Pengaruh Instar Larva Hyposidra talaca Walker dan Hari Panen Polihedra Pascainokulasi terhadap Produksi Polihedra Nucleopolyhedrovirus

Abstract

Nucleopolyhedrovirus (NPV) is an entomovirus that infects caterpillar and causes polyhedrosis. It can be used as a biological agent for controlling tea looper caterpillar population. The objective of this research is to investigate the effect of instars of H. talaca larvae and post-inoculation harvesting time of polyhedra on the production of polyhedra. The NPV’s concentration of 1.59 x 107 PIBs/ml was used as initial inoculum. Third, fourth, and fifth instars of H. talaca larvae were inoculated and reared in room temperature and harvested on the 4th, 5th, and 6th days after inoculation. Polyhedra from different H. talaca instars and harvesting time were extracted and purified using differential sentrifugations, resulting the partially purified polyhedra. The concentrations of polyhedra from different instars and times were counted using Neubauer haemocytometer. Mortality rates ond 3rd instar larvae were higest because 3rd instar larvae were more susceptible to NPV compare to 4th and 5th instars. The concentration of polyhedra harvested from 4th instar larvae on the 6th day after inoculation was the higest. There was a signifigant effect of larvae instars and time of harvest on polyhedra production.