482 Report of the Entomologists of the 



SPECIES OF PLANT LICE UNDER OBSERVATION. 



Tlif^so include two, IfijaUjpterus pruni Fab., which lias bfMj 

 very .abundant on tho plum during the past s^.-ason, causing soriou« 

 injury to tha trcf-s, and Myzus rihis, which has been equally 



abundant and injuiious on ilif- <-urrant. 



Attackino the Plum. 

 Ilyal/jptcruH 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. lOj, causing them to curl and wilt. Their 

 bodies are covered with a bluish- white, mealy jKjwder. 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 rnosr 

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

 be found excepting on the native varieties. 



History and present distrihutkM. — So little attention has been 

 given this insect by writers on economic entomology that it is 

 difficult to learn its 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 sj^^cies wan 

 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 found 

 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 apricot in fhirope. It is known to migrate from 

 tile plum to a species of grass, Phragmitis communis. According 

 to H. Osborne and F. A Sjrrine* it ,'»I.<o infests the choke cherry. 



*Ingect Life. Vol. I, p. 235. 



