Biology and leaf consumption of mango defoliator Cricula trifenestrata Helfer (Lepidoptera: Saturniidae)

Abstract

A study was undertaken to observe the biology and leaf consumption of mango defoliator, Cricula trifenestrata Helfer in the laboratory, Department of Entomology, Hajee Mohammad Danesh Science and lechnology University (HS1U), Dinajpur during the period of April to July, 2007 at 25 + 2°C and 75 = 5 % RH (at room temperature and humidity). The results of biology reveal that the prc-oviposition, OViposition and incubation period of the mango defoliator were 2.3, 0.5 and 8.7 days, respectively. The average number of eggs laid by a female was 141.70 and the hatching rate was 88.81 %. The mean duration of the first, second, third, fourth and the final instar larvae were 5.30, 5.10, 6.10, 5.80 and 6.20 days, respectively. The mean duration of pre-pupa and pupa were 2.50 and 19.55 days. The average longevity of male and female moths was 2.90 and 4.20 days, respectively. The average total developmental periods from egg to adult were 59.2 days. The morphological data show that the average length and breadth of eggs were 2.27 and 1.86 mm, respectively. The mean length and breadth of 1°, 274, 3 4" and 5" instar larvae were 4.08, 13.90, 30.09, 61.37, 81.49 and 2.17, 5.09, 7.23, 11.22, 15.51 mm, respectively. The average length and breadth of male and female cocoons were 41.98, 50.89 and 12.31, 16.22 mm whereas the Iength and breadth of male and female pupae were 31.64, 35.57 and 10.61, 12.58 mm, respectively. The average length and breadth of male and female moths were 22.35, 32.48 and 32.02, 74.14 mm, respectively. The data of the feeding behaviour reveal that 1°, 2°", 3", 4” and 5" instar larvae consumed 10.5, 20.7, 85.3, 415.6 and 650.3 cm” or 0.50, 1.20, 2.80, 8.50 and 16.40 g leaves, respectively. A larva consumed 1164.45 cm’ or 27.2 g leaf during its developmental period and the result shows that the final instar larvae consumed the highest amount of leaf.