Microphorella mamillata, Gatt & Ss & Dj & Uk., 2012

Gatt, Paul, 2012, Two new species of Microphorella Becker (Diptera: Dolichopodidae) from the Mediterranean, Revue suisse de Zoologie 119 (3), pp. 287-302 : 296-300

Microphorella mamillata sp. n.

Figs 9-12

MATERIAL EXAMINED: Holotype ♁; “ TUNISIA: Tabarka / Nefza-Zouara /coastal dunes/ 21.iv.2000 / P. Gatt ”; “HOLOTYPUS / Microphorella / mamillata Gatt ” ( MHNG). The holotype is preserved in alcohol, and is in good condition.

Paratype ♁: TUNISIA; Gulf of Gabes, Hachichina, Khaouala , coastal steppe, 25.iv.2000, P. Gatt ( MHNG) .

ETYMOLOGY: The specific name mamillata refers to the characteristic mamillary process which is present at the caudal pole of the hypandrium of this species.

DIAGNOSIS: A small (1.6 mm), whitish-grey microtrichose species with white macrosetae and clear wings. Wing membrane between C and R 1 yellowish. Postpedicel pear-shaped. Stylus long, as long as postpedicel. Two pairs of fronto-orbital setae. Five pairs of dorsocentral setae. Male: anterior costal margin with long, spine-like setae at middle; fore-femur with a long posteroventral seta on apical third; fore and mid-tibia, posteriorly, with long setae; mid-femur, ventrally, densely clothed with short setulae and some long setae; mid-basitarsus bowed laterally, ventrally with a long row of hook-like spinules. Hypandrium with mamillary process at caudal pole.

DESCRIPTION

Male

Length: Body 1.6 mm, wing 1.4 mm (specimen in alcohol).

Head: Black in ground colour, whitish-grey microtrichose, higher and wider than deep. Eyes widely separated on frons, ommatidia equal in size, sparsely covered with minute ommatrichia. Neck inserted at middle of head. Occiput greyish microtrichose with some brownish tints and metallic reflections, projecting beyond posterior margin of eye, concave above neck, convex below. Frons broad, whitish grey microtrichose with some brownish hues and metallic reflections. Gena very narrow. Face brown microtrichose, long and narrow, narrower than frons above antennae, widening towards mouth edge. Clypeus convex, grey microtrichose. Antenna ( Fig. 9 ) black in ground colour and clothed with short, pale setulae; placed at middle of head in profile, and as long as head is deep; scape cup-shaped; pedicel globular; subequal in length to scape, sparsely grey microtrichose, and with a circlet of subapical setulae; postpedicel long, bulbous in basal half; stylus uniarticulate, long, subequal in length to postpedicel. Labrum very short, brown, projecting forward. Palpus small, grey microtrichose and bearing some long and short setulae; sensory pit not discernable. Chaetotaxy: cephalic setae white, thick and flattened; one pair of strong, lateroclinate anterior ocellars; one pair of weak, lateroclinate posterior ocellars; one pair of minute postocellars; one pair of strong inclinate anterior fronto-orbitals, as strong as anterior ocellars; one pair of shorter, inclinate posterior fronto-orbitals; one pair of long, inclinate medial verticals; one pair of shorter, lateroclinate lateral verticals; postocular occipital setae uniserial above neck, becoming longer and irregularly multiserial below; several longer setae present just behind mouth opening, including postgena.

Thorax: Black in ground colour, generally whitish grey microtrichose; scutum, viewed anteriorly from above with 4 narrow, less microtrichose longitudinal stripes (2 medially and 1 on each side of scutum); viewed posteriorly from above, medial longitudinal stripes very broad. Dorsal surface of mesoscutum moderately arched; prescutellar depression distinct; complete prothoracic precoxal bridge present. Anepisternum bare, greyish brown microtrichose. Chaetotaxy: thoracic setae white, rather thick and flattened. Antepronotum with 4 setulae. Propleuron with one pair of very short setulae. Postpronotum with 3-4 very short setulae. A single pair of long, acrostichal setae on anterior slope of mesoscutum. Five (2+3) pairs of subequal dorsocentral setae, the prescutellar pair longer, wider apart, and shorter than 1 pair of long, inclinate scutellar setae; dorsocentral setae preceded by 1-2 shorter setulae; 3 short supra-alar setae, the posteriormost longest; additional setulae present both inside and outside supra-alar row; 1 postalar seta; 3 notopleural setae.

