Oidardis falcimystax, Cezar, Lucas A., Fisher, Eric M. & Lamas, Carlos J. E., 2013

Cezar, Lucas A., Fisher, Eric M. & Lamas, Carlos J. E., 2013, Four new species of Oidardis Hermann, 1912 (Diptera, Asilidae, Laphriinae, Atomosiini) from two major faunistic surveys in the Atlantic Rainforest, ZooKeys 350, pp. 47-74 : 50-54

Oidardis falcimystax sp. n. Figures 1 A–B, 2A, 3A, 4A, 5A, 6 A–C, 7A, 8C, 10

Diagnosis.

Gibbosity extending through lower half of face or beyond; abdomen cup-shaped; legs yellow or light-brown. Males with modified mystax (pair of regular setae dorsally, pair of dark-brown laterally-flattened setae and pair of white sinuous filiform setae ventrally); modified tibial setae dark-brown, shorter than femur, with dark-brown leaf-shaped, longitudinally-striated lamella on apical 1/5, inserted on middle of hind tibiae.

Description.

Holotype. Male. Body shiny black. Total length, excluding antennae, 5 mm; length of thorax, 1.2 mm; length of wing, 4.4 mm; greatest width of abdomen, 1 mm.

Head, laterally. Face, between antennal insertion and gibbosity, plane with eye margin; gibbosity prominent, equals ventral 0.7 of face height; dorsal occipital setae dark-brown, lateral occipital setae white, ventral occipital setae white; proboscis 0.53 × the height of head, with a pair of yellow macrosetae ventrally; palpus dark-brown, with yellow setae apically. Antenna. Antenna 0.74 × as long as the height of eye, entirely dark-brown, with dark-brown setae and macrosetae; antennal insertion at dorsal 0.2 of head height; scape slightly longer than pedicel, with medium-sized ventral seta, numerous short setae ventrally and around the whole segment apically; pedicel oval; postpedicel oblong, 1.7 × length of basal two segments, brown-pollinose, except for silvery-yellow pollinosity on elliptical sensorial area on inner face, with dorsal spine subapical (3/4 length of postpedicel or beyond). Head, anteriorly. Head 1.39 × as wide as high; face 0.14 × as wide as head, silvery-pollinose, except on shiny upper half of gibbosity; mystax long (extending beyond the apex of proboscis), comprised of 6 macrosetae - dorsal pair regular and dark-brown, middle pair spatulate and dark-brown, and ventral pair sinuous-filiform and white; facial setae, other than mystax, pale-yellow; frons golden-pollinose; orbital setae dark-brown; vertex golden-pollinose; ocellar tubercle golden-pollinose, as high as vertex, 0.29 × as wide as frons, anterior ocellus 0.11 × as wide as frons by the ocellus position.

Thorax. Postpronotal lobe dark-brown; scutum shiny black, not punctate, vestiture golden, equal-sized, longest setae as long as half the scape, reclinate anteriorly and proclinate posteriorly; one dark-brown notopleural; scutellum black, scutellar margin strongly impressed, marginal scutellar macrosetae dark-brown, equal-sized, longest ones much shorter than scutellum (as long as the width of the rim); postalar callosity dark-brown, partly with bright-blue reflections; pleuron shiny dark-brown, with silvery-white pollinosity; setulae on proepisternum, katepisternum and anepisternum yellow; one anepisternal macroseta, plus fine setulae, yellow; tuft of katatergal macrosetae light-brown; anatergite with golden, hair-like setae.

Legs. Coxae orange-yellow; trochanter orange-yellow, with fine yellow setulae; femora yellow, slightly darkened dorsally-except hind femur, only darkened distally, covered with short stout yellow setulae dorsally, with dark setae on apical 1/3 dorsally, hind femur with 4 long yellow ventral macrosetae in a row along proximal half; tibiae entirely yellow, with yellow setulae, long yellow macrosetae and thick spines; hind tibia entirely covered by golden setulae, with white setulae ventrally, long dark-brown macrosetae ventrally and long dark-brown macrosetae anterodorsally; modified tibial setae attached to hind tibia at middle, dark-brown, shorter than femur, with dark-brown leaf-shaped longitudinally-striated lamella on apical 1/5; tarsi yellow, 5th tarsomere dark-brown, with stout yellow setae dorsally, and densely covered with thick spine-like golden setae, 5th tarsomere with 3 setae apically, opposite the claws and longer than them; claws yellow on base and black apically; pulvilli yellow and fringed; empodium shorter than claws.

