SB 

 818 

 C578 

 ENT 



No. 7, Second Series. 



nited States Department of Agriculture, 



DIVISION OF ENTOMOLOGY. 



THE PEAR-TREE PSYLLA. 

 i Psylla pyricola Foerst . I 



An overwhelming invasion of the pear-tree Psylla in the summer of 1894 in one 

 of the largest pear orchards in Maryland, together with similar appearances in 

 Virginia and New Jersey in the same year, gives prominence to an insect which 

 had not previously been reported south of New York, although known to extend 



Fig. I.— Pear-tree Pyslla : Adult female- natural size indicated bj side line (original). 

 westward as far as Michigan and to occur generally in the New England States. 



In view of its previous northern range, its sudden appearance in enormous 

 numbers SO far south was a matter of considerable surprise, and careful 

 examinations Of the work of the insect and experiments with remedies were 

 made. 



The pear-tree Psylla (fig. h is supposed to have been imported into Connec- 

 ticut about L832 from Europe, where this and one or two other species are well- 

 known pear enemies. It is one of the true bugs of the order I lomoptera, and 

 its family, the Psyllidse, is intermediate between or connects the scale insects 

 and the plant-lice on the one hand with the Cicadas and larger plant bugs on 

 the other. The Psyllidse are commonly known as the jumping plant-lice, on 

 account of the considerable vaulting ability of the adult insects. 



