The gypsy moths are back in greater numbers than last year. It’s only the beginning of June and all of the tan egg cases haven’t even hatched. Yet, we’re seeing all kinds of destruction.
There are so many gypsy moth caterpillars that they’re eating any tree they can find. Although their preferred diet is oaks and maples, they’re even eating conifers this year like white pines and blue spruces. While deciduous trees can survive a year or two of a gypsy moth infestation before succumbing to this pest, I don’t believe conifers have that resilience, and expect that we’ll see an unusually high number of fatalities among evergreens.
As if the destruction they wreak on our trees isn’t bad enough, gypsy moth caterpillars make a mess of the properties on which infested trees are located. When a tree canopy becomes overloaded with caterpillars, the weaker ones either fall out of the tree or are pushed out by their stronger relatives. As a result, back yard toys, outdoor furniture, cars and walkways are covered with these hairy caterpillars, identified by parallel rows of red and blue dots on their backs. Some choose to change trees. They spin silk threads to take them down to the ground and land on passerby’s clothes and get tangled in the hair. Those that land on walkways also create a slipping hazard for pedestrians.
Our plant health professionals are spraying smaller trees with a fast-acting insecticide and are injecting material directly into the trunks of large trees. Upon request, they can also apply Bacillus thuringiensis (BT), a bacteria that only attacks caterpillars. However, this organic treatment requires a couple of weeks to begin working and often requires multiple applications for control. Most property owners prefer a single treatment that begins eliminating this pest in days.
Its best to treat your trees now, while the gypsy moth caterpillars are small and weak. They’ll continue to grow all summer, reaching up to two inches. Then they’ll come down the tree, pupate in the soil, emerge as adults, mate, climb up the tree, lay their eggs, and the cycle of destruction will start all over again.
The gypsy moth is an invasive species but not in the sense of some of the more recent invaders who came here undetected in packing material. In the 1860s, gypsy moths were imported from Europe in an effort to establish a silk industry in the United States. Some of the caterpillars escaped and, as they say, the rest is history.
Since gaining their freedom more than 150 years ago, the gypsy moth decimated trees in New England, where the “experiments” were being conducted. They then spread into adjacent states and to the Midwest. Much of the spread has been aided by unwittingly motorists. Gypsy moths lay their eggs in places other than trees, including the undersides of vehicles like campers.
Upon its arrival here, the gypsy moth had no natural enemies. Today, they are subject to attack by some other insects, pathogens, birds and mammals. However, when gypsy moth caterpillars are devouring your valuable trees and raining down on your family and possessions, I doubt if you want to wait for nature to take its course. Our professionally applied control treatment will help you get back to enjoying life again quickly.