Key to Crematogaster Physocrema species

This worker key is based on: [[Media:Hosoishi S Ogata K 2009b.pdf|Hosoishi, S. & Ogata, K. 2009b. A taxonomic revision of the Asian endemic subgenus Physocrema of the genus Crematogaster. Zootaxa 2062: 15-36. PDF]]

Most Physocrema species show strong polymorphism in size and sculpture. Large workers are typically more useful than smaller workers for indentification, particularly in closely similar species.

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 * Crematogaster
 * Physocrema subgenus page

1

 * Propodeal spines developed and with pointed apices . . . . . 2


 * Propodeal spines undeveloped and forming obtuse lobes . . . . . 4

2
return to couplet #1
 * Antennal club 3-jointed. Pronotum raised steeply toward mesonotum in lateral view . . . . . Crematogaster mucronata


 * Antennal club 4-jointed. Pronotum raised moderately toward mesonotum in lateral view . . . . . 3

3
return to couplet #2
 * In lateral view, pronotum and mesonotum forming a single convexity, propodeum distinctly raised relative to promesonotum, metanotal groove deep . . . . . Crematogaster vacca


 * In lateral view, pronotum and mesonotum forming a single convexity, propodeum slightly raised relative to promesonotum, metanotal groove less deep . . . . . Crematogaster yamanei

4
return to couplet #1
 * Dorsal median portion of head swollen . . . . . Crematogaster tanakai


 * Dorsal median portion of head not swollen . . . . . 5

5
return to couplet #4
 * Propodeal spiracle situated near the metapleural gland orifice, the distance between them about the same as the propodeal spiracle diameter (Fig. 4) . . . . . 6


 * Propodeal spiracle situated away from the metapleural gland orifice, the distance between them much greater than the propodeal spiracle diameter (Fig. 3) . . . . . 9

6
return to couplet #5
 * Clypeus smooth and shining without longitudinal rugulae (Fig. 1) . . . . . Crematogaster inflata


 * Clypeus striated with rugulae (Fig. 2) . . . . . 7

7
return to couplet #6
 * Dorsal face of head strongly striated with abundant longitudinal rugulae. Scape not reaching posterior corner of head in large workers. Workers with pronounced size polymorphism . . . . . Crematogaster aurita


 * Dorsal face of head not strongly striated with longitudinal rugulae. Scape reaching posterior corner of head. Workers monomorphic in size . . . . . 8

8
return to couplet #7
 * The posterior portion of pronotum with transverse rugulae in dorsal view (Fig. 6) . . . . . Crematogaster physothorax


 * The posterior portion of pronotum without distinct rugulae in dorsal view (Fig. 7) . . . . . Crematogaster onusta

9
return to couplet #5
 * Dorsal setae on posterior portion of fourth abdominal tergite directed medially (Fig. 8) . . . . . Crematogaster difformis


 * Dorsal setae on fourth abdominal tergite directed posteriorly (Fig. 9) . . . . . 10

10
return to couplet #9
 * In lateral view, dorsal profile of promesonotum convex, propodeum distinctly raised relative to promesonotum, metanotal groove very deep . . . . . Crematogaster sewardi


 * In lateral view, dorsal profile of promesonotum convex, propodeum slightly raised relative to promesonotum, metanotal groove not so deep in dorsal median portion . . . . . Crematogaster ampullaris