262 



Beetles 



the large shield-like prothorax yellowish with a black blotch in the center. 

 In S. noveboracensis only the margin of the prothorax is yellow. 



The burying-beetles, Necrophorus, are large insects from an inch 

 to an inch and a half long, with the body thick and parallel-sided. The 

 commoner species have a pair of dull red transverse blotches on each elytron. 

 In some species the prothorax and head are also marked 

 with red. The common name comes from the well- 

 known habit of these insects of digging underneath small 

 dead animals, as mice or birds, until the corpse is in a 

 hole; it is then covered over and thus really buried. 

 The female lays her eggs on the corpse, and the larvae 

 hatching from them feed on the decaying matter. These 

 FIG. 359. Larva larvae have spiny plates on the back of the body and 

 ^Sttpha^so' (One are otherwise unlike the Silpha larvae. Some Necrophorus 

 and one-half times larvae are predaceous and others feed on decaying vege- 

 natural size.) 



Most of the blind, pale cave-beetles found in caves in this country and 

 Europe are Silphidae. 



The Cucujidae, with a name derived from the Portuguese Cucuyo, a 

 large luminous Brazilian snapping-beetle or elater, of entirely different 

 family, are a family of small beetles, with flattened reddish or light-brown 

 body, whose outdoors haunts are mostly under the bark of trees. Sev- 

 eral species, however, have learned that 

 life in a granary is just as safe from pre- 

 daceous enemies, and a thousand times 

 safer from starvation. Of these sophisticated 

 Cucujids, Silvanus surinamensis , the saw- 

 toothed grain-beetle (Fig. 360), is the most 

 familiar and injurious. The adult is about 

 \ inch long, flat and chocolate-brown, and 

 may be distinguished from the other small 

 beetles similarly attacking stored grain by 

 the serrated margins of its prothorax. It 

 infests dried fruits, nuts, seeds, and dry 

 pantry stores of all sorts, as well as grain bins 

 and cribs. The larvae (Fig. 360) are active 

 little six-legged flattened whitish grubs which run about and nibble indus- 

 triously. When full-grown the larva attaches itself by a gummy excretion 

 to some object, and pupates. When living in light granular substances, 

 as oatmeal, etc., a delicate case is constructed of the material in which to 

 pupate. In summer the life-cycle from egg to adult requires but twenty- 

 four days; in spring from six to ten weeks. Six to seven generations are 



FIG. 360. Larva, pupa, and adult of 

 the saw-toothed grain-beetle, Sil- 

 vanus surinamensis. (After How- 

 ard and Marlatt; much enlarged.) 



