Doru taeniatum (Dohrn, 1862)
Introduction
This week we’ll cover Doru taeniatum (Dohrn, 1862) (Dermaptera: Forficulidae), a New World species commonly referred to as the lined earwig. I have to admit that I am overcome with giddiness every time I find one of these insects at my porch light or in my wood pile – mainly because it isn’t Forficula auricularia Linnaeus, 1758 (Forficulidae) or Labia minor (Linnaeus, 1758) (Spongiphoridae) the abundant, conspicuous, and non-native (at least for F. auricularia) earwig species I normally see here in Raleigh. It’s pretty rare, in fact, to see any native earwigs in the ENT 502 student collections, which is one reason I have ventured into the Dermaptera literature to teach myself about species we can find here in NC.
Taxonomic History
Carl August Dohrn described this species in 1862, based on specimens collected in Mexico. It was originally named Forficula taeniata, but has since been reclassified in Doru. There are two synonyms: Forficula californica Dohrn, 1865 and Forficula exilis Scudder, 1876.
Diagnosis
Wings and tegmina present in adults; 2nd tarsomere greatly expanded distally and overlapping the 3rd tarsomere (a character for recognizing Forficulidae); 2nd flagellomere >2x longer than wide; tegmina yellow, with brown inner margins; male forceps widely separated at base; hind wing visible beyond tegmina.
Natural History
This species can be collected at lights at night, sometimes by the hundreds in the tropics (Langston & Powell, 1975) and during the day one can often find them in leaf rolls, wood piles, leaf litter, and other typical earwig haunts. Very little is known about this species’ feeding habits, but they’re likely omnivorous scavengers. Eisner et al. (2000) published on D. taeniatum’s defensive strategies; these insects employ both mechanical (pinching with forceps) and chemical (an aqueous mixture of quinones and pentadecane, precisely aimed and squirted out of glands on the abdomen) methods.
Distribution
This species can be collected as far south as Bolivia and as far north as Maryland. In the USA it is more common in the southeastern states but has also been seen as far west as California (Hoffman, 1987). Our collection suggests that this species is mostly restricted to the coastal plain in North Carolina. There are no records in GBIF, as of 5 May 2011.
Find out more
- Hoffman, K. M. 1987. Earwigs (Dermaptera) of South Carolina, with a key to the eastern North American species and a checklist of the North American fauna. Proc. Entomol. Soc. Wash. 89: 1-14.
- Dohrn, C.A. 1862. Die Dermaptera von Mexico. Stettiner Entomologische Zeitung, 23: 225-232.
- Langston, R.L & J.A. Powell. 1975. The earwigs of California (Order Dermaptera) (PDF).
- Eisner et al. (2000)Chemical defense of an earwig (Doru taeniatum). Chemoecology 10: 81–87.
Map
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