Limnophora beckeri (Stein)

Michelsen, Verner, 2021, Macaronesian Muscidae (Diptera). II. The genus Limnophora Robineau-Desvoidy with description of a new Canarian endemic species, Zootaxa 4952 (1), pp. 101-127 : 102-103

Limnophora beckeri (Stein)

( Figs 1A‒C )

Calliophrys beckeri Stein ; Becker 1908a: 104 (Tenerife, La Palma); Frey 1936: 132 (Gran Canaria, La Gomera, La Palma). Limnophora (Calliophrys) beckeri (Stein) ; Hennig 1960: 385; Báez 1981: 632, pl. 2 figs 3‒6 (La Gomera, La Palma). Limnophora (Melanochelia) beckeri (Stein) ; Santos Abréu 1976: 108, fig. 15 (La Palma).

Limnophora beckeri (Stein) ; Pont 1986: 179; Couri & Pont 2020: 6 , 50 figs 226‒229 (male syntype, terminalia).

Material examined. [ MZH, NHMD]: CANARY ISLANDS : GRAN CANARIA: Bco. Virgin, Moya, 400m, 1♂ 20.vii.1984 (Olsen, Skule & Stadel). TENERIFE: Puerto de la Cruz, 1♀ 7‒8.v.1947, 1♂, 2♀ 2‒4.ii.1949 (H. Lind- berg); Adeje, Bco del Infierno, 2♀ 24.ii.1950 (H. Lindberg). LA GOMERA: Las Toscas , 28°04´N 17°12´W, 720m, 1♀ 19.xi.2002 ( V. Michelsen); La Laja, 480‒600m, 1♂ 23.xi.2002 ( V. Michelsen); Bco. Arure , 28°06´N 17°19´W, 200‒265m, 2♂, 2♀ 4.ii.2008 ( V. Michelsen ) .

Diagnosis. Very small, wing length 2.4‒3.2mm. Male: Arista short-pubescent, longest branches less than 1.5 times greatest width of arista. Frons nearly horizontal, broad and flat, in dorsal aspect wholly velvety black in contrast to silvery white parafacial plates. Fronto-orbital plate with 2 short orbital setae and 2 frontal setae. Frons and facial margin equally projecting. Mesonotum extensively dark brown pruinose, postpronotal lobes and notopleura silvery grey and a pair of spots near at scutellum light grey. Dorsocentral setae 3 behind suture; acrostichal field with setulae only, arranged in 2‒3 irregular rows. Mid femur with 1 subapical pd seta, without pv setae; mid tibia with 1 pd seta at middle. Hind femur with 1 av seta near apex, without pv setae. Tergite VI merged with prehypopygeal sclerite. Sternite I bare. Sternite V and hypopygium as in Figs 1A‒C . Female: Similar to the male, but frons slightly convex and declining; frontal triangle matt shining, demarcated from velvety black frontal vitta. Dark brown area on mesonotum restricted to a narrow median stripe, a pair of subtriangular marks in front of the suture, a broad band immediately behind the suture and all scutellum. Ovipositor with hind marginal setae on tergite VII forming a complete row, not interrupted laterally as in other examined species. See Table 1 for more ovipositor characters.

Distribution. Canary Islands: Gran Canaria, Tenerife, La Gomera, La Palma. Originally considered endemic to the Canary Islands, but Hennig (1964) recorded it from Iran: Sistan & Baluchestan province, Iranshahr county. Zhang & Xue (1996) further reported L. beckeri from China: Guizhou, included the species in a key to Chinese Limnophora males, and illustrated the male terminalia (figs 10‒12). The Chinese taxon is indeed very similar to L. beckeri , but should be treated as a distinct species on basis of differences in the male terminalia, especially the proportions of the cerci. Stein (1918) recorded Calliophrys beckeri from Taiwan (“Formosa”). The species involved is expectedly identical with the species found in Guizhou.

Figures

FIGURE 1. Limnophora beckeri (Stein) (A‒C), L. bipunctata (Stein) (D‒G). Males. Hypopygium, caudal (A, D) and lateral (B, E); sternite V (C, G); sternites I and II (F). Same scale.