Caddisfly (003)
A caddisfly

Bullhead City, Ariz. is located on the Colorado River, roughly 90 miles south of Las Vegas, in the middle of the Mohave Desert, and home to people from different walks of life, several casinos that draw thousands of tourists and an uninvited nuisance, a species of caddisfly. If you’re vector control and are having a hard time containing the nuisance, what do you do? You call on Millersville University biology professor and expert in medical entomology, Dr. John Wallace.

Caddisflies flying around scientist (002)
Caddisflies flying around a scientist

The caddisfly, (Smicridea fasciatella) is a stream or river insect that does not carry any diseases and is usually an indication of good water quality. However, for residents, businesses and tourists who live, work and visit the casino strip on the Colorado River the caddisfly poses a huge problem.

The adult caddisfly life span varies and can last a few months. The female caddisflies lay their eggs in rock crevices in the Colorado River and hatch when the water temperature warms up. Wallace says the caddisfly does not bite. It is more of a nuisance, like a gnat. “The difference is the caddisfly has little tiny hairs or setae on their wings and when there are so many flying in your face, in your mouth, up your nose and behind your glasses their ‘hairs’ can cause irritation and sometimes respiratory issues.”

This past May, Wallace spent two days on the river working with, Dr. Joe Iburg, the pest abatement manager for Bullhead City and Chris Bramley, the pest abatement manager for Clark County in Nevada, as well as interacting with casino representatives and some of the residents along the Colorado River that flows past Laughlin, Nevada.

Caddisfly on slot machine
Caddisfly on a slot machine.

“It’s a highly politically charged situation. There are casinos involved, many of the residents who have built their houses on the river, business owners, as well as the Native American people who live down the river who this problem impacts,” says Wallace.

The objective of the trip was to make a preliminary assessment of the problem and initiate a research program to try and uncover ways to control the insects or reduce their numbers in a non-toxic way. A few of the ideas that were discussed included using adult caddisfly pheromones to trap male caddisflies, sticky traps to reduce the numbers and increasing trout populations in the river to give people some relief from the insects.

“As far as controlling the whole population, that’s a tall order, but we’re hoping to get a least some sort of trap that we can recommend to people that will help provide relief on their porches,” says Iburg.

In addition to developing control strategies, another objective was to create a citizen science monitoring program that will empower citizens to contribute valuable scientific data to better understand the caddisfly biology and play a role in controlling the numbers of pest caddisflies. Wallace will be returning to Laughlin in September to continue research and data collection.

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