Role of Cotton Trichome Density in Bollworm (Lepidoptera: Noctuidae) Egg Parasitism

Abstract
Field and laboratory studies were conducted to determine effect of cotton trichome density on parasitism of Heliothis zea (Boddie) eggs by Trichogramma pretiosum Riley. No-choice and free-choice field tests showed that fewer eggs were parasitized on Pilose cotton phenotypes compared with Smoothleaf and hirsute cottons. Further, egg parasitism was greater on Smoothleaf compared with hirsute cotton. Laboratory studies demonstrated that cotton leaf trichomes inhibited movement of T. pretiosum females over leaf surfaces. Thus, reduced trichome density on cotton improves the ability of T. pretiosum to find and parasitize H. zea eggs.