HEMIPTERA 



389 



the bark of decaying trees; and the form of the body is especially 

 adapted for gliding about in these cramped situations. They are 

 usually dull brown or black ; sometimes they are varied with reddish 

 or pale markings. The hemelytra are usually well 

 developed, with distinct corium, clavus, and mem- 

 brane; but they are reduced in size, so that when 

 folded they cover only the disk of the abdomen (Fig. 

 450). Ocelli are lacking; the antenna are four-jointed ; 

 the tarsi are two-jointed; and the beak is four-jointed, 

 but often apparently three-jointed. 



These insects are supposed to feed upon fimgi or 

 upon the juices of decaying wood and bark. The 

 family is well represented in this countr}-; fifty-nine species, repre- 

 senting nine genera, are now known, and doubtless many remain to 

 be discovered. 



Fig. 450.— /I r- 

 adus acutiis. 



Fig. 451. — Hemelytron 

 trivittafus. 



Leptocoris 



Family COREID^ 



The Squash-Bug Family 



The members of this family vary greatly in form. Some of the 

 species are among the most formidable in appearance of all of our 

 Hemiptera ; while others are comparatively weak and inconspicuous. 



The family is characterized as 

 follows : the antennse are insert- 

 ed above an ideal line extending 

 from the eye to the base of the 

 rostrum, and are four-jointed; 

 the vertex is not transversely im- 

 pressed; the ocelli are present; 

 the beak is four-jointed; the 

 scutellum is small or of medium 

 size; the hemelytra are usually complete and composed of clavus, 

 coriiim, and membrane; the membrane is furnished with many veins, 

 which spring from a transverse basal vein, and are usually forked 

 (Fig. 451); the tarsi are three-jointed. 



This is a large family ; one hundred and twent}^- 

 four species, representing forty-eight genera, have 

 been found in our fauna. It contains both vegetable 

 feeders and carnivorous forms ; in some cases the same 

 species will feed upon both insects and plants. The 

 most common and best-known species is the following. 

 The squash-bug, Anzsa tnstis. — The form of the 

 body of the adult insect is represented in Figure 452. 

 In this stage the insect appears blackish brown above 

 and dirty yellow beneath. The ground color is really 

 ochre-yellow, darkened by ntunerous minute black 

 punctures. Upon the head are two longitudinal 

 black stripes; the lateral margins of the pro thorax 

 ar3 yellow, owing to the absence of the punctures along a narrow 



Fig. 452. — Anasa 

 tristis. 



