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October 1, 2007

Tiny Bugs Biting You? Have a Thick Skin - They Will Be Gone Soon

Tim Gibb, Insect Diagnostician, Department of Entomology, Purdue University

‘Big bite for such a little bugger!’ pretty much describes the Insidious Flower Bug right now in many areas of Indiana. These bugs became quite a nuisance the last week or so of September and are continuing into October. We expect them to continue until we have a cold snap that will knock them off.

Insidious flower bugs are tiny, only about twice as large as the period at the end of this sentence. They are broadly oval in shape, and black with whitish or silver markings on the back. Insidious flower bugs can fly and are small enough to make their way through window screens, thus providing equal irritation to people inside homes as outside.

Why they bite is still a bit of a mystery. However, we know that they live up to their name "insidious". They seem to bite most often when it is warm and sunny and they usually bite exposed skin that is perspiring slightly.

These bugs do not take blood or inject any saliva - so their bite is not particularly serious to most people. However, bites are certainly annoying especially considering the small size of these bugs. Some people react more to the bite than others and may experience localized swelling, similar to a mosquito bite. Others experience the pain but see no reactions at all.

Not much can be done about these nuisance pests. Insect repellents can be used and will offer some protection but not complete. Covering bare skin will prevent them from biting.

Remember that during the majority of the year, insidious flower bugs are beneficial predators because they feed on small insects and mites or on their eggs (spider mites,
aphids, and thrips are particularly attractive to these bugs). For that reason, general insecticides should not be used against these insects.

The bugs probe into leaf tissue to lay eggs and often go through multiple generations of 3-4 weeks in a season. During most of the summer, these bugs stay close to the where their food sources are. In years when soybeans experience higher than usual aphid outbreaks, insidious flower bug populations seem to be high as well. In the fall time, the aphids begin to disappear and the insidious flower bugs begin dispersing to areas where humans frequent.

If these tiny bugs are bugging you, try avoiding areas close to soybean fields, wear repellants, long sleeved shirts and pants and most importantly have patience and a thick skin. They will be gone soon enough!

Click image to enlarge

Pirate bug

Orius insidiosus (Minute pirate bug) feeding on an aphid
(Photo by Ho Jung Yoo)

Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service