than pedicel; flagellum clavate from about its middle; temple of even width from above to below. Thorax + propodeum: 1.6 mm long; brown; pronotum with ...
Bulletin de la Societe entomologique de France, 107 (3), 2002: 217-221.
A new ensign-fly from the Lower-Middle Miocene Dominican amber (Hymenoptera, Evaniidae) by Andre NEL*, Xavier MARTINEZ-DELCLOS** & Dany AZAR* * Museum national d'Histoire naturelle, lab. d'Entomologie, CNRS UMR 8569, 45 rue Buffon, F - 75005 Paris, ** Univ. de Barcelona, Fac. de Geologia, Paleontologia i Geociencies Marines, Departament d'Estratigrafia, E-08071, Barcelona, Spain Summary. - Brachygaster (Semaeomyia) dominicanus sp. n. is described from the Oligo-Miocene amber of the Dominican Republic. This Neotropical genus is still unknown in the Haiti Island. Resume. - Un nouvel Evaniide du Miocene moyen inferieur de l'ambre de la Dominique (Hymenoptera, Evaniidae). Brachygaster (Semaeomyia) dominicanus sp. n. est decrit de l'ambre miocene de la Republique Dominicaine. Ce genre neotropical est encore inconnu de la faune actuelle de 1'ile d'Hai'ti. Key words. - Hymenoptera, Evaniidae, Brachygaster {Semaeomyia) dominicanus sp. n., Miocene, amber, Dominican Republic.
Evanioid wasps are rare in the fossil record, with less than 20 species described or listed, mainly from Cretaceous and Cenozoic ambers (NEL et al., in press). Except for a specimen listed by POHNAR (1992), no evaniid is known from the Dominican amber. Thus the discovery of a new fossil evaniid wasp from the Miocene Dominican amber is of great systematic and biogeographic interest. The available systematic works are relatively out of date and many modern genera would need a redescription (Huben, pers. comm.). The works of BASIBUYUK et al. (2000 a, b) only concern the phylogeny and systematics of the Mesozoic taxa. Because of the lack of cladistic study of this group (RONQUIST et al., 1999), we could only make a preliminary typological study, based on the available old keys of classification. We follow the standard conventions for wing veins proposed by MASON (1986) and the wing venational terminology of GOULET & HUBER (1993). Family Evaniidae Latreille, 1802 Genus Brachygaster Leach, 1815 Subgenus Semaeomyia Bradley, 1908 Type species of the subgenus: Semaeomya kiefferi Bradley, 1908
Brachygaster (Semaeomyia) dominicanus n. sp. (fig. 1-3) HOLOTYPE : specimen MCAM 0168, Museu de la Ciencia, Fundacio
'la Caixa', Bracelona, Spain.
Locality deposit: the exact location of the outcrop is unknown, Dominican Republic. Geological age: exact age is unknown, Miocene. The age of Dominican amber is late Early Miocene through early Middle Miocene (sensu ITURRALDE-VINENT & MACPHEE, 1996). Etymology of the specific epithet: after the Dominican Republic. Diagnosis: moderately long Brachygaster of subgenus Semaeomyia, with the head scarcely punctuated, with no median tubercle and no carina between or around the eyes; antennal scape 1.9 times longer than antennomeres 2 and 3; temple of even width from above to below; pronotum with rounded humeral angles; basal metathoracic tarsomere as long as the four apical tarsomeres all together.
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Fig. 1. - Brachygaster (Semaeomyia) dominicanus sp. n., habitus of the holotype.
