Paraberismyia mathisi, Woodley, Norman E., 2013

Woodley, Norman E., 2013, A revision of the Neotropical genus Paraberismyia Woodley (Diptera, Stratiomyidae, Beridinae) with three new species, ZooKeys 353, pp. 25-45 : 30-32

Paraberismyia mathisi sp. n. Figs 4, 7-15

Diagnosis.

Paraberismyia mathisi can be distinguished from other species in the genus by having the dorsal half of the anepisternum completely covered with fine tomentum, without a bare, shiny medial area. No other species has this character state. Females have tomentose spots on the lateral margins of the upper frons (Fig. 4) and a relatively broad strip of the occiput (postocular orbit) visible behind the eye in profile covered in conspicuous grayish tomentum (Fig. 10). These two character states are also unique within the genus.

Description.

Male (Figs 7, 9). Head: Black, without metallic reflections; lower frons and face densely silvery gray tomentose, occiput also tomentose except for median occipital sclerite, but tomentum is sparser and dark, not strongly contrasting with background coloration, median area of upper frons very sparsely tomentose; upper frons with sparse dark hairs, lower frons just above antennae with mostly pale pilosity that is shorter than the first antennal segment; face pilose with mostly dark, longer hairs, with a few yellowish hairs intermixed; gena with pale yellowish hairs a little longer than those of face, occiput with scattered long pale hairs; eye densely pilose, hairs brownish black, about half length of first antennal segment; antenna 0.75-0.85 length of head, first two segments and first flagellomere yellowish, following two flagellomeres yellow internally, apical flagellomeres brownish black; first two antennal segments with stiff black hairs, longer hairs on flagellum black; palpus yellow, with numerous long hairs, those on first segment pale yellowish, second segment with hairs mostly black; proboscis yellow.

Thorax: Scutum and scutellum metallic bluish green (Fig. 7), postpronotal lobe and postalar callus brownish; pleura blackish brown, anepisternum and katepisternum with metallic reflections similar to coloration of mesonotum, posterior margin of anepimeron slightly yellowish; mesonotum finely, densely punctate; thorax with grayish tomentum present over most of prothorax, anterior two-thirds of anepisternum, entire katepimeron and meron, anatergite, mediotergite, and subscutellum, most conspicuous on anepisternum, which has the dorsal half completely tomentose medially; mostly pilose with long, erect pale hairs, a little longer than first two antennal segments combined, intermixed with short, pale, semi-appressed hairs on scutum and scutellum, with small strip on anterior part of anepisternum, entire katepimeron, meron, anatergite, mediotergite, and subscutellum bare; hind tarsus with tarsomeres 1-3 moderately inflated; legs (Fig. 9) yellowish, except hind femur brown on apical one-fifth, front tibia brownish anteriorly and dorsally, middle tibia with irregular pale brown infuscation, hind tibia entirely brownish black, and all tarsi are brownish-black except middle basitarsus is paler on basal half, and hind basitarsus is yellowish on basal one-fourth to one-half; legs short pilose, posterior surfaces of all femora with longer, erect pale hairs, posteroventral surface of hind tibia with scattered longer, erect hairs, coloration of pilosity similar to cuticular ground color, except narrow apices of femora have blackish hairs; wing hyaline with brownish infuscation anteriorly and apically, but noticeably hyaline in cells c and r2+3, cell r1 brown, veins brownish, yellowish at extreme base of wing; cell cup with entire surface covered with microtrichia; halter yellowish, knob slightly darker than stem.

Abdomen: Tergites (Fig. 7) dark brownish with extensive translucent pale area on tergites 2-5, the pale area not discreetly defined, tergal grooves brown, tergite 6 and beyond brown; sternite 1 brown except for wide posterior margin pale yellowish, sternites 2-5 pale yellowish, 4 and 5 with vague lateral brown areas, sternite 6 and beyond brown; tergites vaguely, almost imperceptibly tomentose, quite shiny, with short, blackish pilosity, lateral margins with a fringe of pale hairs longer than antennal flagellum, tergites 5 and beyond with some dark hairs intermixed; sternites with short, yellowish hairs, becoming dark on dark-colored posterior segments.

