Management of Heortia vitessoides Moore. a major insect pest of Aquilaria malaccensis Lamk. in North East India

Abstract

Aquilaria malaccensis Lamk. (Agar tree) is one of the most valuable economically important commercial tree species of North East India. Pest survey conducted during 2012-2015 in different Agar plantations revealed that Heortia vitessoides, a lepidopteran insect is responsible for severe defoliation of seedlings and saplings. An attempt was made to manage this pest using different fungal isolates, viz., Fusarium sp., Beauveria bassiana, Metarhizium anisopliae, Aspergillus flavus, Paecilomyces sp., Trichoderma hamatum, Mucor sp., Verticillium lecanii, Aspergillus ochraceus, Fusarium oxysporum, Trichophyton sp., and Penicillium chrysogenum, as biocontrol agents. Spore concentrations, viz. 2.4 x 1010, 2.4 x 108, 2.4 x 106 and 2.4 x 104 spores/ ml of the biocontrol fungi were tested against H. vitessoides in laboratory condition. The highest spore concentration of B. bassiana, M. anisopliae, V. lecanii and Paecilomyces sp., were found to cause percent mortality of 100, 76, 58 and 51, respectively. Further, these four potential isolates were found to cause mortality percent of 90, 52, 38 and 36.6, respectively in field conditions. The present study suggests that field application of B. bassiana and M. anisopliae is an effective management approach against H. vitessoides.