Black Webspinner

Oligotoma nigra

Black Webspinner, Oligotoma nigra, photo © by Mike Plagens

Found at a porch light in a residential area in Glendale, Arizona. April 2012. The enlarged leg segment containing a silk gland is at bottom center in this image. Notice, also, the two cerci - small appendages at the posterior of the abdomen.

Embioptera -- Webspinner Order

The adult males have wings and fly in the evening and are strongly attracted to electric lights. Unlike the adult males, the rest of this insect's stages appear hidden beneath stones and leaves in contact with the soil. There they live within silken tubes and feed on molds, dead leaves, and fallen flowers. Indeed they are important recyclers. The enlarged leg segments are the location of the silk glands.

Webspinners are not an indigenous component of the Sonoran Desert. They were accidentally introduced from the Old World. They are restricted to well-watered habitats that are rare in the desert.

These strange-looking insects are sometimes mistaken for termites. Close inspection of the first pair of legs, however, shows an enlarged segment - a feature never present in termites.

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Copyright Michael J. Plagens, page created 19 September 2012.