REPORT OF THE STATE ENTOMOLOGIST I913 9 



The rhododendron clear-wing (Sesia rhododendri) and 

 the pitted Ambrosia beetle (Corthylus punctatissimus) 

 were also studied. The first deforms and weakens the valuable 

 rhododendron, while the latter may destroy a considerable pro- 

 portion of one or more beds of this shrub. 



The work of the two-lined chestnut borer, Agrilus bilin- 

 e a t u s , a pernicious enemy of both chestnut and oak, was ob- 

 served in several localities about New York City and appropriate 

 recommendations made. A detailed account of this pest has been 

 given in New York State Museum Memoir 8. 



The Entomologist has taken advantage of the recent outbreak by 

 bark beetles, to study the general conditions which may result in 

 serious injury by these borers. A careful examination of weather 

 records, especially those relating to precipitation, tends to support 

 the belief that a series of annual droughts may so weaken the trees 

 as to produce conditions very favorable for the multiplication of 

 the borers. A discussion of the data is given in connection with 

 an account of the hickory bark beetle. 



Flies and mosquitos. The interest in the control of the house 

 fly and the subjection of the mosquito has continued. The Entomol- 

 ogist sent out several warning notices early in the year and pre- 

 pared a brief folder concerning the house fly, which was widely 

 circulated in early summer. He has also participated in several 

 public meetings called for the purpose of arousing interest in the 

 control of both flies and mosquitos. 



Gall midges. Studies in this group (Itonididae) have been con- 

 tinued and a number of species and three new genera described. 

 The practical character of this work is illustrated by the descrip- 

 tion of one midge which is considered a most important natural 

 enemy in controlling the red spider on cotton, and a consultation 

 with Prof. Henry Tryon of the Prickly Pear (traveling) Com- 

 mission respecting the introduction of certain gall midges into 

 Queensland, in the expectation that they might become important 

 agents in practically freeing large areas from the introduced and 

 obnoxious prickly pear. This report contains a detailed account of 

 a Cactus midge, Itonida opuntiae, which may prove of 

 great value in Australia, though regarded as a pest under certain 

 conditions in this country. The rose midge, Dasyneura 

 rhodophaga, an important enemy of the rose grower, has 

 caused considerable apprehension in the vicinity of Rochester on 

 account of its injuries to young plants. 



