BULLETIN 39, UNITED STATES NATIONAL MUSEUM. [18] 



FIG. 20. A Tree-hop- 

 per (Ceresa bubahts). a, 

 side ; l>, top view. 



from two pores, situated ou tlie under side of the metathorax. Such 



well-known insects as the Bed-bug* and Chinch-bug 

 belong here. The habits of the species are varied, 

 and while some are beneficial, others are quite injuri- 

 ous to man. 



"The Whole-winged Bugs (Figs. 20 and 21), on the 

 contrary, are all plant-feeders, and with the excep- 

 tion of a few, such as the Cochineal and Lac insects, 

 are injurious. The secretion of a white, or bluish, 

 waxy, or farinose substance from the surface of the body is as charac- 

 teristic of this section as the 

 nauseous odor is of the first. 

 It forms three natural divi- 

 sions, arranged according to 

 the number of joints to the 

 tarsi namely TEIMERA, Avith 

 three joints; DIMEEA, with 

 two joints, and MONOMERA, 

 with ono joint to the tarsi." 

 Suborder THYSANOPTERA 



(tiusavoq^ a frill gC; TTTSpov, 



wing): This suborder con- 

 tains the single family Tkri- 

 ]>id(e, which comprises minute 

 insects commonly known as 

 Thrips, and of which a common species, Thrips striatux, is shown in 

 the accompanying figure. (See Fig. 22.) They bear strong relations 

 to both the Pseudoneuroptera and the Hemiptera and by later writ- 

 ers are generally associated with the latter order. They feed on plants, 

 puncturing and killing the leaves, or on other plant- feeding species of 

 their own class, and are characterized by having narrow wings crossed 



on the back when at rest, and 

 beautifully fringed, from which lat- 

 ter feature the name of the suborder 

 is derived. 



The mouth parts are peculiar in 

 that they are intermediate in form 

 between the sucking beak of He- 

 miptera and the biting mouth parts 

 of other insects. 



Their eggs resemble those of 

 Hemiptera; the larva? and pupa 1 

 are active, and in form resemble 

 the adult, except in the absence of wings. Some speries, also, are wing- 

 less in the adult stage. 



FIG. 21. A Plant-louse (Schizoneura laniytra). a, infested 

 root; b, larva; c, winged insect; d-g, parts of perfect 

 insect enlarged. 



FIG. 22. Thrips striatim, with wings enlarged 

 at side. 



