ID

ENTO-144NP (ENTO-413NP)

Authors as Published

Authored by Theresa A. Dellinger, Diagnostician, and Eric Day, Lab Manager, Insect Identification Lab, Department of Entomology, Virginia Tech

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Crab lice, Pthirus pubis (L.), are very small (1.5-2 mm; 0.06-0.08 inch), wingless, flattened insects with mouthparts for sucking blood. The body is about as wide as it is long with a small, narrow head (Fig. 1). Crab lice are gray to tan in color. If they have fed recently, the blood meal will be visible through the body and make them appear darker. Crab lice have a large claw at the end of the last two pairs of legs that allows them to cling securely to coarse hair on their host. The claws resemble those of an aquatic crab, hence the common name of “crab lice.” Crab lice cannot fly or jump; they can only crawl. Crab lice are different parasites than head or body lice.


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Publication Date

February 12, 2021