i68 



AN ECONOMIC ENTOMOLOGY. 



long antennae. Some of them are dirty clay-yellow in color, with 

 the disk of the wing-covers marked with black or brown. 



We have only a few species belonging to the genera Caj-abiis 

 and Calosoma, in marked contrast to the great number found in 

 European fields, none of our large forms having found life in 

 tilled land tolerable. The species of Calosoma often ascend trees 

 and feed on caterpillars, the term "caterpillar hunters" having 

 been in consequence applied to them ; but some of the smaller 

 species also have similar habits. In orchards they are som.etimes 

 found hidden just beneath the surface of the soil, close to the base 

 of the trees. 



The " Bombardier beetles," belonging to the genus Brachhius, 

 may be especially mentioned because of their peculiar power of 

 emitting a puff of bluish vapor from the anus when suddenly dis- 

 turbed. They have the body, head, and thorax reddish, the 

 elytra blue, and are found under stones along the edges of roads 

 and near woodlands, or, more rarely, in the loose rubbish at the 

 base of trees. 



A series of very much flattened species frequents flowers, feeding 

 upon the minute insects abundant there, and these are sometimes 

 red and blue, or even brilliant metalHc green, with the wing- 

 covers squarely cut ofl behind so as to expose the tip of the 

 abdomen. Among these is the Lebia grandis, a moderate-sized 

 species, with yellowish-red head and thorax, and blue elytra, that 

 makes itself useful by feeding upon the eggs and larvae of the 

 Colorado potato-beetle. 



But the great majority of our species are moderate in size, and 

 of powerful build, black or nearly so, lurking under all sorts of 

 rubbish in field and orchard, frequently in large numbers, yet 

 rarely observed, and ready at all times to pounce upon any soft- 

 bodied larvae that come within their range of vision. These 

 belong to the genera Pterostichus, Ajiisodactylus, Amara, Har- 

 palus, Agonoderus, or their close allies, and they are decidedly 

 important factors in checking the undue increase of certain species 

 which must go underground to complete their transformations, 

 — the " plum-curculio," " pear-midge," and others. Their 

 larvae are even more retiring and less frequently seen, but live 

 in similar situations. They are slender, more or less flattened, 

 of nearly equal width, with six short legs, a pair of prominent 



