Primary Care

Can Gypsy Moths Make You Sick?

Gypsy moths are back and causing destruction throughout the Finger Lakes region – defoliating trees, leaving behind a mass and if you come into contact, they may give you an irritating rash.

May. 13, 2024 2   min read

Gypsy moth (Lymantria dispar) on a twig in a forest

Throughout New York State and the Finger Lakes region, gypsy moths have come in droves – with hundreds of thousands of caterpillars emerging. Although they typically only show up once every 10-15 years, they can cause a lot of destruction while they’re here. 

So, what are gypsy moths and can they hurt us? We’ve answered a few frequently asked questions about these hairy caterpillars below.

What are gypsy moths?

Gypsy moths are invasive insects that start as caterpillars hatching in early May. They can grow to be about three inches long by July.

At night, they like to eat the leaves of oak, poplar and gray birch trees and can consume up to 90% of the leaves on the trees they attack.

Gypsy moth (Lymantria dispar) on an apple tree closeup

Once they’ve reached maturity, they “pupate” and about two weeks later, adult moths emerge. Female moths are an off-white color with dark markings but cannot fly. The males are smaller and a darker brown color – they are fliers and will be drawn to lights.

How can gypsy moths impact health?

Besides damaging our trees and causing a mess, here are a few ways that gypsy moths can impact your health:

Itchy Rash: The hairs on these caterpillars can cause a red, stinging, itchy rash if they come in contact with your skin. The rash looks similar to that caused by poison ivy.

“Most of the time, the gypsy moth rash is a little red, stinging, and itchy,” explained Dr. Gian Vinelli, a dermatologist with Rochester Regional Health. “The rash may get better with an over-the-counter cortisone in a few days, but in those who have had it before, it can be more severe, similar to poison ivy. If that happens, I would strongly recommend calling your dermatologist or your primary care provider.”

Falls: The caterpillars’ droppings also can become a problem. During their heavy eating period, their droppings can fall from the trees onto surfaces like patios, porches and driveways. These droppings can cause slippery and slick conditions. Wear shoes that have good traction and step carefully in these areas.

Tree Hazards: While many trees can survive a year of defoliation, several repeated years of this (which is common) can start killing trees, causing hazards around roads and on properties. If you notice a tree on your property that is struggling, call an arborist to diagnose the tree and provide care or safe removal if necessary.

Pesticide Use: If you are using pesticides to try to control the gypsy moth caterpillar infestation, please make sure to read the pesticide label and only use it as directed. The CDC recommends choosing a targeted insecticide that minimizes risk to other living things. Children and young pets should be kept away from any treated areas.

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As part of Rochester Regional Health, Genesee Valley Dermatology & Laser Centre is upstate New York's premier provider of dermatological services. Offering the full range of general dermatology, laser, and cosmetic skin care services. From skin cancer screenings to reducing fine lines and wrinkles, the team has the expertise to treat both medical and esthetic conditions.

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