Description : body about 4.1 mm long. Head: 1.1 mm wide, broader but as high as the pronotum, orthognathous, flattened; eyes large, as long as half height of the head; eye in lateral view diagonal; entire head scarcely punctuated and face with nearly no punctures and no median turbercle; three large ocelli in a moderately high triangle; antennae inserted on the forehead, not inserted in a common distinct impressed basin; no carina below and beside the antennae; no interantennal carina; toruli strongly approximate but not joined; mandibles not clearly visible; antennae broken distally, with only seven antennomeres preserved; scape five times longer than pedicel; flagellum clavate from about its middle; temple of even width from above to below. Thorax + propodeum: 1.6 mm long; brown; pronotum with rounded humeral angles; mesonotum and scutellum sculptured similarly to the head, smooth and polished, with few shallow punctures; mesopleura with a quadrangular distinctly polished unpunctated area; propodeum sculptured by a reticulated web of punctures; height of the propodeum, about 0.7 mm; metanotum as seen from the side not deeply depressed, its side slopping gradually; metasternum not visible. Forewings: hyaline, length, 3.0 mm, width, 0.9 mm; pterostigma dark brown, 0.4 mm long; only the veins Sc+R, M+Cu, A, lcu-a, M and basal part of Cu of anterior part of the wing tubular, closing the cells C, R, lCu; all veins and cells of distal part of the wing absent; distal part of veins nebulous. Hindwings: length, about 1.7 mm, width unknown; the wing is folded and covered by fine longitudinal wrinkles; costal vein with several hamuli at its two thirds; no closed cells; presence of a small almost separated posterior lobe. Legs: long and thin; first prothoracic tarsomere with a strigil (or antennal cleaning notch) corresponding to a specialized apical tibial spur; two apical strong spines on meso- and metathoracic tibiae but no small spines along the metathoracic tibias and tarsi; spine of the metathoracic tibia one fourth as long as basitarsus; five tarsomeres on each leg; basal tarsomeres longer than others, basal metathoracic tarsomere as long as the four apical tarsomeres all together; inner tooth of the tarsal claw much larger and stouter than the outer tooth. Metasoma: petiole cylindrical, rough, not punctured, nearly as long as the propodeum height; metasoma, 1.0 mm long and 0.9 mm high, laterally compressed and rounded with its apical end straight; no apical process; pilosity of metasoma not visible.
Discussion. - After the key of the modern evaniid genera proposed by BRADLEY (1908), this fossil would fall in the tribe Hyptiini and the genus Semaeomyia Bradley, 1905 in relation to the following characters: (1) metasoma nearly circular; (2) antennae not inserted in a distinct common impressed basin, and without any carina below, beside or between them; (3) metanotum not deeply depressed; (4) forewing with only the cells C, R and lCu closed;
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Fig. 2 - 3. — Brachygaster {Semaeomyia) dominicanus sp. n., holotype and detail of the head (scale bar = 1 mm).
(5) flagellum suddenly clavate from about the middle; (6) mesopleurae with a distinctly polished unpunctate area; (7) claws with the inner tooth much larger and stouter than the outer tooth. HEDICKE (1939) considered Semaeomyia as the Neotropical subgenus of Brachygaster Leach, 1815, except for S. bidentata (Kieffer, 1911) from Transvaal, Africa. The lack of phylogenetic analysis of the modern species of Semaeomyia and Brachygaster forbids any definite conclusion on this point. BRADLEY (1908) proposed a key of the species he knew. This author separated two groups of species after the Central American and the Brazilian-Argentinian sub-regions. He listed two species from the Central American sub-region, Brachygaster (S.) azteka (Schletterer, 1886),
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NEL et al. - Un nouvel Evaniide fossile miocene de Vambre de la Dominique
