THE LACE BUGS. 



449 



C05t3l area (costal m embrane of Stal J 



Su DCOStal area ( costal area of Stal ) 



m 



u 



<cm, 



mm®$mm§^®gjg$g§ 



'■Po 9°oS>c>0 



mmmmmi 



— •^xSSSSBS 



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Areoles 



msm? 



Fig. 96. Elytron of a Tingid, Physatocheila plexa (Say) showing the areas and 

 the areola or cells. (After Parshley in Hemiptera of Connecticut). 



The family is represented throughout the world, about 350 

 species being known. All are plant feeders, living mainly in 

 all stages on the under sides of leaves, where they suck the 

 sap causing the upper surface to become whitened and the 

 lower one spotted and discolored by their excrement. Each spe- 

 cies has its preferential host-plant on which, or on closely allied 

 plants, it spends its life. The adults of many species hiber- 

 nate beneath bark, dead leaves or other cover. Others pass 

 the winter in the egg stage, the eggs being either attached 

 to the under surface of the leaves and covered with a dark, 

 somewhat shining varnish-like substance, or inserted in the tis- 

 sues and covered with a brownish scab-like crust. The more 

 common or better known species are two-brooded and undergo 

 four or five nymphal stages, the first brood appearing in May or 

 June, the second in late August or September. The principal lit- 

 erature on our American species has appeared in recent years, 

 scores of new species having been described in and since 1916, 

 when Osborn & Drake issued their "Tingitoidea of Ohio." That 

 most useful to the student is as follows: Stal, 1873; Uhler, 

 1878; Distant, 1897; Bueno, 1916; Gibson, 1918, 1919; Barber 

 & Weiss, 1922 ; Bergroth, 1922, and the numerous papers of 

 Osborn & Drake, Parshley, Heidemann and Drake, mentioned 

 in the Bibliography near the end of this work. 



More than 120 species of the family are now recognized from 

 North America, 73 of which occur in the eastern states. These 

 are divided among 22 genera, all belonging to the subfamily 



