PEST PROFILES: MOTH AND BUTTERFLY CATERPILLARS
Male Bagworm on Juniper sp.
Click on image to view larger. Bagworms
These insects are first detected by observing the bags produced by the larval stages.
Larval stages in bags feed on leaves and can defoliate shrubs and trees. Several species occur in Texas.
On evergreens, bagworms spend winter months in the egg stage within the sealed bag produced by females the previous fall. In the spring tiny larvae hatch, lower themselves on silken strands and construct a tiny conical bag that they carry upright as they move. As the larvae mature through 4 or more instars, it enlarges its bag. Full-grown larvae within bags are up to 1 inch long before pupating in August or September. Seven to 10 days later, the pupae of male moths wriggle out of the bag bottom before they emerge. Adult males have short 2 inch-long clear wings. Females remain inside bags and resemble maggots, with no functional eyes, legs, mouthparts or antennae. After mating, females produce a clutch (500 to 1,000) of eggs inside their bodies and die. All feeding larval stages occur during the spring and summer.