Megachile flavipes, Spinola, 1838

Dorchin, Achik & Praz, Christophe J., 2018, Taxonomic revision of the Western Palaearctic bees of the subgenus Pseudomegachile (Hymenoptera, Apiformes, Megachilidae, Megachile), Zootaxa 4524 (3), pp. 251-307 : 294

flavipes species group

This is a large group comprising small to medium sized species with rather homogeneous morphology. In addition, some of the species exhibit geographic variation in the coloration of the integument or of the vestiture. Consequently, species identification is more complicated in this group than in the other Pseudomegachile , and may require comparing a series of specimens or examining the hidden metasomal sternites of males. Numerous features of the flavipes species group are shared only with M. ericetorum , in line with the phylogenetic affinities found between these two taxa.

Western Palaearctic species of the flavipes species group are characterized by the predominantly dark integument, bright ferruginous tibiae and tarsi, and bright or pale ferruginous, fulvous, or greyish-white hairs, often with appressed scale-like, branched hairs, densely covering the metasoma. Characteristics of the female are: mandible slender, reticulate, shiny, and weakly dentate, with narrow premarginal, smooth area along apical margin ( Fig. 9 ), less than 1/3 as long as minimum width of first flagellomere; clypeus flat or weakly convex with anterior margin truncate or inconspicuously emarginated and with short or sometimes inconspicuous premarginal longitudinal tooth ( Figs 14–19 ); clypeus surface densely punctate with punctures largely varying in size across species; vertex relatively short, the ocellocciptal distance 0.8 times to about as long as interocellar distance. Common characteristics of the male are: mandible 3-toothed without inferior projection; front coxal spine short, as long as or slightly longer than medially wide, with apical tuft of short velvety golden hairs conspicuous or weak and without red spicules; front tarsi regularly slender, fringed with short to moderately long light posterior hair fringe ( Figs 30, 31 ) (longest in M. maxschwarzi sp. nov., Fig. 174 ); T6 without lateral tooth, with preapical carina emarginated, multidentate ( Fig. 32 ), but teeth sometimes inconspicuous (as in M. cinnamomea and some specimens of M. farinosa , Fig. 33 ), and median emargination shallow; S4 usually slender with either sharp or obtuse preapical medial carina followed with concaved depression along margin ( Figs 41, 42 , 47, 50, 53, 56 ) (compared to broad preapical ridge in most other species: Fig. 40 ); sternites 5 and 6 scattered with sclerotized capitate or spatulate hairs varying in density on posterior portion, never as dense as in other species, thus hairs not covered by overlapping hairs; S5 typically with some bifid hairs on basomedian area ( Figs 48, 51, 54, 57, 59, 60, 63 ); S6 with 3–5 usually thicker spatulate hairs forming a lateral sloping line at each side of disc (but smaller in M. tecta and M. maxschwarzi sp. nov.) ( Figs 49, 52, 55, 58, 61, 62, 64 ); S8 spear-shaped triangular, fringed along margins with long hairs that extend well beyond margin (Fig. 95); gonoforceps slender, linear, slightly tapering apically, with dense, long branched hairs directed mesally on posterior portion but with no apparent hairs at apex as seen in dorsal view (Fig. 96); penis valve simple, almost linear, with apex bluntly pointed (Fig. 96).

Megachile grisescens Morawitz 1875 , described from Central Asia (“valle Sarafschan” [ Uzbekistan or Tadjikistan], in Ferghana [ Uzbekistan]) is an additional, Central Asian species of the flavipes species group. To our knowledge it does not occur in the western Palaearctic. This species is unusual within the flavipes group in the entirely dark integument of all legs. In addition, the female can be recognized by the coarsely and sparsely punctured clypeus; beside this characteristic, it is similar to a small female of M. ericetorum , but the vertex is shorter, as in species of the flavipes species group. In the male, the front tarsi bear linear, black maculations on the underside. In addition, M. nigrofulva Hedicke 1940 , described from “Kintschou, Provinz Liauhsi” [Jinzhou, Liaoning Province, China], as well as the subspecies M. nigrofulva ordonosa Hedicke 1940 , from “Ordos, Mongolei ” [Ordos, Inner Mongolia Autonomous Region, China], probably both belong to the flavipes species group. We have not examined the type specimens but some specimens from Mongolia, which agree with the description of M. nigrofulva ordonosa ; these specimens are very similar to M. tecta , although slightly larger, with bright fulvous vestiture and the integument of T1 and T2 is ferruginous. It is possible that this taxon is conspecific with M. tecta .

Figures

FIGURES 6–21. Clypeus and mandibles of females. 6: M. foersteri. 7: M. incana. 8: M. blepharis sp. nov.. 9: M. cinnamomea. 10: M. saussurei. 11: M. nigripes. 12: M. seraxensis. 13: M. ericetorum. 14: M. sanguinipes. 15 (hairs removed on left): M. maxschwarzi sp. nov.. 16 (hairs removed on left): M. flavipes. 17 (hairs removed on left): M. tecta. 18: M. cinnamomea. 19, 20 (profile): M. farinosa. 21: M. riyadhensis (profile). CT: clypeal tooth, APA: apical premarginal area of mandible, HT: clypeal hair tuft, FC: facial comb of hairs.

FIGURES 22–37. Diagnostic traits of males. 22: inferior mandibular projection of M. nigripes. Anterior coxal spine of 23: M. nigripes, 24: M. lanata. Front legs of males of 25: M. foersteri (anterior surface), 26: M. cyanipennis (anterior surface), 27: M. ericetorum (ventral surface), 28: M. cinnamomea (ventral surface), 29: M. cyanipennis (ventral surface), 30: M. cinnamomea (dorsal surface), 31: M. farinosa (dorsal surface). T6 and T7 of 32: M. farinosa, 33: M. cinnamomea, 34: M. lanata, 35: M. seraxensis, 36: M. schnabli, 37: M. riyadhensis. IBP: inferior basal projection, ACS: anterior coxal spine, AG: anterior groove, BAM: basitarsal anterior margin, MPS: minute posterior spot, PAC: preapical carina, LS: lateral spine.

FIGURES 171–177. Diagnostic traits of M. maxschwarzi sp. nov.. Female habitus, 171: lateral view, 172: facial view. 173: holotype male (lateral view). 176: holotype male (facial view). Front basitarsus of male, 174: exterior surface, 175: interior surface. 177: tergite 6 of male. PAC: preapical carina.

FIGURES 38–46. Diagnostic traits of males. Profile of T7 of 38: M. ericetorum, 39: M. cinnamomea. Sternite 4 in ventral view of 40: M. saussurei, 41: M. farinosa, 42: M. flavipes, 43: M. lanata. Antenna in dorsal view of 44: M. cyanipennis, 45: M. tecta, 46: M. sanguinipes. AMS: apicomedial spine, IT: inferior tooth, PAR: preapical ridge, PAC: preapical carina, MD: marginal depression, PAMG: preapical medial groove.

FIGURES 47–64. Sternites 4–6 (or sternites 5, 6) of males of the flavipes species group. 47–49: M. flavipes. 50–52: M. tecta. 53–55: M. maxschwarzi sp. nov.. 56–58: M. cinnamomea. 59, 62: sternites 5, 6 of M. sanguinipes. 60, 61: sternites 5, 6 of M. farinosa. 63, 64: sternites 5, 6 of M. farinosa from the southern Jordan Valley of Israel and Palestine. PAC: preapical carina. Scale bars equal 1 mm