482 Report of the Entomologists of the 



SPECIES OF PLANT LICE UNDER OBSERVATION. 



Tliese include two, Eyalopterus pruni Fab., which has been 

 ver J .'abundant on the plum during the past season, causing serious 

 injury to the trees, and Myzus ribis, which has been equally 

 abundant and injurious on the currant. 



Attacking the Plum. 

 Eyalopterus pruni Fab. 



This species attacks the leaves of the plum, collecting in large 

 numbers on the under surfaces. The lice multiply rapidly, be- 

 coming so thick as to cover the entire under surface of the leaves 

 (Plate XXVII, fig. 10), causing them to curl and wilt. Their 

 bodies are covered with a bluish-white, mealy powder. Much 

 injury was caused in both orchards and nurseries by these lice 

 last season. In the Station orchard all of the varieties of plums 

 were attacked during the time when the lice were naturally most 

 numerous, but toward the latter part of the season but few could 

 be found excepting on the native varieties. 



History and present distribution. — ^So little attention has been 

 given this insect by writers on economic entomology that it is 

 difficult to learn itfii history. It is probably of European origin. 

 It was first described by Fabricius who lived in the latter part of 

 the seventeenth century. According to Bucton this species was 

 also mentioned by several early European writers. 



The insect is now known to occur in Germany, England, Aus- 

 tralia and New Zealand, and is probably distributed over a con- 

 siderable portion of the eastern United States. It has been founi! 

 as far west as Iowa. It occurs in abundance in the western part 

 of this State. 



Food plants. — The plum seems to be the principal food plant of 

 this species. It is said to infest the leaves of the grape, peach, 

 nectarine and apiicot in Europe. It is known to migrate from 

 the j)liiin io a species of gi'ass, Phrafjmitis communis. According 

 to II. Osborne jp.kI V. A Sii riiie* it also infests (h;' clioke cherry. 



•Insect Life. Vol. I, p. 235. 



