Synonyms and other taxonomic changes
Includes Brathinidae, Dasyceridae, Empelidae, Micropeplidae, Oxytelidae, Oxyporidae, Pselaphidae and Scaphidiidae.
Explanation of Names
Author of family is
Latreille, 1802. From
Staphylinus, which is New Latin (Linnaeus, 1758) from Greek
staphilinos (σαφυλι&nuοσ), a type of insect. This is originally from Greek σαφυλη, a bunch of grapes
(1).
Numbers
In North America, about 17 subfamilies, 313 genera, 3100 species--the most diverse beetle family in the region
(2). World-wide, this is the second-most diverse beetle family (after the Curculionidae), with about 31 subfamilies, 3200 genera, and 47000 species described so far.
Identification
Thin, active beetles with shortened elytra that do not, at first glance, resemble beetles. In typical form, body appears to be divided into four parts when viewed from above. Family characteristics:
first abdominal sternite entire, not divided by hind coxae (charcteristic of suborder Polyphaga)
body shape typically elongated, with parallel sides
elytra short (about same length as pronotum, or only slightly longer), typically exposing 3-6 (usually 5-6) abdominal segments, though abdomen concealed in a few
though elytra are short, wings are functional in most groups and they fly well
coloration usually brown or black, some brightly colored
antennae thread-like or clubbed
tarsal formula variable, usually 5-5-5, but sometimes 4-5-5, 5-4-4, etc.
Some species run with abdomen curled up over thorax as if it were a stinger but no rove beetle has a stinger. Members of the
genus Paederus, however, do contain a potent toxin, pederin, that can cause a painful or itchy long-lasting welt on the skin.
Distinguishing staphylinid from carabid larvae
If you have a larva in hand (well, with some magnification, probably), you can tell carabids from staphs because the former have 6-segmented legs and often 2 claws, while staphs have only 5-segmented legs and always only 1 claw. Also, nearly all carabids have the urgomphi solidly attached to segment 9 (no joint at the base), and at least some of the ones that do have them articulated basally have more than 2 segments, which staphs never have. Staphs almost always have the urogomphi articulated and they have only one or two segments; the ones with solid urogomphi are all little guys (including pselaphines) and quite different in form from carabid larvae.
(communication to Jim McClarin from Margaret Thayer, Ph.D., Field Museum of Natural History, Chicago IL)
Habitat
Often found under rocks, logs, etc. Some found on edges of bodies of water, others on carrion, decaying fungi, etc.
Food
Most adults and larvae are predatory on other invertebrates. Some larvae feed on decaying vegetation.
See Also
Fairly distinctive among beetles, could be mistaken for earwigs (
Dermaptera) at first glance.
Print References
The Century Dictionary--entry for
Staphylinus (1)
American Beetles, Vol. 1, Chapter 22
(4)
