STATE AGRICULTURAL SOCIETY. 353 



PEAR. TRUNK. 



The bark of this limh was covered with an exceedingly thin 

 gray film, appearing as though it had been coated over with var- 

 nish, which had dried and cracked and was peeling off in small 

 irregular flakes, forming a kind of scurf or dandruff upon the 

 bark. In places this pellicle was more thick and firm and ele- 

 vated into little blister-like spots of a white color and waxy 

 appearance, of a circular or broad oval form, less than the tenth 

 of an inch in diameter, abruptly drawn out into a little point at 

 one end, which point was stained of a pale yellowish color and 

 commonly turned more or less to one side. On breaking open 

 any of these spots with the point of a needle, quite a number of 

 exceedingly minute oval eggs of a glossy bright purple color were 

 found beneath. These eggs probably produce mites of such 

 minute size as to be wholly imperceptible to the naked eye, 

 myriads of which, there is little doubt, at times overrun the bark 

 of particular trees of this kind, exhausting their juices and 

 causing them to pine and droop, when the proprietor is wliully 

 unable to discover the occasion of their unthriftiness. Tlie liabits 

 and changes of this insect will be similar to those of tlie Apple 

 bark-louse, (No. 15) and other kindred species. It is probably 

 this species as it appears in autumn, of which, as this page is pass- 

 ing through the press, I notice some valuable observations ])y A. 

 0. Moore, in the American Agricultuiist, vol. xvi., p. 287. 



55. Pear-tree Psylla, Psylla Pyri, Linn. (Ilomoptera. Psyllidse.) 



The smaller limbs and twigs drooping, their bark rusty black- 

 ish, and a multitude of ants and flies gathering around tliem to 

 feed on the honey dew whicli is dropped copiously by a small 

 yellow jumping insect resembling a louse, which punctures the 

 bark and sucks its juices, frequently killing tlie tree. After the 

 middle of summer appearing with transparent wings, and its head 

 deeply notched in front, its color now being orange yellow with 

 the abdomen greenish. Length 0.10. See Harris's Treatise, p. 

 202. 



50. Pkar ULioiiT BKKTLE, Scolytus Pyri, Peck. (Coleoptera. Scolytidae.) 



Particular twij^s of the pear, apj)le, plum and apricot suddenly 

 witlu'ring anil dying in the middle of the summer; small perfo- 



[Ag. Trans.] W 



