298 ENTOMOLOGICAL NEWS.. [Nov. , '03 



The Plum Webbing Saw-fly. 

 BY H. T. FERNALD, PH.D., Amherst, Mass. 



On June 10, 1902 a letter was received at the Hatch (Mass. 

 Experiment Station, from Northampton, Mass., which stated 

 that a plum tree in the garden of the writer was being seriously 

 injured by some insect. Specimens sent with the letter showed 

 that it was the work of a saw-fly larva, and that the branches 

 were covered with a web somewhat resembling that of the fall 

 web worm. An examination of the infested tree was at once 

 made, and it was found that the larvae were nearly full grown, 

 and that the tree (about twelve feet high) was completely 

 covered with webs. These differed from those of the fall web 

 worm in their darker color and in the fact that the webs did 

 not extend from one branch to another to any great degree, 

 but followed the outline of each branch. 



On June 26th the larvae had all entered the ground, where 

 they were found from four to eight inches beneath the surface, 

 and many were so far from the trunk as to indicate that they 

 had dropped or spun down from the branches rather than had 

 crawled dow 7 n. 



Farther studies show that the larvae burrow down in the 

 earth to a distance of at least six inches from the surface to 

 pass the winter, and that a short period of pupation in the 

 spring is followed about the first of May by the appearance of 

 the adults. 



The adult insect agrees with the description of Lyda rnfipcs 

 Marl., published in Bulletin 48, of the South Dakota Agricul- 

 tural Experiment Station, April, 1896, and the brief account 

 of the habits of that insect there given also agrees with what 

 is here recorded. I learn that specimens of Lyda rufipcs in the 

 National Museum belong to the genus Neurotoma, where the 

 Massachusetts specimens had been placed before Marlatt's 

 description was found, and there can be no doubt that the two 

 are identical. As Marlatt's description seems to have been 

 generally overlooked, I include it in this paper. 



During the spring of 1903 the plum webbing saw-fly has 

 been raised and studied in all stages by Mr. E. A. Back, one 



