ir. INSECTA: UEXAPODA, RHTNC'UOrA. 489 



Order VIII. Rhynchota. 



The Rliynchota, or bugs, in their external appearance are 

 nearest to the Archiptera and Orthoptera. The head, thorax, and 

 abdomen are joined in the same way; the develojiment is hemi- 

 mctabolous, and in the wingless species ametaboh^us. In some 

 cases, as the Cicadas with tlieir membranous wings, the confusion 

 with the Orthojjtera has led to these being called locusts; on the 

 other hand the delicate-winged Aphides resemble the Archiptera. 

 Yet all Ehynchota may be recognized by the sucking proboscis 

 (fig. .523), consisting of the grooved labium in which the needle- 

 like mandibles and maxillaj play. The wing structures afford the 

 basis of division into three sub orders. 



Sub Order I. HEMIPTERA (Heteroptera). Anterior wings hemelytra, 

 i.e., leathery at the base, soft and elastic at the tip (flg. 524); between the 



5 



Fig. ^2i.—Peidatoina rufipes. (From Hajek.) s, scutellum. 



hemelytra is a conspicuous triangular scutellurn (.s) which covers more or 

 less of the dorsal surface. Hemelytra and sculellum occasionally disap- 

 1 ear. A furtlier ciiaracteristio is the presence of stink glands, producing 

 , most disgusting odor, whioli open in the adults ventrally on tlie nieta- 

 thorax; in tlje larvse dorsally on the abdomen. According to habits the 

 many families may be grouped into the aquatic IIydrocores and the 

 terrestrial Geocores. Of tlie first tlie Belostomid^ are noticeable from 

 their size, Belostoma americana* being nearly 3i inches long and capable 

 of inflicting severe wounds. Other families are Nepid.e {Raiiat?a, water 

 scorpion), NoTONECxm^, Hydrobatid^, etc. Of tlie Geocores the Eedu- 

 VHD^, which feed on other insects; the Aca.\thiid.e (Acdrifhia lectuaria* 

 the bed bug); the LYG^Em^, containing the chinch bug. BlU'ms leticop- 

 terus* so injurious to grain; and tlie Pentatomid.b, or stink bugs, may be 

 mentioned. 



Sub Order II. HOMOPTERA. Wings, when not degenerate, similar in 

 texture throughout, althougli often differing in size. They are either parch- 

 ment-like or delicate membranes. The Cicadid.e, represented by Cicada 

 .septendecim,-'' tlie seventeen-year 'locust,' and C. tibicen* or dog-day har- 

 vest fly, are noticeable from their shrill notes, produced by a stridulating 

 drum on the abdomen. C. orni of the Old World fig. 526) punctures ash 

 trees, causing the flow of manna. The Cercopid.e contains the spittle 

 bug {Aj)rop!io?-a *) which causes drops of foam on grass. The leaf hoppers, 



