MORPHOLOGICAL STUDY OF TWO SPOTTED SPIDER MITE AND IT’S BIOLOGY ON BRINJAL

The Present experiment was carried out at the laboratory of Entomology Department of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh in order   to study the biology of two spotted spider mite Tetranychus Urticae Koch (Acari: Tetranychidae) on brinjal. Adult mite was reared in laboratory, the female laid eggs which were translucent and the incubation period lasted for 1-3 days. The larval period varied from 2 to 3 days and calculated 183.43 ± 3.71 µ in length and 130 ± 2.70 µ in width. There were three resting stages during the life cycle of this mite species. First resting stage is called protochrysalis from which protonymph aroused 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 in width. Finally, after the third resting stage which is called teleochrysalis, adult male and female emerged. Adult males were 358.23 ± 13.87 µ in length and 185 ± 5.11 µ in width while the adult females were 468 ± 14.33 µ in length and 283 ± 9.57 µ in width. Males lived for 11-12 days and were smaller than females. The newly emerged females were a dull red color that darkened to a strong brick red color. The adult female was able to live for 19 to 24 days. The pre-oviposition stage lasted anywhere from 2 to 3 days on average. The oviposition period lasted an average of 12.0 days and lasted 11-14 days. Each female laid between 123-160 eggs on average, with a mean of 146.6 eggs.