Colletidae

Engel, Michael S. & Gonzalez, Victor H., 2022, A new bee genus from the pampas of eastern Argentina, with appended notes on the classification of “ paracolletines ” (Hymenoptera: Colletidae), Journal of Melittology 2022 (109), pp. 1-39 : 10-12

Key to Subfamilies and Tribes of Colletidae

(Tribes of Neopasiphaeinae are treated individually by region below)

1. Body usually setose, female with well-formed scopa enclosing fiscina (sensu Engel, 2001; Engel et al., 2021) on underside of metafemur; prepygidial fimbria (apical setal band of tergum V) of female much stronger (setae longer and denser) than setal bands (if any) of preceding terga, and tergum VI with abundant setae (pygidial fimbria) lateral to pygidial plate (except in genera that lack both fimbriae and pygidial plate); pygidial plate of female, if present, usually broad and tapering posteriorly; forewing with three submarginal cells or, if two, then second at least two-thirds as long as first (note that two submarginal cells results from the loss of 1rs-m); 2rs-m sinuate, at acute angle to distal part of Rs forming free part of marginal cell ..................................................................................... 2

—. Body with setae short and relatively sparse, female lacking scopa or with a sparse or short scopa forming fiscina on underside of metafemur; prepygidial and pygidial fimbriae of female nearly always absent; pygidial plate of female absent or, if present, then usually narrow and parallel-sided posteriorly, or spinelike; forewing with two submarginal cells, second usually much shorter than first; 2rs-m usually not sinuate, usually at right or obtuse angle to distal part of Rs .... 8

2(1). Pterostigma small, shorter than prestigma (as measured along posterior margin in first submarginal cell), as wide as prestigma measured to costal wing margin, truncate, sometimes obliquely, inside marginal cell ............................ 3

—. Pterostigma usually large, at least longer than prestigma (sometimes only slightly longer, e.g., Anthoglossa Smith ), usually wider than prestigma measured to wing margin, typically tapering within marginal cell, rarely truncate ................. 6

3(2). Glossa deeply bifid with apical lobes commonly directed strongly apicolaterally; mandible of female bidentate or tridentate [Western Hemisphere] [Subfamily Diphaglossinae ] ............................................................................................. 4

—. Glossa weakly bilobed; mandible of female tridentate owing to bilobed preapical tooth (worn in some individuals) [ Australia] ............................ Paracolletinae

4(3). Episternal groove absent below scrobal groove; flagellomere I much shorter than scape, less than twice as long as middle flagellomeres, not or only moderately petiolate; mandible of female bidentate or tridentate .......................................... 5

—. Episternal groove complete; flagellomere I nearly as long as, to longer than, scape, much longer than subsequent flagellomeres, petiolate; mandible of female bidentate ..................................................................................... Caupolicanini

5(4). Notaulus represented by deep groove in anterior part of mesoscutum; malar space nearly one-third as long as compound eye or longer; mandible of female tridentate .............................................................................................. Diphaglossini

—. Notaulus weak or absent; malar space short or absent; mandible of female bidentate (except tridentate in Mydrosomella ) ...................................... Dissoglotini

6(2). Metabasitibial and pygidial plates present, at least in females (pygidial plate absent in most males; metabasitibial plate absent in both sexes of a few Australian taxa); prepygidial and pygidial fimbriae of female present; sternum VII of male with apicolateral lobes of moderate size (sometimes greatly reduced or absent), disc of sternum and apodemes thus constituting major part of sternum VII ..... 7

—. Metabasitibial and pygidial plates absent; prepygidial and pygidial fimbriae lacking, in both sexes vestiture of terga V and VI thus similar to that of preceding terga; sternum VII of male with apicolateral lobes greatly enlarged, disc of sternum and apodemes reduced, slender and delicate, lobes thus constituting major part of sternum VII [Worldwide except Indo-Australian region] ........ ....................................................................................................................... Colletinae

7(6). Posterior (ventral) surface of prementum lacking a fovea or with only a narrow medial groove; galeal comb usually well developed [South America, Australia] .......................................................................................................... Neopasiphaeinae

—. Posterior (ventral) surface of prementum with a broad longitudinal depression or fovea margined by shiny ridges that diverge on basal part of prementum and converge near base of subligular process; galeal comb reduced to three or four small bristles [Africa] ............................................................................... Scraptrinae

8(1). Facial fovea usually a narrow groove, sometimes a broader area, wider than diameter of scape, absent in a few females and some males; scopa absent; longitudinal part of hypostomal carina usually not longer than clypeus; clypeus usually not protuberant, not much bent back around ends of labrum .............................. 9

—. Facial fovea absent or broad, at least one-third as wide as long; female with sparse scopa on sterna I– III and outlining ventral fiscina on metafemur; longitudinal part of hypostomal carina usually longer than clypeus but, if not, then clypeus protuberant and its lower lateral extremities bent back around ends of labrum [Neotropical] ......................................................................... Xeromelissinae

9(8). Supraclypeal area elevated abruptly above level of antennal torulus; pygidial and metabasitibial plates usually absent but, if present (as in a few Australian and New Guinea species), then pygidial plate of female broad, its margins converging posteriorly; anterior surface of tergum I usually without longitudinal median groove; posterior (ventral) surface of prementum with longitudinal, usually spiculate depression or fovea (weak in a few males) margined by ridges that diverge on basal half of prementum and meet near base of subligular process [Subfamily Hylaeinae ] ................................................................................... 10

—. Supraclypeal area sloping up from level of antennal torulus; apical part of pygidial plate of female slender, sometimes a spine, its margins parallel or converging slightly toward apex or spatulate; metabasitibial plate usually indicated in female, sometimes only by one or more tubercles; anterior surface of tergum I with longitudinal median groove; posterior (ventral) surface of prementum lacking longitudinal medial fovea but with comparable spiculate area [ Australia] [Subfamily Euryglossinae ] .................................................................. 11

10(9). Anterior protibial spine prolonged into long curved process, at least as long as probasitarsal diameter; pterostigma with edge within marginal cell straight; posterior margin of tergum I angulate near apex of lateral carina; apex of sternum I transverse; sternum II strongly produced downward proximally [ Australia, introduced to New Zealand] .......................................................... Hyleoidini

—. Anterior protibial spine small or absent; pterostigma with edge within marginal cell usually convex; posterior margin of tergum I straight or with broadly rounded posterior lateral angle; apex of sternum I with median cleft or slit; sternum II not produced downward proximally [Worldwide] ............... Hylaeini

11(9). Forewing with posterobasal angle of first submarginal cell orthogonal (i.e., 1Rs transverse); posterior margin of second submarginal cell (i.e., Rs+M) straight (also Brachyhesma Michener ); second submarginal cell much less than half as long as first submarginal cell (also present in Brachyhesma ), or absent entirely; 1m-cu meeting first submarginal cell or rarely confluent with 1Rs .... Pachyprosopidini

—. Forewing with posterobasal angle of first submarginal cell acute (i.e., 1Rs oblique); posterior margin of second submarginal cell sinuate (except Brachyhesma ); second submarginal cell nearly half as long as or more than half as long as first submarginal cell (except some Hyphesma Michener ); 1m-cu meeting second submarginal cell ..................................................................................... Euryglossini