Hi Jann,

Thanks for your question and also for including photos as that is critical.  

Spongy moth (previously called 'gypsy' moth) caterpillars have been causing significant damage in the recent years.  This year, however, their numbers have decreased due to the increase in a virus and wasp that attack and kill them.  

The good news is that these moths are a different species from spongy moths - our entomologist confirmed this and her complete note is below with some links to learn more.  Moths can serve as pollinators and they and their caterpillar stage can provide food for many other animals including birds and mammals (notably, bats).   So they are generally a good and key part of a healthy ecosystem.

The moths should not cause any damage to your cabin and are not harmful.  If the moths are bothering you, you can try to discourage them from aggregating on your cabin by decreasing outside lights at night which can attract them.

As a bright side, perhaps you will see an increase in nesting birds next year as the caterpillars provide food for baby birds!

From UVM entomologist:  Indeed, neither of these are spongy moth adults. The pale greenish moth is Campaea perlata. They have one generation per year here, and they occur throughout North America. They feed on a variety of deciduous forest trees, including ash, alder, poplar and willow. It overwinters as a larva on bark flaps. Therefore, these adults are likely to lay eggs which will hatch into larvae and feed until it gets cold. They are found in large numbers some years. They are attracted to light. One way to discourage them from collecting on the side of the cabin would be to make sure the outside lights are turned off. It is not considered a serious forest tree pest.

Here is additional information about this insect:

https://bugguide.net/node/view/13845

http://somethingscrawlinginmyhair.com/2016/03/02/pale-green-moth-with-greenwhite-stripe-pale-beauty/

https://www.mothidentification.com/pale-beauty-moth.htm

The other species (grey-brownish moth) was difficult to identify from the photo provided. It is a geometrid moth of some sort, but we cannot be more specific than that.

Geometer moths are an amazingly diverse family with more than 23,000 species! Here is some information about them: https://www.mothidentification.com/geometer-moth