Villalus inanis ( Philippi, 1865 )

Barahona-Segovia, Rodrigo M., Guzmán, Vicente Valdés & Pañinao-Monsálvez, Laura, 2021, Review of Chilean Cyrtinae (Diptera: Acroceridae) with the Description of Three New Species and the First Record of Villalus inanis from Argentina, Zoological Studies 60 (35), pp. 1-18 : 11-14

Villalus inanis ( Philippi, 1865) : 645–646

( Figs. 24 , 28–36 )

= Villalus chilensis Cole, 1918: 63–64 .

= Lasia dimidiata Cole, 1918: 61 (nomen nudum).

M a t e r i a l e x a m i n e d: H o l o t y p e: “Valdivia,

Chile” (A MNHNCL); other specimens: CHILE.

Valparaíso: Parque Peñuelas, 23.iv.1965, Leg. N. Hichins (MNHNCL); Valparaíso, vii.1966, Leg. W.H. Sielfield (MNHNCL); Biobío: **Tirúa, Lago Lleu-Lleu, 25.iii.2020, phot. Leg. Ignacio Valeria (CSP, electronic voucher: https://figshare.com/ s/0e733c2cecb30b0de50b); La Araucanía: **Parque Nacional Nahuelbuta, 7.iii.1982, Leg. L.H. Pincheira (MZUC); **Fundo El Carmen, Temuco, iv.2016, phot. Leg. Lucas Nuñez (CSP, electronic voucher: https://figshare.com/s/aba8eb49b2a1a1bf3999); **Gorbea, 29.iii.2020, phot. Leg. William Tarrant (CSP, electronic voucher: https://figshare.com/s/ c98c392e4847aedbe437); Los Ríos: **Panguipulli, 1983, Leg. G. Piel (UACH); **Pichoy, 30.ii.1991, Leg. E. Krahmer (UACH); **Parque Llancahue, 25.iii.1978, Leg. E. Krahmer (UACH); **Santo Domingo, 8.iv.1984, 3.iv.1987, 2.iv.1989, Leg. E. Krahmer (UACH); Valdivia, 5.IV.1977, 3.iv.1981, 30.iii.1983, 13.iii.1985, 2. v. 1985, Leg. Krahmer (UACH, MNHNCL); **Chahuilco, 11.iii.1990, Leg. E. Krahmer (UACH); **Reumen, 15.iii.1991, Leg. Lula Mata (UACH); Los Lagos: **San Pablo, Osorno, 24.iii.2020, phot. Leg. Claudia Veas (CSP, electronic voucher: https://figshare. com/s/d771abe10446bd766c93). ARGENTINA. Chubut: **S. Argentina, El Puelo, Topal, Nr. 354, 25.iii.1961, Leg. NN (USNM); **S. Argentina, Rio Negro, El Bolson, Topal, Nr. 322, 15.iii.1961, Leg. NN (USNM).

Type locality: Valdivia, Chile ( Pape and Thompson 2013).

Diagnosis: Orange-yellowish species. Head and eyes black. Head with half that maximum height of thorax. Scutum with two black, but very light longitudinal bands. Yellowish pilosity in all thoracic segments. Katepisternum brownish in ventral part. Meron grey and elongated with yellow margin. Legs completely yellowish. The cells sc, c, br, r 1, r 2+3, r 4+5 and m 1 smoked with microtrichia. R 4 and R 5 not forked. Abdomen globose and slightly longer than thorax in dorsal view. Tergites and sclerites orange-yellowish with pilosity similar in color.

