Termites in Wisconsin Arango continues historic research

In collaboration with San Diego State University and University of Wisconsin researchers, FPL termite experts have provided an update on previous work with termites in Wisconsin. In this post, Rachel Arango explains how her team’s work adds to greater understanding of northern termite biology, colony formation, and the possible impacts of climate change.

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Rachel Arango in the lab.

Guest Lab Notes post by Rachel Arango.

Although subterranean termites are more common in the southern U.S., they have also been found in colder climates such as Wisconsin. New research suggests that a changing climate may allow termite colonies to spread even further in the warmer north by formation of winged reproductives.

Little attention was paid to northern termite activity until Dr. Glenn Esenther’s historic work in Sheboygan, Wis. His 1969 paper, “Termites in Wisconsin,” highlighted areas of termite activity in the state and gave some insight regarding termite biology. Despite this work, research on termite reproduction, caste formation, and distribution is still needed to facilitate control strategies.

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Caste diversity in R. flavipe.

This study updates Esenther’s early work, further pinpointing areas of termite activity in the state. Only one species of termite is established in Wisconsin, Reticulitermes flavipes, the eastern subterranean termite. Results indicate that termite populations still appear to be limited to the southern half of the state, supporting the idea that Wisconsin lies on the northern boundary of termite territory. One long standing hypothesis about termites in this northern range is that they tend not to form the winged reproductive forms (alates) as often as their southern counterparts. Instead, numerous secondary reproductives are thought to be responsible for colony expansion.

For this work, we were seeking clues about how new termite colonies form. We used a genetic technique that has been useful in other population genetic studies to determine genetic variation within and among Wisconsin termites. Analysis of the genetic data showed significant differences among the populations collected around the state. This supports the idea that human introduction, rather than introduction by winged termites, was likely the origin of termite colonies in the state.

The exact triggers for colony formation of winged reproductives are still unknown but this study afforded an interesting observation of numerous alates in the field after a particularly mild winter. This suggests that temperature plays a role in termite wing development. It is possible that changing climate trends could allow for formation of these winged termites, rapidly expanding their distribution throughout the state.

Click here to see the technical poster about this project from the recent American Wood Protection Association conference.