98 
Against these insects, methods of protection must evidently !, e 
the main reliance. If the nurseryman waits until their injuries 
alarm him, the time for checking their ravages is substantially 
past. Both these species pupate in the leaves, either upon the tree 
or upon the ground, and may be destroyed by collecting and bur¬ 
ning the rubbish between the rows; or watching for their first ap¬ 
pearance early in the season, the foliage may be sprayed with ar¬ 
senical solutions, or with Paris green or London purple in suspen- 
sion, thus poisoning the young larvae as they hatch or the older 
ones’as they extend their webs. 
5. Crepidodera helxines, L. 
Order Lepidoptera. Family Chrysomelid.e. 
The little flea beetle was noticed June 22, riddling the leaves of 
apple trees near Normal; and the common cucumber flea beetle, 
Crepidodera cucumeris, was also detected at the same work as early 
as the 10th of May. 
6. The Apple Plant Louse. 
[Aphis mail, Fab.) 
Order Hemiptera. Family Aphidim. 
/ ' jg!li 
In his article on this species in the Eighth Report from this 
office, Dr. Thomas expresses a doubt whether the common apple 
leaf aphis of Illinois, is the above species or that described by Fitch 
from Mercer county, Illinois, under the name of Aphis maltfolia .* 
Careful examination of the winged form of all the apple aphides in 
the collections which we have made during the last two years in 
Southern and Central Illinois, shows not a single specimen of 
malifolice, all being distinctly mail. 
It is worthy of remark that the second fork of the third vein of 
the anterior wing is often very small, and sometimes even dis¬ 
appears entirely, so that this vein presents but a single fork,—a 
character which, taken by itself, would exclude such specimens from 
the genus Aphis. When present, the fork varies from one-half to 
one-sixth or one-seventh of the length of the first. 
7. The Yellow Jumping Pear Louse. 
• (Trioza pyrifolice, n. s.) 
Order Hemiptera. Family Psyllih®. 
(Plate X. Fig. (5.) 
The injuries to the pear done by the common jumping pear louse 
[Psylia pyri) are well known to economic entomologists, and nave 
