I’m wondering about the behaviour with moths. I hadn’t seen any outside in my backyard for over a week, and recently we had a frost warning and it has been much colder outside. Now, I see a sudden increase in moths in my backyard as the weather grows cold. I wonder because I know they’re not cold weather insects, and seeing a high number of them in my backyard all of a sudden has me curious.
I want to hear people’s thoughts because I am always very interested in learning more and I want to know reasons for this behaviour, even if it is very simple explanation.
I don’t know why the moths do that either, but I have seen the same thing. Since September I have seen more moths than I did over the whole summer.
Perhaps they are coming out more to look for places to hibernate.
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Looks like you are located in the North East US based on some of your recent observations. I’m therefore assuming you have had a fairly similar pattern for recent weather as me in Southern Ontario.
I am thinking the recent cold weather might have less to do with the moth presence than the unusually warm weather we had preceeding. I’m thinking the insects might have gotten signals that another reproduction cycle was possible due to the heat.
But then again I’m no bug expert… for all I know they’re reproduction cycles might be more daylight dependent (like deciduous trees and their leaves’ cycle).
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I’ve never noticed this. For me there are fewer and fewer moths as the cold creeps in.
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Yeah, I agree.
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It’s interesting that you’re seeing more moths after colder weather and a frost warning. Moths aren’t typically cold-weather insects, but what you’re observing could be linked to their seasonal behaviors. As the temperature drops, they might be making a final push for food, mating, or laying eggs before it gets too cold for them to be active. In some cases, cooler temperatures might trigger increased activity, signaling that time is running out before winter fully sets in.
Also, some moth species migrate, so you could be seeing more them as they move to warmer areas. The shorter days may make them more visible, especially around outdoor lights, which they tend to gather.
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To some extent, the amount of cloud cover is almost as important as temperature. Moths prefer cloudy, overcast, even drizzly weather. Clear nights are generally bad for them. I usually have more luck on a cool, cloudy night than a warm, clear one.
Also, I’m not sure what time of the night/ morning you are looking for moths? They are more actively flying around on warm nights, but more likely to settle down at a light and still be there in the morning on a cool night. If you don’t check your lights before daylight, birds will nab them or most moths will fly away, unless it is cold. Colder weather makes the moths sluggish and more likely to stick around until the morning.
And as mentioned above, there are usually some late season pushes of migrant moths from the south. It just depends on weather patterns, but where I live in Ohio, we usually get a couple of good waves of migrants in late September and October. Some uncommon species can turn up this time of the year if you are lucky.
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Also, some species of moths will nectar more in the daytime when it gets too cold at night. Right now, I am seeing tons of Celery Loopers, Corn Earworm moths, Spotted Beet Webworms etc. nectaring right alongside the butterflies in the middle of the day. It seems like they nectar more in daytime and evenings if the nights are really cold.
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Right, this is why I was so curious about it because it is unusual. I was thinking some sort of final push due to the cold weather like you mentioned.
It also got cold very suddenly, from 70 at nights to 30-40.
So, I assume they hadn’t completed their usual warm weather cycles yet or weren’t expecting the sudden cold.
As of tonight (currently 7:40, I’m usually out around this time) I have not seen any moths, whereas the last couple nights I saw a ton of them.
Strange.
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Lots of the “cold-weather” species in the Northeast (Lithophane, Eupsilia, all the -glaea genera, Pyreferra, Xylena, etc.) will wait in their pupae until the first few really cold nights, and then eclose. These genera can all survive frosts as adults, and they specialize in being active late in the season when lots of the moth-eating predators have left the area or become inactive for the season. Here in Pennsylvania, the most abundant moth by far in this category is Sunira bicolorago- it’s not unusual to see hundreds of them every night when baiting for moths this time of year. So if the temps got cold enough recently that they started eclosing, you’d probably notice a burst in moth activity.
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