Insects and Spiders - native

Western Thatching Ant (Formica obscuripes) on Feb 5, 2011

Submitter does not have a specimen

Description of specimen

ants with red heads and black bodies

Commentary

Hi Kristi, I shared your report with Oregon Department of Agriculture entomologist Jim Labonte. Here's his response. Thank you for the report!

"These are not fire ants. They are a native species, the western thatching ant, Formica obscuripes. Although they can aggressively defend their nest, they are otherwise harmless and are valuable as predators of many other insects and invertebrates, including some forest pests. As the name suggests, they create large mounds comprised of plant debris ("thatch")." - James LaBonte, Oregon Department of Agriculture

Lisa DeBruyckere
Feb. 7, 2011, 12:28 a.m.

Location

I saw a mound of red headed ants (IFA?) on a log along the path that goes out to New River from Lower Fourmile Lane, just before 86482 Lower Fourmile Lane, where the parking lot and sign is. A lot of people and animals use that path, and don't know if these are the aggressive fire ants or not.

Expert Reviewer

Ms. Lisa DeBruyckere
Oregon Invasive Species Council Coordinator

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