Numbers
Nomina Nearctica has 3 genera:
Doru
Forficula
Setocordax
Florida Earwigs(pdf format) adds 2 recently-recorded genera:
Kleter
Neolobophora
Identification
In the 3 tarsal ("foot") segments, the 2nd one extends under the outermost one, and is wider. Chelisochidae also has a 2nd tarsal segment extending under the final one, but it's the same width as or narrower than the part it extends under, and has a brush of bristles on the underside.
Range
Widespread.
These are the most cold-tolerant of the earwigs, so they can be found not only throught the US, but into Canada- even in the colder interior.
Food
Both plant and animal matter, including bits of organic matter in soil and leaf cover.
Life Cycle
The female lays her eggs together in one place and tends them until they hatch, then cares for the nymphs until they can fend for themselves.
The nymphs are like smaller versions of the parents, but have no wings. As the nymphs near adulthood, the developing wings can be seen on the thorax, becoming fully developed, functional wings at the last molt.
Remarks
While some can become minor pests by eating fruits and vegetables, their voracious appetite for insects and other invertebrates (most notably ground-dwelling termites) usually far outbalances their negative impact.
