We have been getting lots of calls and emails about the Browntail Moth infestation around the watershed. Caterpillars are raining down from the trees and people are coming down with rashes. The tops of the oak trees are already defoliated by the caterpillars.
The big question is what’s the best way to get rid of the pest on houses, decks, and vehicles? For small or moderate numbers of caterpillars the simplest way is to pick them up (using gloves or pliers) and put them in a dish of soapy water. For larger numbers the Maine Forest Service advises using a wet/dry vacuum (shopvac) with a HEPA filter. Put a couple of inches of soapy water in the vacuum and suck up the caterpillars. Here is a link to the Maine Forest Service FAQs on the Browntail Moth: https://www.maine.gov/dacf/mfs/forest_health/invasive_threats/browntail_moth_faqs.htm
For more information on health concerns you can call or text 211 to get the Maine CDC hotline.
Important- look before you leave!
It is from this point in their life cycle, through the end of the adult activity that you can most easily spread browntail moth to new areas. Caterpillars, pupae and adults can all travel with you, in or on your vehicle. Look before you leave! People need to check your person and vehicle for browntail moth before traveling. When possible, don’t park near infested trees, learn to recognize the caterpillars and remove them if you find them. If you frequently travel between infested and uninfested areas, be on the lookout for signs you’ve taken this hitchhiker for a ride.
Finally, here is possibly some good news from the Maine Forest Service May 29 Conditions Update:
Although it has been a dreary and dismal spring so far weather wise, we’re in good shape for an outbreak of Entomophaga aulicae, the fungus that attacks browntail moth. If this weather streak keeps up through June, we’ll likely see some local population collapses.
In collaboration with UMaine’s Dr. Ellie Groden and Karla Boyd, we will be monitoring various browntail caterpillar populations into late June/early July to assess if there will be an outbreak of any of the pathogens that attack browntail moth; we are eager to see the results. The caterpillars have been somewhat delayed this year due to the cooler wet weather. We’ve seen some caterpillars feeding, however most are still clinging/basking on their nests waiting for slightly warmer weather and for more foliage to unfurl.