INCIDENCE OF MAJOR INSECT PESTS AND NATURAL ENEMIES ON Bt AND NON-Bt BRINJAL (SOLANUM MELONGENA L.) VARIETIES

ABSTRACT: Eight species of insect pests belonging to four orders and eight families were found to infest at different growth stages of brinjal crop in the experimental field, Sher-e-Bangla Agricultural University, Dhaka during October, 2018 to April, 2019. Among the insects, five namely, Brinjal shoot and fruit borer (BSFB), (Leucinodes orbonalis), epilachna beetle (Epilachna dodecastigma), jassid (Amrasca biguttula biguttula), aphid (Aphis gossypii) and whitefly (Bemisiatabaci) were recorded as the major pests and the rests were of minor pests. Four species of natural enemies namely, coccinellid beetles Coccinella septempunctata, Coccinella transversalis, Menochilus sexmaculatus and spider, Argiope luzona were also recorded in the experimental field. Among the pests, BSFB was borer and epilachna beetle was chewing pests and rests were considered as sucking pests of brinjal. Brinjal shoot and fruit borer (BSFB) infestation showed significant variation among the varieties. Most of the pest incidence was observed maximum in the 3rd week of April at the fruiting stage of the crop. The maximum shoot and fruit infestation (38.75% and 53.68%) recorded in non-Bt brinjal during 3rd week of April, 2019, while Bt brinjal suffered minimum shoot and fruit infestation (1.22% and 1.98%).Among the varieties BARI Bt begun-2 received the lowest BSFB incidence (0.92 in number) while the highest was 15.23 observed from Jashore local. Average healthy fruit yield of Bt and non-Btbrinjal were recorded 39.89 t ha-1 and 24.36 t ha-1, respectively. While infested fruit yield of Bt and non-Bt brinjal were 1.19 t ha-1 and 11.88 t ha-1, respectively.

Keywords: Bt and non-Bt brinjal varieties, major insect pests, natural enemies.