Corresponding author: Michael S. Engel (
Academic editor: Michael Ohl
A new subgenus,
The Southeast Asian fauna of megachiline bees is particularly diverse but simultaneously poorly documented, underrepresented in collections, and with many species largely confused (especially in the diverse subgenus
Following the classificatory proposal of
We also briefly discuss the phylogenetic relationships of
Morphological terminology follows that of
To explore the phylogenetic relationships of these rare bees, we used the morphological characters and data set of
Large (ca. 20–25 mm), black, parallel-sided megachilines resembling some large, black species of
The new genus-group name is a combination of the Greek words
In addition to the type species the subgenus includes the following taxa:
The five currently included species are superficially quite similar, but for the hyaline or dark fuscous, rather than yellow, wings in
Thailand: ♂, Sakaerat DDF [Nakhon Ratchasima Province, Sakaerat Environmental Research Area, ca. 40 km South Nakhon Ratchasima], 20 June 1995 (SEMC).
Thailand: ♀, Sakaerat DDF [Nakhon Ratchasima Province, Sakaerat Environmental Research Area, ca. 40 km South Nakhon Ratchasima], 17 June 1995 (SEMC); 1♂, Siam (SEMC).
Myanmar: 1♀, Middle Tenasserim, Thaungyin Valley, 5.93 [May 1893], C.T. Bingham (NHML).
Both sexes of this species have yellow forewings with grayish hyaline apex. The male can be easily distinguished by the clypeus densely covered by long, appressed, apically-directed setae obscuring integument (
As for the subgenus with the following additions:
Integument black throughout except tegula, legs, and metasomal sterna largely dark reddish brown (nearly black in many areas), and expansion of protarsi more translucent brown. Wings orange-yellow except apical margin of forewing and apical and posterior margins of hind wing grayish hyaline (
Mandible with outer surface dull, irregularly punctate and microreticulate; labrum strongly imbricate and impunctate; clypeus with small, contiguous punctures, with thin mediolongitudinal impunctate area; supraclypeal area and face below ocelli with small, contiguous punctures, punctures becoming more irregular at level of median ocellus; area between ocelli with small, contiguous punctures; ocellocular area with somewhat larger, coarser punctures separated by areas of finely imbricate integument; vertex with coarse, shallow punctures separated by a puncture width or less, integument between finely imbricate, punctures becoming more shallow and faint toward preoccipital carina; upper gena with irregular, elongate punctures separated by finely imbricate integument, remainder of gena and posterior postgena with more regular punctures separated by a puncture width or less, integument otherwise finely imbricate; postgenal surface inside of deep postgenal depression with scattered minute punctures separated by faintly imbricate to smooth integument; outer surface of juxtamandibular lamella with irregular punctures and imbricate integument. Pronotum imbricate, with small punctures separated by a puncture width or less; mesoscutum anteriorly and medially transversely wrinkled with irregular punctures, such integument blending laterally outside of parapsidal lines and posteriorly to coarsely punctate, punctures separated by a puncture width or less, those outside of parapsidal lines somewhat smaller and more regularly defined than those posteriorly, integument between punctures finely imbricate; tegula finely imbricate and minutely punctate, punctures separated by less than a puncture width, except along outer rim impunctate; axillae and mesoscutellum coarsely and contiguously punctate except mediobasally on mesoscutellum with punctures smaller and gradually becoming separated by a puncture width or less; metanotum imbricate with small punctures separated by a puncture width or less; pleura coarsely and contiguously punctate, those punctures along omaular ridge and ventrally somewhat dorsoventrally elongate, giving ventral surface a somewhat dorsoventrally rugulose appearance; declivitous basal area of propodeum with single row of coarse alveolae along extreme basal border, row interrupted medially, otherwise surface imbricate and impunctate; lateral surface imbricate with small punctures separated by less than a puncture width, gradually becoming more widely spaced posteriorly and on posterior surface. Anterior-facing surface of first metasomal tergum finely imbricate, dorsal-facing surface imbricate with small punctures separated by a puncture width or less, nearly contiguous in most areas; remaining terga sculptured as on dorsal-facing surface of first metasomal tergum; terga with narrow impunctate apical rims; sterna smooth to finely imbricate, with small punctures separated by less than a puncture width.
