84 NEW YORK STATE MUSEUM 



IV 



REPORT OF THE STATE ENTOMOLOGIST 



The State Entomologist reports that two leaf feeders attracted 

 general notice the past season, namely, the apple tent caterpillar and 

 the allied forest tent caterpillar. The former, devouring the leaves 

 of many orchard and wild cherry trees, was easily recognized by 

 the large nests in the forks of the limbs. It was particularly in- 

 jurious in the upper Hudson and Mohawk valleys. The latter 

 pest, distinguished by the somewhat diamond-shaped, silvery .white 

 spots down the back, defoliated extensive areas of oaks on Long 

 Island, attacked the sugar maples in the upper Hudson valley and 

 stripped poplars in the Adirondacks. The probabilities of such 

 injuries were foreseen last year and timely warnings issued. A 

 number of rare or particularly interesting species have been ob- 

 served during the year, and brief notes concerning a number of 

 them are given in the Entomologist's report. 



Petroleum compounds as insecticides. The serious condition 

 of many sugar maples, following the application of miscible oils in 

 1911 and similar trouble in several apple orchards in 1912, was 

 followed up the past season by studies of some cases and these, in 

 connection with certain experiments, have resulted in confirming 

 the Entomologist's opinion as to the cause of the trouble. This is 

 a matter of much practical importance, since the injudicious use 

 of these materials may jeopardize the existence of hundreds of 

 valuable shade or fruit trees. The details of this work are given 

 in the Entomologist's report. 



Fruit tree pests. The studies and experiments of the last four 

 years on the codling moth were continued. In midsurrimer some 

 fruit growers became apprehensive of severe injury by larvae of 

 the second brood. Examinations failed to disclose a substantial 

 basis for such fears, and this opinion was confirmed in October by 

 observations made in the orchards of Messrs W. H. Hart of 

 Arlington and Edward Van Alstyne of Kinderhook. The owners 

 sprayed under strictly commercial conditions and with no ex- 

 pectations that the trees would be subjected to a test later. There 

 was a good crop and it was found that from 95 to 97 per cent of 

 the entire yield were worm-free as a result of one timely spraying. 



A small parasite has been exceedingly abundant and widely dis- 

 tributed in orchards infested by San Jose scale, and in not a few 

 instances has been an important factor in reducing the numbers of 

 the pest. Observations show that in most cases the trees in un- 



