54 NEW YORK STATE MUSEUM 



expected that considerable dead wood will be found another spring. 

 All such trees should receive special attention next season. The 

 dead wood should be removed and this possibly supplemented by 

 judicious pruning, the exposed cut surfaces being protected from 

 the weather by applications of tar, paint or similar materials. 



Most important of all, these trees should also be protected from 

 the continued ravages by the elm leaf beetle. Experience has 

 demonstrated time and again the entire practicability of con- 

 trolling this pest by thorough and timely applications of an arsenate 

 of lead (15 per cent arsenic oxide) to the under surface of the 

 foliage at about the time the leaves are three-quarter to full grown, 

 something depending upon the number of trees to be treated. The 

 most effectual spraying for this pest must be done between the 

 middle of May and the 25th of June. It is practically useless to 

 apply poison after the grubs commence to forsake the trees unless 

 the foliage has been so thoroughly skeletonized that the majority 

 of the leaves will drop and a new crop appear. Spraying for the 

 protection of this new foliage is always justified by results, and 

 the late applications may also be of service in protecting foliage 

 which had escaped injury earlier in the season. There are three im- 

 portant factors to be observed in this work if one would secure satis- 

 factory results ; namely, timeliness, the securing of proper material 

 and its thorough application to the under surface of the leaves. 

 Inattention to any one of these details will result in unsatisfactory 

 work, if not in a complete failure in the efficacy of the operations. 

 Our modern high power spray apparatus makes it possible to treat 

 such trees rapidly and without great expense. These methods, if 

 carried out faithfully, should insure practical immunity from ser- 

 ious injury and enable the elms to regain some of their normal vigor. 

 It is perhaps unnecessary to add that so far as the elm leaf beetle 

 is concerned, the application of sticky bands to the trunks of the 

 trees, or the scraping off of the rough bark, are of so little value as 

 not to deserve serious consideration at the hands of the practical 

 man. 



Bag worm (Thyridopteryx ephemeraeformis 

 Haw.). Numerous half grown larvae of this species were received 

 June 3, 1910 from Mr M. C. Albright, who took them at New Balti- 

 more. This, as has been previously pointed out, is near the northern 

 limit of this species. 



Sugar maple borer (Plagionotus speciosus 

 Say). The presence of this pernicious borer at Fulton was recorded 

 in our report for last year. An examination the present season 



