HICKORY. TRUNK WALNUT ANT. TICKS UPON. 153 



tance of an inch or more. This discoloration will be observed in 

 every part of the trunk and limbs of the walnut tree, wherever 

 the burrows of these ants occur. And it seems quite probable 

 that the ant by thus saturating the wood with acid, hastens its 

 decay, in order to adapt it for being more easily mined. If we 

 are correct in this supposition, this curious faculty which our 

 walnut ant possesses of softening the wood in order that it may 

 be able to gnaw and excavate it more readily, renders this species 

 much more injurious than it otherwise would be. 



It is commonly stated of the insects of this family that males 

 and females are developed only in the summer, and that it is the 

 neuters alone that are to be found at other seasons of the year; 

 but of this species I meet with all three of the sexes, in a torpid 

 state in their burrows in the winter season. Those parts of the 

 burrows where the ants were present had their walls quite wet, 

 probably from the perspiration given off from their bodies. 

 And nestling in this wet surface a few larvse of the ants were 

 also met with. 



These larvx were very small footless grubs, measuring from 0.03 to 0.08 in 

 length, the largest individuals being about 0.03 in diameter. They are of a 

 cylindrical form, but always lie with the body doubled together in the form of 

 the letter U, or in the larger individuals with the head bent downwards against 

 the breast. They are of a white color, shining and semipellucid, with a black- 

 ish cloud in the center of the body from alimentary matter in the viscera. 

 The surface is covered with numerous shortish white hairs, and the segments 

 are marked by transverse impressed lines, which are much more obvious in 

 the large than in the small individuals. No projecting jaws can be discerned 

 at the mouth. 



Upon the wet surface of the walls of the cavities occupied by 

 these ants, extremely minute ticks may also be met with, numer- 

 ous in particular places, and of a pale red color, bearing some re- 

 semblance to a minute Coccinella or Lady-bird. These, it is 

 probable, are parasites living upon the ants. They are similar in 

 their form, texture, &c, to the common Beetle-tick (Gamasus 

 coleoptratorura, Lin.), but the hard shining plate covering their 

 back consists of one piece only. They consequently pertain to 

 the genus Unopoda of Latrielle, and the species may appropriately 

 be named Formica, or the Ant-tick. Of the species fio-ured in 

 Baron Walckenaer's Atlas of Apterous Insects, it bears the closest 



