Eomacropis glaesaria, Engel, 2001

ENGEL, MICHAEL S., 2001, A Monograph Of The Baltic Amber Bees And Evolution Of The Apoidea (Hymenoptera), Bulletin of the American Museum of Natural History 2001 (259), pp. 1-1 : 1-

Eomacropis glaesaria , new species Figures 21–25 Plate 1e,f

DIAGNOSIS: As for the genus (see above).

DESCRIPTION: Female. Total body length 12.4 mm; forewing length 10.1 mm. Head slightly wider than long (length 2.65 mm, width 2.85 mm). Distal half of clypeus extending below lower tangent of compound eyes (fig. 21). Frontal line carinate from an­ tennal sockets to approximately 1 OD from median ocellus. Upper interorbital distance 1.65 mm; lower interorbital distance 1.55 mm. Interocellar distance 0.35 mm; ocellocular distance 0.4 mm; median to lateral ocellus 0.15 mm. Scutellum slightly less than twice length of metanotum; metanotum slightly longer than basal area of propodeum. Malus serrate; distal section of protibial spur beyond velum slightly shorter than section of spur bordering velum. Intertegular distance 1.9 mm. Second abscissa of Rs strongly basad 1m­cu (fig. 23); 2rs­m distad 2m­cu by three times vein width; first submarginal cell slightly shorter than second submarginal cell; eight distal hamuli, arranged in a single evenly spaced series.

Labrum with minute, scattered punctures, integument between smooth. Clypeus with sparse, faint, coarse punctures. Face with small punctures separated by a puncture width, integument between smooth. Vertex with punctures becoming faint, coarse, and sparsely distributed. Gena sculptured like face. Postgena imbricate and impunctate. Mesoscutum and scutellum with small punctures separated by a puncture width or less, integument between smooth. Tegula impunctate and smooth. Metanotum rugulose. Pleura with small punctures separated by a puncture width or less, integument between smooth. Terga and sterna imbricate.

Head dark brown to black with light brown to yellowish marks lateral to clypeus and near lower, inner margin of compound eyes. Mesosoma dark brown to black; legs dark brown. Wing membrane lightly fuscous; veins dark brown. Metasoma dark brown.

Labrum with scattered, short, erect, simple setae. Face with scattered, short, suberect, simple setae. Postgena with moderate­length, erect, simple setae. Mesoscutum with moderate­length, erect, simple seate, a few with minute branches. Scutellum with pubescence as described for mesoscutum except setae longer and with more numerous branches along posterior border. Metanotum with short, scattered setae each with minute branches. Pleura with scattered, long, simple setae, a few with branches, setae becoming progressively longer and more dense ventrally. Scopa on metatibia and metabasitarus composed of dense, long, plumose setae; metafemur with long, branched setae on upper and anterior border. Terga with sparse, minute, simple setae; sterna with scattered, long, simple setae.

MATERIAL: One specimen. Holotype. Female ( SAMH) labeled: ‘‘ Holotype, Eomacropis glaesaria Engel’’.

ETYMOLOGY: The specific epithet is derived from the Latin word glaesarius (meaning ‘‘of amber’’).

COMMENTS: The holotype of Eomacropis is preserved with a staphyliniform beetle lar­ va on its dorsum (fig. 22, pl. 1f). Presumably the two insects were accidentally preserved together, as there is no such association known among living bees today; this, however, does not preclude such an association in the past. Moreover, the beetle is simply too large to have been carried by the bee in the same manner as bees carry triungulin meloids.

LONG­ TONGUED BEES

Family MEGACHILIDAE Latreille

DIAGNOSIS: The megachilids are most notable for the development of the scopa on the metasomal sterna [subsequently reduced on the hind legs in Lithurginae (tribe Lithurgini ) and Megachilinae ; see below] and the structure of the subantennal suture which meets the outer margin of the antennal socket in Lithurginae and Megachilinae . The labrum is broadly articulated to the head capsule and in all except some Fideliinae and the fossils discussed below it is longer than broad.

DESCRIPTION: Labrum broadly articulated to clypeus, frequently longer than wide. Single subantennal suture; suture meets lower margin of antennal socket in Fideliinae , meets outer margin of antennal socket in Megachilinae and Lithurginae . Facial foveae absent. Lower lateral margins of clypeus not bent posteriorly on either side of labrum. Flabellum present; glossa acute; labial palpus with first two segments flattened, sheath­like, and elongate; submentum strongly V­shaped and sclerotized, submental arms articulating with cardines slightly above cardo­stipital articulations. Galeal comb absent; stipital comb and concavity present; basistiptial process elongate. Preëpisternal groove absent. Mesocoxa entirely exposed. Metabasitibial plate variable (present in Protolithurgini and some Lithurgini along posterior margin; absent in Fideliinae and Megachilinae ). Jugal lobe short. Metasomal scopa present (in nonparasitic females). Metapostnotum setose. Pygidial plate and fimbria of female present in Fideliinae and Lithurginae , absent in Megachilinae .

COMMENTS: The family Megachilidae consists of three subfamilies: Fideliinae , Lithurginae , and Megachilinae (see table 7). The fideliines have at times been accorded family rank (e.g., Moure and Michener, 1955; Michener and Greenberg, 1980). Within the family the scopa on the hind legs has generally been reduced (owing to the use of the metasomal scopa). It would appear that the scopa of the hind legs has been primitively retained in Fideliinae and an extinct tribe of Lithurginae ( Protolithurgini ; see below); however, these setae are not used for the transport of pollen (like other megachilids, pollen is transported in the metasomal scopa) and are instead used in flinging sand during nest building (Rozen, 1970, 1973). Thus, these setae in fideliines are not a true scopa.

Key to Subfamilies of Megachilidae

Figures

Figs. 21–22. Holotype female of Eomacropis glaesaria, new species. 21. Frontal view of head. 22. Right dorsolateral oblique view of mesosoma, posterior border of prosoma, and anterior border of metasoma. NOTE: Staphyliniform beetle larva on mesoscutum of the holotype. Scale bars = 1 mm (a = fig. 22; b = fig. 21).