Wing. Brownish, darker along upper margin; cell r1 with short slightly-concave stalk (2 × the length of r-m); crossvein r-m at proximal half of cell d, aligned to the end of Sc; cell m3 narrowing distally (M2 and M3 converging by the end of cell m3), with stalk slightly longer than r-m, apex of m3 and apex of cell d parallel and unaligned, apex of m3 beyond apex of d; crossvein bm-cu long, base of M3 and CuA1 distant from each other and not appearing as an “X”; cell cup with stalk shorter than r-m; posterior margin of wing slightly convex at distal half; calypters orange, with light-brown margin and fringe of short brown setae; halter with orange stem, white knob.

Abdomen. Black, punctate, with sides diverging posteriorly, T2 1.9 × wider than long; vestiture longer and lighter laterally and ventrally, several white macrosetae present on lateral margin of T1 and T2. Male terminalia. Hypopygium barely conspicuous; hypandrium regular-sized (2/3 the width of hypopygium or more), much wider than long, anterior margin straight to slightly convex, posterior margin sharply pointed; gonocoxites free, gonocoxal prolongation thin, smoothly curved inwards, with 2 spines at apex; gonostylus reduced, round, laterally flattened, free, attached to the base of gonocoxite; apex of phallus with three equal-sized prongs; epandrium straight in lateral view; lobes of hypoproct short.

Female. Total length, excluding antennae, 5.3-6.2 mm, (n=5); length of thorax, 1.4-1.7 mm, (n=5); length of wing, 4.6-5.4 mm, (n=5); greatest width of abdomen, 1.0-1.3 mm, (n=3). Differs from male as follows: gibbosity that equals ventral 0.5-0.64 of face height; proboscis 0.48-0.55 × the height of head; antenna 0.68-0.8 × as long as the height of eye; antennal insertion at dorsal 0.22-0.4 of head height; postpedicel 1.4-1.5 × length of basal two segments; head 1.3-1.43 × as wide as high; face 0.11-0.14 × as wide as head; mystax comprised of regular golden-brown macrosetae; ocellar tubercle 0.28-0.37 × as wide as frons; anterior ocellus 0.13-0.17 × as wide as frons by the ocellus position; hind tibiae with fine, medium-sized, golden setae ventrally, long, yellow macroseta inserted ventrally on the middle, and long, dark-brown macrosetae anterodorsally; modified tibial setae absent; T2 2.13-2.29 × wider than long; Female genitalia. Three spermathecae; reservoirs cylindrical, disposed in a spiral; spermathecal ducts opening independently at the bursa; genital fork rectangular, U-shaped, arms anteriorly thick, posteriorly truncate, divergent; accessory glands undistinguishable.

Morphological variation. Total length, excluding antennae, 5.0-6.3 mm, (n=10); length of thorax, 1.2-1.5 mm, (n=10); length of wing, 4.2-4.9 mm, (n=9); greatest width of abdomen, 0.9-1.2 mm, (n=9). Some specimens differed from the holotype, as follows: gibbosity that equals ventral 0.5-0.7 of face height; lateral occipital setae dark-brown; proboscis 0.35-0.53 × the height of head; proboscis with dark-brown macrosetae, ventrally; antenna 0.7-0.8 × as long as the height of eye; antennal insertion at dorsal 0.2-0.27 of head height; numerous short setae on a row around the scape; postpedicel 1.4-1.8 × length of basal two segments; postpedicel golden-pollinose; head 1.22-1.43 × as wide as high; face 0.07-0.21 × as wide as head; frons silvery-pollinose; orbital setae golden-brown; ocellar tubercle 0.29-0.33 × as wide as frons; anterior ocellus 0.11-0.14 × as wide as frons by the ocellus position; postpronotal lobe black with yellow spot dorsal to mesothoracic spiracle; scutal vestiture dark-brown; longest marginal scutellar macrosetae shorter than scutellum; postalar callosity light-brown; fore and mid tibiae with yellow setulae, long dark-brown macrosetae, and thick spines; tarsi with stout dark-brown setae dorsally and densely covered with thick spine-like golden setae; claws reddish on base and black apically; calypters white, with light-brown margin and fringe of short yellow setae; halter knob pale-yellow; T2 1.63-2.13 × wider than long.

Distribution.

Peru, Bolivia, Brazil ( Goiás, Mato Grosso, São Paulo and Paraná) and Argentina.

Remarks.

This species share with an undescribed species from Panama–” Oidardis signaseta " Fisher (nomen nudum) ( Fisher 2009: pp. 600, 604, 624, figs 46, 77)-several peculiar characters regarding the shape of gibbosity and mystax. The main difference between those two species is that " Oidardis signaseta " males bear two pairs of modified blade-shaped setae, whilst Oidardis falcimystax males bear only one pair, along with a pair of white sinuous filiform setae.

