Hilarempis xanthocera Bezzi, 1905

Rafael, J. A., 2012, Revision of Neotropical species of Empididae (Diptera) described by Mario Bezzi. VIII. The species described in Hilarempis Bezzi, Zootaxa 3189 (1), pp. 56-68 : 66-67

Hilarempis xanthocera Bezzi

( Figs. 58–69 , 75 )

Hilarempis xanthocera Bezzi, 1905: 444 ; 1909: 367 (female description); Melander 1928: 130 (checklist); Collin 1933: 110 (citation); Smith 1967:36 (catalogue); Yang et al. 2007: 244 (catalogue).

Diagnosis. Dark brown to black with halter black; palpus and base of antenna yellow; frons setose; face with short setae placed medially and transversely; thorax with dark longitudinal bands; legs predominantly yellow, hind pair darker; fore tarsomere 1 not swollen; veins robust, A 1 long; tergites densely grey pruinose basally and laterally.

Re-description. Female. Body 6.3 mm; wing 6.2 mm. Head ( Fig. 58 ). Dichoptic; ommatidia subequal. Frons ( Fig. 60 ) wider than ocellar tubercle, slightly higher than greatest width, slightly divergent near antenna, grey pruinose, except between setae and matte-black eyes, with 8 proclinate setae. Face as high as frons, divergent at ventral margin, grey pruinose with short slender setae, rather inconspicuous, placed medially and transversely. Palpus yellow, slender, with distinct yellow setae. Proboscis ( Fig. 58 ) length equal to head height, labrum straight, shiny, yellowish-brown at base, black at apex. Ocellar tubercle slightly protuberant with reddish ocelli, glassy; anterior ocellar seta robust, divergent (damaged) and 3 short posterior setae, aligned. Antenna ( Fig. 61 ) yellow, except from distal half of postpedicel velvety matte black; postpedicel around 1.4X longer than length of scape and pedicel combined and around 1.6X longer than three-segmented stylus. Segment 1 of stylus short, segment 2 around 0.5 postpedicel length and 4X longer than thin segment 3. Postcranium ( Fig. 59 ) densely grey pruinose; setae of upper half more robust, black; of lower half slender, light yellow. Inner vertical and outer vertical setae slightly longer and more robust than adjacent setae; postocular setae short. Gena and postgena with slender light-yellow setae.

Thorax ( Fig. 62 ). Dark brown to black, grey pruinose; postalar callus slightly yellowish-brown; scutum with dark longitudinal band between acrostichal and dorsocentral rows of setae and between dorsocentral and supra-alar rows, latter band wider and contiguous posteriorly. Setae severely damaged, observed from alveoli (most of them not represented in the figure). Chaetotaxy: 3 antepronotals, lateral more robust; 1 robust postpronotals and 8–10 slender; around 6 slender proepisternals, light yellow; more than 15 light yellow slender proepimerals; acrostichals short, misaligned biserial or uniserial; dorsocentrals apparently uniserial, short, except last robust located near postalar callus; some short intra-alar presuturals; intra-alar postsuturals not observed; apparently 3–4 short supra-alar presuturals; 2–3 supra-alar postsuturals, posterior robust; 3 robust notopleurals and several slender; 3 scutellars.

Legs ( Figs. 63–65 ). Yellow with coxae, hind femora and all tibiae and tarsi dark brown; trochanter with small apical black spot ventrally. Setae short, some of them more robust. Fore tibia ( Fig. 63 ) with 1 anteroventral and 1 apical posteroventral seta. Mid tibia ( Fig. 64 ) with 3 anteroventral, 4 posteroventral setae on distal half, last two close together. Fore tarsomere 1 not swollen, less than 0.5X length of fore tibia. Hind tibia ( Fig. 65 ) with 4–5 anteroventral setae, last two close together, and 2 dorsal submedially. Tarsomeres with ventral setae more robust.

Wing ( Fig. 75 ). Slightly brown infuscate, veins distinctly black; pterostigma distinct, brown. A 1 evanescent only distally. Halter yellow.

Abdomen dark brown to black, densely grey pruinose more distinct basally and laterally; all tergites grey pruinose in certain angles, notably on last two tergites when viewed anterolaterally; setae clear, small, longer laterally on tergite 1. Posterior tergites with narrow yellow band across hind margin. Sternites dark brown basally, yellowish brown distally; sternite 5 light yellow on posterior margin.

Terminalia ( Figs. 66–68 ). Tergite 8 with apical sinus and tergite 10 with basal cleft ( Fig. 67 ); cercus short, acuminate distally; sternite 8 more sclerotized laterally, rather acuminate distally. Genital fork subtriangular ( Fig. 67 ). Spermathecal receptacle oval ( Fig. 69 ).

Geographic distribution. Peru.

Material examined. “ PERU, Pichis-weg , i.1904 [300 – 400 m]” (1 ♀) .

Variations. The female specimen re-described here fits very well the original description of the male, except in the following attributes: male with acrostichal setae quadriserial and 2 supra-alar setae, while the female here described the acrostichal setae are biserial and with only 1 supra-alar postsutural seta (observed through alveoli). Probably, Bezzi’s interpretation that acrostichal row is quadriserial is because they are somewhat separate, giving impression that each row is biserial and all together are quadriserial.

Remarks. The male holotype specimen from Peru, Callanga was deposited in the Hungarian Natural History Museum and destroyed in 1956 when Russian artillery bombed Budapest. Bezzi (1909: 367) described a conspecific female specimen from Peru, Pichisweg, and this specimen is re-described here.

Discussion. The male holotype of Hilarempis xanthocera was originally described as dichoptic (oculis s ejunctis). Besides this character the thorax is dark ground-colour, antenna yellow and mesonotum with four dark bands. These characters take this species to couplet 13 of H. argyrozona (Philippi, 1865) in Collin’s (1933) key. The latter species was re-described by Collin (1933). Both species have cell dm slightly produced ( Fig. 75 ). They differ by ocellar setae robust (small, no longer and hardly stronger than short setae on frons in H. argyrozona ), antennae entirely yellow (postpedicel black in H. argyrozona ), legs with hind femur and all tibiae dark brown (yellowish in H. argyrozona ). The examined specimen is female and not possible to compare with genitalia figured by Collin (1933).

Figures

FIGURES 58–69. Hilarempis xanthocera Bezzi, ♀ specimen from Peru. 58, head, lateral view; 59, postcranium, posterolateral view; 60, frons, frontal view; 61, antenna, lateral view; 62, thorax, dorsal view; 63, right fore leg, posterior view; 64, left mid leg, posterior view; 65, left hind leg, anterior view; 66, tergite and sternite 8, tergite and sternite 10 and cercus, lateral view; 67, tergite 8, tergite 10 and cercus, dorsal view; 68, sternite 8, sternite 10 and cercus, ventral view; 69, spermathecal receptacle. Abbreviations: ce = cercus, g fk = genital fork, ST = sternite, T = tergite. Scale bars: 58, 62, 63–65 = 1.0 mm; 59–61, = 0.5 mm; 66–68 = 0.2 mm; 69 = 0.1 mm.

FIGURES 70–75. Wings. 70, Hilarempis argentifera Bezzi, holotype ♀; 71, H. barbatula Bezzi, lectotype ♂ (pres. desig.); 72, H. carinata Bezzi, lectotype ♂ (pres. desig.); 73, H. elegans Bezzi, holotype ♂; 74, H. gymnaspis Bezzi, lectotype ♂ (pres. desig.); 75, H. xanthocera Bezzi, ♀ specimen from Peru.