06 REPORT OF THE STATE ENTOMOLOGIST 1 92 1 



ish caterpillars of this insect confine their attack to portions of many 

 leaves (frequently practically all the leaves on a tree may be eaten 

 in this manner), feeding near the center under a slight web and 

 extending upward and outward to include most of the tip of the 

 leaf. Areas on each side of the basal portion of the leaf are fre- 

 quently left untouched, and not uncommonly the margins to the 

 width of one-half of an inch or so are turned over. There is no 

 webbing together and inclosing leaves in masses as does the fall 

 web worm or, to a less extent, the brown tail moth caterpillars. Both 

 of these last named species produce moderately firm to firm webs, 

 which inclose the leaves, something never done by the apple and 

 thorn skeletonizer. 



The observations of Henry Bird, of Rye, showed that this insect 

 was abundant on May 23d and in about the same numbers as the 

 preceding fall, at which time the moths were unusually numerous. 

 On June 12th he estimated that there might have been 10,000 larvae 

 at work upon a moderate sized apple tree and yet the tree was not 

 injured to any material extent, though the foliage had become some- 

 what thinned. He states that by September 8th the fourth larval 

 brood were very generally spinning their cocoons, although there was 

 considerable overlapping and moths from the previous generation 

 were still to be seen depositing eggs. He adds that the moths are 

 actively on the wing after 3 o'clock in the afternoon and have a 

 characteristic swinging flight. He states that last year the brood 

 appearing the latter half of September was the most conspicuous, 

 whereas the past season the indications are that it was quite negli- 

 gible. On October 7th he found a very few full-grown larvae on 

 new foliage under conditions indicating that they might represent 

 a partial fifth brood. 



Mr Bird noted a marked, though unaccountable falling off in the 

 numbers of the insects as the season advanced. He states that all 

 kinds of insectivorous birds destroy the larvae, though it seems 

 unlikely that they would act as a drastic check. He observed para- 

 sitism in the first brood only and this was less than 3 per cent in 

 1000 newly spun cocoons. The indications in early October were 

 to the effect that fewer adults would go into hibernation than was 

 the case last year. 



A general account of this insect was published as Cornell Exten- 

 sion Bulletin No. 27 in February 1918 and a more detailed one 

 appears in the Report of the Entomologist for 191 7, New York 

 State Museum Bulletin No. 202, pages 33-39. Both of these con- 



