BUGS. 223 



showy species of the entire group. It may be recognized by the shorter antennae, 

 composed of six joints, the last one often ending in a spur much like a supple- 

 mentary joint, and by having the fourth vein of 

 the fore-wings nearly straight, the stigma linear, 

 and the body coated with white powder. 



Lachnus caryce is a showy form, about one- 

 fourth of an inch in length, of a bluish slate- 

 color, with four transverse rows of black dots, 

 reddish thighs, no stylet to the venter, and only 

 very short honey-tubes. It dwells in loose 



, , . . -, i FIG. 300. - Lachnus punctatus. 



clusters on the twigs ot the pignut hickory, and 



is seen fully winged in the autumn. This species is in marked contrast with the com- 

 mon garden or field forms of the aphides, which are generally glossy, more flask- 

 shaped, delicately built, with green, yellow, or black bodies, and long, seven-jointed 

 antennae. 



In the Pemphigina the body is obese and blunt, clothed with cottony secretion, 

 the honey-tubes small or absent, the antenna short and six-jointed, the fore-wings 

 with only one fork to the third discoidal vein, and the hind-wings with one or two 

 oblique veins. They live chiefly on bushes and forest trees, a few only on fruit- 

 trees. 



The Chermesina have only two discoidal veins to the fore-wings, and the antennae 

 are usually composed of five joints, but exceptionally of only three. This group includes 

 the dreaded Phylloxera of the vine, and is composed of very small insects, usually of 

 a black or yellow color, living upon different kinds of forest trees in Europe and 

 North America. 



As the name implies, the Rhizobiina live upon the roots of plants. Only apterous 

 subterranean forms have yet been found, and these are commonly of a depressed 

 figure, tinted with pale brown or yellow colors. One form has been found common on 

 the roots of lettuce, in the State of New York ; and another species lives on the same 

 parts of the Poa grass, at Carbondale, Illinois. 



About one thousand species of the entire family have thus far been brought to the 

 notice of entomologists, and those chiefly from Europe and North America, but by far 

 the greater number still remain unrecorded ; and in the United States they have been 

 so much neglected that scarcely two hundred species have yet been made known. 

 They flourish best in the temperate climates, and are to be met with in smaller num- 

 bers in many parts of tropical America ; but they are by no means absent from the 

 colder regions, and are well represented in the highlands of Scotland, in Sweden, and 

 in the extreme north of British America. 



A step in advance leads to the less comprehensive, but singular family PSYLLIDJE, or 

 Jumping-lice. These are moderately small insects, of firmer texture and stouter limbs 

 than the aphides, but, like them, live solely upon the juices of vegetation, and cause 

 serious injuries to various fruit-trees and bushes. 



They somewhat resemble Cicadas in miniature, and their wing-covers rest slanting 

 as in most of the higher Homoptera. The thighs are thick, the hindmost shanks are 

 armed at tip with stout spurs to aid in leaping, and the tarsi two-jointed. They have 

 generally a flat, transverse forehead, with three gem-like ocelli, one situated on each 

 inner angle next the eye, and the third in the suture of the face between the lobes. A 

 very marked feature is seen on the epistoma, which is decidedly cleft, and the lobes 



