increase in canibalism with the increase in larval density. Better standardization of larvae at inoculation improved efficiency in NPV production.