Rhamphomyia (Holoclera) subvariabilis, Barták & Kubík, 2012

Barták, Miroslav & Kubík, Stepán, 2012, A review of the Palaearctic species of Rhamphomyia subgenus Holoclera (Diptera: Empididae) with description of 5 new species, Revue suisse de Zoologie 119 (3), pp. 385-407 : 397-401

Rhamphomyia (Holoclera) subvariabilis sp. n. Figs 5 , 6

HOLOTYPE: CULSP; 1 Ƌ; Russia, Caucasus , Azau, 43°15´47´´N, 42°29´21´´E, 2 300m; 25.vi.-7.vii.1976; M. Barták.

PARATYPES: CULSP; 1 ♀; same data as the Holotype .

DISTRIBUTION: Russia (Caucasus).

DATE OF OCCURRENCE: June-July.

DESCRIPTION

Male: Eyes holoptic, facets in ventral half of eye much smaller than in dorsal half. Frons (small area just above antenna and below ocellar triangle) brown, light grey microtrichose, bare. Ocellar setae black, more than half as long as frons, ocellar triangle with a pair of rather long additional setae on hind part. Face brown, light grey microtrichose, about 0.18? mm broad ventrally and 0,12? mm long, bare. Occiput blackish-brown, light grey microtrichose, with rather strong black setae arranged in two nearly regular rows, postocular row complete, subparallel to hind eye margin, irregular ventrally. Antenna black, both basal antennomeres yellowish-brown, length of antennal segments (in 0.01 mm scale) = 8?: 7: 28: 16, both basal antennomeres rather short setose (the longest setae about 0.11 mm long). Labrum yellow, lustrous, nearly twice as long as head is high. Palpus yellow with several brown setae. Gena very narrow and microtrichose, clypeus microtrichose. Thorax brown, humeri, anterior part of notopleuron and stripes under presutural dorsocentrals yellowish translucent, mesoscutum grey or brownish-grey microtrichose, with more greyish median stripe between dorsocentrals with darker margins. All thoracic setae dark. Chaetotaxy: proepisternum entirely setose; prosternum bare; proepisternal depression with a single small seta; acrostichals absent; 7-8 uniserial dorsocentrals about 0.30 mm long in middle of their rows, ending in 2-3 prescutellars; intrahumeral present; 1 strong posthumeral (1-2 additional setae laterad of dorsocentrals on posthumeral area); 1 postpronotal and about 8 shorter but relatively strong setae on postpronotum; 3-4 notopleurals (anterior part of notopleuron with 3-4 setae); 1 very long supraalar and 3-4 setae on prealar area; 1 long and 1 short and fine postalars; 4 scutellars; laterotergite with dark setae. Legs including coxae yellow, base of coxae and tarsi slightly darkened. Legs microtrichose (femora sublustrous), covered with dark setae. One long seta present in posteroapical comb on hind tibia. Fore femur short setose. Fore tibia with 3 anterodorsal and 4-5 posterodorsal setae slightly longer than tibia is deep. Mid femur with 2 anterior setae in apical third, otherwise short setose except preapical setae. Mid tibia with 3-4 anterodorsal (or anterior) and 4 posterodorsal setae slightly longer than tibia is deep, otherwise short setose. Hind femur similarly setose as mid femur. Hind tibia with 4-5 anterodorsal and 5-6 posterodorsal setae slightly longer than tibia is deep, ventral setae short. Basal tarsomeres of all legs thin and short setose, with short spines ventrally. Measurements (in 0.01 mm scale): length: f1 (140), f2 (183), f3 (235), t1 (145), t2 (169), t3 (203), bt1 (104), bt2 (89), bt3 (125), width: bt1 (5), bt2 (6), bt3 (7). Wing clear, slightly iridescent, stigma hyaline, veins yellowish-brown, anal vein (A1) complete. Costal seta present, axillary angle acute. M2/D = 1.4-1.5, CuA1 ratio = 2.5, lw: ww = 2.8-2.9. Halter yellow, calypter yellow with dark fringes. Abdomen brown, hind margin of segments and last two sternites translucent yelow, abdomen microtrichose and dark setose. Hind marginal setae on sides of tergites subequally long as segments, discal setae much shorter than marginals. Dorsum of tergites shorter setose. 8th segment forming syntergosternite, cranial part depigmented ventrally and in dorsal third. Terminalia ( Figs 5 , 6 ): cercus trilobate; phallus short and thick, axe-like broadened at apex and slightly narrowed before middle; hypandrium with two short Rhamphomyia (Holoclera) subvariabilis sp. n., male terminalia (macerated), lateral view. Scale 0.1 mm.

