Field Identification
The larva of a noctuid moth that bores into sweet corn ears, tomatoes, peppers, and many other crops, leaving frass and open wounds for rot. Same animal as the cotton bollworm—different common name, same appetite.
Caterpillars vary from green to brown with longitudinal stripes and microscopic spines; head capsule darkens with age. Adults are robust, dull brown moths with a dark spot on each forewing.
How to Deal With It
Organic Control Methods
Bacillus thuringiensis kurstaki (Bt) on small larvae; spinosad where allowed—cover undersides and silking corn before larvae tunnel deep; neem has limited knockdown once inside ears.
Trichogramma egg parasitoids, parasitic flies (Tachinidae), and predatory bugs—support them with floral resources and selective sprays.
Plant corn in a tight window to avoid prolonged moth flights; interplant with repellent companions modestly; destroy crop residues that harbor pupae.
Corn varieties with tight long husks; for home garden, oil drops on silks or physical ear bags timed after pollination reduce ear entry.
Pheromone traps for monitoring flight peaks; rotate away from continuous solanaceous/corn sequences in small plots.
Let Nature Handle It
Natural Enemies
- Trichogramma spp.
- Tachinid flies
- Predatory stink bugs
- Birds
Threat Map