Biological attributes and qualitative damage of Oligonychus mangiferus (Rahman & Sapra) (Acariformes: Tetranychidae) on the medicinal plant Ichnocarpus frutescens (L.) W.T. Aiton

Abstract

Oligonychus mangiferus (Rahman & Sapra) was found infesting the medicinal plant, Ichnocarpus frutescens L. Its biology and reproduction were studied at four different constant temperature conditions in the laboratory. O. mangiferus completed its development faster (7.10 to 8.77 days) at 30° - 32°C. Its egg-laying was highest at 20°C (31.03 eggs/female), but with similar progenial sex ratio ( :? ) (1:2.68 to 1:2.84) across different temperatures. At 25°C, Mean Generation Time (T) and Doubling Time (DT) were lowest 15.26 days and 8.95 days, respectively, while, Intrinsic Rate of Natural Increase (rm) was highest (0.085 female off-springs/female/day). Feeding damage by mangiferus resulted in apparent decline in chlorophyll and flavonoid contents, while alkaloid and terpenoid contents showed increase in mite infested leaves. Observed changes in the quantity of secondary metabolites like alkaloids, flavonoids and terpenoids, subsequent to mite feeding was significant, owing to the medicinal value of the herb. Further investigation on these biochemical changes may throw light on more advantageous medicinal use of Ichnocarpus for treating many human disorders.