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Gypsy
moths
should be
less plentiful
Good news from the insect front: The state entomologist does not foresee a horrendous gypsy moth outbreak this year.
Experts did document some moderate to heavy egg masses in some areas and advise that there may be some locally heavy pockets of gypsy moth activity this year.
The Northeast District Department of Health is again receiving multiple inquiries regarding the recent hatching of gypsy moth eggs. There is no public health threat associated with this natural, temporary phenomenon.
The Connecticut Agricultural Experiment Station (CAES) in New Haven and state Entomologist Dr. Kirby C. Stafford III, Ph.D. predict no extensive activity or widespread defoliation this year. “This is due to the extensive number of caterpillars that were killed by the fungus before they were able to pupate (morph) into moths,” officials said.
In 2017, the gypsy moth outbreak was extensive and severe throughout eastern Connecticut, affecting 1.1 million acres; the greatest extent of defoliation seen since the early 1980s.
High activity in 2017 was due to nearly three years of drought that prevented or limited the growth of a fungus (Entomophaga maimaiga) that typically kills the gypsy moth caterpillars. Rains received in June, 2017 began to advance fungus activity which successfully eliminated a large amount of caterpillars.
They added, remaining fungal spores left in the environment from last year can infect the caterpillars in 2018 if we get the necessary spring-early summer rains. There is no way to predict if rains will arrive at the right time to get the fungus going in 2018, but we have had a rainy spring season so far.
Gypsy moth eggs hatch late April to early May. These small larval “instars” (i.e., stages of the caterpillar) “balloon” off of the trees and the wind carries them to multiple locations. The ballooning stage does not last long. Within a couple of weeks, older caterpillars settle into the trees to feed, crawling up and down, and eventually deforest the tree. The natural fungus with long-lasting spores is toward the bottom of the tree and soil. The fungus requires rain to germinate, infect, and kill the caterpillars … so a wet spring is a good thing!
While the fungus infects the older caterpillars as they move up and down the tree, it can affect the younger instars as well, providing optimism that the fungus will provide natural control of the gypsy moth caterpillars again this year. This is a temporary phenomenon. It may take some time for nature to catch up but there are good odds that the issue will take care of itself.
The NDDH noted that Gypsy moth larvae (i.e., caterpillars) do not bite. They do have two types of hair (called setae) that they use to defend themselves which can create a stinging sensation. Reactions to these stinging hairs vary from mild to moderately severe itching with an accompanying rash, similar to contact dermatitis. The onset of discomfort is usually noticed within 8-12 hours after contact, often becoming more pronounced one to two days later. Most cases resolve in a few days or up to 2 weeks.
Delayed hypersensitivity reactions sometimes result in irritation to the eyes, inflammation of the nasal passages, and shortness of breath. This is especially common in the case of airborne hairs of adult gypsy moths, or contact with clothes hanging on outdoor lines when the moth is locally abundant.
Exposure to the larvae and hairs is more likely while the young larvae are “ballooning” or contact w/ the adults.
What You Can Do
Homeowners should check their property (e.g., trees, fence posts, brick walls, cars, outdoor furniture, etc.) for egg masses, which can be scraped, removed, and destroyed. There are no state programs for spraying. It is recommended that people with sensitivities limit their exposure.