Aztecatopse diabolica ( Duda 1928 ) Haenni & Huerta & Ch-, 2014

Haenni, Jean-Paul & Huerta, Herón, 2014, The identity of Scatopse diabolica Duda, 1928, with description of a new genus from Mexico (Diptera, Scatopsidae), Revue suisse de Zoologie 121 (2), pp. 249-260 : 254-259

Aztecatopse diabolica ( Duda 1928) , comb. n. Figs 2-16

Scatopse diabolica Duda, 1928: 285 , figs 15 (3 hypopygium), 16 (3 wing).

Rhegmoclemina (Rhegmoclemina) diabolica . – Cook, 1967: 3.

Quateiella diabolica . – Amorim, 2008: 12.

MATERIAL STUDIED: Type material: the first author has examined 3 males syntypes labelled respectively “ MB 5.III.24 / Chapingo Garten”, “ diabolica n.sp. 3 det. Duda” [in Duda’ handwriting], “ Syntypus ”; “ MB 58 30.5.24, Chapingo”, “ S. diabolica n.sp. ”, “ Syntypus Zool. Mus. Berlin ”, “ Scatopse diabolica Duda, 1928 3 Lectotype, des. Haenni & Huerta 2008 ”, “ Aztecatopse diabolica (Duda) , det. J.-P. Haenni 2008”; “ MB 222” 23.IV.1924 [?], “diabolica 3”, “ Syntypus ”, all deposited in ZMB. These three specimens are micropinned and double mounted. The first two are well preserved while the third is in a poorer state of conservation. The second specimen is here designated as lectotype and has been labelled accordingly.

OTHER MATERIAL: 4 33, 8 ♀♀, Mexico: Estado de México, Otumba, loc. Coyotepec, 2530 m, 19º 39’ 09.3’’ N; 98º 45’ 25.7’’ W, 12.IV-4. V.2007, Malaise Trap , D. Hernández Zetina leg. , CAIM / MHNN (partly in alcohol, partly slide mounted). – 13, 1♀, same data except 24.V-14. VI.2007. – 233, 1♀, same data except 5-26. VI.2007. – 2♀♀, same data except 4-13.X.2007 . – 13, same data except 23.I-13.II.2008 , all in CAIM.

DIAGNOSIS: Males of A. diabolica are readily distinguished by the shape of tergite 7, bearing posteriorly a pair of pointed and somewhat upcurved lateral projections (Figs 8, 14) and by the ventrally projected, plough-like genital capsule Aztecatopse diabolica ( Duda, 1928) . (2) Head, ♀, lateral view. (3) Antenna, 3. (4) Thorax, ♀, lateral view. (5) Spiracular sclerite, 3. (6) Wing, 3. (7) Tip of hind tibia, 3. (2-7: Coyotepec) (Photographs Herón Huerta).

(Figs 13, 16). Females are distinguished by the shape of sternite 8, triangular with a deep and narrow U-shaped median incision densely beset with long pilosity (Fig. 12).

DESCRIPTION

Male: A shining brownish-black species in general colour; body length 1.5- 1.75 mm (in pinned material, nearly 3 mm long in distended material in alcohol), wing length 2 mm. Head shining black, higher than long, antennae (Fig. 3) longer than head height, 8 flagellomeres, first rather quadrate, the following twice as wide as long, each bearing a whorl of setae, last flagellomere rounded, as long as 2 preceding ones, bearing 3 whorls of setae; palpi elongate, reniform, apically pointed; labella nearly as long as palpi. Thorax. Notum narrow, much longer than wide, covered with dense short pilosity, with well-marked row of 9-12 supraalar setae, scutellum with a row of 12-14 elongate marginal setae; anterior spiracular sclerite setose, with a well-marked anterodorsal pointed projection, spiracle large, not longer than high (Fig. 5); pleural setae: 14-18 anepisternal, in upper anterior corner of sclerite, 9-11 subalar, 5-8 subspiracular, no epimeral. Wing (Fig. 6) 2 mm long, membrane with dense microtrichia; no macrotrichia on membrane except for usual row along posterior margin; R 4+5 reaching costa beyond middle of wing, and slightly beyond level of fork of M; M fork nearly twice as long as stem, with fork gradually widening towards wing margin; second costal section shorter than first, false vein present between M 2 and CuA 1; CuA 2 smoothly angled near middle, reaching wing margin obliquely. Halteres brown, bearing row of 4-5 setae on stem; legs concolorous with body, tarsi somewhat lighter, especially the posterior ones; comb of setae on posteroapical part of hind tibia well developed (Fig. 7); first tarsomere of posterior leg longer than second. Abdomen with tergites and sternites shining. Tergites with pilosity much reduced on anterior segments, becoming denser on posterior segments. Tergite 2 with well defined sublateral lunula-like pretergites. Sternite 1 unsclerotized, 2 to 7 normally sclerotized, regularly beset with pilosity and micropilosity; segment 7 with a narrow anterior ring of sclerotization joining tergite and sternite; tergite 7 long, pilose, bearing posteriorly paired lateral, somewhat upcurved pointed projections (Figs 8, 13, 14), more heavily sclerotized on posterior third, except for oval median zone close to posterior margin; apparent sclerotized concave inner fold well developed, but its relation with tergite 7 not fully clear; sternite 7 nearly entirely devoid of micropilosity, broad, slightly emarginate anteriorly, rounded laterally, with deep complex W-shaped posterior emargination (Fig. 14); genital capsule (Figs 9, 15-16) elongate, epandrium prolonged into broadly triangular, ploughlike projection, somewhat reminiscent in shape of that in Quateiella ; gonocoxites fused to epandrium, prolonged into pair of apico-lateral, spatulate, pilose lobes; aedeagus long and thick, pilose apically; parameres elongate, narrow, Y-shaped, bearing median, ventrally directed, apically pilose process; aedeagus with sperm-duct enlarged, pilose apically (Figs 10, 16); sperm pump elongate, large, with comparatively small vesica.

