River insects bug students, show Fox River improvement

Amy Sandquist

For the past weeks, Lawrence students and faculty have grown accustomed to sharing the campus with thousands of insects. The insects swarm in thick clouds, forcing people to cover their faces when walking outside.
Some unlucky students, like sophomores Jismy Raju and Jennifer Compton, even experienced an insect invasion of sorts when dozens of tiny insects crept through the holes in their window screen.
“They were everywhere, near the windows, in the tiles of the ceiling, and in my bed,” Raju said. The insects that invaded Raju and Compton’s room were small and black, but multitudes of moth-like insects have also been thriving on Lawrence’s campus.
Senior Jessica Beyer, a biology major and two-time participant in Associate Professor of Biology Bart De Stasio’s summer aquatic ecology lab, explained the differences between the two insect species and the reasons for their sudden proliferation.
Over the past two weeks, both types of insects emerged from the Fox River. The smaller insects swarming around Lawrence are midges, commonly referred to as gnats.
Professor Brad Rence of the biology department noted that, though the midges may appear similar to mosquitoes, they are harmless.
The moth-like insects are called caddisflies and, according to Beyer, differ from moths in several ways. Most noticeably, “their wings are covered in hair, instead of the scales that we see on moths and butterflies,” Beyer said.
Both species emerge from the Fox River in order to mate and therefore pose no threat, other than annoyance, to students.
Rence explained that neither species of adult insect “even has any mouthparts, so neither species can feed.” Rence added, “They depend wholly on the energy stored up from the larval feeding stage.”
In fact, both species spend most of their life cycle in aquatic larval stages. Beyer noted that the caddisfly larvae form “beautiful tube-like houses out of rocks, sticks, or sand,” and that both the adult caddisflies and midges lay their eggs on or near the water.
Eggs hatch into larvae, and the larvae move into the river where they feed on other organisms, detritus or algae until they emerge as adults the following year. Beyer explained that because the only role of the adult stage of the caddisfly and midge adults is to reproduce, their life expectancy is about one to two weeks.
Though the insects are annoying, their presence on campus indicates a positive change in the environment around the university. According to Lawrence fellow Brigid O’Donnell, “Large emergences of insects from freshwater systems are usually a good thing.” The insects indicate that the Fox River is a clean enough environment to sustain and nurture life.
Rence recollected that when he arrived in Appleton 30 years ago, “there were virtually no bugs coming out of the Fox.” Both O’Donnell and Rence see the large insect populations as positive consequences of efforts to curb pollution in the Fox River.
Beyer believes that walking through swarms of insects is the price that Lawrentians pay for living so near the river, the insects’ home. “Plus,” she added, “Have you seen how excited the birds are? The swifts and swallows are thrilled.

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