STUDY ON BIOLOGY AND EFFECTIVENESS OF SOME CHEMICAL INSECTICIDES AGAINST JUTE HAIRY CATERPILLAR, SPILOSOMA OBLIQUA (WALKER)

Abstract

Study on biology of jute hairy caterpillar, Spilosoma obliqua (walker) and insecticidal tests were made in the laboratory and in the field of Central station, Bangladesh Jute Research Institute (BJRI), Dhaka and JAES, Manikganj during March to September, 2017. The study revealed that the incubation period was 5.5 ± 0.29 day, total larval period of jute hairy caterpillar was 19.91 ± 0.47 days, pupal period 9.83 ± 0.42 days, eggadult

(female) 42.67 ± 0.69 days and egg-adult (male) 38.67 ± 0.75 days. The preoviposition

and oviposition periods were 1.42 ± 0.15 days and 3.5 ± 0.29 days respectively. The longevity of female and male moths was 7.41 ± 0.34 days and 3.42 ± 0.26 days. Treatment with Quinalphos: Mekalux 25EC gave the best performance with more than 95% mortality followed by Spinosad: Base 45SP. Emacto 5WDG @ 1.5 kg/ha, Fusion @ 500ml/ha, Rescue 6WDG @ 250/ha, Hayron 5EC @ 500ml/ha, Base 45SP @ 250 ml/ha, Perfect 30 WDG @ 100gm/ha and Mekalux 25EC @ 1.5/ha performed more than 85% mortality of jute hairy caterpillar. All selected doses of insecticides showed more than 80% reduction of plant infestation over control in both two locations Central station, BJRI, Dhaka and JAES, Manikganj. The result of trial in two locations clearly indicated that all the insecticides were effective against jute hairy caterpillar. The application of insecticides had effects on plant height, base diameter and fibre yield of jute in the field.