“When did worms start wearing bags over their bodies, sort of like humans wearing camouflage? That’s kind of sneaky, hiding in a “bag” of plant debris that grows in size as the worm inside gets bigger.”
In our landscapes, we usually don’t notice a small conical structure that to some resembles a tiny upside down ice-cream cone. By the time branch tips of juniper, arborvitae, Southern red cedar, and willow appear brown and unhealthy looking, the bagworm has grown from its initial size of about ½ “, to a mature size of an 2” or more. And it lives to eat, consuming enough foliage to cause severe defoliation and even death to some trees, especially evergreens.
Why mention this worm now, when damage doesn’t begin until late spring and early summer? Because the casing, or “bag” of the common bagworm, known officially as Thyridopteryx ephemeraeformis is still attached to some trees and shrubs in our landscapes! And with leaves gone from deciduous trees, it is easier for us to spot the little bags, which are filled with eggs right now, and remove them to a bucket of soapy water or sealable bag.
Bagworms produce only one generation per year in this part of the southeast, so by removing the bag with its cache of 500-1000 eggs tucked inside the pupal case, we’re removing a bit of the next generation taking a step toward controlling bagworms. By the way, these eggs will overwinter inside the case, so hopes that cold temperatures will destroy the eggs aren’t realistic.
If you know that bagworms have done damage in your landscape this past summer, seeking out and removing bags now will help reduce populations as the worms don’t normally travel far from the host plant. As one source puts it “handpicking is most effective from late fall to early spring before adults reproduce and new bagworm larvae disperse”.
As in many cases involving control of pests and diseases, such as getting the jump on bagworm damage, timing has a lot to do with success!
By Sallie Lee, Urban Regional Extension Agent, Alabama Cooperative Extension System. Contact Sallie at firstname.lastname@example.org.
The Alabama Cooperative Extension System (ACES) operates as the primary outreach organization for the land-grant functions of Alabama A&M and Auburn Universities. ACES is committed to affirmative action, equal opportunity and the diversity of its workforce. Educational programs of ACES serve all people regardless of race, color, age, sex, religion, disability, sexual orientation, or national origin.