Chlerogas, Vachal, 1904

Engel, Michael, 2010, The bee genus Chlerogas in Bolivia (Hymenoptera, Halictidae), ZooKeys 46 (46), pp. 61-70 : 68-69

Key to species of Chlerogas

The key presented here is corrected and updated from that provided by Engel and Gonzalez (2009).

1. Antenna with 10 flagellar articles; medioapical margin of metasomal tergum V entire (males) ......................................................................................... 2

– Antenna with nine flagellar articles; medioapical margin of metasomal tergum V with slit (females) ......................................................................... 11

2(1). Metasomal terga metallic green to blue; legs dark brown to black............... 3

– Metasomal terga and legs largely amber to brown or black, not metallic..... 4

3(2). Integument between punctures ventrally on mesepisternum polished smooth or very faintly imbricate and shining; basal area of propodeum with weak striae in basal quarter to third ( Peru)........................... C. chlerogas (Vachal)

– Integument between punctures ventrally on mesepisternum strongly imbricate and weakly shining; basal area of propodeum with distinct and complete striae ( Colombia, Ecuador) .............................. C. cyaneus Brooks & Engel

4(2). Head and mesosoma not metallic, brown to black; leg coloration variable .... 5

– Head and mesosoma metallic green to blue, sometimes coloration is rather subdued on mesosoma and face (i.e., C. tatamaensis ); legs largely amber, nev- er entirely dark brown to black................................................................... 7

5(4). Legs largely amber; apex of clypeus with transverse amber marking............ 6

– Legs dark brown to black, without amber podites or markings; apex of clypeus with narrow brown or amber ( Bolivia)............... C. aterrimus sp. n.

6(5). Metasomal sterna I–III brown ( Peru) ................. C. hirsutipennis Cockerell

– Metasomal sterna I–III amber ( Ecuador) .................. C. cooperi Engel et al.

7(4). Metasomal terga I and II amber with transverse dark brown bands ............ 8

– Metasomal terga I and II entirely amber ( Colombia).................................... ................................................................ C. colombiensis Brooks & Engel

8(7). Antennal scape dark brown to black........................................................... 9

– Antennal scape entirely amber ( Venezuela)............ C. tiara Brooks & Engel

9(8). Apical margin of metasomal sternum V deeply concave ........................... 10

– Apical margin of metasomal sternum V entire ( Venezuela)........................... .................................................................. C. araguaensis Brooks & Engel

10(9). Integument around median line of mesoscutum with well defined, small punctures separated by 0.5–1.75 times puncture width and imbricate; metallic green of head and mesosoma brilliant and shining ( Venezuela)................ ......................................................................... C. townesi Brooks & Engel

– Integument around median line of mesoscutum granulose and imbricate, with shallow, ill-defined largely contiguous punctures; metallic green of head and mesosoma dark and subdued, particularly on mesosoma where it appears largely as highlights dorsally or as dark metallic green on pleura and propodeum ( Colombia) .................................. C. tatamaensis Engel & Gonzalez

11(1). Metasomal terga metallic green to blue, or nearly black with scattered metallic highlights; legs dark brown to black, without amber coloration........... 12

– Metasomal terga without metallic coloration, instead amber and/or brown; legs largely amber, although some with extensive brown markings ........... 15

12(11). Basal area of propodeum with distinct striae, sometimes only basally ....... 13

– Basal area of propodeum granular, without distinct striae......................... 14

13(12). Basal area of propodeum with distinct and complete striae; integument between punctures ventrally on mesepisternum strongly imbricate and weakly shining; malar space to compound eye length ratio 0.37 ( Colombia, Ecuador).................................................................. C. cyaneus Brooks & Engel

– Basal area of propodeum with weak striae in basal quarter to third; integument between punctures ventrally on mesepisternum polished smooth or very faintly imbricate and shining; malar space to compound eye length ratio 0.48 ( Peru).................................................................. C. chlerogas (Vachal)

14(12). Head and mesosoma dark metallic blue-green or green with blue and purple highlights; metasoma metallic green with scattered to strong blue to purple highlights ( Bolivia) ...................................... C. boliviensis Brooks & Engel

– Head and mesosoma black to dark brown with faint metallic highlights; metasoma black to dark brown ( Bolivia) ........................ C. aterrimus sp. n.

15(11). Face brilliant metallic green or brassy green.............................................. 16

– Face black or dark brown, with green or gold highlights ( Ecuador).............. ................................................................................. C. cooperi Engel et al.

16(15). Mesoscutum with median longitudinal area of dark brown to black, nonmetallic integument, laterally metallic green ................................................. 17

– Mesoscutum entirely metallic green ( Colombia)..... C. nephos Brooks & Engel

17(16). Metasomal tergum II almost entirely brown; malar space to compound eye length ratio 0.32 ( Venezuela) ................................ C. tiara Brooks & Engel

– Metasomal tergum II entirely amber, or nearly so; malar space to compound eye length ratio 0.41 ( Venezuela) ...................... C. townesi Brooks & Engel