2IO AN INTRODUCTION TO ENTOMOLOGY. 



Y-shaped, and includes the antennal tubercles. The membrane of 

 the wing-covers lacks the discal white spots, and the basal half of the 

 clavus is red. 



Among the many smaller representatives of this family the fol- 

 lowing is the best known : 



The Chinch-bug, Blissus lencopterus. This well-known pest of 

 grain-fields is a small bug, which when fully grown measures a little 

 less than 4 mm. (0.16 in.) in length. It is blackish in color, with con- 

 spicuous snowy- white wing-covers. There is on the costal margin of 

 each wing-cover near the middle of its length a black spot ; from each 

 of these spots there extends towards the head a somewhat Y-shaped 

 dusky line. The body is clothed with numerous microscopic hairs. 

 In Fig. 1 80 this insect is represented natural size 

 and enlarged. The species is dimorphic, there being 

 a short-winged form. 



There are two generations of the Chinch-bug each 

 year. The insects winter in the adult state, hiding 

 FIG. 180. BUS- beneath rubbish of any kind; they even penetrate 



sus leucopterus. , . . 



forests and creep under leaves, and into crevices in 

 bark. In early spring they emerge from their winter quarters 

 and pair ; soon after the females begin to lay their eggs ; this 

 they do leisurely, the process being carried on for two or three 

 weeks. The eggs are yellowish ; about 500 are laid by a single in- 

 sect ; they are deposited in fields of grain, beneath the ground upon 

 the roots, or on the stem near the surface. The eggs hatch in about 

 two weeks after being laid. The newly-hatched bugs are red ; they 

 feed at first on the roots of the plants which they infest, sucking the 

 juices ; afterwards they attack the stalks. The bugs become full- 

 grown in from forty to fifty days. Before the females of this brood 

 deposit their eggs, they leave their original quarters and migrate in 

 search of a more abundant supply of food. About this time the 

 wheat becomes dry and hard ; and the migration appears to be a 

 very general one. Although the insects sometimes go in different 

 directions, as a general rule the masses take one direction, which is 

 towards the nearest field of oats, corn, or some other cereal or grass 

 that is still in a succulent state. At this time many of the bugs 

 have not reached the adult state ; and even in the case of the fully- 

 winged individuals the migration is usually on foot. In their new 

 quarters the bugs lay the eggs for the second or fall brood. 



Satisfactory means of preventing the ravages of this insect are 



