While spending some quality time picking bagworms off a big blue spruce in our yard the thought occurred to me that readers might be interested in some information about the life cycle of this native American--bagworm trivia, if you will.

Bagworm Trivia

Everyone recognizes this native American pest--at least when it is inside its familiar 1 1/2-2 inch bag.   Inside each one of these bags are 500 to1000 eggs that hatch in May and June.  Each newly hatched larva will spin down on a thread and land on any available host where it spins a bag, allowing it to feed and grow, until it eventually enters the pupal stage in August.  In September the males emerge as moths, and they mate with the wingless, legless females who never get to leave the bag.  After mating, the females then die inside the bag, and the next generation is ready to hatch from the bag the following May.

Usually bagworms aren't noticeable until they have already matured and natural predators (parasitic wasps) aren't adequate to control the population, so the concerned homeowner is forced to use some kind of a control program.

• Handpicking is the control method of choice for most homeowners.  It's safe, and it doesn't cost anything but time.  It can involve the whole family or it can provide solitude and a time for reflection.  In any event, do this during winter or spring before the eggs have hatched!  Don't leave the bags on the ground, though.   Destroy them by crushing or burning.
• Biological control, using Bacillus thuringiensis (Bt) may be used early on against the newly hatched larvae, aiming for the end of June after all the eggs have hatched.   This method claims to be 75-90% effective when used against the small bags--before they are an inch long.
• Insecticides are effective if applied at the right time of development, but not all insecticides that are considered safe for home use may be used on all plants because it may kill the plant.  So if you are inclined to use an insecticide, read the label instructions!  Know what kind of a plant you are spraying and whether or not that spray is safe for that plant. Keep in mind to use caution and always avoid exposure to humans and pets, and store the pesticides out of reach of children!