478 Report of the Department of Entomology of the 



siderable oviposition by niveus and here and there an egg puncture 

 with the characteristic affected area surrounding it. 



Of the insects in this State which produce scarification and dis- 

 figurement of bark and wood of apple trees the most prominent 

 species, with the exception of the seventeen-year cicada (Tibicen 

 septendecim) , which is restricted to limited areas, are the buffalo 

 tree-hopper and the snowy tree cricket, which are very common 

 and widely distributed. Both insects are most injurious in plant- 

 ings that lack care with respect to approved orchard practices. 

 Both produce damage to trees as a result of their habits of oviposition, 

 and not infrequently the effects of their work may be observed on 

 the same tree. In the positions selected for the reception of the 

 eggs and in the effects of egg-laying upon the health of the trees, 

 the two insects show characteristic differences. The foregoing tree- 

 hopper (Ceresa bubalus) deposits its eggs in the bark of the newer 

 growth. In the case of young trees oviposition may be so extensive 

 that portions of the tree are stunted and the tree becomes ill- 

 shaped. The vitality of the older trees is generally not seriously 

 affected, the principal damage being scarification and roughening 

 of the bark if the deposition of eggs has been extensive. On the 

 other hand niveus prefers for egg-laying soft, fleshy bark, preferably 

 that of wood from one to three inches in diameter. By reason of 

 this habit apple wood is subject to oviposition by this insect over an 

 extended period of years, which results in considerable pitting, 

 scarring and other disfigurations of the bark. (Plate XXX, fig. 1.) 

 The extent to which apple wood is sought by this cricket for egg- 

 laying purposes is best observed by removing the bark, which will 

 reveal discolored areas in the cambium and wood (Plate XXX, fig. 2.) 

 and by making cross sections of the wood as shown in Plate XXX, fig. 3. 

 The chief damage by niveus on apples arises apparently from the 

 establishment of a bark disease in its oviposition punctures, which 

 causes the bark of the older wood to become scarred and roughened 

 or kills the bark on the younger wood, with resultant weakening 

 or death of small branches and twigs. 



occurrence of Leptosphceria coniothyrium about oviposition 



punctures. 



Cultural and microscopical studies by Mr. W. O. Gloyer of the 

 Department of Botany to identify the infectious agent which becomes 