from Mexico, and B. (S.) nitida (Cameron, 1887), from Panama. B. (S.) dominicanus shares with B. (S.) nitida a mesonotum smooth with few punctures, a metathoracic basal tarsomere as long as all the others together, a head moderately punctate, temples of even width from above to below and pronotal humeral angles rounded. B. (S.) dominicanus has a scape 1.9 times as long as joints 2 and 3, unlike B. (S.) nitida (only 1.5 times longer). B. (S.) bicolor (Westwood, 1841), from Mexico, has a distinctly longer wing, 1.1 cm long (WESTWOOD, 1843). Among species not listed by BRADLEY (1908), B. (S.) flaviscapa (Kieffer, 1911), from Mexico, is distinctly smaller (body length 1.8 mm) than B. (S.) dominicanus (KIEFFER, 1911b). B. (S.) leucomelas (Kieffer, 1911) has a head densely punctuate and pilose, unlike B. (S.) dominicanus (KIEFFER, 1911b) Among the species from Brazilian and Argentinian sub-region listed by BRADLEY (1908), the closest species would be B. (S.) albata (Schletterer, 1889) found in Colombia and B. (S.) gayi (Spinola, 1851), found in Colombia and Argentina. B. (S.) dominicanus has shorter metathoracic tibial spurs than B. (S.) albata. B. (S.) dominicanus has some punctures on its face, unlike the face 'smooth and unpunctate' of B. (S.) gayi. Also, B. (S.) dominicanus has a body longer than S. gayi (4.1 mm long against 3 to 3.5 mm long). Among the species not listed by BRADLEY (1908), B. (S.) troglodytes (Kieffer, 1910), from the British Honduras, has a tubercle before the antennal bases and the eyes posteriorly touching the occipital margin, unlike B. (S.) dominicanus (Kieffer, 1910). B. (S.) spinotarsis (Kieffer, 1910), from the British Honduras, has two longitudinal carinae between the eyes and the mandible bases and a scape shorter than the second + third articles of the pedicel, unlike B. (S.) dominicanus (Kieffer, 1910). B. (S.) leucomelas (Kieffer, 1911) has a head densely punctured and pilose, unlike B. (S.) dominicanus (see KIEFFER, 1911b). B. (S.) amazonica Roman, 1917, from Amazonia, Brazil, has a scape as long as the second + third articles of the pedicel, not distinctly longer, as in B. (S.) dominicanus (Roman, 1917). After SCHLETTERER (1886), B. (S.) pygmaea (Fabricius, 1804) has its first article of the pedicel as long as second and third, unlike B. (S.) dominicanus. After SCHLETTERER (1886), B. (S.) crassicornis (Spinola, 1842), from Columbia, has a punctuate head, unlike B. (S.) dominicanus. B. (S.) minutissima (Enderlein, 1909), from Brazil, is distinctly smaller than B. (S.) dominicanus (body length, 2.25 mm long instead of 4.1 mm) (ENDERLEIN, 1909). B. {S.) catharinensis (Enderlein, 1909) and B. (S.) laevis (Enderlein, 1906), both from Brazil, have a median crest on the head, unlike B. (S.) dominicanus (after ENDERLEIN, 1909). B. (S.) bidentata (Kieffer, 1911), from Transvaal, Africa, has two longitudinal carinae on its face and its petiole densely punctured, unlike B. (S.) dominicanus (see KIEFFER, 191 la). Biogeographic remarks: BRISCHKE (1886) indicated the presence in Baltic amber of twenty two specimens he attributed to the genus Brachygaster. They would be closely similar to the modem species B. minor. This material has never been described (SPAHR, 1987). BRUES (1910) also listed the genus Brachygaster from the Baltic amber. The degree of affinity of this Baltic amber material with the Neotropical (sub)genus Semaeomyia remains undetermined, as well as the exact relationships between Brachygaster and Semaeomyia. The subgenus Semaeomyia is probably still present in the modern fauna of the Dominican Republic, but so far as we know, it has not yet been recorded there. It would be of a great interest to discover it and compare with this fossil species. ACKNOWLEDGEMENTS. — We would like to express our gratitude to Dr Jorge Wagensberg, Director of the Museu de la Ciencia de la Fundacio La Caixa (Barcelona) and Dr Marta Solsona, Curator of the palaeontological collection, for putting this specimen at our disposal.
