582 THE STUDY OF INSECTS. 



the peas is not so generally understood. The eggs of the 

 Pea-weevil are laid upon the pod while the peas are quite 

 small ; when the larvae hatch they bore through the pod 

 into the young peas. Here they feed upon the substance 

 of the seed, which ripens, however, and in some cases will 

 germinate when planted. The larva before transforming 

 eats a circular hole on one side of the seed, leaving only a 

 thin scale, which is easily pushed away by the mature beetle. 

 The adult is about one fifth inch in length ; it is dark brown, 

 with a few white spots on the wing-covers, and one on the 

 prothorax near the middle. Sometimes the beetles leave 

 the peas during the autumn or winter ; but as a rule they 

 remain in the seed till spring, and are often planted with it. 

 Seed peas should be placed in water, and the infested ones, 

 which will float, should be picked out and destroyed. This 

 species is not known to oviposit on dry peas. 



This and other grain-infesting insects can be destroyed 

 by placing the grain into a close receptacle with a small 

 quantity of bisulphide of carbon. 



The Bean-weevil, Briichus obtectus (B. ob-tec'tus). — This 

 species resembles the preceding quite closely; but it is a 

 little smaller (Fig. 709), and lacks the white markings char- 

 acteristic of B. pisi. It infests beans, and often several indi- 

 viduals inhabit a single bean. The eggs are laid within the 

 pod, being pushed through a slit which the female gnaws 

 through the pod. This species will oviposit on dry beans, 

 peas, and other grain, and will continue to breed for many 

 generations in stored beans and peas. 



Family Tenebrionid^e (Te-neb-ri-on'i-dse). 



The Darkling Beetles. 



The darkling beetles are nearly all of a uniform black 

 color, although some are gray, and a few are marked with 

 bright colors. The different species vary greatly in size and 



