Olfactory and Visual Response by Black Cutworm Larvae (Lepidoptera: Noctuidae) in Locating a Bait Trap 1

Abstract

Field studies were conducted to examine whether vision and odor are factors used by black cutworm (BCW) larvae when orienting to the modified Missouri larva bait trap (Story and Keaster 1983). The wheat bran treatments were from 52 to 121% more effective in attracting larvae than similar treatments without bran during 1981 and 1982. These results indicate that BCW larvae use odor to discriminate between attractive and unattractive hosts. In 1982, treatments with wheat seedlings and with simulated seedlings (sticks) showed that 93% more BCW larvae were captured with the wheat seedlings than with simulated wheat seedlings. The wheat seedlings attracted BCW larvae by olfactory rather than visual cues. However, the addition of vertical screens to the larva trap significantly enhanced larval BCW captures by from 30 to 82%. Therefore, the attractiveness of the modified Missouri larva trap was due to a visual response (vertical screen) and an olfactory response (wheat seedlings and wheat bran).