THE CHINCH-BUG FAMILY. 337 



abdomen, rarely brachypterous ; claval commissure usually 

 present ; connexivum narrowly or not at all exposed ; membrane 

 with four or five usually simple veins arising from the base; 

 front femora often swollen and armed beneath with teeth or 

 spines; tarsi 3- jointed; claws with arolia; osteolar openings 

 distinct. 



The family is a very large one, about 1,400 species being 

 known. Of these Van Duzee (1917) recognized 187 from 

 America north of Mexico, and a score or more have since been 

 discovered or described. Of these 120 are known or recorded 

 from the eastern states and included in this work. Both in 

 this country and our territory the family, therefore, ranks sec- 

 ond, or next to the Miridse, in number of species. In habits they 

 are for the most part phytophagous, feeding upon the juices 

 of many plants and one of them, the "chinch-bug," Blissus leu- 

 copterus (Say), is the most injurious Heteroptid known. How- 

 ever, the members of the large subfamily Rhyparochrominae 

 are thought to be mainly predatory or carnivorous, as their 

 front legs are more or less raptorial in structure, the femora 

 being usually swollen and armed beneath with teeth. The prin- 

 cipal literature treating of our eastern forms is by : Say, 1832 ; 

 Stal, 1872, 1874; Distant, 1882; Van Duzee, 1909, 1909a, 

 1910; McAtee, 1914; Barber, 1917, 1918, 1918a, 1918b, 1921, 

 1921a, 1923. 



In his "Synoptic Keys to the Lygseidse of the United States," 

 Barber (1917, 1918) , following Stal, has separated the Lygseidse 

 into eight subfamilies, seven of which are represented in the 

 eastern states. These are separated by a modification of his 

 keys, the structural characters used being mostly shown in 

 figures 69 and 70. 



KEY TO EASTERN SUBFAMILIES OF LYG^EID/E. 



a. All sutures between the ventral segments of abdomen straight and 

 reaching the lateral margins on each side; head usually without 

 setze near the eyes. 

 b. Front femora, as compared with the others, not much swollen, 

 rarely armed beneath with teeth or spines; hind margin of pro- 

 notum, or at least that portion of it in front of scutellum, turned 

 down convexly; all of the abdominal spiracles located on the dor- 

 sum or upper surface. 

 c. Elytra, and often the entire upper surface, impunctate; hind mar- 

 gin of pronotum between scutellum and lateral angles more 

 or less impressed or depressed ; membrane with two inner 

 veins usually united near base by a transverse vein. 



Subfamily I. Lycein^e, p. 339. 



