1802.] 



297 



Fia.I 



Fiy. ZT. 



Fig.in: 





FigNJK 



[Note. The above wood-cut was kindly loaned by the Secretary of the Illinois State 

 Agricultural Society.] 



SYNOPTICAL TABLE OF THE U. S. GENERA. 



Honey-tubes present. 

 (Antennte T-jninted : 

 front wings with ?> 

 diseoidals. the third 

 two-branched ; hind 

 wings with 2 diseoi- 

 dals.) 



Honey-tubes long. 

 ( Antennas with 

 joint 7 longer than 

 6.) 



Stigmal vein present. 



Honey tubes short, 

 subobsolete. (An- 

 tennce with joint ' 

 7 shorter than 6.) 



I Stigmal vein absent. 



Diseoidals of the front 

 wings of equal thick- 

 ness. ( Wings hori- 

 zontally folded.) 



Front wings with the 

 two first diseoidals 

 more robust. (Wings 

 steeply roofed.) 



Aphis, (figs. 1 and 2) 

 Foliage and roots. 



Calaphis, u.g. Foliage. 



■ Callipterus. Foliage. 



Lachnus. Twigs. 



("» 



Honey tubes obsolete. 

 ( Antennse short, with 

 not over six distinct 

 joints, 7 being obso- 

 lete or represented 

 by a very small un- 

 guicul'is nttaclied to 

 6.) 



Front wings with 

 ?> diseoidals, the 

 third 1-branched. 

 (Antennae 6-joint- 

 ed, 6 longer than 

 5.) 



Front wings with .3 

 simple diseoidals. 

 (Ilind wings with 

 2 diseoidals.) 



Hind wings with two 



diseoidals. ( Wings 



roofed.) 

 Hind wings with one 



discoidal. ( Wings 



horizontal.) 



Antennae 6-jointed, G 

 nearly as long as 4 

 and 5 together. 



Antennae 6-jointed, 4 

 -6 subequal,5 a little 

 the longest, 

 Front wings with two simple diseoidals. 

 (Hind wings with one discoidal; anten- 

 nae 4 or jointed?) 



Front wings witli one one-branched dis- 

 coidal. (Hind wings with no discoidal; 

 autennte 4 or 5 jointed ?) 



1 Eriosoma'? Twigs, 

 \ limbs and roots. 



[ Thelaxes. (fig. 5) Galls. 



' Byrsocrypta. (fig. 7) 

 (■ Galls. 



Pemphigus, (fig.6) 

 Roots. 



Chermes. Foliage. 



\ 



\ 



\ Phylloxera. ( fig. S ) ♦ 

 f Galls. 



