290 CHINCH BUG LARVA, AND VARIETIES, 



bug, though of a brighter red color When it is small. One of 

 these young chinch bugs which I met with in some diseased 

 wheat straw sent from Virginia presented the following charac- 

 ters : 



The young larva when 0.06 long is about 0.03 in width, with a very flattened 

 body of an oval form and a bright blood red color, with a band across its middle 

 above, of a yellowish white color, occupying the two first or basal segments of its 

 abdomen, behind which, in the centre of the back are two black spots, one behiud 

 the other. Its six legs and its beak or sucker, are of a honey-yellow color. Its 

 antennne are analagous to what they are in the mature insect, having four joints, 

 the last enlarged, forming an oval knob tapering to a point at its end, the two ba- 

 sal joints being light yellow, and the two last ones dark brown. 



These larva? as they advance in size become darker colored 

 and finally blackish, still showing the white band across the 

 middle of their bodies. At length this band disappears, and 

 the insect becomes a pupa. It is now much like the perfect in- 

 sect in its form and colors, except that it is destitute of the white 

 wings upon its back, having in place of them an oval black 

 scale upon each side of the base of the abdomen. The edges of 

 the abdomen in the pupa are also of a dull pale yellow color. 

 So late as the fore part of October I met with several of these in- 

 sects still in their pupa state, and some of these I do not doubt, 

 would pass the winter in that state, and therefore would not de- 

 posit their eggs until the following spring. 



The females of this species are tenfold more numerous than 

 the males. The magnified illustration, plate 4, fig. 2 a, shows all 

 parts of the insect so distinctly and exact that no description of 

 it is necessary, beyond what is given in Dr. Le Baron's account. 

 It may be observed that the hind edge of the thorax is of the 

 same deep honey-yellow color with the legs, the beak, and the 

 base of the antenna?, all the rest of the body and the antenna? 

 being coal-black and clothed with fine erect hairs, except the 

 wing-covers which are snow white. The anterior end of the 

 thorax is not so full and broad as represented in the figure, and 

 extending across the thorax rather back of its middle is a trans- 

 verse depression, much more deep and distinct in some individ- 

 uals than in others. 



This species presents several varieties. On a comparison of numerous speci- 

 mens the following will be readily distinguished: 

 a, immarginatus. Basal margin of the thorax not edged with yellowish. Common. 



