HEMIPTERA 



375 



The Isometopidas is closely allied to the following family, the 

 Miridag; by some writers it has been classed as a subfamily of that 

 family. In both families the antennas 

 are fonr-jointed; the beak is four-jointed; 

 the hemelytra are composed of clavus, 

 corium, cuneus, and membrane; at the 

 base of the membrane there are one or 

 two cells ; otherwise the membrane is with 

 out veins. The Isometopidae is dis- 

 tinguished from the following family by 

 the presence of ocelli, two in number. 



Only four species of this family have 

 been found in our fauna; one in Texas, 

 one in Arizona, and two in the East. 

 The Eastern species are Myiomma cixii- 

 formis, which is dull black in color with a 

 narrow white band across the base of the 

 cuneus; and Isometopus pulchellus, which 

 is easily recognizable by its contrasting 

 colors of dark brown and yellowish white 

 (Fig. 430). Both are exceedingly rare in- 

 sects. 



Family MIRID.E 

 The Leaf-Bugs 



Fig. 430. — Isometopus pulchel- 

 lus. (After Heidemann.) 



This family, which has been known as the Capsidce, is more large- 

 ly represented in this country than any other family of the Hemiptera. 

 Van Duzee in his "Catalogue of the Hemiptera North of Mexico" 

 lists 398 species, which represent 129 genera. The species are usually 

 of medium or small size. The form of the body varies greatly in the 



different genera, which makes 

 it difficult to characterize the 

 family. 



The most available char- 

 acter for distinguishing these 

 insects is the structure of the 

 hemelytra. These are almost 

 always complete, and com- 

 posed of clavus, corium, cuneus, 

 and membrane. At the base of the membrane there are one or two 

 cells; otherwise the membrane is without veins (Fig. 431). Other 

 characters of the family are as follows : the ocelli are wanting ; the 

 beak and the antennae are each four-jointed ; the coxae are subelongate ; 

 and the tarsi are three-jointed. 



It is impracticable to discuss here the divisions of this family; 



reference can be made to only a few of the more common species. 



The four-lined leaf-bug, PoEcilocdpsus linedtus. — This is a bright 



Fig. 431. — Hemelytron of Pcecilocapsus 

 lineatus. 



