REPORT OF THE STATE ENTOMOLOGIST [916 63 



Conditions in western Now York appear to have been more favor- 

 able for the development of San Josd scale, though even there the 

 insect was certainly no more abundant as a rule than in the last two 

 or three years. 



SHADE TREE INSECTS 



Maple leaf-stem borer (Caulacampus acericaulis 

 MacG.). A borer in the leaf stems of sugar and other maple trees 

 has been reported from time to time and until within recent years 

 it has been commonly supposed that one or two Microlepidoptera, 

 namely Stenganoptycha claypoliana Riley and Pro- 

 teoteras aesculana Riley, were responsible for most of the 

 injury of this type. The investigations of Dr W. E. Britton, state 

 entomologist of Connecticut, during the last decade have resulted 

 in definitely associating injuries of this character with the above- 

 named sawfly, and it is probable that considerable of the work 

 attributed in earlier years to Lepidopterous borers is in reality the 

 work of this species. 



Observations the last of June on a sugar maple on the estate of 

 Mr Helme Straiter, Rye, N. Y., showed it to be rather badly infested 

 with this insect, some 30 per cent of the leaves on the south side of 

 a tree with a trunk diameter of approximately 1 5 inches having been 

 destroyed by 'this leaf stem borer. It was evident that the injury 

 was restricted in a considerable measure to the lower branches and 

 the sunny side of the tree. The foliage was noticeably thin and 

 here and there were to be found the greater portion of the leaf petiole, 

 the free part browned and shrunken, while the basal part was infested 

 by a pale yellowish green larva about one-fourth of an inch long. 

 The entire inside of these stems may be eaten out without deformation, 

 aside from a perceptible swelling frequently caused by the interior 

 being closely packed with borings. 



The dropping of leaves late in May or early in June, with a piece 

 of a leaf stem from one-fourth to one-half of an inch long attached 

 to the blade, is a characteristic of infestation by this species. The 

 remaining portion of the stem or leaf petiole remains upon the tree 

 and is not shed for some ten days or two weeks. At the time of 

 our examination, the last of June, a few of the injured leaf petioles 

 remained upon the tree, though by far the larger proportion had 

 dropped to the ground and it was comparatively easy to pick up 

 hundreds upon the lawn, a small number of which were still inhabited 

 by the borer. This species appears to be a very local one. There 

 is but one generation annually. The eggs, according to the obser- 



