A New Species of Xenotriphleba Buck (Diptera: Phoridae) from Baltic Amber

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<ul><li><p>BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofitpublishers, academic institutions, research libraries, and research funders in the common goal of maximizing access tocritical research.</p><p>A New Species of Xenotriphleba Buck (Diptera: Phoridae) fromBaltic AmberAuthor(s): Brian V. BrownSource: Proceedings of the Entomological Society of Washington, 111(1):33-37.2009.Published By: Entomological Society of WashingtonDOI: http://dx.doi.org/10.4289/0013-8797-111.1.33URL: http://www.bioone.org/doi/full/10.4289/0013-8797-111.1.33</p><p>BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in thebiological, ecological, and environmental sciences. BioOne provides a sustainable onlineplatform for over 170 journals and books published by nonprofit societies, associations,museums, institutions, and presses.</p><p>Your use of this PDF, the BioOne Web site, and all posted and associated contentindicates your acceptance of BioOnes Terms of Use, available at www.bioone.org/page/terms_of_use.</p><p>Usage of BioOne content is strictly limited to personal, educational, and non-commercialuse. Commercial inquiries or rights and permissions requests should be directed to theindividual publisher as copyright holder.</p><p>http://dx.doi.org/10.4289/0013-8797-111.1.33http://www.bioone.org/doi/full/10.4289/0013-8797-111.1.33http://www.bioone.orghttp://www.bioone.org/page/terms_of_usehttp://www.bioone.org/page/terms_of_use</p></li><li><p>A NEW SPECIES OF XENOTRIPHLEBA BUCK (DIPTERA: PHORIDAE)FROM BALTIC AMBER</p><p>BRIAN V. BROWN</p><p>Entomology Section, Natural History Museum of Los Angeles County, 900</p><p>Exposition Boulevard, Los Angeles, CA, 90007, U.S.A. (e-mail: bbrown@nhm.org)</p><p>Abstract.A new fossil species of the enigmatic genus Xenotriphleba Buck, X.antiqua, is defined from a single specimen in Baltic amber. Its differences from andsimilarities with the single extant species, X. dentistylata Buck, are discussed.</p><p>Key Words: Diptera, Phoridae, Xenotriphleba, fossil, amber</p><p>The genus Xenotriphleba Buck is one of</p><p>the most unusual non-metopinine phorids</p><p>that has been described in recent years.</p><p>Because specimens of the sole species, the</p><p>European X. dentistylata Buck, bear a</p><p>suite of characters that make their rela-</p><p>tionship to other phorid genera highly</p><p>problematic, Buck (1997) tried but was</p><p>unable to place them within the systematic</p><p>framework proposed by Brown (1992).</p><p>Specimens of X. dentistylata Buck are</p><p>rarely collected, and their natural history</p><p>is unknown. The type series included</p><p>specimens found in Germany and Swit-</p><p>zerland, and there are additional male</p><p>specimens in the collection of the Natu-</p><p>ral History Museum of Los Angeles</p><p>County (LACM) from Russia (near</p><p>Moscow) and far eastern Russia (see</p><p>also similar records in Michailovskaya</p><p>2004). Records of occurrence in Hungary</p><p>(Papp 2002) and Poland (Durska et al.</p><p>2005) further indicate the widespread</p><p>distribution of this species.</p><p>Because of the systematic questions</p><p>raised by this enigmatic genus, the</p><p>discovery of a fossil specimen is of great</p><p>interest. The new species is defined</p><p>below, with emphasis on differences</p><p>from X. dentistylata.</p><p>SYSTEMATICS</p><p>Xenotriphleba Buck</p><p>Xenotriphleba Buck, 1997: 351. Type</p><p>species: Xenotriphleba dentistylata</p><p>Buck, by original designation.</p><p>Xenotriphleba dentistylata Buck</p><p>Xenotriphleba dentistylata Buck, 1997:</p><p>352.</p><p>Material examined.RUSSIA: Mos-</p><p>cow, Friazevo, 55.75uN, 37.70uE, 1-,25.vii.2000, M. Tretiakov, Malaise trap</p><p>in garden; Primoskiy krai, Gornotayozh-</p><p>noye, 43.66uN, 132.25uE, 1 -, vii.2000,M. Michailovskaya, yellow pan trap</p><p>(both LACM).