Montismyia lauta ( Hine, 1920 ) González, 2017

González, Christian R., 2017, The genus Acellomyia González, a new taxonomic arrangement of its species and descriptions of a new genus and two new species from southern South America (Diptera: Tabanidae: Diachlorini), Zootaxa 4337 (4), pp. 523-539 : 535-537

Montismyia lauta ( Hine, 1920) comb.nov.

( Figs. 6a– i )

Tabanus lautus Hine, 1920: 192 .

Dasybasis (Agelanius) lauta Coscarón & Philip, 1967: 202 .

Dasybasis (Agelanius) lauta Coscarón & Philip, 1967 of Wilkerson & Fairchild, 1985: 47. Dasybasis (Agelanius) sublauta Coscarón & Philip , l967: 204 (as var. lauta ) of Fairchild & Burger, 1994: 70. Acellomyia lauta ( Hine, 1920) of González, 1999: 159.

Acellomyia lauta ( Hine, 1920) of Cárdenas et al. 2009: 526.

Type-locality. Matucana , Perú. Holotype: ♀ ( OSUC)

Diagnosis. Body color brown ( Fig. 6a ). Eyes blackish, with abundant and long grayish ommatrichia. Frons moderately broad, parallel-sided. Basal callus brown, subquadrate with median dorsal projection extending more than half the height of the frons. Ocellar triangle vestigial, without ocelli. First flagellomere strongly excavated dorsally. Maxillary palpus with abundant and short black setae. Mesonotum with dark brown integument, with gray longitudinal stripes anteriorly. Wings with clouds on the crossveins; R4 with a short appendix. Abdomen. Brownish dorsally, with dorsal longitudinal black band starting on tergite 3 and reaching until tergite 5.

Head. Eyes blackish, with abundant and long grayish ommatrichia. Frons moderately broad, parallel-sided with pale brownish pruiniscence, browner toward the vertex, and with long black setae, frontal index 2.6–2.7 ( Fig. 6b ). Vertex with pale brownish pruiniscence, and long black setae. Basal callus brown, subquadrate with median dorsal projection extending more than half the height of the frons, touching subcallus, not touching eyes ( Fig. 6b ). Ocellar triangle vestigial, without ocelli and with long black setae. Subcallus covered with yellowish gray pruiniscence, and with short gray setae. Clypeus and genae with grayish pruiniscence, and with long yellowish setae; clypeus medially without setae. Beard with long yellowish setae ( Fig. 6c ). Scape of antenna pale brown, with long and erect black setae, pedicel concolorous, bearing long setae, with dorsal projection present. First flagellomere reddish brown, darker apically, strongly excavated dorsally, apical flagellomeres dark brown short and slightly thickened ( Fig. 6d ). Maxillary palpus with yellowish pruiniscence, slender, broadest in middle, first segment with long yellowish setae, second segment with abundant and short black setae, inner side without setae. Proboscis dark brown with yellowish-white ventral bristles on basal half but black on ventral area of labella, labella large and fleshy ( Fig. 6d ). Occiput with gray pruinescence and black setae on dorsal edge. Thorax. Mesonotum with dark brown integument, with gray longitudinal stripes anteriorly, bearing abundant grayish brown setae. Postpronotal lobes reddish gray, with long grayish black setae. Scutellum dark brown, with long gray setae laterally and shorter setae on the disc ( Fig. 6e ). Pleura coated with reddish gray pruiniscence anteriorly and posteriorly, with long gray setae; anepisternum with short black and gray setae. Legs brown, coxae with long blackish setae, femora darker with long gray and black setae; tibiae lighter and with long black setae, remaining leg segments with short black setae. Wings with clouds on the crossveins of cells bm, br, and d; Sc and R1 with short black setae; R4 with a short appendix ( Fig. 6f ). Basicosta with short setae. Halter dark brown, apex whitish. Squamae concolorous with wing base. Upper calypter yellowish, lower calypter lighter. Abdomen. Brownish dorsally, with dorsal longitudinal black band starting on tergite 3 and reaching until tergite 5, but distal margin of tergites 4 and 5 brownish without band, grayish pilose, tergites 2–7 with grayish setae and long black and gray setae laterally ( Fig. 6g ). Sternites pale brown, with long grayish and black setae ( Fig. 6h ). Terminalia (follows Coscarón & Philip, 1967). Cerci subovoid. Tergites 9 and 10 with long setae. Gonapophysis with distal border slightly projecting and sinuous. Sternite 8 with straight, wide base and long setae. Genital fork with narrow base, neck wide basally and a long spine present on comb. Spermathecal ducts short.

Male. Length 13.5 mm, wing length 11.5 mm. Similar to female except as follows: eyes with more abundant and longer ommatrichia. Ocellar triangle small, with three small ocelli. Genae with dark brown setae. Maxillary palpus pale brown, short and semicircular. First flagellomere pale brown. Postpronotal lobe dark brown. Longitudinal stripes on mesonotum more diffuse. Wings more hyaline than the female and with appendix on R4 longer. Tibiae with longer setae.

Comments. Hine (1920) described this species as Tabanus lautus from Peru. Later, Coscarón & Philip (1967) transferred this species to Dasybasis . Fairchild & Burger (1994), proposed that D. (A.) lauta var. sublauta Coscarón & Philip is placed as a synonym of D. lauta . González (1999) transferred Dasybasis (Agelanius) lauta to new genus Acellomyia , although stated that this species shares the general external characteristics of Acellomyia ; however, the pilose eyes are intermediate between Agelanius and Acellomyia .

The species M. lauta , formerly placed in Acellomyia , is included in the monotypic new genus Montismyia . With this transfer, the genus Acellomyia is more consistently defined, and no longer includes species with very different generalized characters than in Agelanius .

The possibility of reviewing, by photos, the type material of M. lauta deposited in C.A. Triplehorn Insect Collection, Ohio State University, Columbus, Ohio, USA, has made it possible to confirm differences with Acellomyia .

Distribution. This species occurs in Peru in the Department of Lima, and in Ecuador in Azuay Province.

Material examined. PERU: Depto. Lima, Matucana 1 ♀. VI-VII.1913, 7300 ft., C.T. Brues (topotype) ( Fig. 6i ) ( OSUC); 1 ♀, 27.V.1920, Cornell Univ. Exped. Coll.; 1 ♀, 28–30.VI. l974, C. Porter & L. Stange ( MLP); 2 ♀, 27.V.1930 (without coll.) ( MLP); 2 ♀, 7–9.VII.1975, C. Porter & L. Stange ( MLP); 1 ♂, Surco, Rimac Valley , 26.VI.1945, without coll. (MLP); 1 ♂, Valle Sta. Eulalia, 5.VI. (without other dates) (MLP); 1 ♂, San Mateo, 3100 masl without date, Weyrauch (MLP). ECUADOR: Prov. Azuay, 1 ♀, Cumbe , 26.IX.1946, 2500 masl, Z. Müller ( MLP).

In addition to the characters mentioned in the generic diagnosis of Montismyia gen.n. and description of Acellomyia species, other differences are shown in table 3.

Figures

FIGURE 6. Female of Montismyia lauta (Hine) comb. nov. a. Habitus; b. Head in frontal view; c. Head in ventral view; d. Head, antennae, maxillary palpus and thorax in lateral view (scale bar = 0.5 mm); e. Mesonotum in dorsal view (scale bar = 0.5 mm); f. Wing; g. Abdomen in dorsal view; h. Abdomen in lateral view; i. labels of holotype.