334 FAMILY XI. — STAPlIYLINIDvE. 



Family XT. STAPH Yl.lNI D.K. 

 The Kovk Beetles. Tin; Shoht-winged Scavenger Beetles. 



A very large family of slender-bodied, small or medium-sized 

 beetles having the elytra truncate and very short, leaving always 

 some of the abdominal segments exposed, and covering usually only 

 two or three of them. Th(! abdomen, both al)ove and beneath, is of 

 corneous or horn-like texture, yet very flexible, and when the in- 

 sect i.s disturbed it is turned uj) ovei- the back as if the beetle were 

 about to sting. However, they are perfectly liarmless, though some- 

 times disagreeable on account of emitting an odorous fluid from the 

 tip of the abdomen. The ventral segments are eight (rarely seven) 

 in number, while there arc ten dorsal ones. The wings are usually 

 fully develoi)ed, often exceeding the abdomen in length, and when 

 not in use are folded beneath the short elytra. 



In addition to the characters mentioned, the Staph3dinida3 have 

 Ihe labial palpi three- jointed except in Tribe I; maxillary palpi 4- 

 jointed (5-jointed in Aleorhara) ; mandibles long, sharp and sickle- 

 shaped, usually crossing one anothei' at tips when at rest ; au- 

 tennffi variable in insertion and form, 11- (rarely 10-) jointed; 

 mesosternum short, its sidepieces large ; metasternum rather large, 

 with narrow sidepieces; front coxa^ usually large, conical, promi- 

 nent and contiguous, the coxal cavities rarely closed behind; hind 

 coxge contiguous except in the second subfamily; tarsi usually 5- 

 jointed, rarely 4- or 3-jointed. 



In habits the Staphylinids are to be classed as beneficial, as they 

 feed upon decaying animal and vegetable substances, and thus not 

 only act as scavengers. Imt also aid in reducing the manure heap, 

 and the manure when spread, into a more available form of plant 

 food. The larvae, except in the absence of wings, resemble the 

 adults both in structure and habits, and together with them occur 

 beneath bark, in fungi and in decaying plants, while some are guests 

 in the nests of ants, being reared and attended as carefully while 

 young, as are the young of the ants themselves. 



Sharp says that "it is pi-obal)le that one-hundred thousand spe- 

 cies or even more of Staphylinida^ are at present in existence." 

 This may be an exaggeration. But 9,000 species are at present de- 

 scribed, 1,500 of which are from the ITnited States alone, and many 

 new ones are turning up each year. As in the other families, the 

 present papei- treats only of those which have been taken in the 

 State, or which, from their known range, should occui\ It is prob- 

 a.ble that fully half as many more really occur, many of which are 

 at present unknown to science. The literature treating of the 



