Division of Entomology, Indian Agricultural Research Institute, New Delhi-110 012 (India).
*Present address: 219 Hodson Hall, 1980 Folwell Avenue, St. Paul, Minnesota 55108, USA.
The phenomenon of maturation of resistance in the larvae of Spodoptera lirura (Fabricius) was experimentally assessed. The increase in LD50 values over age was several times higher than the increase in larval body weight. The role of haemolymph proteins present only in susceptible larvae up to day 7 and in resistance larvae after day 9 may be contributing to viral infection. The ratio of LTaP (remaining development time) revealed that the larvae above 8.1 day were not infected with NPV.
