Insects turn up in some odd places

By Ed Adcock, College of Agriculture and Life Sciences Communications Service

Greg Courtney, an Iowa State University entomology professor who specializes in aquatic insects, has traveled the world looking for new or rare species.

He and Stephen Marshall, a Canadian entomologist, plan to photograph live specimens of all aquatic insect families from around the world for a textbook they hope to have published in 2020. As a preliminary step, Courtney identified some families of mayflies that he’d never photographed and asked colleagues for locations to find them.

“So I was going out to northwest Colorado even as far as southern Alberta and I started finding some of these groups, but then I come back to Ames and I find some of them literally a five-minute walk from my back door, down the hill from where I live,” Courtney said.

The mayfly Courtney discovered in his “backyard.”

It’s not unusual to find new species in some poorly collected areas, he said of trips to such places as South America, Madagascar, Australia and New Zealand. “But what continues to surprise me is just how many things turn up locally that had never been recorded locally,” he said.

This fall, one of his classes trapping at night found a species of lacewing in Ames on the Skunk River that feeds on freshwater sponges. It had never been seen in central Iowa before, although they have been recorded in the northeast part of the state.

Greg Courtney

“I've been mucking around the river for years and I've never turned up a freshwater sponge let alone a larva of one of these insects. So maybe I just had the black light set up in an ideal spot this year or they moved in this year,” Courtney said.

It may be environmental changes brought on by climate change that are expanding the distribution of some insects, but it might be that past surveys have missed some species because of timing. Insects, like mayflies, appear sporadically and you have to be lucky to spot them sometimes.

“The groups that I specialize on, most of them live in waterfalls in torrential streams and in some cases the adults live less than an hour,” he said.

In other cases, the stage of the insect spotted needs to be an adult for a definitive identification.

Experience collecting and identifying insects also is necessary, but Courtney said a handy resource is, which is administered by Iowa State. The online resource is a collaboration of professional entomologists and citizen scientists and currently contains more than 1.3 million images of insects and other arthropods, most of them submitted by people interested in insects.

November 28, 2018