154 EXPERIMENT STATION. [Jan. 



correspondence. In addition, a number of other articles too 

 brief for bulletin material or not adapted for a pul^lication of 

 this nature have appeared elsewhere, and several more are nearly 

 ready for the printer. 



Insects of the Year. 



The year 1907 has brought many inquiries about different 

 insects. As heretofore, however, the San Jose scale has been 

 most prominent in the correspondence, followed closely by the 

 oyster-shell scale, plant lice, — particularly the woolly apple 

 louse, — the codling moth, the plum curculio as an apple pest, 

 the elm-leaf beetle and the apple maggot or railroad worm. 



The elm-leaf beetle, after several years of comparative unim- 

 portance, is again becoming a serious pest. In 1900 and 1901 

 it caused much injury in the Connecticut valley and in eastern 

 Massachusetts, and in 1902 its work was also very noticeable. 

 In the spring of 1903 the beetles were abundant, large numbers 

 of egg clusters were found, and there was every promise of an- 

 other year of serious injury. Diu^ing May and June, however, 

 there was a drought so marked that grass dried in the fields 

 and the leaves of the elms became hard and tough and many 

 fell off. It was noticed that many of the egg clusters of the 

 elm-leaf beetle failed to hatch under these conditions, and that 

 the young larvae in many other cases seemed unable to bite into 

 the tough, dry leaves, so that the work of this insect in 1903 

 was unimportant. The following winter was unusually severe, 

 but whether this was also a factor in the result cannot be stated. 

 Whatever the cause, however, few elm-leaf beetles were present 

 in 1904, 1905 and 1906, though in the year last named they 

 were increasing in abundance; but last summer (1907) they 

 had become quite plentiful, at least in certain localities, and it 

 is probable that they will be as injurious as formerly in a year 

 or two, unless climatic Victors again cause their destruction. 



Just how far the drought of 1903 was responsible for the 

 destruction of these insects it is of course impossible to say ; 

 but the abundance of unhatched egg clusters and the evident 

 struggles of the tiny grubs to break through the unusually 

 toughened epidermis of the leaves during that period are very 

 suggestive. 



