Courtesy of Advanced Systems NJ
The Gypsy Moth larva caterpillar stage is most destructive.
As the Gypsy moths develop, they develop a distinctive color pattern of five pairs of blue dots followed by six pairs of red dots along their backs.
After mating, the female moth lays a small quarter sized egg mass on any available surface including trees, rocks, fences and other man made outdoor articles. They do not make a tent. The eggs hatch in late February through April.
Emerging larvae caterpillars move to the tops of trees and are carried many miles on wind currents; wind-aided dispersal is the primary dispersal mechanism for the gypsy moth.
Young caterpillars land on the ground, then climb back up a tree to feed primarily on oaks, aspen, birch, willows and alder. The older larvae feed on a broader range of trees including cedar, pine, spruce and fir.
These Gypsy Moth caterpillars are often confused with eastern tent caterpillars, forest tent caterpillars and the fall web worm. For a comparison chart that tells the differences about these 3 confusing caterpillars, please click here.
- Scrape off the egg masses but do not crush them as they may survive. It is better to place them in a jar of soapy water or microwave them, they throw them away.
- Spray the egg cases with horticultural oil (not motor oil) from a garden store.
- Parasitic wasps purchased on the internet are quite effective at killing these Gypsy Moth larvae.
- Bands around trees then covered with sticky stuff designed for bird control will capture the caterpillars after they fall to the ground and are climbing back up into the trees to eat.
- Insecticides: Biological (growth inhibitors) or chemical pesticides certified for Gypsy Moth use are easily available locally and do a acceptable job of killing the caterpillars.