Pubescence generally dark fuscous to black except as follows: clypeus, supraclypeal area, and face outside of antennal toruli with dense, long, minutely-branched, tawny to white setae, largely obscuring the integument, those on clypeus more strongly tawny and largely appressed and apically directed; thin fringe of short, fine, silvery white setae along outer border of patch of black setae on median inferior protuberance and running proximally to mandibular condyle; dense patch of white pubescence immediately posterior to dense patch of somewhat shorter black setae at posterior end of postgenal depression, white patch largely occupying area at meeting of postgena and ventral area of gena; white, long setae on pronotal lateral surfaces, outer borders of propleura, outer base of procoxa, and preomaular area; white and black setae arranged on protarsus and apex of protibia as in
Clypeus imbricate with coarse, shallow punctures separated by less than a puncture width in basal half except medially such punctures restricted to basal border; supraclypeal area with smaller coarse punctures than those on clypeus, punctures separated by less than a puncture width; face below ocelli with small, contiguous punctures, punctures becoming more irregular at level of median ocellus; ocellocular area with somewhat larger, coarser punctures separated by areas of finely imbricate integument; vertex with coarse, shallow punctures separated by 0.5–1.5 times a puncture width, integument between finely imbricate, punctures becoming more shallow and faint toward preoccipital carina; postgena strongly rugulose; hypostoma imbricate. Mesoscutum anteriorly and medially transversely wrinkled, more weakly so than in male, with irregular punctures, such integument blending laterally and posteriorly to faintly coarsely punctate, punctures separated by less than a puncture width, those outside of parapsidal lines sparse, integument between punctures finely imbricate; axillae and mesoscutellum strongly coarsely and contiguously punctate except mediobasally on mesoscutellum with punctures smaller and gradually becoming separated by a puncture width or less. Dorsal-facing surface of first metasomal tergum imbricate with small punctures separated by a puncture width or less medially and nearly contiguous laterally; remaining terga sculptured as on lateral areas of dorsal-facing surface of first metasomal tergum.
Usual sex differences in setation; pubescence dark fuscous to black except microtrichia on inner surface of mandible dark golden and small dirty white patch on lateral surface of propodeum near metacoxa; clypeus and supraclypeal area not obscured by dense pubescence; ventral surfaces of mesepisternum, coxae, trochanters, base of femora, anterior margins of metatibia and metafemur, and sternal scopa with capitate setae.
Summary of currently included species in subgenus
Species | General distribution |
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Philippines: Mindanao: Davao del Sur | |
Sulawesi | |
Myanmar: Tanintharyi Division (= Tenasserim) | |
Thailand: Uthai Thani Province | |
Malaysia: Pahang State, Negeri Sembilan State | |
Malaysia: Penang State, Perak State, Selangor State, Pahang State | |
Thailand: Nakhon Ratchasima Province | |
Myanmar: Tanintharyi Division |
Photomicrographs of male of
Photomicrographs of female of
The specific epithet is a combination of the Greek word
The holotype and paratype from Sakaerat were captured at flowers of
Philippines: ♂, Mindanao, Tagurano [Davao del Sur, near Mt. Apo and Mt. Apo National Park], Davao City, 25–26.vi.1977 [25–26 June 1977], Y. Kurosawa (NSMT).
The new species is most similar to
As described for
Wings dark fuscous, infumate (
Mesoscutum anteriorly and medially transversely somewhat wrinkled (not as strongly so as in
Pubescence generally dark fuscous to black except as follows: clypeus and face outside of antennal toruli with dense, long, minutely-branched, reddish setae, largely obscuring the integument, those on clypeus more strongly reddish and largely appressed and apically directed; supraclypeal area with similar setae to those on face except more tawny in color (
The specific epithet is a combination of Mount Apo and the Latin suffix –
Permission to dissect the holotype and only known specimen was not provided and thus the genitalia remain unknown for this distinctive species. Nonetheless, genitalic variation is relatively minor across species of
Photomicrographs of male of
Photomicrographs of male head of
Malaysia (Peninsular): ♂, Malaya, Penang, Batu Feringgi, 17 November 1963, H.T. Pagden (NHML).
