STUDY ON THE BIOLOGY OF TWO SPOTTED SPIDER MITE (Tetranychus urticae) PEST IN BRINJAL AND BITTER GOURD: IMPACT OF ITS ECO- FRIENDLY MANAGEMENT

Abstract

The present study was carried out in the laboratory of Entomology Department and in the central farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh in order to conduct biological study of two spotted spider mite pests attacking brinjal and bitter gourd. Also studied the effectiveness of entomopathogenic fungi (Trichoderma sp), some botanicals and biopesticides (neem oil, mehagany oil, spinomax, biomax) and common insecticide (Ripcord) for the eco-friendly management of the pests. The experiment consisted of seven treatments and was laid in a single factor Randomized Complete Block Design (RCBD) with three replications. Mite pests were present in both brinjal and bitter gourd field. Adult mite was reared in laboratory, the female laid translucent eggs and the incubation period lasted for 1-3 days. The larval period ranged from 2 to 3 days and measured 183.43 ± 3.71 µ in length and 130 ± 2.70 µ in width. There were three resting stage during the life cycle of mite pests. First resting stage is called protochrysalis from which protonymph arised which was measured 243.72 ± 5.81 µ in length and 159.92 ± 4.65 µ in width. Second resting stage is deutochrysalis; the deutonymph emerged from deutochrysalis which was 382.54 ± 4.40 µ in length and 228 ± 3.6 µ width. Finally after the third resting stage which is called teleochrysalis, adult male and female emerged. Eventually different biorational control tactics, treatments showed varied response against mite pests. Trichoderma spp. showed the best result which was followed by Neem oil against mite pests infesting brinjal and bitter gourd field. The results showed that the total number of fruit set, % healthy fruit and infested fruit was higher with the treatment of Trichoderma spp. In most cases, except control treatment, ripcord showed the worst results against mite pests.