216 Maine Agricultural Experiment Station. 1919. 



KEY TO EASTERN SPECIES OF MACROSIPHUM.* 



1. Species developing on Compositae either ex- 



clusively or for a part of the life cycle 29 



Species not developing exclusively on Com- 

 positae 2 



2. Apex of cornicle with distinct reticulated area 



(e. g. solanifolii) 3 



Apex of cornicle inbricated (e. g. pisi) or in- 

 differently characterized (e. g. pelargonii) 22 



3. Apterous female with III closely imbricated 



throughout. Setae of III very short and 



stubby carpinicolens 



Apterous female not exceptional in foregoing 

 respect 4 



Species known only for Orchidaceae luteum 



4. Apterous female with base of VI nearer 3 



times length of II than 2 J / 2 times length of 

 II and base of VI more than 2 times length 



of hind tarsus 5 



Apterous female with base of VI nearer 2^ 

 times length of II than 3 times length of II 

 (or if not then base of VI not more than 2 

 times length of hind tarsus) 6 



5. Cornicle with distal half having strong imbri- 



cations extending to area of reticulation ptericolens 



Cornicle without strong imbrications leading 

 to area of reticulations diervillae 



6. Ill with numerous sensoria not in a row 7 



III with sensoria confined approximately to 



single row 10 



7. Ill of apterous female with sensoria not much 



exceeding basal half 8 



III of apterous female with sensoria extend- 

 ing over at least 2 /z length 9 



8. Cornicle with distal area of reticulation approx- 



imately 14, its length rosae 



Cornicle with distal area of reticulation ex- 

 ceeding Y^ its length impatiensicolens 



9. Cornicle with area of reticulation less than Y% 



its length albif rons 



Cornicle with area of reticulation more than }i 



its length amelanchiericolens 



10. Fore wing with Cu and A heavily shaded 11 



Fore wing with Cu and A not heavily shaded, 



though sometimes darker than other veins.... 12 



*Tarsal measurements in this key include only second joint of tarsus 



exclusive of . claw. Unless otherwise stated the alate form is indicated. 



