PATHOGENIC EFFECT OF METARHIZIUM ANISOPLIAE ON THE LARVAL GROWTH AND DEVELOPMENT OF OCINARA VARIANS WALKER (LEPIDOPTERA: BOMBYCIDAE)

Ocinara varians Walker is considered as an important pest of Ficus microcarpa and other ornamental plants. The present study explained the pathogenic effect of Metarhizium anisopliae on the growth (body weight), mortality, development and various growth indices on newly moulted (III-V) instar larvae at a concentration of 1 × 10^7 spores/ml. Our laboratory experiments showed that there was no difference in the susceptibility of the different larval stages tested in terms of effectiveness on O. varians. These fungal spores retarded the larval growth (35%-76%), which resulted in a prolonged developmental time of the infected larvae. Food consumption (21-27%), relative consumption rate (31-48%), efficiency of conversion of ingested food (18-69%), efficiency of conversion of digested food (26-70%), and relative growth rate (42-84%) values declined significantly, but concurrently a significant increase in approximate digestibility (3-36%) was observed. These results suggest that M. anisopliae may be an alternative for synthetic pesticides in order to protect ornamental plants against O. varians.