Legs: Long and slender, black in ground colour, greyish microtrichose and clothed with short, white setulae; trochanters, apices of femora and all tibiae and tarsi paler, brownish. Femora equally thick, not much stronger than tibiae. Basitarsi shorter than following tarsal segments combined. Fore coxa densely setulose; mid-coxa with some long setulae. Hind trochanter with 1 short, ventral seta. All tarsomeres with short, spine-like subapical setae, stronger and in groups of 4 on middle segments. Tarsal claws, pulvilli and empodium developed on all legs; pulvilli and empodium haired. Fore femur with 1 long posteroventral seta in apical third; some longish setae near apex and at base. Fore tibia with a posterior row of 8 long posteriorly curved setae, as long as or longer than greatest width of tibia; bearing anterior apical comb; pigmented spinulated tubercles absent. Mid-femur with a dense tuft of very short setulae along middle third of ventral surface, and with a fringe of 10 long pale ventral setae, as long as or longer than femur is deep. Mid-tibia with a posterior row of 4-5 long setae, and one spine-like subapical seta. Mid-basitarsus with 2 black spine-like setae ventrally at base; curved laterally, and with a long row of some 23 short ventral spinules having curved, hook-like apices. Hind leg simple. Hind femur with a dorsal row of longer setae. Hind tibia with an apical posterior comb of closely set spinules. Hind basitarsus with an apical posterior comb of short setae.

Wing: Very similar to previous species, 3.5 times longer than broad, axillary lobe hardly developed; wing membrane clear; space between C and R 1 brown; membrane, including veins, covered with microtrichia; macrosetae white; hind marginal fringe longest at base of wing; wing veins brown, stigma absent; C circumambient; C with 3 short basal setae, anterior costal margin with a row of spine-like setae, very long and stronger at middle of wing; longest seta as long as crossvein DM-Cu. Sc parallel to R 1, upturning to C before merging imperceptibly into membrane; humeral crossvein indistinct; Rs originating opposite humeral crossvein; R 1 sinuous, meeting C beyond tip of discal cell; R 2+3 sinuous, upcurved at its junction with C; R 4+5 almost straight, downturned to C and ending in C before tip of wing; crossvein R-M present, discal cell incompletely separated from second basal cell by incomplete crossvein BM-Cu, closed distally by crossvein DM-Cu and emitting 3 veins to wing margin; base of M 2 complete; crossvein DM-Cu complete; CuA 2 curved; A 1 absent; A 2 present on posterobasal margin of wing. Alula absent. Squama brown, short, with a fringe of long, pale hairs. Knob of haltere large, quadrate, brown with white margins; stem of haltere darker than knob.

Abdomen: Black in ground colour, brownish-grey microtrichose; sclerites with sparse, white setulae on posterior margins and on disc. Abdominal muscle plaques distinct. Tergites 1-4 and sternites 1-3 unmodified. Tergite 7 not setulose. Postabdomen beginning with sternite 5, rotated and lateroflexed to the right. Sternites 1 and 2 short; sternite 3 without long setae on posterior margin; sternite 4 with a posteromedian membranous area, fringed on each side with a number of long setae; long setae present also on posterior margin of sclerite. Sternite 5 short, bare, with a robust, sclerotised, bifid posteromedian projection; tips of bifurcation broadly membranous; ventral tubercle at point of bifurcation hardly developed. Sternites 6 and 7 bare, simple. Sternite 8 large, subrectangular, subshining and bearing very long setulae on posterior margin and shorter setulae on disc; tergite 8 atrophied. Terminalia ( Figs 10-12 ) lateroflexed to the right, inverted and with caudal pole directed forward, asymmetrical. Hypandrium large, separated from epandrium, produced at apex and with several accessory processes, subshining; bearing distinct mamillary process at caudal pole, pointing to the left ( Fig. 10 arrow). Ventral appendage of left epandrial lamella more or less symmetrical, with two arms: the right arm setulose at middle; the left arm without toothlike processes on concave margin. Cerci large, the right cercus larger, both setulose; each with 3 short, inclinate spine-like setae medially; apicolateral corners produced. Left cercus with medial margin not smoothly rounded; apicolateral corner long and broad, spatulate; 1 very long hair-like seta on apical margin, and another long seta arising from a setulose, mamillary process. Right cercus with 2 long, hair-like setae arising from apical margin. Phallus directed forwards, apex pointed; dorsal surface bearing 1 broad, arcuate expansion.

Variation: Paratype: postocellar setae absent; the 4 narrow, less microtrichose stripes present on the scutum of the holotype are absent, and are replaced by 2 narrow, brown microtrichose longitudinal stripes along dorsocentral lines.

Female: unknown.

BIOLOGY: Unknown. Specimens were collected from coastal sand dunes and steppes suggesting that the species inhabits sandy, coastal biotopes.

DISTRIBUTION: Hitherto known only from two localities in Tunisia, the Tabarka embayment and the gulf of Gabes.

Figures

FIG. 9 Microphorella mamillata sp. n. ♁ antenna, lateral view. Scale bar = 0.1mm.

FIG. 10 Microphorella mamillata sp. n. ♁ hypopygium, dorsal view from the right. Scale bar = 0.5mm. Arrow: mamillary process of hypandrium. Abbreviations explained in the text.

FIG. 11 Microphorella mamillata sp. n. ♁ hypopygium viewed from the left (postgonites omitted). Scale bar = 0.5mm. Arrow: mamillary process of hypandrium. Abbreviations explained in the text.

FIG. 12 Microphorella mamillata sp. n. ♁ hypopygium viewed from the right (postgonites omitted). Scale bar = 0.5mm. Abbreviations explained in the text.