Clues to identifying bed bug lookalikes

Monday, April 18, 2016

Cimicids that feed on bats and birds can be mistaken for bed bugs. These lookalikes will bite people but are not known to survive on humans alone.

With all the bed bug (Cimex lectularius) activity these days, it’s common for someone to bring you a bug desperately hoping it’s not a bed bug. It doesn’t mean a closer look is unnecessary because it looks like a bed bug. Although bed bugs are far more common now than their lookalikes, it’s important to recognize the imposters when they do show up.

The most common are bat bugs, but there are also swallow bugs, chimney swift bugs, and a handful of others. There are at least 16 species of Cimicids reported in North America. Some can be difficult to tell apart even with a microscope, but those most commonly seen can be distinguished with a little effort.

• Bat bugs (Cimex adjunctus) are the same size as bed bugs, but with a little magnification, the differences are pretty clear. The fringe hairs of the pronotum of the bat bug are significantly longer than those of the bed bug. The key character is that the hairs of bed bugs are shorter than the width of the eye itself, whereas those on the bat bug are as long as or longer than the eye. Quite simply, they look like fuzzy bed bugs.
• Swallow bugs (Oeciacus vicarius) feed on cliff and barn swallows. They differ in appearance from bed bugs in that they are smaller and clothed all over in long, fine hairs. With magnification, the last two segments of the antenna are equal in length in swallow bugs.
• Chimney swift bugs (Cimexopsis nyctalis) feed on chimney swifts (go figure) and, like swallow bugs, are smaller than bed bugs. Also, their last two antennal segments are equal in length. Unlike swallow bugs, however, the chimney swift bugs are not as hairy in appearance.

Read the full article "Clues to identifying bed bug lookalikes" in the March issue of Pest Management Professional

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