December, '10] 



DAVIS: ILLINOIS APHIDID.E 



491 



in all my winged specimens are exceptionally constant and the fact 

 that spirceella rolls the leaves and as Schouteden says, "Die Blatt- 

 mitzbilbungen, welche Aphis spircea [ = spir(£tella] erzeugt, sind 

 bereits von verschiedenen Cecidiologen beobachtet worden."^ 

 The following table of comparison may be of interest : 



Winged viviparous female. 



A. spiraella. Schout. 

 Under rolled leaves o{ Spircea ulmaria. 



Abdomen green, usually marbled. 

 Head and thorax black. 



Antennal measurements, 



III = longest. 



IV = three-fourths of III. 

 V =one-half of III. 



(VI)=one-halfof (VII). 

 (VII) =about three-fourths of III. 



Beak reaching to hind legs. 



Style half the length of cornicles, dark green. 



Cornicles black, paler at tip. 



Wings transparent, wing veins (Wurzel und 

 Unterrandader) greenish, cubitus twice or only 

 once branched. 



Last segment of abdomen sometimes marked or 

 striped with black. 



A. spirceella ?? from Illinois. 



Colonizing on the tender terminal shoots and 

 leaves of S. vanhouttei and S. salicifolia. 



Abdomen pale green. 



Head and thorax black. 



Antennal measurements, 



III = four-fifths of (VII). 



IV = three-fourths of III. 

 V = three-fourths of III. 



(VI) =one-third of (VII). 

 (VII) = longest. 



Beak reaching to second pair of legs. 



Style more than half the length of cornicles, 

 black. 



Cornicles black. 



Wings transparent, wing veins pale brownish, 

 cubitus twice branched. 



Sometimes with dusky markings on abdomen as 

 given, description below. 



Wingless viviparous female. 



Antennse shorter than body, blackish, third 

 segment pale. 



Relative antennal measurements about as in 

 winged. 



Legs greenish, tips of femora and tibise and the 

 tarsi dark green. 



Style hairy, nearly half length of cornicles, dark 

 green. 



Cornicles dark green, black' and somewhat thinner 

 at tips. 



Antennae shorter than body, segments I and II 

 dusky. III and IV pale, V and VI darkening to 

 black. 



Relative antennal measurements about as in 

 winged. 



Legs pale greenish white, excepting " knee " 

 joint, tip of tibiae and tarsi blackish. 



Style moderately hairy, nearly half length of cor- 

 nicles, black. 



Cornicles black, gradually narrowing towards the 

 tip. 



Winged viviparoiis female. — Head (PI. 32, fig. 14) and thorax black, abdomen 

 pale green, and sometimes with a row of three dusky spots on each side anterior to the 

 cornicles, one at the base of each cornicle, and a faint dusky transverse marking 

 on each of the last two segments. Eyes black. Antennae pale except the two 

 basal segments which are dusky and the distal ends of V and all of VI which are 

 blackish (in some specimens only the basal ends of the segments are pale, the tips 

 being dusky to blackish), not reaching the base of cornicles, filament VI longest, 

 III four fifths of filament VI, IV and V subequal and each about three fourths of 

 III, base VI one third of filament VI; 6 or 7 rather large circular sensoria in a row on 

 segment III, sometimes one or two on IV, and the usual ones at the distal ends of V 

 and base VI (PI. 32, fig. 16). Wing veins pale brownish, first and second discoidals 



1 Loc. cit. p. 657 



