The Purdue Plant and Pest Diagnostic Laboratory

What's Hot on October 17, 2005
at the P&PDL!


Boxelder Bugs

Timothy J. Gibb, Department of Entomology, Purdue University

Boxelder bugs are congregating on the outside of homes or other residential buildings, trying to get in for the winter. While they do not bite people nor harm the home or its contents, they can still be a nuisance, particularly when they occur in large numbers. Boxelder bugs derive their name from the boxelder tree where they feed and reproduce during the summer months. They also live on ash, maple, plum, cherry, peach, pear and other trees, however.

Damage to the trees by boxelder bugs is minimal and does not justify controls. However, homeowners with constantly reoccurring boxelder bug problems in their homes have found that spraying their host trees during the late summer, when the bugs are still concentrated there, is helpful. If only a single tree is the source of the problem and if that tree is of no particular value, its removal will provide long term control.

After feeding and reproducing in trees during the summer months, boxelder bugs are attracted to homes and other buildings where they seek shelter from the winter. To prevent them from entering homes, insecticides labeled for perimeter application against occasional invading insects‚ can be used. These must be applied during the fall to the outside perimeter of the home and must be used according to label directions. Once boxelder bugs find their way inside a home, it is usually best to remove them physically by sweeping or vacuuming them up.


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Invasion of the Asian Ladybeetles

Timothy J. Gibb, Department of Entomology, Purdue University and
Gail Ruhl, Senior Plant Disease Diagnostician, Purdue University

They are back -- swarming homes, buzzing around porches and doorways and bumping into people working in the yard.

Ladybeetles are attracted to light colored buildings and especially to those areas that are illuminated by the sun. For this reason, beetles usually first appear on the southwest-facing sides of light-colored buildings close to wooded areas. Once several beetles have settled on a suitable site, they release an air-borne, chemical, signal which attracts even more beetles. Congregating usually begins in mid October and seems to reach its peak by the end of the month. During this congregating activity, hundreds of thousands of beetles may appear around homes. When outside temperatures fall, the beetles move into tight cracks and crevices such as under siding or in wall voids, or cluster tightly into the corners of attics or garages. Once there the beetles eventually find their way through cracks and crevices, natural breaks in window sills, door jams or foundations. There the beetles essentially laze about in a hibernation-like mode, not eating nor moving much, for several months. When out of sight during the winter months, homeowners are often fooled into believing that the beetles are gone. That is, until the first warm days of late winter or early spring, when the beetles seem to come to life again and begin crawling about. For more information on these pesky beetles check out publication E-214-W.


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