Liotrigonopsis, 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-

Liotrigonopsis , new genus

TYPE SPECIES: Liotrigonopsis rozeni Engel , new species.

DIAGNOSIS: In keys to the genera of Meliponini this group runs to the African and

Malagasy genus Liotrigona Moure (1961) . This fossil differs, however, in the following generic characteristics: antennae inserted low on face (separated from clypeus by less than 1 OD) and not far above lower tangent of compound eyes as well as vein M without apical bend among other, more trivial, features. Liotrigonopsis can be separated from Kelneriapis , also in Baltic amber, by the characters presented above in the Diagnosis for Kelneriapis .

DESCRIPTION: Malar space shorter than basal mandibular width (fig. 112). Antennal sockets set near base of clypeus, separated by less than an antennal socket diameter (fig. 112). F1 approximately equal in length to F2; F2 approximately equal in length to F3; flagellomeres with numerous, minute sensillar plates. Preoccipital area rounded. Anterior border of mesoscutum broadly rounded; tegula oval; scutellum clearly not projecting over metanotum, without medioapical Vshaped notch, apical margin rounded. Basal area of propodeum as long as scutellum, horizontal. Posterior angle of corbicula sharply angled (as in Liotrigona ) (fig. 114); inner surface of metatibia with narrow keirotrichiate field, keirotrichiate field not elevated, bordered by broad, glabrous zone; inner surface of metabasitarsus without basal sericeous area. Forewing without distal bend at point where 1m­cu would meet M (fig. 113); without indication of submarginal cells (fig. 113); marginal cell apex open; hind wing difficult to see, apparently without closed cells.

ETYMOLOGY: The new genus­group name is a combination of Liotrigona and the suffix ­ opsis (Greek, meaning ‘‘appearing like’’). The name is a reference to the similarity between the fossil and Liotrigona , a genus of African and Malagasy stingless bees. The name is feminine.

Liotrigonopsis rozeni , new species

Figures 112–115

Plate 7f

DIAGNOSIS: As for the genus (see above).

DESCRIPTION: Female. Total body length 3.37 mm; forewing length 2.8 mm. Head length 0.87 mm (width indeterminate from specimen). Basal vein distad cu­a by three times vein width; minute basal stub of first

abcissa of Rs after separation from M present , M terminating shortly thereafter without apical bend.

Integument of head, mesosoma, and legs smooth and impunctate. Terga and sterna finely imbricate and impunctate.

Head and mesosoma dark brown except scape light brown (remainder of antenna dark brown). Legs and metasoma light brown or ferruginous. Wing membrane hyaline; veins, when present, light brown.

Pubesence golden, sparse, and simple. Setae not apparent on head. Mesosoma with sparse, simple, short, erect setae. Setae of legs simple and scattered; inner surface of metatibia densely covered by keirotrichiae except narrow (ca. 0.75 OD) glabrous posterior border; rastellar bristles of moderate length, tapering at apices, not flattened. Terga with exceedingly sparse, short, suberect setae; setae of sterna sparse, restricted to apical thirds, and moderately long.

MATERIAL: One specimen. Holotype. Female, worker caste, B­JH 79 ( AMNH) labeled: ‘‘Baltic amber: Eocene, Kaliningrad, Yantarny’’ // ‘‘ Holotype, Liotrigonopsis rozeni Engel. ’’ The specimen is partially preserved along the edge of the amber piece with the left half of the head and left anterior portion of the mesosoma missing. Enough of the specimen is preserved to allow for not only identification but for meaningful comparison to living species.

ETYMOLOGY: The specific epithet is a patronymic honoring Dr. Jerome G. Rozen, Jr. for his friendship and support of my studies on bees.

APOIDEA INCERTAE SEDIS

Genus and Species Indeterminate

The following specimens are too poorly preserved to allow identification below the

level of family. I have listed them here simply as a record of the families and for the total number of individual bees recognized in Baltic amber.

APIDAE gen. et sp. indet.: One female, MB. I.1938 (ZMHB) labeled: ‘‘Museum für Naturkunde Berlin, Paläontologisches Museum, Inv. Nr. MB. I.1938 (No. 53)’’ // ‘‘53’’ // ‘‘ Apidae indet., det. M. S. Engel’’. One female, Nr. 2616 (CCGG) labeled: ‘‘Nr. 2616’’ // ‘‘ Apidae indet., det. M. S. Engel’’.

MEGACHILIDAE gen. et sp. indet.: One female, Nr. 8 (CSUL) labeled: ‘‘ Megachilidae indet., det. M. S. Engel’’.

Figures

Fig. 112. Right lateral view of head of holotype female of Liotrigonopsis rozeni, new species. Scale bar = 0.5 mm.

Figs. 113–115. Mesosomal structures of Liotrigonopsis rozeni, new species. 113. Forewing. 114. Outer surface of metatibia and metatarsus. 115. Metadistitarsus, claw, and arolium. Scale bars = 0.5 mm (a: for fig. 113) (b: for fig. 114); 0.25 mm (b: for fig. 115).