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LITERATURE
BASIBUYUK H.H., FITTON M.G., RASNITSYN A.P. & QuiCKE D.L.J., 2000a. - Two new genera of the Evaniidae from Late Cretaceous of New Jersey amber, p. 315-325. In: Grimaldi D. A. (ed.). Studies on fossils in amber, with particular reference to the Cretaceous of New Jersey. Blackhuys, Leiden. BASIBUYUK H.H., RASNTTSYN A.P., FITTON M.G. & QUICKE D.L.J., 2000b. - An archaic new genus of
Evaniidae (Insecta: Hymenoptera) and implications for the biology of ancestral evanioids. Bulletin of the Natural History Museum, London, Geology, 56:53-58. BRADLEY J.C., 1908. - The Evaniidae, ensign-flies, an archaic family of Hymenoptera. Transactions of the American Entomological Society, 34:101-194. BRISCHKE D., 1886. - Die Hymenopteren der Bernsteins. Schriften der Naturforschenden Gesellschaft in Danzig, N.F., 6:278-279. BRUES C.T., 1910. - Some notes on the geological history of the parasitic Hymenoptera. Journal of the New York Entomological Society, 18:1-22. ENDERLEIN G., 1909. - Neue Evaniiden aus Formosa und Sudamerika. Stettiner Entomologische Zeitung, 70:245-262. GOULET H. & HUBER J.T., 1993. - Hymenoptera of the World: an identification guide to families. Research Branch Agriculture Canada Publication, 1894/E: 1-668. HEDICKE H., 1939. - Evaniidae. In : Hedicke H. (ed.). Hymenopterorum Catalogus, 9, Junk W. publ., 50 p. ITURRALDE-VINENT M.A. & MACPHEE R.D., 1996. - Age and Paleogeographical Origin of Dominican Amber. Science, 273:1850-1852. KIEFFER J.-J., 1910. - Nouveaux Evaniides d'Amerique (Hym.). Annales de la Societe entomologique de France, 80:57-81. 1911a. - Diagnoses de nouveaux Evaniides (Hym.). Bulletin de la Societe entomologique de France, 1911:303-305. 1911b. - Etude sur les Evaniides exotiques (Hym.) du British Museum de Londres. Annales de la Societe entomologique de France, 80:155-231. MASON W.R.M., 1986. - Standard drawing conventions and definitions for venational and other features of wings of Hymenoptera. Proceedings of the Entomological Society of Washington, 88:1-7. NEL A., WALLER A., HODEBERT G. & DE PLOEG G., in press. - Description of an ensign-fly in the
Lowermost Eocene amber from the Paris basin (Hymenoptera: Evaniidae). Annales de la Societe entomologique de France. POINAR G.O. Jr., 1992. - Life in amber, Stanford University Press, Palo Alto, California, U.S.A.: 350 p. ROMAN A., 1917. - Schlupfwespen aus Amazonien. Arkiv for Zoologi, 11:1-24. RONQUIST F., RASNITSYN A.P., ROY A., ERIKSSON K. & LlNDGREN M., 1999. - Phylogeny of the Hymenoptera: a cladistic reanalysis of Rasnitsyn's (1988) data. Zoologica Scripta, 28:13-50. SCHLETTERER A., 1886. - Ueber die Hymenopteren-Gattung Evania Fabr. Verhandlungen der KaiserlichKoniglichen Zoologisch-Botanischen Gesellschaft in Wien, Abhandlungen, 36: 1-46. 1889. - Die Hymenopteren-Gruppe der Evaniiden. III. Abteilung. Annalen des K. K. Naturhistorischen Hofmuseums, 4:373-546. SPAHR U. von, 1987. - Erganzungen und Berichtigungen zu R. Keilbachs Bibliographie und liste der Bernsteinfossilien. Ordnung Hymenoptera. Stuttgarter Beitrage zur Naturkunde (B), 127:1-121. WESTWOOD J.O., 1843. — On Evania and some allied genera of hymenopterous insects. Transactions of the Entomological Society, London, 3:237-278.
