Studies on cannibalism by Heliothis armigera (Hubn.) larvae on nuclear polyhedrosis virus (NPV)-infected larvae and feeding on virosed cadavers indicated that feeding was significantly higher on 4-day-old virosed cadavers followed by 1-day-old cadavers than on healthy or NPVinfected living larvae. The data revealed that cannibalism was significantly higher on NPV-infected (3 days post inoculation) larvae than either healthy larvae or those which had been just inoculated. However, the extent of feeding was higher on healthy larvae (cannibalistic feeding) than on cadavers. Significantly more number of larvae became infected by NPV when they fed on NPVkilled cadavers than on NPV-infected living larvae. Some of the larvae which had fed on either virosed cadavers or NPV-infected larvae survived. But, the disease was expressed in the pupal stage. Pupal mortality was significantly higher in larvae which fed on NPV-inoculated larvae (3 days post inoculation). The multiple choice test to find out the feeding preference of the larvae showed that the larvae had a greater preference to feed on virosed cadavers than either the healthy larvae or the host plant. The role of cannibalistic behaviour in the dissemination of the virus disease under field conditions is discussed.
Results of field experiments revealed that three releases of biocontrol agents viz., Tricbogramma chilonis (1,00O,OOO/ha/release) and Brinckocbrysa scelestes (50,0OO/ha/release) on 90, 105 and 120 days after sowing could effectively check the population of Heliotbis armigera and Bemisia tabaci which was equal to that of insecticides. Two applications of nuclear polyhedrosis virus of Spodoptera litura at 250 larval equivalents (LE)/ha with adjuvants could effectively control S. litura larval population and damage. The seed cotton yield could also be increased in biocontrol plots which was equal to that of insecticide treated plots.I . T~-~chogrammu cbilonis (Ishii.) at 1,000,000 parasitoids/hdrelease, 2. Bririckocl~rysa ( C h r y s o p~) scelestes (Banks) grubs at 50,000/ha/rclcase, 3 . Spodopteru litura NPV at 250 LE with adjuvants crude sugar, 2.50 kg + cotton seed kernal powder (CSKP) 0.3 kg/ha. U.S.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.