April, '09] JOURNAL OF ECONOMIC ENTOMOLOGY 125 



reddish brown color, with a purplish tinge, and they are more or less 

 circular in outline, varying from one quarter of an inch to one inch 

 in diameter. From these there are occasionally lateral extensions of 

 dead and depressed bark, which may be larger than the original 

 wound. In comparison with published descriptions .of the various 

 canker diseases known to attack apple trees they resemble closely the 

 pit cankers, which have been shown by WhetzeP to be due to the same 

 "bacterium which causes the blight of the pear. Our interest in these 

 •cankers was aroused by discovering that in many of these affected 

 areas, usually about the center, there was a puncture in the bark, 

 which generally led to an orthopterous egg. From these eggs young 

 tree crickets have been hatched, which on attaining maturity were 

 kindly identified for us by Dr. W. S. Blatchley as Oecanthus niveus 

 De Geer. 



Injuries of this character by this cricket have been mentioned by 

 other writers. In 1898 Dr. A. D. Hopkins- described a cankerous con- 

 dition of bark, which was common in the older apple orchards, and 

 obtained eggs from apple branches, which he identified as belonging 

 to a species of tree cricket. The diseased areas were attributed to 

 I)light and woolly aphis, which apparently became established in the 

 wounds made by tree crickets in ovipositing. More recently Prof. C. 

 O. Houghton^ mentioned the occurrence of an insect's punctures, some- 

 times accompanied with depressed areas of bark, which were abundant 

 on the trunks of young plum trees. In the wounds were eggs, from 

 which specimens of Oecanthus m'vfus De Geer were reared. Similar 

 punctures, although fewer in numbers, were observed in the bark of 

 small apple and peach trees, and in raspberry canes. 



In our studies on the habits of the Snowy Tree Cricket on apple, we 

 "have found that eggs of this species are quite common on neglected 

 trees by the sides of ravines and highways, or on trees in orchards 

 that are given indifferent tillage or are grown in grass, in which weeds 

 to a more or less extent abound. Punctures in the bark by this species 

 are quite common with both old and young trees growing under these 

 conditions about Geneva. One Red Astrachan. surrounded by trees 

 of the same age of other varieties, seems to be especially attractive to 

 these insects. No difficulty is experienced in obtaining goodly num- 

 bers of eggs from limbs of this tree averaging about six inches in di- 

 ameter down to branches as small as one inch in diameter. The bark 



'Bull. 236, N. Y. Cornell Sta. 

 ='Biall. 50, W. Va. Exp. Sta.. p. 39. 



'Fifteenth Ann. Rept. Del. Exp. Sta., p. 150, and Entomological News, Vol. 

 XV, p. 57. 



