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Andrea Belcher came to the
University of Illinois five years ago as a graduate student to study ants with entomology
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.
[Photo: Two carpenter ants of different species locked in combat. Credit, Selina Ruzi.]
In contrast to many other young biologists, who are drawn to genetic studies and lab work, Belcher was 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.
Belcher’s article describing that project is published in the Fall 2016 issue of American Entomologist, under the title “Urbana House Ants 2.0: Revisiting M.R. Smith’s 1926 Survey of House-Infesting Ants in Central Illinois After 87 Years.”
In contrast to many other young biologists, who are drawn to genetic studies and lab work, Belcher was 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.
Belcher’s article describing that project is published in the Fall 2016 issue of American Entomologist, under the title “Urbana House Ants 2.0: Revisiting M.R. Smith’s 1926 Survey of House-Infesting Ants in Central Illinois After 87 Years.”
Belcher’s survey had three
goals: To identify ant species that infest houses now, to analyze the methods
people use to control pest ants, and to compare her results with those found by
Smith.
Following in Smith’s
footsteps, literally, Belcher focused her study on two intersecting streets
that form a cross in central Urbana, an area that encompassed about 300
single-family homes, as well as 40 multi-unit buildings.
Like Smith before her, Belcher relied on the cooperation of residents in the study area. First, she asked them to become “citizen scientists” and collect any ants found within their homes. This was 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, Belcher sought permission from residents for herself and an assistant to walk around their yards once and collect any active ants they found to help determine the total diversity of ants in Urbana. Beyond that, Belcher sampled ants from three nearby fragments of forest, to allow for some comparisons between them and the urban setting.
Like Smith before her, Belcher relied on the cooperation of residents in the study area. First, she asked them to become “citizen scientists” and collect any ants found within their homes. This was 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, Belcher sought permission from residents for herself and an assistant to walk around their yards once and collect any active ants they found to help determine the total diversity of ants in Urbana. Beyond that, Belcher sampled ants from three nearby fragments of forest, to allow for some comparisons between them and the urban setting.
What
changed for ants in Urbana over the 87 years between Smith’s and Belcher’s
studies?
Fewer species seem to be
inhabiting human residences. Belcher turned up only eight, whereas Smith had 11.
An exotic species, pavement
ants, seem to have spread into or increased in abundance in Urbana. They were
the fourth most commonly collected species in residences in 2012-2013; Smith
had found none of them.
People have adopted safer,
more selective methods for chemical control of insects indoors. Survey
respondents in the 1920s used broadly toxic chemical controls including
compounds containing arsenic and mercury. Respondents from 2012-2013 reported using
targeted, “least toxic” compounds, frequently baits that workers carry back to
the nest.
Some decline in the total
number of local ant species may have taken place. Despite sampling more
habitats using a greater variety of methods, Belcher found only 44 species
whereas Smith had 47.
For the present, Andrea
Belcher’s work no longer focuses on ants. With a spouse in the military, she
has landed in Santa Cruz, California, where she works primarily as an
interpreter and tour leader at Natural Bridges State Beach. Insects are still
part of the picture for her though, as she also assists researchers studying
the monarch butterflies that overwinter there.
She, Berenbaum and Suarez all
hope her study inspires other entomologists to examine the archives at their
own institutions for studies from the past that might be replicated to help us
understand how the insect world has changed over time.
