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The Vinalhaven Sightings Report is organized and edited by Kirk Gentalen on behalf of Vinalhaven Land Trust and Maine Coast Heritage Trust. Out and about on Vinalhaven, MCHT steward Kirk Gentalen reports on what he and others have seen in their travels. Contributions of stories and photos are welcome, and can be sent to


Sunday, April 21, 2013

Welcome to the Winter Moth Action Update

April 17th, 2013

“Spray it, just don’t say it” – which means spray it.


A kindly reminder that we are not alone out here….


Well, where were we…..ahhh, yes…..when last reported Winter Moth (pesky bustards) were filling the skies with bodies and pheromones, laying eggs everywhere and getting caught in bands. So now what?


If you live in town (or on the outskirts, the rougher neighborhoods) and did not band your trees in the fall your hardwoods are likely covered in winter moth eggs. Sorry dudes and duders, there’s no candy-coating it (or is it sugar coating?). Soon enough (like in the next few weeks) your (the royal “your”) winter moths (they ain’t mine!) will hatch from said eggs – spraintloads of caterpillars all at one time!- and begin devouring leaf buds and emerging leaves in a feeding frenzy that may leave your tree looking like its winter – no leaves!  Hopefully your tree has enough stamina to pump out another set of leaves. We all wish we had that kind of stamina. Anyway!


Well, if you are someone who didn’t get your bands up in time (happens to the best of us) and you had moths all around your yard and neighborhood, then your next opportunity for action is at hand. In other words – it’s time to spray! (“late april” has been a landmark to base activity around.)


What’s the deal with spraying? Here’s something we lifted from a winter moth management article/hand out thing… here’s the link to the full article….


Given that many winter moth eggs are exposed on the bark, the potential to manage them with a horticultural oil spray exists. Typically, dormant oil sprays are applied in the very late winter or very early spring depending on temperatures and host plant phenology. Oil sprays can be applied in the fall but it is of no use for winter moth given that the eggs do not appear until very late fall and into the early winter. When applying oil sprays, it is prudent to have temperatures above 45° F and to avoid applying oil when temperatures may dip below freezing for 24-48 hours after application. Temperatures below this threshold greatly increase the risk of causing injury to the plant (phytotoxicity). Certain weather conditions, such as when it is cool and cloudy, can also delay drying time and enhance the potential for injury. Oils work by suffocation and can be effective on the eggs. Oils must cover the target organism at the time of application or no insecticidal effects will result. Eggs that are protectively hidden within crevices and under lichen will not be covered by the spray nor killed. “


Huh, there are a lot of specifics here to think about, mostly temperature and weather stuff, but also about Horticulture Oil.  And even though the oils won’t get every egg, let’s remember that every caterpillar counts, one less means more leaves.


So how do we go about getting that oil slathered all over the trees? Call Carla (of course!). Carla Harris, of Peaceful Harbor Farm Fame, is not giving “peace” a chance when it comes to Winter Moth. “Bring ‘em on!” Carla was rumored to have said recently and we have to say – that’s the aggressive spirit. Carla has spraying equipment and has been tending trees on the island for other “pesky bustards” for years and she understands the intricacies of the timing of applications and is ready to help your yard out! Give Carla a call – 863 – 4837 – to set up spraying of your trees and other questions you might have.


Stay vigilant, and we’ll certainly have more updates as things progress.