REPORT OF THE STATE ENTOMOLOGIST I915 '83 



section the latter part of July. It is probable that many of the 

 insects succumbed to the last treatment. The evidence at hand 

 indicates considerable protection from a poisoned spray, and the 

 m_ost economical and practical method of controlling this insect, 

 with our present knowledge, would doubtless be to watch for the 

 earliest feeding punctures and then spray thoroughly at once, and 

 if this treatment be given early, make a second application a week 

 to two weeks later, the greater delay being presumably advisable 

 if the earliest feeding occurs the latter part of May. 



Cherry leaf beetle (Galerucella cavicollis Lee.) . 

 This small, red leaf beetle was exceptionally abundant in Chautau- 

 qua, Cattaraugus, Erie and Niagara counties in particular, though 

 it was also reported from some other portions of the State. It 

 excited considerable attention and some apprehension because 

 of depredations on peach and cherry trees, it displaying a marked 

 preference for sour cherries. The feeding in most instances did not 

 seriously damage the trees, though in some cases it amounted to 

 partial defoliation. This is a common species in the Adirondacks, 

 occasionally becoming so numerous as nearly to defoliate the some- 

 what abundant wild red cherry, Prunus pennsylvanica, 

 frequently known as the bird, fire or pin cherry. 



This outbreak is by no means unprecedented, since several similar 

 though not such widespread depredations have been recorded by 

 the late Doctor Lintner (nth Rep't, N.Y. State Ent., pages 197-98, 

 1896). This peculiar condition of affairs may have been due, in 

 the opinion of Mr F. Z. Hartzell, to an unusual abundance of the 

 beetles in connection with the general defoliation of wild cherry 

 trees by apple tent caterpillars. The appearance of this insect in 

 Niagara county, according to Mr J. B. Achilles, was preceded by 

 about thirteen days of northeast winds, which suggests a possibility 

 that the beetles may have drifted from the Adirondacks where they 

 appear to be much more abundant than on wild cherry trees in the 

 western part of the State. 



This beetle, like other leaf -feeding insects, is susceptible to arsenical 

 poisons, and experiments conducted by Mr Hartzell at Fredonia, 

 showed that the trees could be protected if arsenate of lead was 

 used at the rate of 4 pounds to 50 gallons of water and the applica- 

 tion made to the lower as well as the upper surfaces of the leaves. 

 The most satisfactory results are obtained when the poison is com- 

 bined with bordeaux mixture. Tobacco extract, 40 per cent nicotine, 

 will also destroy the beetles but affords no subsequent protection 

 to the plants, since the volatile contact insecticide destroys only 



