Earwigs in general
The Latin name for earwigs, "Dermaptera," translates to "skin wings." This refers to the leathery forewings (present in most species, but NOT in the maritime earwig) which cover over the hind pair of folded, membranous wings. Although earwigs like to spend time in dark, warm, humid places, they do not seek out human ears to in which to hide away! Earwigs are readily distinguishable by the pincers, or "forceps" protruding from the tip of their abdomen. These may be used for capturing prey, defense, or mating. The vast majority of earwig diversity occurs in the tropics, and of the 22 species known from North America, over half are introduced from other parts of the world. To date, we have found two species of earwigs on the Boston Harbor Islands.
How to identify maritime earwigs
These are large earwigs, adults can reach up to 25-30 mm (an inch or more). As with all earwigs, this species has large pincers or "forceps" at the tip of the abdomen.
Males are easy to tell apart from females by the shape of the forceps (see photo). Note that the male forceps are asymmetrical. Unlike the other common European earwig species on the islands, the maritime earwig does not have wings. Legs are pale yellow.
Where to find maritime earwigs on the Boston Harbor Islands
As its name suggests, the maritime earwig is very common on beaches. Check for it under seaweed, driftwood, and other tidal debris at the high tide "wrack line."
How maritime earwigs make a living
Maritime earwigs are primarily predators. They are active at night and feed on other small invertebrates on the beach, such as beach fleas (amphipods), crickets, smaller earwigs, and probably ants, small beetles, and sowbugs (isopods). They have been observed to capture prey with their forceps. Females lay clusters of eggs in crevices or burrows and guard them while keeping them neat and clean. This degree of maternal care is uncommon among insects.
Where in the world maritime earwigs occur
Maritime earwigs were introduced to North America, but now occur along the Pacific, Atlantic, and Gulf coasts. Transported around the world in commercial ships, maritime earwigs presently occur worldwide, with the exception of the Artic and Antarctic.
To learn more about maritime earwigs (and earwigs in general)
On the web:
http://bugguide.net/node/view/142736/bgimage (for images of live maritime earwigs)
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. Proceedings of the Entomological Society of Washington 89(1):1-14.
Langston, R.L. 1974. The maritime earwig in California. The Pan-Pacific Entomologist 50(1): 28-34.