Home » News

5 facts about Utah's moth invasion

Published June 13, 2014 6:55 pm

This is an archived article that was published on sltrib.com in 2014, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

http://local.sltrib.com/sheena/mothra.jpg" width="55%">

Can't get away from the moths that seem to be flying at every light fixture and buzzing you at the office?

Here are five facts you need to know about Utah's Mothmageddon.

Mild winters equal lots of moths

http://local.sltrib.com/sheena/caterpillar.jpg" width="55%">

A particularly mild winter allowed moths in their caterpillar and pupa form to survive, meaning that the winged creatures we think of as moths are quite abundant this year, said Jose Crespo, a postdoctoral researcher at the University of Utah's Department of Biology and moth expert.

"It's a little unusual, but not really surprising," Crespo said. "It's unusual because the number of moths is not the same. Temperature and humidity are the most important environmental factors."

Moth to a flame

http://local.sltrib.com/sheena/bugs.jpg" width="70%">

Scientists have been studying why moths love light so much, but no one has come up with a definitive answer, Crespo said. The prevailing theory is that bright light sources throw off the moths' navigation and they'll fly to and around the light and "exhaust themselves to death." To keep them from gathering at your home, turn off your lights at night, or turn on fewer lights.

Your clothes are safe

http://local.sltrib.com/sheena/clothes.jpg" width="70%">

Miller moths, or army moths, are the ones that you're seeing so many of around Utah right now. But they're harmless — they won't even attack your favorite clothing. The only people who need to be concerned are those with specific allergies to moths. The creatures are covered in scales, which turn to dust, which can act as an irritant for folks sensitive to it.

Important pollinators

http://local.sltrib.com/sheena/flowers.jpg" width="70%">

Miller moths are nocturnal and play a crucial role in pollinating nighttime flowers as they feed off nectar. Crespo says if a moth is in your home, it's OK to swat it (or vacuum it up as they do at his lab), because the moth is going to die indoors anyway. But if you have moths in your flowerbeds and bushes, leave them be as they have important work to do.

They won't be here much longer

http://local.sltrib.com/sheena/mountain.jpg" width="70%">

Most moths live only a week to 10 days, but miller moths live for at least a few months. They also migrate to escape excessive heat.

"In late June and early July, they'll move to higher altitudes and return in the fall," Crespo said.


Twitter: @sheena5427 —


Have you been attacked by moths? Share your experience on Twitter with #utahmoth