Comparative Natural Resistance of Different Clones of Tectona grandis Lf. To Teak Skeletoniser Eutectona machaeralis Wlk. (Lepidoptera: Pyralidae)

16 clones of Tectona grandis (viz Bori. FG-1, Gorakhpur, FG-19, Denedel, Haldwani, Bogor. Teli, Kurseong. Nilambur, 1 aos, nimao, Coorg, Orissa, Togo, Allapalla) maintained in teak germ plasm bank at New Forest, Dehra Dun were evaluated for their natural variation in susceptibility to leak defoliator Eutectona machaeralis wlk On the basis of quantity of food (Leaf) consumed by larvae (per gm larvae/day), clone Bori and FG.-I (306 mg) seems to be the most resistant followed by Gorakbpur (340 mg). FG-19 (349 mg), Denedel (359 mg). Allapalla (1.54 gm). Togo (1.25 gm) and Orissa (867 mg) are most susceptible. A similar trend has been observed by consumption/day/larva. A definite correlation for natural variation in resistance could not be established on digestion coefficient (D C.%) by the larvae.