302 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



Linnaeus in this publication. This aphid passes the winter and 

 spring on Ribes and the summer on Sonchus and Lactuca. For 

 figures see Patch (1914a). 

 A. nabali (Oestlund). Rhopalosiphum nabali Oestlund. 



Aphid, Minn., 34, 1887. 



Since this species was published by Oestlund (1887) it nas no * 



appeared in literature. It is not, however, uncommon in the east 



on the upper stalk and flower heads of Prenanthes (Nabalus) alba. 



A. rhois (Monell). Rhopalosiphum rhois Monell. Amphoro- 



phora howardii Wilson. (PL vii, 6.) 



Bull. U. S. Geol. Geog. Surv. Terr., v, 27, 1879. 



This aphid accepts Rhus for its winter host and various grasses 

 for the summer. 



On Rhus glabra, New Haven, 9 July, 1909 (A. I. B.). 



Toxoptera Koch. 

 T, graminum Rondani. 



Nuov. Ann. Sci. Nat. Rend., Ser. 3, vi, 10, 1852. 



This highly economic species occurs frequently in literature, two 

 references to which are Hunter (1909) and Webster and Phillips 

 (1912). 



Myzus Passerini. 



Key to Species. 



1. Large sensorium of antennal segment vi not much if any farther 



from juncture of v and vi than large sensorium of v 2 



Large sensorium of antennal segment vi at least about four times 

 as far from juncture of segments v and vi as large sensorium of v 3 



2. Large sensorium of antennal segment v typically more than twice 



its diameter from end of segment dispar 



Large sensorium of v typically less than twice its diameter from 

 end of segment ribis 



3. Large sensorium of antennal segment vi conspicuously larger than 



neighboring sensoria which are about uniform 4 



Large sensorium of vi approached in size by two of the neighbor- 

 ing sensoria which are larger than the others cerasi 



4. Sensoria of antennal segment iii more or less in a row -. 5 



Sensoria of iii numerous, not in a row 7 



5. Cornicle cylindrical 6 



Cornicle swollen _ persicae 



6. Very small species on strawberries (Fragaria) porosus 



Fair-sized species on wide range of plants, usually in greenhouse 



circumflexum 



7. Sensoria abundant on antennal segment iv 8 



Sensoria frequently present but few on antennal segments iv and v 



rosarum 



8. Cornicle incrassate 9 



Cornicle cylindrical : • -braggii 



9. Wing veins ordinary hippophaes 



Wing veins strongly shaded violae 



