508 ^A^ INTRODUCTION TO ENTOMOLOGY 



The family BYRRHID-^, or the pill-beetles, are short, very con- 

 vex beetles of small or moderate size; some, however, are 12 mm. in 

 length. The body is clothed with hair or minute scales. The legs can 

 be folded up very compactly, the tibia usually having a furrow for 

 the reception of the tarsus. These beetles are found upon walks and 

 at the roots of trees and grass; a few live under the bark of trees. 

 Nearly one hundred species have been found in this country. 



The family NOSODENDRID^ includes two species of Noso- 

 dendron, one found in the East and one in California. They were 

 formerly included in the Byrrhidas, but differ from that family in 

 having the head prominent and the mentum large. These beetles live 

 under the bark of trees. 



The family RHYSODID^ includes only four species, two from 

 each side of the continent. They are elongate, somewhat flattened 

 beetles, with the head and prothorax deeply furrowed with longi- 

 tudinal grooves; and the abdomen with six ventral segments, the 

 first broadly triangular, widely separating the coxce. They are found 

 under bark. See footnote, page 470. 



The family OSTOMID^ includes oblong, somewhat flattened 

 beetles, of a black or reddish black color. Most of them live under 

 bark; but some are found in granaries, and have been widely dis- 

 tributed by commerce. The larva of a species found under bark has 

 been observed to feed on the larva of the codlin-moth. 



One well-known species, Tenebroides mauritanicus, infests gran- 

 aries. It is a shining brown beetle measuring about 8 mm. in length; 

 it is commonly known as the cadelle. Both adult beetles and larvae 

 feed on grain, but are also predacious, feeding on other insects infest- 

 ing grain. The larvae when full-grown burrow into the sides of the 

 bins, where they transform. 



The family NITIDULID^ comprises small, somewhat flattened 

 beetles. With many species the prothorax has wide, thin margins, 

 and the wing-covers are more or less truncate, so as to leave the tip 

 of the abdomen exposed; but sometimes the elytra are entire. The 

 tarsi are usually five-jointed, with the fourth segment very small; 

 they are more or less dilated; the posterior coxae are flat, not sulcate; 

 the anterior cox£e are transverse; and the abdomen has five free 

 ventral segments. 



Most species of this family feed on the juices of fruits and ferment- 

 ing sap that exudes from trees; a few are found on flowers, and others 

 on fungi or carrion. About one hundred thirty species are known 



ffrom North America. One of the most common species is 

 Glischrochlus (I ps) fasctdtus (Fig. 606). This is a shining 

 black species, with two conspicuous, interrupted, reddish 

 bands across the wing-covers, 

 p. gQg The family RHIZOPH AGID^ includes only the genus 



7?/jz2(5^AagM5, of which there are fourteen North American 

 species. These are small, slender, elongate species, which live 

 beneath bark. This genus was formerly included in the preceding 

 family; it differs from that family in that the antennae are only 

 ten-jointed, and the club of the antennae is two-jointed. 



