Thursday, June 13, 2013

U of I student replicating 1927 study of ants in Urbana

U of I student replicating 1927 study of ants in Urbana

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Andrea Walker came to the University of Illinois in 2011 as a graduate student in the Department of Entomology intending to study ants with professor Andrew Suarez. In her own words, she was “always interested in small things,” and the research opportunities she took advantage of as an undergraduate in her native Texas led her to focus on ants.

In contrast to many other young biologists, who are drawn to genetic studies and lab work, Walker is especially interested in the study of her subjects in the field.

That made her an ideal candidate for a project department head May Berenbaum had been hoping to have someone take on, which was to replicate a study of ants in and around homes in Urbana done by a U of I PhD student in the 1920s.

That study, titled “Ants of a typical middle western city, with particular reference to the house-infesting species,” was conducted by Marion Russell Smith, who went on to a long and illustrious career as an ant scientist.

There are three goals of Walker’s survey. She intends to 1) identify ant species that infest houses now, 2) analyze the methods people use to control pest ants and 3) compare her results with those found by Smith.

Following Smith, Walker is focusing her study on two intersecting transects that form a cross in central Urbana. Currently the study area encompasses about 300 single-family homes, as well as 40 multi-unit buildings.

Like Smith before her, Walker is relying on the cooperation of residents in the study area. First, she asks them to become “citizen scientists” and collect any ants found within their homes. This is done by capturing the ants on sticky tape and recording some basic information about them: where they were found, how many there were, if and what they were eating and what, if any, measures were used to control them.

In addition, Walker seeks permission from residents for herself and an assistant to walk around their yards once and collect any active ants they find to help determine the total diversity of ants in Urbana.

Last year, people at 30 residences participated actively in the study. Those included 18 households reporting no ants were found, and 12 where ants were observed and collected indoors. In her outdoor sampling last year, Walker collected more than 3000 ants at 70 residences. Among these were ants representing about 40 species in 13 different genera.

How do Walker’s findings from the first year of her study compare to Smith’s from 1927?

The most significant difference she has noted so far is a decline in the diversity of the ants collected by residents inside their houses. Smith’s volunteers collected 11 species of ants, while Walker’s have collected only five.

Walker’s field work continues this summer. If you are an Urbana resident and you are curious about the ants you find in your house or around your yard, she would be interested to hear from you. Better still, if you live in her study area and you would be willing to participate by collecting ants, please contact her via email at

The following link takes you to the map of her study site: