ASEF 1-2-2010.indb - Laboratoire de Zoologie

ARTICLEAnn. soc. entomol. Fr. (n.s.), 2010, 46 (1–2) : 100-102The second fossil ceratocombid bug from the Miocene amberof Chiapas (Mexico) (Hemiptera: Ceratocombidae)Dany Azar (1) , André Nel (2) , David Coty (3) & Romain Garrouste (4)(1)Lebanese University, Faculty of Sciences II, Department of Biology, Fanar – Matn - P. O. box 26110217, Lebanon(2)UMR CNRS 7205, Muséum National d’Histoire Naturelle, Entomologie, 45 rue Buffon, F-75005 Paris, France(3)2 rue du Bois de Boulogne, F-92210 St Cloud, France(4)USM 203 / DHT, Entomologie, Muséum national d’Histoire naturelle, 45 rue Buffon, F-75005 Paris, FranceAbstract. The second fossil Ceratocombidae Leptonannus miocenicus n. sp. is described asfi rst extinct representative of the genus, from the Middle Miocene Mexican amber. The species isdistinguished from its related taxa, a discussion is given.Résumé. Le second Ceratocombidae fossile dans l’ambre miocène du Chiapas (Mexique)(Hemiptera). Leptonannus miocenicus n. sp., premier représentant fossile du genre, est décritde l’ambre miocène moyen du Mexique. Cette espèce est comparée aux taxons apparentés; unediscussion est donnée.Keywords: Hemiptera; Heteroptera; Ceratocombidae; Leptonannus; Mexican amber.The Ceratocombidae is a small family ofdipsocoromorphan bugs living in humid leaflitter, decaying vegetation, mosses, etc. (Stys 1995).Only one fossil species is described, Ceratocombushurdi Wygodzinsky 1959 from the Miocene MexicanChiapas amber (Wygodzinsky 1959). Here we describethe second fossil representative of this family that weattribute to the recent genus Leptonannus Reuter1891, closely related to Ceratocombus Signoret 1852.The fossil comes from a small new outcrop close tothe village Rio Totolapa Salado (Chiapas, Mexico),probably of the same age as the other Chiapas amber(Kraemer 2007). This area was already known forarchaeological amber (Bryant 1983).Family Ceratocombidae Fieber 1861Genus Leptonannus Reuter 1891Leptonannus miocenicus n. sp.(Figs. 1–5)Material. Holotype specimen in collection David Coty (sexunknown), provisionally stored in the Muséum Nationald’Histoire Naturelle, Paris, France.Etymology. Named after the Miocene period.E-mail: azar@mnhn.fr, anel@mnhn.fr, coty.david@gmail.com,romain.garrouste@univ-tln.frAccepté le e 29 juin 2009Age and outcrop. Middle Miocene, Rio Totolapa SaladoVillage, Chiapas, Mexico.Diagnosis. Very small size (pronotum 0.4 mm wide); unusuallyrobust, broad shape; only two large cells in forewing membrane;corium sclerotized only in basal part of costal margin; six ormore pairs of fine and short dorsal hairs on second rostralsegment; two long bristles on the lateral margin of pronotum.Description. Macropterous, length to apex of forewing 1.2mm; body shape elongate oval; color brown, with pronotumand scutellum polished, shining; wings brown with apex ofmembrane hyaline; head 0.23 mm long, 0.3 mm wide; 1+1+1macrochaetae dorsally near border of eyes, 2+2 on eyes but nocentral bristle in eye, small ocelli present near eyes; rostrumslender reaching to midcoxae, with first segment the shortest,second distinctly longer than third + fourth, second with six ormore pairs of fine and short dorsal hairs; pronotum transverse,length 0.2 mm, width 0.4 mm, with one pair of macrochaetaenear posterior angles and one near anterior angles; surfacewith numerous uniformly distributed microchaetae; scutellumsomewhat depressed on disc.Tarsal formula 3/3/3; tarsi long and slender, very strong simpleclaws.Fore- and hind wings as in fig. 5. Hind wing with one visibleincision.No asymmetrical and no appendage-like laterotergite ofabdomen.DiscussionThis fossil can be attributed to the Ceratocombidaeon the basis of its general habitus and forewing venationtypical of this family, and in the Ceratocombinae:Ceratocombini for the absence of strong central bristlein the eyes and the forewing with only two largecells in distal part (one vein emanating from discal100

