42. Effect of temperature on the life cycle of Trilocha varians (Lepidoptera: Bombycidae) in Pakistan

Abstract

Ficus benjamina is known as weeping fig, planted along roadsides in Pakistan to increase the aesthetic value of the country. It is native to tropical and sub-tropical regions of the world. In 2019, plants were infested by leaf eating caterpillar, identified as Trilocha varians. The larvae of the pest were caused up to 100% defoliation of F. benjamina. The aim of the recent study was to determine the life cycle of T. varians under two different environmental temperatures i.e. 26°C ± 1.0 controlled and uncontrolled 33°C ±2.0.  The recent study was obtained that there was significant difference in the time taken for eggs, larval and pupal period of T. varians between high and low environmental temperatures. The life cycle of the test insect, T. varians was increased at low temperature and reduced in high temperature. The results showed that the fecundity of female ranged from 164 to 275 and 130-190 under controlled and uncontrolled conditions respectively.  T. varians has complete metamorphosis and five larval stages.  The last instar transferred into dark reddish colour prior to adult formation. The longevity of females and males was 10.0 ± 0.43 and 5.4±0.35 days, respectively. Pupa of the pest was obtect. Our present study results were effective for future management of T. varians in Pakistan.

Keywords: Bombycid moth; Climatic conditions; Life history; Ornamental plants; Pakistan

http://dx.doi.org/10.19045/bspab.2020.90047