Malaysia (Peninsular): 2♂♂, Malaya, Pangkor Island, 5.i.1958 [5 January 1958], H.T. Pagden (NHML); 1♂, Malaya, Penang, Botanical Gardens at flowers
Both sexes of this species have yellow forewings with grayish hyaline apex. The male can be easily recognized by the clypeus with the disc not densely covered by setae (
As described for
Integument black throughout except tegula, legs, and metasomal sterna largely dark reddish brown (nearly black in many areas), and expansions of protarsi dark brown. Wings orange-yellow except apical margin of forewing and apical and posterior margins of hind wing grayish hyaline (
Mandible with outer surface shiny, irregularly punctate; vertex with coarse, shallow punctures separated by less than a puncture width, integument between finely imbricate, punctures becoming more shallow toward preoccipital carina; upper gena with irregular punctures separated by finely imbricate integument, remainder of gena and posterior postgena with more regular punctures separated by a puncture width or frequently less, integument otherwise finely imbricate. Mesoscutum anteriorly and medially transversely wrinkled with irregular punctures, such integument blending laterally outside of parapsidal lines and posteriorly to coarsely and contiguously punctate, integument between (where evident) finely imbricate; axillae and mesoscutellum coarsely and contiguously punctate throughout. Dorsal-facing surface of first metasomal tergum imbricate with small punctures nearly contiguous; remaining terga sculptured as on dorsal-facing surface of first metasomal tergum.
Pubescence generally dark fuscous to black except as follows: clypeus apically with dense fringe of long, apically-directed reddish setae (
Mandible with outer surface dull, irregularly punctate and microreticulate; clypeus imbricate with coarse, shallow punctures separated by less than a puncture width except along apical border. Mesoscutum anteriorly and medially transversely wrinkled, more weakly so than in male, with irregular punctures, such integument blending laterally and posteriorly to coarsely punctate, punctures separated by less than a puncture width, integument between punctures finely imbricate; axillae and mesoscutellum strongly coarsely punctate, punctures separated by less than a puncture width throughout.
Usual sex differences in setation; pubescence dark fuscous to black except microtrichia on inner surface of mandible dark golden and small dirty white patch on lateral surface of propodeum near metacoxa; clypeus and supraclypeal area not obscured by dense pubescence.
The specific epithet is based on the plant generic name
The paratype females were captured at flowers of “
Photomicrographs of male of
Photomicrographs of female of
Photomicrographs of representative male genitalia for species of
Indonesia (Sulawesi): 1♂, 1♀, Central Sulawesi, Palolo nr. Palu, vii.1995 [July 1995] (SEMC); 1♂, Central Sulawesi, Sintuwu, SE of Palu, 1.xii.2000 [1 December 2000], I. Steffan-Dewenter (SEMC).
Both sexes of this species are easily recognized by the largely hyaline forewings with fuscous apex and dark brown to black venation (
Malaysia (Peninsular): 3♀♀, Pahang, Batu Balai Estate, 18 March 1927, E. Seimund, Ex F.M.S. [Federated Malay States] Museum (NHML); 1♂, 1♀, Negri Sembilan, Gunong Angsi, 2000–2790’ [feet], April 1918, Ex F.M.S. [Federated Malay States] Museum (NHML).
Thailand: 1♀, Uthai Thani Province [western Thailand], Huay Kha Khaeng Wildlife Sanctuary, 15º36’ N, 99º20’ E, 1.xi.1995 [1 November 1995], J. Gazhoul, captured at
The female of this species can be recognized by the clypeus lacking a medioapical tubercle, short mandibles (
It should be noted that Meade-Waldo’s (1914) material from “Middle Tenasserim” is not conspecific with his type (B.M. Type Hym.17a2037) for
Photomicrographs of male of
Photomicrographs of female of
1 | Forewing either largely hyaline with fuscous apex ( |
2 |
– | Forewing yellow, like parchment, with smoky fuscous or grayish hyaline apex ( |
3 |
2(1) | Male clypeal disc largely exposed, not obscured by dense, appressed setae ( |
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– | Male clypeal surface largely obscured by dense, long, appressed, reddish setae ( |
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3(1) | Female clypeus with pronounced, erect, medioapical tubercle ( |
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– | Female clypeus without medioapical tubercle; female mandibles short ( |
