582 Agricultural Experiment Station, Ithaca, N. Y. 



efforts in this line did not noticeably diminish the crop of these 

 caterpillars. Some sprayed with the poison three or four times 

 during the time tlie worms were at work. Mr. Albert Wood, 

 Carlton, N. Y., collected 60 live worms and placed 20 on each of 

 three large branches loaded with young apples; the branches were 

 cut off and nailed up somewhere. One branch was sprayed with 

 kerosene emulsion, one with arsenate of lead and the third with 

 hellebore. Two days after the worms were all lively and well, 

 and had kept on eating apples. The orchard from which these 

 worms were taken had received three thorough applications of 

 Bordeaux mixture and Paris green. 



It is possible that one or two thorough applications of Paris 

 green, made before the blossoms open, when the caterpillars are 

 small and feeding on the buds and leaves, might kill many of 

 them. However, the concensus of opinion among our correspond- 

 ents seems to be that they cannot be effectually reached with a 

 spray at any time. It is probably true that it is practically im- 

 possible to sufficiently coat the outside of a young apple with a 

 poison spray, so that one of the caterpillars would get enough to 

 kill it when it eats into the fruit. For this reason we concur in 

 the belief that the worms cannot be effectually checked with a 

 spray of any kind after the fruit gets large enough for them to 

 feed upon it. But the young worms must feed upon the buds and 

 leaves for a time before the fruit gets large enough, and it seems 

 plausible that a Paris green spray, thoroughly applied at least 

 once before the trees blossom, must result in the death of many 

 of the worms. We would like to see this tried, but there is one 

 difficulty which will always arise; that is, one can rarely, if ever, 

 tell whether the insects are present in his orchard in destructive 

 numbers until they begin to eat the fruit. It is always a good 

 practice, however, to spray orchard fruits at least once (where bud 

 moths or case-bearers are thick, ttvice) before the blossoms open 

 with the combined Bordeaux and Paris green. 



One correspondent writes that the caterpillars were the most 

 numerous in a cultivated orchard. This does not agree with the 

 observations of Professor Comstock made during the outbreak in 

 1877; he states that the fruit was injured most in those orchards 