apical spine like setae; epandrium attached to hypandrium some distance from hypandrial articulation with phallobase (short hypandrial arms present). Length of body 4.6 mm, wing 5.0 mm.

Female: Similar to male but with the following differences. Eyes narrowly dichoptic (0.05 mm broad in the narrowest place), ventral facets only slightly smaller than dorsal ones. Frons 0.32 mm long, with a pair of setae in the dorsal part. Face as in male, yellowish only ventrally. Length of antennal segments = 9: 7: 26: 15. Ocellar setae 2/3 as long as frons. Occiput translucent yellow near neck. Thorax similarly coloured and setose as in male, only yellow parts more extensive (practically whole of prothorax and broad stripes below dorsocentrals yellow), median grey stripe without dark margins, all setae slightly shorter and finer than in male (dorsocentrals about 0.25 mm long), short setae on postpronotum not strong. Legs including coxae similarly colored as in male, also arrangement of setae similar, only anterior setae on hind femur less distinct and anterodorsal and posterodorsal setae on tibiae slightly shorter than in male. Leg measurements (in 0.01 mm scale): length: f1 (125), f2 (160), f3 (210), t1 Rhamphomyia (Holoclera) subvariabilis sp. n., male phallus (lateral view) and cerci (dorsal view). Scale 0.1 mm.

(125), t2 (143), t3 (184), bt1 (85), bt2 (72), bt3 (104), width: bt1 and bt2 (5), bt3 (7?). M2/D = 1.3-1.4, CuA1 ratio = 2.6-2.7, lw: ww = 2.9. Abdomen brownish-yellow (front part darker than more yellowish hind third), microtrichose. Hind marginal setae on sides of tergites 2-3 almost as long as their corresponding segments, on segment 4 half as long and on the following segments much shorter. Length of body: 4.0 mm, wing: 5.0 mm.

DIFFERENTIAL DIAGNOSIS: Rhamphomyia (Holoclera) subvariabilis sp. n. belongs to the R.­ flava group of Holoclera and due to the absence of acrostichals it is most similar to R.­ variabilis (Fallén) . The main characteristics distinguishing these two species are as follows: antennal stylus in R.­ variabilis is much shorter than the 1st flagellomere (being less than 1/3 as long), mid and hind tibiae with strong anteroventral setae. In R.­ subvariabilis , antennal stylus is more than half as long as the 3rd segment and the mid and hind tibiae are without anteroventral setae. Moreover, there are differences in male genitalia (compare Figs 5 & 6 with Fig. 7 and with Barták, 1982: fig. 17c). Hypandrium bears several strong submedian setae in R. variabilis but Rhamphomyia (Holoclera) variabilis (Fallén, 1816) , male phallus (lateral view) and cerci (dorsal view). Scale 0.1 mm.

only two very short apical spines in R.­ subvariabilis ; dorsobasal projection of cercus is triangle-shaped, lustrous, bare and inflated (not visible in lateral view) in R.­ variabilis but finger-like microtrichose, with fine setae and laterally visible in R.­ subvariabilis ; and tip of phallus also differs markedly in both species (compare Figs 6 and 7 ).

DERIVATIO NOMINIS: the specific name refers to the similarity with R.­ variabilis .

Figures

FIG. 5

FIG. 6

FIG. 7