Female: Body 2.4 mm (somewhat longer in alcohol-preserved distended specimens), wing 1.9 mm. Similar to male in morphology and coloration, but palpi somewhat shorter and less pointed apically (Fig. 2). Thorax (Fig. 4). Terminalia: tergite 7 (Fig. 11) with posterior margin slightly emarginate medially, narrowly more sclerotized than rest of tergite; sternite 7 (Fig. 11) with posterior margin weakly undulate, with well-sclerotized rounded inner fold; tergite 8 long, bearing pair of basal submedian spiracles, entire, only weakly emarginate posteriorly; sternite 8 a triangular plate with deep and narrow U-shaped median incision densely beset with long pilosity (Fig. 12); tergite 10 divided into pair of short triangular sclerites; genital furca present, weakly sclerotized; spermatheca oval-rounded.

Bionomics. In the original description Duda (1928) mentions that the material collected by Dampf was swept in different localities in Central Mexico from plants along a brook and along a drainage ditch, and in fallow land. In the recent 2007-08 survey A. diabolica was caught by Malaise trap in an arid environment dominated by Agavaceae and Cactaceae ( Fig. 1 ). The flight-period covers January to June and October.

Aztecatopse diabolica ( Duda, 1928) (8) Tergite 7, 3. (9) Genital capsule, 3, ventral view. (10) Genitalia 3, lateral view, with tip of aedeagus. (11) Pregenital segment 7, ♀ (sternite left, tergite right). (12) Sternite 8, ♀, ventral view. (8-12: Coyotepec) (Photographs Herón Huerta).

DISTRIBUTION: Known till now only from four localities in a small region of

Estado de México.

DISCUSSION: The species was thoroughly described and figured by Duda (1928) in the catch-all genus Scatopse , but it has not been collected again until now. The species was included in Rhegmoclemina (Rhegmoclemina) in the Catalogue of Aztecatopse diabolica ( Duda, 1928) , 3 (13) Lectotype 3, tip of abdomen, lateral view. (14) Pregenital segment 7, 3 (tergite left, sternite right). (15) Genital capsule, 3, ventral view. (16) Genital capsule, 3, lateral view. (13: Chapingo, 14-16: Coyotepec). Abbreviations: Ae = aedeagus; Ep = epandrium; Gx = gonocoxite; Gx ap = gonocoxal apodeme; Pa = paramere; S9 = sternite 9) [drawings by Mathieu Rapp (13) and Herón Huerta (14-16)].

Neotropical Scatopsidae by Cook (1967) although it obviously does not present the typical S-curved CuA 2 of this genus and of most Rhegmoclematini, as can easily be seen on the figure of the wing by Duda (1928: fig. 16). More recently Amorim (2008) transferred S. diabolica to Quateiella within the Swammerdamellini, probably on the basis of the ventrally directed beak-like projection of the male genital capsule and of the wing venation as figured by Duda (1928). However, the well-developed sternites 2-4 (absent in Quateiella ) and the general structure of the genital capsule clearly exclude the species from this genus.

Figures

FIG. 1