Spider beetle

Spider beetles make up the subfamily Ptininae, in the family Ptinidae. There are approximately 70 genera and 600 species in the subfamily, with about 12 genera and 70 species in North America north of Mexico.
Spider beetles have round bodies with long, slender legs. Many species are flightless, either in females only or both sexes. They are generally 1–5 mm long, and reproduce at the rate of two to three generations per year. They are so named because of a resemblance to spiders. Some species have long legs, antennae that can seem like an additional pair of legs, and a body shape that may appear superficially like that of a spider.
The larvae and the adults of most spider beetles are scavengers on dry plant or animal matter, but some species are known to be myrmecophilic, or ant affiliates.
The subfamily Ptininae, along with Anobiinae and several others, were formerly considered members of the family Anobiidae, but the family name has since been changed to Ptinidae.

Genera

These genera belong to the subfamily Ptininae:Acanthaptinus Philips, 2005Africogenius Borowski, 2000Bellesus Özdikmen, 2010Casapus Wollaston, 1862^gCavoptinus Pic, 1931Chilenogenius Pic, 1947Coleoaethes Philips, 1998^gCryptopeniculus Philips, 2004^gCylindroptinus Pic, 1910Cyphoniptus Bellés, 1992Dignomus Wollaston, 1862^gDiphobia Olliff, 1886Diplocotes Westwood, 1869^gDiplocotidus Peringuey, 1899Ectrephes Pascoe, 1866^gEnasiba Olliff, 1886Epauloecus Mulsant & Rey, 1868^bEurostodes Reitter, 1884^gEurostoptinus Pic, 1895Gibbium Scopoli, 1777^{i c g b}Gnostus Westwood, 1855^{i c g b}Hanumanus Bellés, 1991Hexaplocotes Lea, 1906Kedirinus Bellés, 1991^gLachnoniptus Philip, 1998^gLapidoniptus Belles, 1981^gLuzonoptinus Pic, 1923Maheoptinus Pic, 1903Meziomorphum Pic, 1898^gMezium Curtis, 1828^{i c g b}Myrmecoptinus Wasmann, 1916^gNeoptinus Gahan, 1900Niptinus Fall, 1905^{i c g b}Niptodes Reitter, 1884^gNiptomezium Pic, 1902Niptus Boieldieu, 1856^{i c g b}Okamninus Mynhardt & Philips, 2013^gOviedinus Bellés, 2010^gPaulianoptinus Bellés, 1991Paussoptinus Lea, 1905Piarus Wollaston, 1862^gPitnus Gorham, 1883^{i c g}Polyplocotes Westwood, 1869Prosternoptinus Bellés, 1985Pseudeurostus Heyden, 1906^{i c g b}Ptinus Linnaeus, 1766^{i c g b}Silisoptinus Pic, 1917Singularivultus Bellés, 1991Sphaericus Wollaston, 1854^{i c g b}Stereocaulophilus Belles, 1994^gSucinoptinus Bellés, 2007^gSulcoptinus Bellés, 1988^gTipnus Thomson, 1863^{i c g}Trigonogenioptinus Pic, 1937Trigonogenius Solier, 1849^{i g b}Tropicoptinus Belles, 1998^gTrymolophus Bellés, 1990^gXylodes Waterhouse, 1876^g
Data sources: i = ITIS, c = Catalogue of Life, g = GBIF, b = Bugguide.net