3G2 ANNUAL REPORT OF NEW-YORK 



PLUM. LEAYES. 



ascertain whether it is not these incisions which lay the foundation 

 for this disease, as Mr. Clark states. Where the incisions are 

 made by tree hoppers the insects will all escape before the swelling 

 in the limb commences, but the slits in the bark will remain, to 

 prove that these insects have been there. Where the plum weevil 

 makes the incisions its larv£e will be present in the excrescence; 

 and this will account for the fact long ago published by Prof. 

 Peck, that he had bred the plum weevil from these excrescences, 

 and hence inferred it was this insect which caused this disease. 



AFFECTING THE LEAVES. 



The May beetle a large thick-bodied chestnut or black beetle 

 about the middle of May eats the leaves of this and the cherry 

 tree. See No. 75. 



The Rose-bug, a smaller buff yellow beetle also feeds upon 

 them the last of June. See No. 50. 



The Grape-vine flea-beetle, No. 128, sometimes eats numerous 

 small holes in plum leaves also. A young plum tree in my yard 

 had its leaves nearly all destroyed by this insect, every summer, 

 for many years in succession, and other trees near this were more 

 or less injured. Dusting the leaves with caustic and bitter pow- 

 ders proved to be of little if any benefit. At last I resolved to 

 give this unfortunate tree a respite from its enemies, for one season 

 at least, and accordingly picked off and crushed in my fingers 

 every insect that could be found upon it. They were less active 

 after sunset, and with a sudden dart one or two could be caught 

 between the thumb and finger upon almost every leaf. From 

 fifty to two hundred were thus killed daily, for a week or longer, 

 and the hunt was persevered in as long as any insects could be 

 found. This treatment was even more successful than I antici- 

 pated, for I have never seen a flea beetle upon my plum trees since 

 that season. 



65. Plum Sphinx, Sphinx drupiferarum, Smith and Abbott. (Lepidoptera. 

 Sphingidse.) 



A large cylindrical apple-green worm with a curved violet-blue 

 horn on the hind end of its back, and along each side seven 



