258 MAINE AGRICULTUR.\L EXPERIMENT STATION. I914. 



FRAGARIA. Stra\\^berry. 



Myzus porosus Sanderson. 



(Figure 91, J-M. Figure 96, H.) 

 On September 24, 1912, some wild strawberry vines growing 

 in the Station greenhouse near an open window were found to be 

 heavily infested with pale yellow and pale green apterous ovipa- 

 rous aphids with pale cornicles. Winged males were also pres- 

 ent. The plants were colonized on both upper and lower sur- 

 face of leaves, on the leaf stem and along the runners. An- 

 tenna of male has III with 15 or 20 sensoria, IV with i to 10, 

 and V with 8 more or less, as shown in the figures. The 

 cornicle is graceful and slender. Maine collection No. 171-12. 



PRUNUS. Cherry. 

 Myzus cerasi (Fab). 



(Figure 92, H-K. Figure 95, B.) 



A species so distinctive that there is no danger of confusing 

 it with other aphids is rather a relief. Mycus cerasi is a glossy 

 black plant louse of world wide distribution and a common pest 

 upon both wild and cultivated cherries, congregating on grow- 

 ing shoots and ventral surface of leaves which become badly 

 deformed. I have taken it in Maine on Primus pennsylvanica. 

 L. and P. serotina Ehrh, but have not followed the fortunes of 

 this insect through its seasonal history. 



Apterous females of collection 57-06 taken July 3 are re- 

 corded as follows : — head and eyes black, antenna black with 

 III and IV pale and with no sensoria except those usual for 

 V and VI ; prothorax and thorax, black, leg with femora pale 

 proximally and black distally, tibia pale except distal tip, tarsus 

 black; abdomen, long tapering cornicles, and cauda black. 



Alate females of the same collection had head and eyes 

 black, antenna black with about 12 sensoria on III (collections 

 of subsequent years had as many as 18) in a somewhat irregu- 

 lar row, usually none on IV, and with two_ of the marginal 

 sensoria on VI approximately as large as the terminal senso- 

 rium thus giving three large sensoria and several small ones 

 in the group at base of spur ; prothorax and thorax black, pro- 

 thoracic tubercle very small, wing with slender brown veins, 



