THE STUDY OF INSECTS. 



the pygidium of both sexes is undivided, and may be cov- 

 ered or uncovered by the wing-covers, but is not surrounded 

 at the edge by them, as in the Scolytidae ; the tibiae are not 

 serrate ; the antennae are elbowed ; and the labrum is want- 

 ing. The larvae of the larger species bore in the stems of 

 plants, while those of the smaller species infest grains and 

 seeds. 



Among the more common members of this family are 

 several species of the genus Sphenophorus(Sp\\Q-nop\\'o-rus)\ 

 one of these is represented by Figure 727. These are 

 of medium or rather large size, and are often marked 

 in a very characteristic manner by longitudinal, 

 elevated bands of darker color. 



One of the most important members of the family, 

 FIG. 727. from an economic standpoint, is the Rice-weevil, Ca- 

 landra oryza (Ca-lan'dra o-ry'zas). This is a small snout- 

 beetle, measuring only one fifth inch in length. It is usually 

 black, but sometimes it is of pale-chestnut color, or some 

 shade between the two. It is exceedingly abundant, espe- 

 cially in the Southern States, where it does great injury to 

 stored grain of all kinds. 



Family SCOLYTID^; (Sco-lyt'i-dae). 



The Engraver-beetles. 



If the bark be pulled from dead branches or trunks 

 of trees, the inner layer and the sap-wood will be found 

 to be ornamented in many cases with burrows of more or 

 less regular form. These smoothly cut figures are the 

 mines of the engraver-beetles. Many kinds of these engrav- 

 ings can be found, each characteristic of a particular kind of 

 engraver-beetle. A common pattern is shown in Figure 728. 



The beetles that do this work are mostly of cylindrical 

 form and of small size ; many species are almost microscopic, 

 and the larger ones rarely exceed a quarter of an inch in 

 length. They are usually brown, sometimes black ; and 



