98 



Against these insects, methods of protection must evidently be 

 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 hclxlncs, L. 



Order Lepidoptera. Family Chrysomelidje. 



The little flea beetle was noticed -June 22, riddling the leaves of 

 apple trees near Normal ; and the common cucumber flea beetle, 

 Crepidodera cmumeris, was also detected at the same work as early 

 as the 10th of May. 



6. The Apple Plant Louse. 



[Aphis mall, Fab.) 



Order Hemiptera. Family AphididjE. 



In his article on , this species in the Eighth Eeport 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 Apkis malifolice* 

 Careful examination of the winged form of all the apple aphides m 

 the collections which we have made during the last two years in 

 Southern and Central Illinois, shows not a single specimen of 

 malifolia, all being distinctly Diali. 



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 -Tu:mping Pear Louse. 



{Trioza pyrifolifr, n. s.) 

 Order Hemiptera. Family Psyllid^. 



(Plate X. Pig. 6.) 



The injuries to the pear done by the common jumping pear louse 

 (Psylla pyri) are well known to economic entomologists, and have 