Terminalia: Gonocoxites (Fig. 11) with lateral margins tapering anteriorly, slightly arcuate, with low, broadly rounded process ventral to gonostylus; gonocoxal apodemes short, not reaching anterior margin of genital capsule; synsternite of genital capsule with triangular-shaped process that is broadly rounded at apex (Fig. 11); gonostylus (Figs 11, 12) slightly arcuate, shorter than in Paraberismyia tzontehuitza , with internal triangular process near apex of ventral margin that is proportionately larger than in Paraberismyia tzontehuitza ; phallic complex (Figs 13, 14) trifid, moderately arcuate in lateral view, lateral lobes nearly parallel, medial lobe only slightly shorter than lateral lobes; epandrium (Fig. 15) narrow, posterior margin evenly rounded; cercus of moderate width, apex moderately rounded.

Length: 5.7-6.1 mm.

Female (Figs 8, 10). Differs from male as follows: Head: Frons 0.25-0.28 width of head at anterior ocellus; upper frons (Fig. 4) black with greenish metallic reflections, very finely punctate, with lateral silvery gray tomentose spots, lower frons with inverted triangular bare area which extends from upper frons; occiput (posterior orbit) (Fig. 10) visible in profile, slightly wider than length of scape, densely silvery gray tomentose; pilosity of head shorter than in male, at most one-half length of scape, except on gena; upper frons evenly, sparsely pilose with pale hairs; antenna longer than in male, 0.96-1.04 length of head, flagellomeres 1-3 yellow; palpus more robust, entirely pale pilose except for a few dark hairs at apex.

Thorax: Scutum and scutellum metallic bluish green (Fig. 8), but postpronotal lobe yellow, postalar callus pale brownish, and entire remainder of thorax yellow (Fig. 10), except subscutellum and mediotergite, which are brownish; tomentum as in male, but more whitish on pale cuticular areas; pilosity generally shorter, on scutum at most as long as first antennal segment and without longer, erect hairs; hind tarsus without inflated tarsomeres; leg coloration as in male, but hind femur with a brownish black blotch near apex which is less extensive than in male, front tibia light brownish anteriorly, middle tibiae wholly yellow, hind tibia yellowish to brownish, not as dark as in male, middle basitarsus yellowish on basal half, hind basitarsus yellow except at apex; pilosity of legs similar to that of male, but posterior hairs on femora are shorter; halter pale yellowish.

Abdomen: Tergites (Fig. 8) with yellowish areas not especially translucent, this coloration confined to medial third of tergites 2-5; sternites entirely yellow; cerci small but robust, second segment shorter than first, first segment yellow, second slightly infused with brownish color, hairs yellowish except some on second segment dark.

Length: 5.4-5.6 mm.

Distribution.

Known only from the state of Chiapas, Mexico.

Type material.

Holotype male (USNM), MEXICO: Chiapas, El Triunfo (49 km S of Jaltenango, 15°39.4'N, 92°48.5'W), 1300-2000 meters, 13-15.v.1985, W.N. Mathis. The holotype is in excellent condition. Paratypes (all in USNM): 1 male, 2 females, same data as holotype; 2 males, same data as holotype except collected by A. Freidberg; 2 females, same data as holotype except elevation 1500 meters and collected by A. Freidberg; 1 male, same data as holotype except elevation 2000 meters and collected by A. Freidberg.

Etymology.

The species epithet, mathisi, is a patronym honoring Wayne N. Mathis of the Smithsonian Institution, who collected part of the type series. Wayne has been a colleague and friend for nearly 40 years. He has collected many interesting Stratiomyidae in the course of his extensive field work.

Remarks.

This distinctive species is the smallest in the genus, and has several character states not found in other species of the genus as noted in the diagnosis.