Oidardis falcimystax , in its farther western occurrences, inhabit Peruvian and Bolivian Amazon forests, as do its congeners Oidardis aenescens Hermann, 1912, and Oidardis gibbosa Hermann, 1912; yet, due to the singular morphology of its facial gibbosity and mystax, and the modified tibial seta, Oidardis falcimystax can be readily distinguished from these other two species. Oidardis aenescens have similar size and overall coloration, and even presents a similarly-prominent gibbosity, but its extent reaches no more than the ventral third of the face; besides, males of this species do not present any striking modification on mystax or tibial setae. Oidardis gibbosa presents a completely different color pattern, along with distinctly modified tibial seta, among other characters. Oidardis aenescens and Oidardis gibbosa will be thoroughly presented in future publications.

This species, along with Oidardis maculiseta , is the first occurrence of Oidardis in the Cerrado area, since the genus is almost exclusively found in dense-forest biomes. Those occurrences are, though, probably related to the higher forest environments in Cerrado, “Cerradão”, and riparian forests, which have been noticed to share fauna of the Lower Diptera , at least, with Atlantic Semi-deciduous Forest areas (D. S. Amorim, unpublished data).

Etymology.

From the Latin, falx = scythe, and the Greek, mystax = moustache. Refers to the flattened blade-shaped mystacal macrosetae.

Type-material examined.

Holotype: Brazil: São Paulo, Sertãozinho, elev. 550 m (21°9.14'S, 48°5.72'W), 10-24.xi.2010, coll. V. C. Silva & P. F. Donda (Frag. 2) - male (MZUSP) Paratypes: Argentina: Misiones, Puerto Iguazu, behind Hotel Orquídeas, (25°37'29.59"S, 54°33'2.65"W), 1-6.ii.1992, coll. S.A. Marshall - 1 female (EFISHER); Bolivia: Beni, Palos Blancos, elev. 600 m (15°35'S, 67°15'0"W), 11-15.i.1976, coll. L.E. Pena - 2 males (CNC); Brazil: Goiás, Jataí, (17°52'33.25"S, 51°43'17.19"W), xi.1972, coll. F. M. Oliveira - 1 female (MZUSP); Mato Grosso, Chapada dos Guimarães, (15°27'10.26"S, 55°44'21.02"W), 21.xi.1983, coll. Exc. Dep. ZOO - 4 males (DZUP, MZUSP); same locality, 24.xi.1983, coll. Exc. Dep. ZOO - 1 male (DZUP); Paraná, Fênix, Reserva Estadual ITCF, (23°55'0.05"S, 51°57'38.26"W), 24.xi.1986, coll. Lev. Ent. PROFAUPAR - 1 male (MZUSP); same locality, 8.xii.1986, coll. Lev. Ent. PROFAUPAR - 5 males (DZUP); same locality, 15.xii.1986, coll. Lev. Ent. PROFAUPAR - 2 males (DZUP); same locality, 22.xii.1986, coll. Lev. Ent. PROFAUPAR - 5 males (DZUP); same locality, 29.xii.1986, coll. Lev. Ent. PROFAUPAR - 5 males (DZUP); Foz do Iguaçu, (25°32'48.83"S, 54°35'17.42"W), 3.xii.1966, coll. Exc. Dep. ZOO - 1 female (DZUP); same locality, 5.xii.1966, coll. Exc. Dep. ZOO - 1 female (DZUP); same locality, 7.xii.1966, coll. Exc. Dep. ZOO - 1 female, 3 males (incl. 4 paratypes) (DZUP, MZUSP); same locality, 12.xii.1966, coll. Exc. Dep. ZOO - 3 males (DZUP); São Paulo, Sertãozinho, elev. 550 m (21°9.14'S, 48°5.72'W), 19.i.2011, coll. V. C. Silva & P. F. Donda (Frag. 1) - 1 male (MZUSP); same locality, 2.ii.2011, coll. V. C. Silva & P. F. Donda (Frag. 1) - 1 female (MZUSP); same locality, 16.ii.2011, coll. V. C. Silva, P. F. Donda, G. P. Ignácio & D. S. Amorim (Frag. 1) - 1 female (MZUSP); Peru: Madre de Diós, Tambopata Reserve - 30 km SW Puerto Maldonado, (12°44'50.9"S, 69°25'46.46"W), 6.xii.1982, coll. J.J. Anderson - 1 male (EFISHER).