Bionomics of diamondback moth, Plutella xylostella (Linn.) on cabbage crop under laboratory condition

Abstract

Investigations on biology of diamondback moth were carried out in the laboratory of Department of Entomology at Indira Gandhi Agricultural University, Raipur (C.G.) during year 2015-16 and 2016-17 on cabbage plant leaves with temperature range of 25.12 0C –38.9 0C. Total 140-175 eggs laid by a single female and mean incubation period was recorded 4.4±0.22 days. The period of incubation of egg was 4-6 days. Total four instars 1st, 2nd, 3rd and 4th were recorded as 2-4, 2-3, 2-3 and 3-4 days with mean 2.5±0.16, 2.6±0.16, 2.3±0.15, and 3.4±0.17days, respectively. The total larval period was observed for 10.7±0.52 days with range 9-14 days. Length of DBM larvae for different stages i.e. 1st, 2nd, 3rd and 4th instars were recorded as 1.22-1.34, 2.78-3.53, 4.05-5.92 and 6.72- 9.92 mm, respectively. Similarly range for breadth measurement for 1st, 2nd, 3rd and 4th instars were recorded as 0.16-0.20, 0.23-0.25, 1.09-1.18 and 1.32-1.50 mm, respectively and larval head capsule observed with range 0.11-0.17, 0.21-0.31, 0.33-0.47 and 0.52-0.61 mm, respectively. The combined pre-pupal and pupal period was 5.8 ± 0.39 days with range 4-8 days. The range of length and breadth of pupa recorded was 7.50-8.50 mm and 2.50-3.00 mm. The range of development period from egg to adult stage of male and female was observed as 24-36 days and 27-41 days, respectively. Adult emergence calculated in per cent for male and female both were 65% and 35%, respectively.