</p><p>Xenotriphleba antiqua Brown,new species</p><p>(Figs. 15)</p><p>Recognition.This fossil is classified</p><p>in the genus Xenotriphleba based on the</p><p>presence of large tibial setae, one pair of</p><p>reclinate supra-antennal setae, large</p><p>rounded surstyli with thick, peglike setae</p><p>medially, and the lack of wing vein* Accepted by David R. Smith</p><p>PROC. ENTOMOL. SOC. WASH.</p><p>111(1), 2009, pp. 3337</p></li><li><p>Figs. 12. Xenotriphleba antiqua. 1, Head, anterior. 2, Right wing, dorsal.</p><p>34 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON</p></li><li><p>A1+CuA2. It differs from the definitionof X. dentistylata by the much larger</p><p>body size, the presence of wing vein R2+3,</p><p>the presence of a long foretibial seta, and</p><p>other details listed in the description and</p><p>Table 1.</p><p>Description of holotype.Body</p><p>length 3.2 mm (not including termina-</p><p>lia). Frons relatively narrow, approxi-mately 0.34 head width (Fig. 1). Usual</p><p>12 frontal setae (arranged 4-4-4) present,</p><p>plus one pair of reclinate supra-antennal</p><p>setae (Fig. 1). Flagellomere 1 oval,</p><p>slightly pointed, arista dorsal, preapical.</p><p>Palpal setae relatively short. Anepister-</p><p>num bare, without furrows. Scutellum</p><p>with two subequal pairs of setae. Winglength 2.85 mm. Costa 0.56 wing length.</p><p>Vein R2+3 present (Fig. 2). First costal</p><p>sector not measurable, second costal</p><p>sector (insertion of vein R1 to insertion</p><p>of vein R2+3) 1.8 times length of sector 3</p><p>(R2+3 to end of costa). Vein Rs notthickened, with row of about 20 extreme-</p><p>ly short, widely spaced setae extending to</p><p>approximate level of vein R2+3. Vein</p><p>A1+CuA2 (fourth thin vein) not visible(Fig. 3). Foretarsomeres elongate, not</p><p>shortened as in X. dentistylata. Foretibia</p><p>with one long dorsal seta near midlength</p><p>and eight smaller ones more distally(Fig. 3). Midtibia with pair of setae near</p><p>base, one anterior and one posterior, and</p><p>one long anterior seta near apex; apical</p><p>seta clearly longer than width of tibia.</p><p>Hind tibia with two long anterodorsal</p><p>setae, one slightly basal to midlength and</p><p>one near apex (Fig. 3), and one poster-</p><p>odorsal seta near base. All tibiae lackingsetal palisades and ctenidia. Male termi-</p><p>nalia largely obscured (on left side by</p><p>lobelike distortions of the abdominal</p><p>membrane), but small rounded cercus</p><p>and large surstyli visible (Fig. 4), as in X.</p><p>Fig. 3. Xenotriphleba antiqua, habitus, left lateral (blank areas obscured by milky substance in amber).</p><p>VOLUME 111, NUMBER 1 35</p></li><li><p>dentistylata. Medial surface of at least</p><p>left surstylus with peglike setae (Fig. 5,</p><p>only visible from right side by tilting</p><p>specimen).</p><p>Derivation of species name.From</p><p>Latin antiquus for old.</p><p>Holotype.-, Baltic amber, localityunknown, specimen number G 1283,</p><p>University of Gottingen collection, Ger-</p><p>many.</p><p>Systematic affinities.Buck (1997)</p><p>proposed some apomorphic characters</p><p>for genus Xenotriphleba based on male</p><p>and female specimens of X. dentistylata.</p><p>Three of these were given as definite apo-</p><p>morphies of the group: absence of vein</p><p>R2+3, absence of vein A1+CuA2, andstructure of female tergite 6. Based on X.</p><p>antiqua, however, the absence of vein R2+3might have occurred after the origin of the</p><p>genus, in the lineage leading to X. dentis-</p><p>tylata only. Similarly, the lack of a</p><p>dorsobasal foretibial seta in X. dentistylata</p><p>may be the result of a loss of this structure</p><p>after the origin of Xenotriphleba.</p><p>Many of the character states in which</p><p>X. antiqua visibly differs from X. dentis-</p><p>tylata seem to be present in a primitive</p><p>state in X. antiqua (Table 1). One inter-</p><p>esting character in this regard is the</p><p>presence of a nearly complete row of</p><p>setulae along the dorsal surface of vein</p><p>Figs. 45. Xenotriphleba antiqua, male terminalia. 