Key to species groups

Step 1: Scapal sinus without a denticle or process, apart from the inter-insertional projection ……… –> 2
(not Lower scapular sinus with denticle or carinate process independent of the inter-insertional structure)

Male like female, without a process or tooth in the lower scapal region (apart from the short interantennal ridge)

Key to species groups

Step 2: Propodeum - dorsal surfaces very incompletely separated from lateral surfaces; stigmatic carina generally absent or indistinct ….. –> 4
(notdorsal surface completely separated from the lateral surfaces by a keel that passes under the stigma; lateral surfaces with a distinct stigmatic keel)

Male like female, propodeum with no sharp division between the dorsal and lateral surfaces

Male like female, the prepectus rounded.

Male like female, propodeum without median longitudinal groove

re first option for Key Step 6:

The shape of the marginal cell does not match the description for Group clavipes, nor the illustration at Fig. 106 (see ‘Bits & pieces’ section for excerpt).

re second option for Key Step 6:

The shape of the first gastral segment is not subrectangular. And it is distinctly ovoid posteriorly. This therefore procludes moving on to Step 7.

Key to species groups

Step 8: space between the antennal insertions without protrusion; insertions separated by an entirely pubescent, flat space
(not with a compressed, non-pubescent, very distinct projection) … 11

Male like female, femur more or less elliptical, not abruptly widened at base

Key to species groups

Step 11: Pygidial area not punctate posteriorly, almost entirely glabrous with just a few bristles … –> 12
(not densely punctate and with adpressed setae)

Key to species groups

Step 12: Gaster pedunculate … –> 14
(notwith sessile or subsessile gaster)

Step 14: Female pygidial area triangular, flat, and with straight sides … 16
(not with pygidial area very long, very narrow; and not with segment I of metasoma trapezoid)

Key to species groups

Step 16: Mandible with single strong tooth, plus a recessed lower tooth* … –> 17
(notbidentate)
* it is somewhat unclear whether this should be considered bidentate

Male like female (gaster pedunculate, not sessile or subsessile)

Pygidial area rimmed, partly smooth, with some distinct punctures –> to Step 20

Genae black, including near mandibular socket. Gaster and thorax also entirely black/dark –> to Step 22

Pronotal collar not laterally dilated into conical tubercles (as it is in R. etiratum) –> to Step 23

Prepectus rounded: omaulal area not in two perfectly perpendicular flat planes –> to Step 29

Front femur elliptical, not suddenly enlarged at base (as it is in R. etiratum). –> to Step 29

Gaster black, legs extensively black. not with extensive orange colouration (as in R. transiens & species group coarctatum) –> to Step 32

Space between antennal insertions setose and without protrusion –> to Step 34

Propodeum shiny –> to Step 34

Gaster pedunculate, not sessile or subsessile –> to Step 41

Head much wider than long (not subsquare), with definite punctation –> to Step 42

41. Mesoscutum with punctations, not smooth & shiny –> to Step 42

42. Scutellum similarly sculptured, not striated –> to Step 43

43. Punctures on mesoscutum relatively dense, without large smooth intervals –> to Step 51

Mandible black, not ivory or yellow. Scape extensively black, not entirely pale –> to Step 51

51. Mandible apparently bidentate, with the lower tooth shorter and recessed –> (to Step 59) … I have elected to follow Step 52*

* In Leclercq’s 1957 key to species group the ‘unidentate’ option included the caveate ‘rarely with a trace of a very recessed lower tooth’

52. Mandible black, without light citrine or ivory markings –> to Step 53 (Group variitarse)

Clypeus margin subtruncate medially (dotted region), with prominent tooth on each side (arrows). Lateral teeth longer than the middle margin = R. coriolum

Male like female, mandible with strong, rounded upper tooth and much smaller, recessed lower tooth. Mandibles entirely black.

The scape is extensively yellow beneath.

Occipital carina ending ventrally in a denticle (arrows) = R. coliolum