The adult cotton square borer is a slate or bluish- gray butterfly. It has two large black spots on each wing with smaller reddish-orange spots above these at the back edge of the hind wing. There are usually two or three thin tails that mimic antennae on the hind wing (Figs. 66 and 67). The larval stage is a velvety, light green, slug-shaped worm (Fig. 68).
The adult begins laying eggs early in the spring.
They take about 6 days to hatch; then the small larvae feed on cotton squares for around 20 days.
The presence of adult butterflies is usually the first indication of cotton square borer activity. However, hollowed-out squares with almost perfectly round entrance and exit holes are another sign.
Unlike bollworm or tobacco budworm damage, there is no frass (the excrement of insect larvae) present with cotton square borer damage. Insecticide treatment for cotton square borer control is almost never necessary in Texas.