Fig. 2. Screwworm adult flies. Male on left; female on right. Adults are about 3x the size of the common housefly. (Author)



Fig. 3. Screwworm egg masses. Females lay up to 300 eggs per mass, firmly glued together on the dry edge of a wound. Eggs hatch in 12 to 24 hours. (Author)



Fig. 4. Full-grown 3rd instar screwworm larvae, 1/2 inch long, weigh 90 to 120 mg. when reared in a live host, but weigh considerably less when reared on artificial diets . Dark trachea on posterior distinguish screwworm larvae from other blow flies. Larvae feed for 6 to 7 days before leaving wound or artificial diet to pupate in soil or medium. (Author)


Fig. 5. Screwworm pupae. Adults emerge in 7 days and oviposit at 6 to 7 days completing the life cycle in 21 days at an average temperature of 80F. (Author)