Larval survival of newly enclosed Heliothis virescens (F) was measured in field artificial infestation studies on two high terpenoid and one standard cotton grown under high and low nitrogen (N) fertilizer regimes. Infestations were made during the first and fourth week of flowering and for both periods lowest levels of survivorship and damage after 7 days were observed with the high terpenoid line. NST-113. Larval survival was increased in each of the 3 genotypes grown with supplemental fertilizer, however, differences in larval survival were observed only in the more mature cotton.