224 INSECTS AFFECTING VEGETATION 



however, feed upon grain. The corn silvanus is to be found over 

 almost the entire globe, infesting granaries, barns, dwelling houses, 



frocery stores, and in fact almost any place where it may find food, 

 t is very common in flour, meal, corn, dried fruits, rice, and bread. 

 It is a common pest in the museum specimens here at the Station, 

 and with the rust-red flour beetle is responsible for much of the dam- 

 age done to the entomological collection. 



The adult Silvanus is only about one-tenth of an inch in length, 

 with a slender, much flattened body of a chocolate brown color. The 

 thorax on each side is provided with six teeth-like projections, while 

 the upper surface has two shallow longtitudinal grooves. The larva 

 is a yellowish white, worm-like insect about one-fourth of an inch in 

 length, provided with three pairs of well developed legs. It is ex- 

 ceedingly active, readily passing from one seed to another for food. 

 The pupa is a little shorter than the beetle, of a yellowish white 

 color, and has spinous processes on both sides of the thorax and 

 abdomen. 



The life cycle in this climate requires about four weeks; it is 

 thus readily seen that there may be many generations during the 

 year. The eggs deposited among the grain soon hatch and the ac- 

 tive larvaB begin to feed. When ready to pupate the larva constructs 

 a protecting case by jointing together bits of trash and food material 

 with a silken secretion. In this case the pupal state is passed, and 

 from which the adult beetle emerges later on. Unlike the Angu- 

 mois grain moth the adult of this insect feeds upon the grain with 

 the larva. 



The Grain-Eating Bracliy tarsus. This is an insect that has 

 not heretofore been recorded as injurious to stored grain. The larvae 

 of the genus Brachy tarsus have been supposed to be parasitic on scale 

 insects, but this species has been found feeding, both in the larval 

 and adult condition, on stored corn, cow-peas and English peas, and 

 doing serious damage. The English name of grain-eating Brachy- 

 tarsus has, therefore, been given to this species, indicating its grain- 

 eating habits. Many of the species of the family to which this in- 

 sect belongs, infest seeds, and the stems of plants, in their larval 

 state; it is not the cause of much surprise therefore, to find this 

 species of snout beetle feeding upon various seeds. 



The adult is quite a thick bodied insect of an ashy brown color, 

 and densely hairy. The wing-covers are marked with punctured 

 lines, and a series of gray and black spots. These spots are due to the 

 presence or absence of the light colored hairs. It is about one-fifth 

 of an inch long. 



The pupa is about five thirty-seconds of an inch in length, 

 whitish, and densely covered with short spine like protuberances. 

 Rather long hairs are sparsely distributed over the body. The head 

 is bent down on the ventral surface of the prothorax. Each wing- 

 cover is marked with two pairs of rather prominent lines, the lines 

 of each pair curving in and meeting each other at the distal extrem- 

 ity of the wing-cover. 



