Press Herald speaks with Groden about browntail moths

The Portland Press Herald spoke with Eleanor Groden, a professor of entomology at the University of Maine, for the article “This season may be the worst yet for browntail moths in Maine.” The caterpillars of the browntail moth feed on oak leaves. Their hairs, which can remain toxic for years, can cause a poison ivy-like rash and respiratory problems in people who come into contact with them. The range of high-risk areas for infestation has expanded across many Maine towns, and this season is predicted to be the worst in recent memory, with the high season for the caterpillars lasting from mid-May to mid-June, the article states. Browntail moth infestations are cyclical and weather-dependent, and Maine’s problem has worsened in the past five years. While the moth has no natural predators, a fungus can sometimes appear after a particularly wet spring and kill some of them, according to the Press Herald. “If we get a wet April, the caterpillars are still protected very well in their webs,” said Groden, who noted a wet spring would only temporarily reduce numbers. “They thrive in dry weather.” Research on how to reduce the moth population is in early stages and focuses on finding a biological treatment to weaken webs over the winter so cold, windy days could destroy them. “We have a walk-in cooler (at UMaine) filled with caterpillars in their webs. We are just beginning to understand the winter web integrity, the chemical structure of the webbing, and what makes them so strong,” said Groden. Aerial sprays and chemical pesticides may not be effective and raise environmental concerns. Tree trimming also is not a highly effective method of browntail moth population reduction, according to Groden. The Times Record published the Press Herald article.