SYNOPTICAL KEY TO THE APHIDIDAE OF MINNESOTA 135 
70. Genus SYMYDOBIUS Mordwilko, 1894. Type: Aphis oblonga 
Heyden, 1837. Our American representative of this genus has long 
been considered the same as the type form of Europe, but Baker has 
lately indicated it as distinct. 
(74) SYMYDOBIUS AMERICANUS Baker 
Found on shoots and twigs of Betula papyracea. 
71. Subtribe PANAPHIDII. Juglans-Myrica group. Antennae 
usually much shorter than the body; spur shorter than the base; anal 
plate emarginated. Found on walnut and hickory. The following 
genera may be indicated : 
a. Antennae less than half the length of the body....... Genus PANAPHIS 72 
b. Antennae about half the length of the body...... Genus CHROMAPHIS 73 
c. Antennae as iong as or longer than the body.......... Genus MONELLIA 74 
d. Antennae longer then the body; many spine-like tubercles on various parts 
GieGMeRDOUVAN, Sac <cs cess = oor Sites TE Ste Genus MELANOCALLIS 75 
72. Genus PANAPHIS Kirkaldy, 1904. Type: Aphis juglandis 
(Frisch) Gmelin, 1788. The very short antennae and spur led Pas- 
serini to consider juglandis the type of his Callipterus which was 
placed with the Lachnini. Koch considered it a Callipterint. 
(7s) PANAPHIS JUGLANDIS (Gmelin) Kirkaldy, 1904 
On the upper sides of the leaves of walnut. Not known from 
Minnesota but may be looked for. 
73. Genus CHROMAPHIS Walker, 1870. Type: Lachnus jug- 
landicola Kaltenbach, 1843. Antennae about half the length of the 
body. 
(76) CHROMAPHIS JUGLANDICOLA (Kaltenbach) Walker, 1870 
Found on the underside of the leaves of walnut. 
74. Genus MONELLIA Oestlund, 1887. Type: Aphis caryella 
Fitch, 1855. Antennae longer than the body; spur of the terminal 
segment somewhat shorter than the base; cornicles very short, small 
and primitive and not far in advance of the lateral tubercle type. 
The following species are found here: 
(77) MONELLIA CARYELLA (Fitch) Oestlund, 1887 
This delicate whitish form is rather common on the leaves of 
hickory. 
(78) MONELLIA CARYAE (Monell) Gillette, 1910 
Found with the ebove species; not as depressed and wings held 
roof-like at rest. 
