378 



AN INTRODUCTION TO ENTOMOLOGY 



Fig. 433. — Hcmelytron of Triphelps. 



and the hemelytra are almost always fully developed and are furnished 



with an embolium (Fig. 433). As in the following family, the beak 



consists of three segments; the 

 antennae, of four; and the tarsi, 

 of three. 



The species are small. They 

 are found in a great variety of 

 situations, often upon trees and 

 on flowers, sometimes under bark 

 or rubbish. They are predacious. 

 Thirty-six species have been 

 catalogued in our fauna; these 



represent thirteen genera. The following species will serve as an 



example. 



The insidious flower-bug, Triphelps insididsus. — This is perhaps 

 the best -known of our species. It is a small black bug, measuring 

 only 2 mm. in length; the hemelytra are yellowish white on the 

 corium, at the tip of which is a large, triangular, blackish spot; the 

 membrane is milky white. This species is widely distributed; it is 

 common on flowers, and is often found preying upon the leaf -inhabit- 

 ing form of the grape Phylloxera; it is also often found in company 

 with the chinch-bug, upon which it preys and for which it is some- 

 times mistaken. 



Family CIMICID.E 



The Bedbug Family 



The members of this family are parasitic bugs, which are either 

 wingless or possess only vestigial hemelytra. In these insects the 

 ocelli are absent, the antennas are four-jointed, the beak is three- 

 jointed, and the tarsi are three-jointed. Only four species belonging 

 to this family have been found in America north of Mexico. These 

 can be separated by the following table, which is based on a more 

 detailed one given by Riley and Johannsen ('15). 



A, Beak short, reaching to about the anterior coxae. 



B. Pronotum with the anterior margin very deeply sinuate. The genus Clmex. 



C. Body covered with very short hairs; second segment of the antennae 



shorter than the third; hemelytra with the inner margin rounded and 



shorter than the scutellum. The common hedhxxg . . .C . lectuldrius 



CC. Body covered with longer hairs; second and third segments of the an- 



tennee of equal length; hemelytra with the inner margin straight 



and longer than the scutellum. Species found on bats. . .C.pilosellus 



BB. Anterior margin of the pronotum very slightly sinuate or nearly straight 



in the middle. Species found in swallows' nests. . .CEciacusvicdrius 



PiA.. Beak long, reaching to the posterior coxae. Infests poultry in southwest 



United States and in Mexico Hamatoslphon inodorus 



The common bedbug, Cimex lectuldrius. — ^The body is ovate in 

 outline and is very flat (Fig. 434) ; it is reddish brown in color, and is 

 4-5 mm. long by 3 mm. broad when full-grown. This pest is a noc- 



