Miller Moths – those brown and white flying nuisances – arrive toward the end of May, but this year their arrival was a bit delayed due to dry spring weather. However, now that they’re here, the lil critters are lingering because the weather’s cool.
They pupate in the soils of eastern Colorado/western Kansas (as well as neighboring states of Nebraska and Wyoming), particularly in wheat or alfalfa fields. The most common Miller moth is the adult form of army cutworms Euxoa auxiliaris.
Once they molt into winged adults, they migrate westward to the mountains, where there’s an abundance of flowers with nectar for food. It’s also speculated that they are the victims of peter pan syndrome and don’t want to age; the only thing that staves this off are the cool temperatures found at higher elevations.
The Front Range is in their flight path and if the weather’s right, they’ll hang out here with us. You can tell that they’re in the area by the way birds – particularly swallows – work the intersections of roadways trying to scoop up flitting moths. Look closely the next time you’re at an intersection (and the light is red) to see if you can find the little moth flying in panic just in front of the dipping, swooping bird.
What determines the numbers of bugs in any given year will be the temperatures and moisture over winter, the pressure of pesticides in their staging grounds, and prevalent weather once they emerge. Plus, rollercoaster temps that may warm up enough to signal the time for adult emergence will have moths literally freeze their bottoms off when the cold front moves through.
This kills a LOT of bugs, as do flocks of birds nearby – imagine popping out of your cocoon to say “Hello world!” and have a beak scoop you up to eat you.
Although they are irritating when they fly about our homes, you can have fun with them. Jingling keys makes a noise that causes them to dive for cover, and they’ll land on any surface nearby. This can provide hours of fun if you’re tied up at an airport or waiting in line at a bank; just jingle you keys when the moth is flying over a person to try and get the moth to land on or near that person.
You don’t need to worry about controlling these insects – they’ll move on once the weather warms. In the meantime, keep your screens closed and the porch light off to limit the numbers of moths attracted to your house.