Apalocnemis cingulata Bezzi

Sinclair, Bradley J., 2012, Revision of Neotropical species of Empidoidea (Diptera) described by Mario Bezzi. X. The species described in Apalocnemis Philippi (Brachystomatidae, Trichopezinae), Zootaxa 3270, pp. 58-62 : 59-61

Apalocnemis cingulata Bezzi

( Figs. 1–14 )

Apalocnemis cingulata Bezzi, 1909: 383 , fig. 9; Melander, 1928: 101 (checklist); Collin, 1933: 76 (citation); Smith, 1967: 28 (catalogue); Yang et al. 2007: 448 (catalogue).

Diagnosis. Male specimen holoptic; ocellar triangle protruding; upper half of postcranium with no occipital setae, lower half with many stout setae. Pedicel with stout setae; postpedicel short; stylus thickened, longer than basal segments combined. Proboscis short, retracted within open mouth, almost hidden, upward-curved. All thoracic setae stout; katepisternum glabrous. Abdominal tergites with wide band of grey pruinescence across posterior margin. Cell r4 narrow. Postgonite slender and finger-like.

Re-description. Lectotype male. Body 3.9 mm, wing 4.3 mm. Head ( Fig. 1 ) holoptic on frons. Upper ommatidia slightly larger. Ocellar tubercle dark brown, matt velvety, protruding, with 4 long slender setae. Small triangle of frons above antennae brown. Face short, wide, glabrous, grey pruinose. Proboscis with no sclerotized areas, small, brown, partially retracted within open mouth. Palpus yellow, small, porrect, spatuliform, with few short apical setae. Postcranium dark brown to black, matt velvety, with grey-brown pruinescence; postocular setae long, proclinate over eyes; vertical setae subequal to adjacent postocular ones; upper half of postcranium with no occipital setae and lower half with many black stout setae ( Fig. 1 ). Gena with setae slightly more slender and lighter than on lower postcranium, rather upward-curved. Postgena with row of stout setae, ventral setae slender. Antenna dark brown to black, matt velvety; pedicel with stout setae, some on outer face notably longer; postpedicel small, semicircular, almost 1.5X longer than scape and pedicel combined; stylus thick, elongated, slightly longer than basal segments.

Thorax ( Figs. 2–3 ). Scutum dark brown to black; matt velvety with grey-brown pruinescence in certain perspectives, denser on anterior region, along dorsocentral row of setae, on posterior region, and laterally. Mesopleuron grey pruinose but anepisternum brown pruinose in certain views. Postpronotal lobe and postalar callus yellowish. Chaetotaxy: about 15 uniserial antepronotals; 9–10 postpronotals; 0 proepisternal; about 15 proepimerals arranged in upward-curved tuft; 9 – 10 uniserial acrostichals; 13 uniserial dorsocentrals arranged in complete row, posterior setae longer; 3 presutural supra-alars; 7 postsutural supra-alars curved anteriorly just behind transverse suture, first three setae of this row may belong to postsutural intra-alar row; around 17 notopleurals; 3 postalars and 7 scutellars subparallel-sided.

Legs ( Figs. 4 – 6 ). Subshining; coxae, trochanter and femora brown, except extreme distal portion of femora yellow; tibiae and basal tarsomeres yellow, distal tarsomeres darker; grey pruinescence more distinct on coxae, trochanter and femora. All coxae with longer setae on anterior face; still longer setae on all femora anteroventrally and posteroventrally, fore femur posterodorsally and hind femur anterodorsally; dorsal setae slightly shorter. Tibiae with short setae; mid tibia with 2 subapical setae slightly stouter, 1 anteroventral and 1 posteroventral. All tarsi longer than respective tibiae.

Wing ( Fig. 14 ). Hyaline with brown veins. Costal vein with slightly longer setae at base (rather inconspicuous in figure); Sc almost complete; R1 lacking setae; pterostigma light brown; cell r4 narrow; A1 evanescent distally. Alula yellow with paler setae. Halter yellow.

Abdomen ( Fig. 7 ). Dark brown to black, matt velvety. Tergites with band of grey pruinescence across posterior margin and with slender and long setae, the lateral and posterior setae notably longer. Sternites concolorous with tergites, each with grey pruinescence across posterior margin but narrower and less distinct than on tergites. Tergite 8 narrower than sternite 8 ( Fig. 10 ).

Terminalia ( Figs. 8 – 13 ). Concolorous with preabdomen tergites, except epandrium yellow; small, dorsally directed, not keel-shaped. Epandrium ( Fig. 11 ) with long curved process and pair of stout setae medially. Cercus slightly shorter than surstylus. Postgonite distinct, elongate with small denticles subapically. Phallus ( Figs. 12, 13 ) rather complex, with two hat-shaped subapical expansions. Ejaculatory apodeme ( Fig. 12 ) plate-like.

Female specimen not examined. Originally described as: “eyes dichoptic; terminalia black, ventrally yellow, robust with yellow spines distally; femora yellow, except brown medially”.

Geographic distribution. Peru, Bolivia.

Material examined. LECTOTYPE ɗ (here designated), “ PERU [Cuzco], Sicuani, 17.vi.1903 [3500 m]” (SMT).

Lectotype condition. Right postpedicel lost. Right wing mounted on microslide. Terminalia in vial with glycerin.

Remarks. This species was described based on four specimens from Peru and Bolivia. The single remaining specimen in Dresden has been labelled lectotype by the present author to fix and stabilize the current concept of the name.

Discussion. Using the key of Collin (1933, p. 74), the male specimen of A. cingulata runs to “group D” with vein R1 bare, head holoptic and no “intrahumeral” setae. It does not fit any couplet of “group D”. It runs to couplet 17 by having more than four scutellar bristles but thereafter does not fit couplet 18 (two notopleurals) or couplet 21 (three strong notopleurals in a line) as it has about 17 notopleural bristles (see Fig. 3 ). Based on the figures in Collin (1933, fig. 15g, p. 78), A. cingulata has an antenna rather similar to A. innocua Collin, 1933 with a short and rather truncate postpedicel. It also appears to be closely related to A. mediocris Collin, 1933 . When comparing both, they present similar antennal shape (except stylus is subapical in A. mediocris as in figs. 16g –h of Collin 1933, p. 82), a similar pattern of setae on postcranium, and similar terminalia shape ( Collin 1933, figs. 16g –h, p. 82). The original description of A. mediocris differs from A. cingulata by the number of setae on notopleuron and scutellum, by the size and number of ocellar setae and some details in the coloration. Based on characters presented here A. cingulata is not conspecific with these two species.

Figures

FIGURE 14. Wing. Apalocnemis cingulata Bezzi, lectotype ɗ (pres. desig.).

FIGURES 1 – 13. Apalocnemis cingulata Bezzi, lectotype ɗ (pres. desig.). 1, head, lateral view; 2, thorax, dorsal view; 3, thoracic dorsum, lateral view; 4, right fore leg, anterior view; 5, left mid leg, posterior view; 6, left hind leg, posterior view; 7, abdomen, dorsal view; 8, tergite 8, dorsal view; 9, terminalia, dorsal view; 10, terminalia, lateral view, 11, epandrium and cercus, lateral view; 12, hypandrium and phallus, lateral view; 13, ejaculatory apodeme and phallus, posterior view. Abbreviations: CE = cercus; EP, epandrium; HYP = hypandrium; PGT = postgonite; PH = phallus; ST = sternite; SU = surstylus; T = tergite. Scale bars: Figs. 1 – 3, 4 – 6, 7 = 0.5 mm; 8 – 12 = 0.2 mm; 13 = 0.1 mm.