4, Left lateral. 5, Apex, right lateral.</p><p>Table 1. Comparison of character states in specimens of extinct fossil Xenotriphleba antiqua and</p><p>extant X. dentistylata.</p><p>Character State X. antiqua X. dentistylata</p><p>body length large (3.2 mm) small (1.3 mm)</p><p>frontal width narrow (0.34 head width) broad (0.61 head width)</p><p>palpus with short setae with long setae</p><p>anterior scutellar seta subequal to posterior much smaller than posterior</p><p>vein R2+3 present absent</p><p>vein Rs setulose with one basal seta</p><p>vein Rs thin thickened</p><p>foretibia with dorsal seta without setae</p><p>foretarsomeres elongate short</p><p>36 PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON</p></li><li><p>Rs. Although this character is useful for</p><p>separating some modern genera (such asAnevrina Lioy and Aenigmatias Meinert),</p><p>it is also unexpectedly present in some</p><p>fossil species of modern genera that lack</p><p>it, such as Hypocera Lioy and Chaeto-</p><p>pleurophora Schmitz (Brown in press).</p><p>Possibly this character was a groundplan</p><p>condition of the common ancestor of</p><p>these groups. Some primitive charactersof X. antiqua, such as the presence of</p><p>vein R2+3 and the setulose Rs, are also</p><p>found in another phorid with separate,</p><p>subequal surstyli, Burmophora Beyer, a</p><p>genus that Brown (1992) proposed re-</p><p>tained the most primitive male surstyli</p><p>known at the time.</p><p>Characters that might be apomorphic inX. antiqua, relative to X. dentistylata, are</p><p>the narrow frons and the short setae of the</p><p>palpus. Without detailed knowledge of the</p><p>outgroup of Xenotriphleba, however, it is</p><p>difficult to know whether these characters</p><p>are truly apomorphic within the genus.</p><p>Unfortunately, the new fossil species</p><p>does not give us any new insights into theclosest relatives of Xenotriphleba. The</p><p>ancestry of phorid genera is a question</p><p>being addressed using molecular data by B.</p><p>Brown and P. Smith (in preparation), after</p><p>preliminary work by Cook et al. (2004).</p><p>ACKNOWLEDGMENTS</p><p>Illustrations were skillfully producedby Brian Koehler. I thank Mike Reich</p><p>for the loan of phorid specimens in</p><p>amber from the collection in Gottingen,Germany, G. Kung for commenting on</p><p>an earlier version of the manuscript, and</p><p>reviews by M. Buck and H. Disney. My</p><p>research on non-metopinine phorids is</p><p>funded by NSF grant DEB 0516420 to B.</p><p>Brown and P. Smith.</p><p>LITERATURE CITED</p><p>Brown, B. V. 1992. Generic revision of Phoridae of</p><p>the Nearctic Region and phylogenetic classifi-</p><p>cation of Phoridae, Sciadoceridae and Irono-</p><p>myiidae (Diptera: Phoridea). Memoirs of the</p><p>Entomological Society of Canada, No. 164,</p><p>144 pp.</p><p>. In press. Novel character states in fossil</p><p>species of modern phorid genera (Diptera:</p><p>Phoridae). Studia Dipterologica.</p><p>Buck, M. 1997. A new genus and species of</p><p>Phoridae (Diptera) from central Europe with</p><p>remarkably primitive male genitalia. Entomo-</p><p>logica Scandinavica 28: 351359.</p><p>Cook, C. E., J. J. Austin, and R. H. L. Disney.</p><p>2004. A mitochondrial 12 s and 16 s rRNA</p><p>phylogeny of critical genera of Phoridae</p><p>(Diptera) and related families of Aschiza.</p><p>Zootaxa 593: 111.</p><p>Durska, E., E. Kaczorowska, and R. H. L. Disney.</p><p>2005. Scuttle flies (Diptera: Phoridae) of saline</p><p>habitats in the Gulf of Gdansk, Poland.</p><p>Entomologica Fennica 16: 159164.</p><p>Michailovskaya, M. B. 2004. Scuttle flies (Dip-</p><p>tera: Phoridae) of the Far East of Russia.</p><p>Russian Academy of Sciences, Far Eastern</p><p>Branch, V. L. Komarovs Mountain-Taiga</p><p>Station. Dalnauka, Vladivostok. 148 pp.</p><p>Papp, L. 2002. New records of Phoridae (Diptera)</p><p>from Hungary. Folia Entomologica Hungarica</p><p>63: 163180.</p><p>VOLUME 111, NUMBER 1 37</p></li></ul>