4 |
4(3) | Female mesoscutum with pronounced transverse wrinkling on disc, posteriorly with well-defined coarse punctures separated by a less than a puncture width, punctures irregular, not loosely arranged in transverse series like those in wrinkles ( |
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– | Female mesoscutum with central wrinkling of integument less pronounced, posteriorly with ill-defined, somewhat transverse punctures separated by a puncture width or more and loosely in transverse rows like weak wrinkles on disc ( |
A total of 157 most parsimonious trees (Length = 2275, Consistency Index = 12, Retention Index = 53) were obtained when including
Photomicrographs of female of
The presence of a dense patch of black setae on the forewing of males (except in one species), resembling the dense patch of setae among the submarginal cells of
Based on the phylogenetic analysis, it may seems best to regard
Female characters (e.g., mandible with outer surface of dull, microreticulate to finely punctuate integument, without cutting edges, mesepisternum coarsely punctuate, forming strong rows with distinct shining ridges among them, and body parallel-sided) also clearly associate
A preliminary morphological analysis of
Some morphological characters of certain species of
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- | - | 6 | - | - | - | - | - | - | - | - | - | - | - | - | - | + | - | + | - | - | + | E | |
- | - | 4 | - | - | - | - | - | - | - | - | + | - | - | + | + | + | + | - | - | + | + | E, S | |
+ | + | 3 | + | - | - | + | + | +* | + | - | + | + | + | + | + | + | + | - | + | - | + | O | |
- | + | 4 | + | - | - | + | + | +* | + | - | + | + | + | + | + | + | + | + | + | - | + | E | |
+ | + | 4 | + | - | - | + | + | - | - | - | + | + | + | + | + | + | + | + | + | + | + | E | |
- | - | 4 | - | - | - | - | + | +* | + | + | + | + | - | - | - | + | - | + | + | + | + | O | |
+ | + | 3 | + | - | - | - | + | - | - | - | - | - | + | + | + | + | + | + | + | + | + | E | |
- | + | 5 | - | + | - | - | + | + | + | + | + | + | - | - | - | + | - | - | + | + | + | O | |
+ | + | 3 | + | - | - | - | + | +* | - | + | + | - | - | + | + | + | + | + | + | + | + | E | |
- | + | 5 | - | - | - | - | + | + | - | + | + | + | - | - | - | - | - | - | + | + | + | O | |
- | + | 4 | - | - | - | - | + | + | - | + | + | + | - | - | - | - | - | - | + | + | + | O | |
- | + | 4 | + | - | - | + | + | +* | + | - | + | + | + | + | + | + | + | + | + | + | + | E | |
- | - | 5 | - | + | - | - | + | - | - | + | + | + | - | - | - | + | + | + | + | + | + | A | |
+ | - | 3 | + | - | - | - | + | +* | - | + | + | - | - | + | + | + | + | + | + | + | + | E | |
- | + | 4 | - | - | - | - | - | - | - | - | - | + | - | - | + | + | - | - | - | + | + | O | |
+ | + | 4 | + | - | - | - | + | +* | - | + | + | + | - | + | + | + | + | + | + | + | + | E | |
+ | + | 3 | + | - | - | - | + | +* | - | + | + | + | - | + | + | + | + | + | + | + | + | E | |
+ | + | 4 | + | - | - | - | + | +* | - | - | - | + | + | + | + | + | + | + | + | + | + | E | |
- | + | 5 | - | + | + | - | + | - | - | + | + | - | - | - | + | - | - | - | + | - | + | O | |
‘Carinula’ group | |||||||||||||||||||||||
- | - | 4 | - | + | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | E | |
- | - | 5 | - | + | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | E | |
- | - | 5 | - | + | - | - | - | - | - | - | + | - | - | - | - | - | - | - | - | - | - | E | |
‘Eumegachilana’ group | |||||||||||||||||||||||
+ | - | 3 | + | - | - | + | - | - | - | - | - | - | - | - | - | + | - | + | + | + | + | O | |
+ | - | 3 | + | - | - | + | - | - | - | - | - | - | - | - | - | + | - | + | + | + | + | O | |
+ | - | 3 | + | - | - | - | + | - | - | - | - | - | - | + | + | + | + | + | + | + | + | O | |
+ | - | 3 | + | - | - | + | - | - | - | - | - | + | - | - | - | + | - | - | + | + | + | O |
The senior author is grateful to Akihiko Shinohara (NSMT), Hirohiko Nagase, David G. Notton (NHML), and the late Donald B. Baker for assistance with the early phases of this study. We are further thankful to two anonymous reviewers and to Charles D. Michener for comments on the manuscript. Partial support was provided by US National Science Foundation grants EF-0341724, DEB-0542909, and DBI-1057366 (to MSE). This is a contribution of the Division of Entomology, University of Kansas Natural History Museum.