A ceratocombid bug from Miocene ambercell) (McAtee & Malloch 1925; Štys 1983, 1995).Furthermore Leptonannus miocenicus n. sp. falls in thegenus Leptonannus for its habitus non-coleopteriform,collum reduced, pilosity of head, thorax and legswith a few outstanding hairs (synapomorphy of theCeratocombinae), a bristle behind eye and two on lateralmargin of pronotum, and membrane of forewing withtwo cells (autapomorphy) (McAtee & Malloch 1925;Štys 1982). The recent genus Leptonnanus comprisesthree species: L. biguttulus Reuter 1891 from Africa,and the two New World species L. latipennis (Uhler1904) and L. minutus (Uhler 1894) (Wygodzinsky1953). Leptonannus is a cosmotropical, probablypolyphyletic genus (Štys comm. pers.). L. miocenicusn. sp. and L. latipennis differ from L. biguttulus inthe presence of only two large cells in the forewingmembrane, instead of two large plus one very small,and in the corium sclerotized only in basal part of thecostal margin (McAtee & Malloch 1925; Wygodzinsky1953). L. miocenicus n. sp. and L. latipennis differfrom L. minutus in the presence of six or more pairs offine and short dorsal hairs on second rostral segment(McAtee & Malloch 1925). L. miocenicus n. sp.differs from L. latipennis in its distinctly smaller size(pronotum 0.4 mm wide instead of 0.75 mm in thelatter) (Uhler 1904).L. miocenicus n. sp. differs from the fossil Ceratocombushurdi from the same amber in the presence ofonly two large cells in forewing membrane instead ofthree, plus only two long bristles on the lateral marginof pronotum, instead of three (Wygodzinsky 1959).Kraemer (2007) interpreted the palaeoenvironmentof the Chiapas amber as a ‘lowland tropical dry forestwith a mangrove region’, which could fit well with thepresence of these ceratocombid bugs.Acknowledgements. We sincerely thank Pr Pavel Štys and DrDominique Pluot-Sigwald for their helpful and kind review ofthe first version of the paper. This work is a contribution to theproject ‘The Study of the Fossil Insects and their Outcrops: Geologyof the Outcrops – Historical and Biodiversity Evolution’accorded by the Lebanese University to DA.Figures 1–3Leptonannus miocenicus n. sp., holotype, photograph of specimen; 1, dorsal view; 2, left lateral view; 3, right lateral view.101

D. Azar, A. Nel, D. Coty & R. GarrousteFigures 4–5Leptonannus miocenicus n. sp., holotype; 4, drawing of dorsal and right lateral view of head and prothorax (scale bar represents 0.5 mm); 5, drawing of foreand hind wings (scale bar represents 0.3 mm).ReferencesBryant D. D. 1983. A recently discovered amber source near Totolapa,Chiapas, Mexico. American Antiquity 48: 354-357.Kraemer M. M. S. 2007. Systematic, palaeoecology, and palaeobiogeography ofthe insect fauna from Mexican amber. Palaeontographica (A) 282: 1-133.McAtee W. L., Malloch J. R. 1925. Revision of the bugs of the familyCryptostemmatidae in the collection of the United States NationalMuseum. Proceedings of the United States National Museum 67: 1-42.Štys P. 1982. A new Oriental genus of Ceratocombidae and higher classificationof the family (Heteroptera). Acta Entomologica Bohemoslovaca79: 354-376.Štys P. 1983. A new coleopteriform genus and species of Ceratocombinaefrom Zaire (Dipsocoromorpha). Vestnik Ceskoslovenko Spolia Zoologica47: 221-230.Štys P. 1995. Chapter 15. Ceratocombidae, p. 75-78 in: Schuh R. T.,Slater J. A. (eds). True bugs of the World (Hemiptera: Heteroptera).Classification and natural history. Comstock Publishing Associates,Cornell University Press, Ithaca and London, xii + 336 p.Uhler P. R. 1904. List of Hemiptera-Heteroptera of Las Vegas hot springs,New Mexico, collected by Messrs. E.A. Schwarz and Herbert S. Barber.Proceedings of the United States National Museum 27: 349-364.Wygodzinsky P. 1953. Cryptostemmatinae from Angola (Cryptostemmatidae,Hemiptera). Publicaçoes Culturais da Companhia de Diamantesde Angola 16: 29-47.Wygodzinsky P. 1959. A new hemipteran (Dipsocoridae) from the Mioceneamber of Chiapas (Mexico). Journal of Paleontology 33: 853-854.102