Abstract

Biological aspects of Trabala vishnou (Lefevere) on Populus commonly known as poplar were studied during the months of August to November under laboratory conditions with temperature 25.16 ± 0.430C and relataive humidity 71.19 ± 4.81%. This study reveals that the insect has a fecundity of 215.93 ± 30.20 eggs. The incubation period in 11.23 ± 1.05 days. The duration of the first instar larvae is 16.24 ± 1.5 days, of second 17.12 ± 2.13 days, of third 16.18 ± 2.30 days, of fourth 15.64 ± 3.29 days and of the fifth is 20.10 ± 4.28 days. The pre-pupal period is of 3-5 days and pupal period of 15.0 ±1.39 days. The insect completes the life cycle in 114.51 ± 6.68 days. The pre-oviposition and oviposition period are 1.20 ± 0.53 days and 3.39 ± 0.82 days respectively. The sex ratio (Male : Female) is 6:1. Observations on feeding behaviour indicate that the younger instars (1-3) feed gregariously while the later instars (4 & 5) are solitary and voracious feeders.

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