Bugs, Cicadas, Aphids, and Scale-insects 207 



sharp stylets or lancets (maxilla; and mandibles) to lacerate the plant-tissues, 

 and then the pharyngeal pump sucks up from the wound the flowing sap. 

 When too many pumps are drawing away too much sap, the leaves wilt, 

 yellow, and die. When too many leaves wilt, the plant starves to death. 

 And if the leaves happen to be the corn-leaves, and the pumpers chinch- 

 bugs, we have the result estimated for us (by the official U. S. statistician) in 

 millions of dollars of loss, as in 1887, when this particular loss in the Missis- 

 sippi Valley states was $60,000,000. 



The eleven plant-feeding families of true bugs (Heteroptera) can be 

 distinguished by the following key: 



Antennae 4-segmentcd. 



Fore wings reticulated and of uniform thin substance throughout Tingitid.e. 



Fore wings of various forms or absent, but not reticulated, and not of uniform thin 

 substanc^ throughout. 



Beak 3-segmented; body greatly flattened Aradid-E. 



Beak 4-segmented; body not greatly flattened. 



Membrane (apical area) of fore wings with one or two closed cells at base, but 



otherwis^e without veins (Fig. 268) Capsid.c 



Membrane of fore wings with four or five simple or anastomosing longitudinal 

 veins arising from the base; or with a larger number of veins arising from 

 a cross-vein at the base. 

 Ocelli wanting; membrane of fore wings with two large cells at the base, and 



from these arise branching veins (Fig. 268) Pyrrhocoridj;. 



Ocelli present. 



Head with a transverse incision in front of the ocelli Bervtid.e. 



Head without transverse incision. 



Membrane of fore wings with four or five simple veins arising from the 

 base of the membrane; the two inner ones sometimes joined to a 



cell near the base (Fig. 268) Lyg.eid.e. 



Membrane of fore wings with many usually forked veins springing from 



a transverse basal vein (Fig. 268) COREIDJE. 



Antennje 5-segmented. 



Scutellum nearly flat, narrowed behind. 



Tibi;e unarmed or furnished with very fine short spines Pentatomid.e. 



Tibia; armed with strong spines in rows CvDNlDi;. 



Scutellum very convex and covering nearly the whole of the abdomen. 



Small, black (sometimes with bluish or greenish tinge) CorimeL;ENID.e. 



Not black Sctn'ELLERID.E. 



The first of the families in the above table, the Tingitidse, includes the 

 curious small lace-bugs (Fig. 287), readily recognized by the delicate gauze- 

 or lace-like appearance of the back, due to the uniform thin and reticulated 

 character of the fore wings and of the wing-like expansions of the prothorax. 

 About twenty-five species are found in this country, all being plant-feeders, 

 living mostly on shrubs and trees. Hawthorn-bushes and oak-, sycamore-, 

 and butternut-trees all have particular species of lace-bugs on them. In the 



