147 



The antennae are long and tapering, mostly longer than the head 

 and thcrax, and often considerably longer than the body ; the body is 

 elongated; the tarsi are always distinctly four-jointed, spongy beneath 

 and the next to the last joint distinctly bilobed. 



Many of them when captured make a slight stridulating or creak- 

 ing sound by rubbing the parts of the thorax against each other. 

 Our species are usually of a medium size or large. 



The larvae are usually rather thick, fleshy grubs, generally somewhat 

 enlarged in front and tapering backwards, cylindrical or slightly flat- 

 tened, with deep incisions between the segments. The head is small 

 and more or less hid in the thorax. Most of them have six small 

 thoracic feet, but a number are entirely footless. They are, as a rule, 

 wood-borers. 



The family is divisible into four sub-families. 



1. Sub-fam. Prioninje. Body broad and depressed ; thorax trans- 

 versely oblong, with sharp lateral margins, usually toothed ; thighs 

 never clavate ; anterior coxae strongly transversal ; size large ; colors 

 uniform brown or black. The larvae have six small feet. Several 

 species of this sub-family are found in Illinois, all doubtless more 

 or less injurious to vegetation, but so far as known, only two claim 

 attention on account of the injury done to useful plants. 



Prionus laticollis — Dru. (The Broad-necked Prionus.) 



This is one of our largest beetles, and may 

 be readily distinguished by the following 

 characteristics : 



It is of a long oval shape, varying in 

 length from a little over one inch to nearly 

 one inch and three-fourths ; the width across 

 the wing-cases is nearly one-half the length. 

 The body is considerably flattened, and the 

 thorax, which is about twice as wide as it is 

 long, has three teeth on each lateral margin, 

 the middle tooth being the most prominent. 

 The antenna?, which are about half as long 

 as the body, are serrate, but these serratures 

 are not extended into long sharp teeth, as in 

 the following species. They are about 12- 

 iointed. The color is almost uniform ma- 



PRiuxisLATicoLLis.Drury; female. « hoganybrown . sometimes q uite black. 



The larva, or grub, is of a creamy white color, with a pale bluish 

 line along the back ; the first segment is large, being as long or 

 longer than the next three combined ; it decreases gradually in size 

 from the third segment backward to the end; underside somewhat 

 flattened ; head brown ; legs minute. When fully grown it is nearly 

 three inches long, and as large as a man's thumb. Dr. Harris says 

 they live in the roots of the Balm of Gilead, Lombardy poplar, and 

 probably in those of other kinds of poplar also. It had been observed 

 by various persons, boring into and hollowing out the roots of grape- 

 vine's, but the particular species it belonged to was not known until 

 Prof. Riley succeeded in rearing some to the perfect state from speci- 



