Monday, July 13, 2009


I was fortunate to receive a few insect specimens from Kit's mom in Virginia - one of which is difficult to find on the west coast of the US: a cicada. Now, my text puts cicadas in a family in the order Hemiptera, but they used to be placed in their own order, Homoptera. Since my text does not key beyond the family (and in rare cases subfamilies for very diverse families), I had to look online to get a more accurate identification. Simply based on its size (body length ~37mm) it is a member of the genus Tibicen. The most famous cicadas, those that emerge after 13 or 17 year cycles, have bodies 19-33mm long, averaging 25mm - significantly smaller than the cicada pictured below.

Hemiptera; Auchenorrhyncha; Cicadoidea; Cicadidae; Cicadinae; Tibicen sp.
Common Name: Dog-Day Cicada, Harvestfly

Cicadas are usually recognized by their characteristic shape, large size, and three ocelli. This group contains some of the largest Hemiptera in the United states, particularly the genus Tibicen. There are 157 species in the US. The suborder Auchenorrhyncha are active insects, being good fliers or jumpers. They have short antennae and three-segmented tarsi. All produce sound, but Cicadidae is the only family to produce sounds audible to humans. The males of each species have a characteristic song and also produce different "protest" sounds when disturbed and "courtship" songs when a male is approaching a female. The specimen above is a male, and the sound organs (tympanum) are right beneath the large flaps (operculums) below the third pair of legs.

Tibicen species is the largest, and appear late in the summer around July and August. They are generally black insects with greenish markings. They are called "annual" cicadas because they are usually seen each year, but the actual life cycle may be up to 3 years long. Like periodical cicadas, the larvae are laid in the ground where they feed on tree roots, and then emerge to mate. To get a better idea of the kinds of cicadas that there are in the US, check out this page.

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