Abstract
Studies on the bionomics of brinjal shoot and fruit borer (BSFB), Leucinodes orbonalis Guenee and
its insecticide based management were carried out in the field and laboratory during April 2007 to
March 2010. Different parameters on the biology of BSFB studied in the laboratory showed that
moths were usually active at night for mating, oviposition and adult emergence. Maximum mating
occurred usually at late night between 4.00 to 6.00 AM in the night of emergence. Oviposition
usually occurred in the second night of emergence when 86.62% of eggs were deposited during the
first half of the night. A female laid 288.05 eggs in 2.65 days in summer and 185.55 eggs in 2.70
days in winter. The egg hatching, larval and pupal period of BSFB were 4.13, 10.40 and 6.60 days in
summer and 6.90, 14.50 and 10.65 days in winter. Adult emergence started just after sunset and was
maximum (88.90%) during the first half of the night. Male and female adult longevity was 3.50 and
6.20 days in summer and 4.85 and 8.90 days in winter. Potato was found as promising medium for
rearing BSFB where an average of 40 larvae could develop successfully in a single potato tuber of
size 70-80g. A highest percentage (4.87%) of neonate larvae was settled in immature brinjal fruits
up to 9 day old. About 75% BSFB infestation was found in the fruits. Maximum infestation
(69.47%) оccurred in early growing stage of brinjal fruits usually when the fruits remain covered by
the calyx. About 42% of the infested fruits were found inconsumable. Fruit infestation was found
influenced by the plant age showing the highest infestation (38.56%) level in 14th week of
transplanting. Minimum fruit infestation (5.26%) occurred in January while the peak (56.38%) was
in September. Development of BSFB was temperature dependent showing moderate temperature
(20-25°C) as favourable for the development of all the stages. Survey study in Jessore, Chittagong
and Mymensingh region revealed that use of insecticides was found as common control practice by
the farmers (89.31%) where only a few farmers (5.54%) practised IPM. About 50% farmers used
over dose of insecticide and cocktail in controlling BSFB. Trial with insecticides showed that the
chemicals were highly effective against BSFB in the egg stage and early larval stage. 100%
mortality was found in eggs and 1st instar larvae while it was 45.04% in the 2nd instar larvae. Later
instars (3rd_5th instar) escaped the action of insecticides. There was a relationship between depth of
boring and larval mortality due to application of insecticides. Insecticides were not effective against
the pupal stage. Insecticidal efficacy was found to be influenced by the amounts of rain and the
interval between the spraying and raining. No prominent resistance development in BSFB against
Ostad, Marshal, Kinalux and Shobicron was found in bioassay test except in the case of Marshal in
Jessore region. Implications of different experimental results are discussed in the context of BSFB
management in the field.