We don’t like to think of eastern tent caterpillars (Malacosoma americanum) as pests, but instead, they are juicy nuggets of protein for the birds. Since birds and other wildlife eat them, we advise against using pesticides or the destruction of silky tents. And since the moths reproduce only one generation per year, there’s plenty of time for the defoliated section to recover.
The life cycle of the lappet moth is a long and interesting one. Soon after emergence from their cocoons, the moths mate, and females attach eggs to branches in masses of 150 to 400 eggs. In about 3 weeks, embryos develop to first-stage larvae and spend summer, fall and most of the winter unhatched. Eggs begin to hatch in early spring, just as leaves begin to develop on trees. Newly hatched caterpillars feed on the egg mass covering and then move to a nearby fork in the branches where they spin their silken tents. As the caterpillars grow, the tent is added onto to accommodate their size.
Vulnerable to birds, parasitic insects, squirrels, lizards, frogs, and other forest dwellers when they leave the nest to feed on leaves, they return to the warmth and safety of the family tent to rest and grow. By leaving exploratory trails, the caterpillars follow the pheromone paths back to the nest. After 4 to 6 weeks and 6 larval instars, caterpillars are fully grown. They then leave the tent alone and spin a silk cocoon in a protected nook. The pupal stage lasts 3 to 4 weeks. The adult moths live about 5 days. Images by Project Manager, Stella Pfau
