Evaluation of certain plant hosts for the lac insect

Abstract

Lac, a natural resinous substance having profound economic importance, is a secretion of Lac insect Kerria chinensis (Hemiptera: Kerridae). Lac is widely cultivated in different states of India on several host plants. North eastern region particularly Assam is one of the biodiversity hotspots with approximately 4000 species of plants but exploitation of these natural flora for commercial production of lac is very limited. This present study aims to explore the suitability of eight native plants viz., Flemingia semialata Roxb., Flemingia strobilifera (L.) W.T.Aiton, Indigofera teysmannii L., Ficus religiosa L., Zizyphus mauritiana Lam., Litchi chinensis Sonn., Hibiscus rosa-sinensis L. and Cajanus cajan L. as hosts of lac insect. Both field and laboratory experiments were carried out to study the productivity linked parameters and life cycle of the lac insect on the respective plants. Biochemical constituents of the host plants were also studied to find out their role in resin production. Among the eight native plants, F. semialata showed highest productivity of broodlac (0.30 kg) and longest life cycle duration (164.5 ± 2.5 days) in winter lac cultivation. Phenol content of the bark registered a significant positive correlation with the production of lac whereas both alkaloid and flavonoid were found non- significant with the production of lac.