124 NEW YORK STATE MUSEUM 



The dead bees, three times washed in ammonia water, the latter not 

 reveaHng the presence of the arsenic externally, when tested showed its 

 presence internally. Brood from uncapped cells (larvae) of a colony sud- 

 denly dying without other apparent cause gave evidence of having died 

 from the effect of arsenic which could have been introduced only from 

 without. 



" In summing up the matter, then, I can see no other conclusion that 

 can be drawn from the results of my experiments than that bees are liable 

 to be poisoned by spraying the bloom of fruit trees, the liability increas- 

 ing in proportion as the weather is favorable for the activity of the bees, 

 and that all bloom must have fallen from the trees before the danger will 

 have ceased." 



On the Girdling of Elm Twigs by the Larvae of Orgyia 

 leucostigma, and its Results. 



(Read before the American Association for the Advancement of Science at its Springfield 



meeting, September 3, 1895.)* 



The white-marked tussock moth, Orgyia leucostigtna, has for a long 

 term of years been exceedingly destructive to the foliage of the elms, 

 horse-chestnut and fruit trees in Albany. Fruit trees of considerable 

 size have been killed by their defoliation in a few days, toward the 

 maturity of the caterpillar. Large elms and horse-chestnuts have had 

 the foliage entirely consumed, only the ribs and principal veins remaining. 



In the summer of 1883, a new form of attack by this insect was 

 observed by me in Albany. About the middle of June of that year, the 

 sidewalks, streets and public parks where the white elm, Ulmus Americana, 

 was growing, were seen to be thickly strewn with the tips of elms two to 

 three inches in length, bearing from four to ten fresh leaves, and com- 

 prising nearly all of the new growth of the season. On examination it 

 was found that above the point where the tips had been broken off, the 

 bark had been removed for an extent averaging about one- tenth of an 

 inch, apparently by an insect. 



As the Orgyia larvae were then occurring in abundance on the trees 

 they were suspected of being the authors of this injury, and the suspicion 

 was verified by ascending to a house-top, where the roof was found to be 

 heaped in the corners with the severed tips, and the caterpillars engaged 

 upon the branches in the girdling. The explanation of the breaking-off 



* Published in the American Naturalist, xxx, January, 1896, pp. 74, 75. 