Description: Length: 6.49 ± 0.18 mm; width: 1.78 ± 0.05 mm (head), 3.13 ± 0.09 mm (thorax) and 4.36 ± 0.16 mm (abdomen); wing: 6.96 ± 0.16 mm; female: head: black; the size is approximately the half of the maximum height of the thorax; antenna inserted in the middle of the head; scape and pedicelum orange and similar in size among them; flagellum styliform and 3 times longer than pedicelum + scape together; antenna shorter than head length; eyes with short and yellowish pilosity; three ocelli brownish with ocellar triangle black, protuberant and with 6–8 yellow hairs; occiput black with long yellowish pilosity; mouth parts brownish; thorax: globose shape ( Figs. 28–29 ); orange scutum with two dark longitudinal bands slightly visible; scutum covered with long and dense orange-yellowish pilosity; pilosity sparse but uniformly distributed; postocellar lobe orange and yellowish pilosity; anterior spiracle light yellow; anepisternum globose and orange; katepisternum brownish in ventral part; anepisternum yellowish; meron grey and elongated with yellow margin; katepimeron and anatergite orange-yellow with few pilosity; scutellum orange and widest than long with yellowish pilosity; ( Figs. 28–29 , 33–34 ); legs: coxa, trochanters, femora, tibia and tarsi yellow covered by dense yellow pilosity; black claws; wings: all veins brownish; cell sc, c, br, r 1, r 2+3, r 4+5 and m 1 smoked with microtrichia; other cell hyaline and membranous appearance; R 4 and R 5 not forked; M 1, M 2 and M 3+4 are long, but not reaching the wing margin; all M veins similar in size; cell r 4+5 elongated and width, with more than 1/2 length of R 2+3 vein; cell m 3 absent; halters brownish; calypter rim blackish and interior part is brownish with dense and yellowish pilosity; abdomen: globose and slightly longer than thorax; in dorsal view the width is the double of thorax and rough; all tergites orange with dense yellowish pilosity; tergites 1–3 similar in length; in dead animals, all sternites yellow with pilosity of same color and a big brown maculae in the middle ( Fig. 32 ); in living animals, tergites 3–6 present a large brownish area in the middle ( Figs. 30–31 ); interior parts of tergites 4–6 covered with black and granulate plates; genitalia: cerci globose and yellow with pilosity of the same color in dorsal view ( Fig. 24 ).

Male: head: similar to female; thorax: postocellar lobe yellow; scutum and scutellum brownish with short yellowish pilosity; anterior spiracle yellow; superior part of anespisternum yellow and inferior brownish; katepisternum, anepimeron, meron, katatergite and anatergite brown ( Figs. 35–36 ); legs and wings: similar to female; abdomen: all tergites brown with long and yellow pilosity; sclerites yellowish; tergites 1–4 with same width; all sternites yellow with short pilosity of the same color. Genitalia: not detached. However, cerci and epandrium have globose shape and yellow color ( Fig. 35 ).

Distribution: Chile, from Valparaíso region to Los Ríos region and Argentina (first record; Shaun Winterton, pers. comm.) ( Fig. 37 ).

Remarks: native species distributed from the Santiagan province in central Chile subregion to Valdivian forest province in subantarctic subregion ( Morrone 2015). We extend the historical distributional range 224 km to north from Valdivia (type locality) to Nahuelbuta National Park and we fill the gaps in the La Araucanía region and also, we extend in 65.83 km southeast from Valdivia to San Pablo, Los Lagos region (new distribution record). This species has been recently observed associated to semi-rural environments thanks to the citizen science program ( Figs. 30–32 ). Villalus inanis seems to be mainly distributed by the coastal forest which has been highly fragmented by forestry, urbanization and crops. The host is unknown.

The female holotype of V. chilensis described by Cole (1918; Figs. 33–34 ), looks as all V. inanis examined for this work and therefore both species were considered the same. All morphological characteristics, especially wing veins are completely similar to specimens reviewed. According with Shaun Winterton (pers. comm.), two males of this species possess sexual dimorphism because they are smaller than females with many brown (mainly thorax and tergites) and yellow segments ( Figs. 35–36 ).

Curatorial note: According to González et al. (2018) the type specimen is not deposited in MNHNCL. Currently, the holotype is in the California Department of Food and Agriculture and on loan from USNM.

Figures

Figs. 21–26. Genitalia of Holops and Villalus: (21) dorsal view of H. cyanea (Philippi), female; (22) dorsal view of H. pullomen sp. nov.; (23) dorsal and lateral view of H. frauenfeldi Schiner, male; (24) dorsal view of V. inanis (Philippi), female; (25) lateral view of H. pullomen, male; (26) dorsal view of gonocoxa of H. anarayae sp. nov. epa = epandrium; gncx = gonocoxa.

Figs. 28–32. Villalus inanis (Philippi, 1865): (28) dorsal view; (29) lateral view; (30) in situ, lateral view (photo: William Tarrant); (31) in situ, dorsal view (photographed by Ignacio Valeria), and (33) dead, ventral view (photographed by Claudia Veas). Scale bars = 1 mm.

Figs. 33–36. Villalus inanis (Philippi, 1865): (33) female, lateral view, holotype, (34) female, dorsal view, holotype, (35) male, lateral view and (36) male, frontal view. Scale bars are not available.

Fig. 37. Distributional map of Villalus inanis (Philippi, 1865).