Pictorial key to the ant genera of Illinois

by N.C. Wilkins and S.B. Menke

Fig. 87 Myrmica fracticornis (antweb.org)

Fig. 88 Temnothorax pergandei (antweb.org)

Fig. 89 Stenamma diecki (antweb.org)

Fig. 90 Pheidole pilifera (antweb.org)

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A Propodeum slightly depressed below level of promesonotum.

 

B Antennal sockets widely separated by the median posterior portion of the clypeus, which forms a broadly rounded or triangular shape.

 

C Metanotal impression sometimes substantial, separating promesonotum and propodeum into separate, evenly rounded convexities.
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27'
AA Propodeum usually notably depressed below level of promesonotum.

 

BB If only slightly depressed, then antennal sockets closely approximated, with the median posterior portion of the clypeus forming a narrow, finger-like lobe.

 

CC Metanotal impression variable. Dorsal surface of propodeum often flattened, but sometimes convex.
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