Limnellia vounitis

Costa, Daniel N. R., Savaris, Marcoandre, Marinoni, Luciane & Mathis, Wayne N., 2016, Two new, brachypterous Limnellia species from the Venezuelan Andes (Diptera: Ephydridae), Zootaxa 4144 (3), pp. 301-315: 304-310

publication ID

http://doi.org/10.11646/zootaxa.4144.3.1

publication LSID

lsid:zoobank.org:pub:B73CFE90-BDF1-47EA-BBD6-52A8DB2B144C

persistent identifier

http://treatment.plazi.org/id/EA2A612C-D03B-131A-FF65-F8DA97E10EFD

treatment provided by

Plazi

scientific name

Limnellia vounitis
status

 

Limnellia vounitis  Costa, Savaris, Marinoni & Mathis n.sp. 

( Figs. 1‒4, 7View FIGURES 1 ‒ 8, 7, 9‒12View FIGURES 9 ‒ 14, 15‒29View FIGURES 15 ‒ 23View FIGURES 24 ‒ 29, 38‒42View FIGURES 38 ‒ 42, 47View FIGURES 43 ‒ 47)

Diagnosis. This species is distinguished from related congeners by the following combination of characters: Very small shore flies, body length 1.00 mm ( Figs. 1‒4View FIGURES 1 ‒ 8, 7, 16View FIGURES 15 ‒ 23, 24View FIGURES 24 ‒ 29); general coloration shiny black. Head: ( Figs. 9‒12View FIGURES 9 ‒ 14, 32View FIGURES 30 ‒ 37) Frons generally black, shiny; mesofrons without any setae or setulae, except for very small pseudopostocellar setae; ocellar triangle and ocellar setae absent ( Fig. 27View FIGURES 24 ‒ 29); 1 pair of medial vertical setae present, lateral vertical seta absent ( Fig. 25View FIGURES 24 ‒ 29); very narrow parafrons and fronto-orbital plate; 2 pairs of very small lateroclinate fronto-orbital setae ( Fig. 26View FIGURES 24 ‒ 29). Antenna light brown, pedicel slightly darker; arista long, about 4 times length of basal flagellomere, with very small, sparse dorsal rays ( Fig. 19View FIGURES 15 ‒ 23). Face shiny black, with transverse sculpturing; medial facial area and ventral facial margin with small and sparse setae; two vertical rows of setae approximate to parafacials ( Fig. 17View FIGURES 15 ‒ 23). Gena narrow, covered with setulae; gena-to-eye ratio 0.25. Genal seta absent or indistinguishable from setulae. Sclerotized mouth parts black, membranous parts brown.

Thorax: Black, short, as long as head; pleural sclerites broadly fused and difficult to discern. Mesonotum bare of microtomentum, with transverse rugosity; 2 very small acrostichal setae; 2 very small dorsocentral setae; prescutellar acrostichal setae present ( Fig. 25View FIGURES 24 ‒ 29). Scutellum very small, without setae; one notopleural seta. Pleurae covered with microtomentum. Postsutural supra-alar seta present, same length as notopleural seta. One seta on posterior margin of anepisternum. Wing ( Figs. 7View FIGURES 1 ‒ 8, 7, 28View FIGURES 24 ‒ 29) brachypterous; wing length 0.32 mm; dark brown, with leather-like texture, veins not visible, reduced or absent. Halter very small, near wing base ( Figs. 13View FIGURES 9 ‒ 14, 18View FIGURES 15 ‒ 23). Legs dark brown, except for light brown tarsi; femora distinctly larger than tibiae; femora and tibiae bare of microtomentum, with sparse setulae; tarsi covered with setulae. Tarsal claws curved and pulvilli normally developed ( Fig. 20View FIGURES 15 ‒ 23).

Abdomen: Tergites shiny black, bare of microtomentum; with very sparse, small setulae ( Figs. 16, 21View FIGURES 15 ‒ 23, 24View FIGURES 24 ‒ 29). Tergite 1 not visible or absent; tergite 2 larger than subsequent tergites. Male terminalia ( Figs. 29View FIGURES 24 ‒ 29, 38‒42View FIGURES 38 ‒ 42): Epandrium in posterior view ( Figs. 29View FIGURES 24 ‒ 29, 38View FIGURES 38 ‒ 42) wider than high, more or less rectangular with corners rounded, narrowly connected dorsally above cercal cavity, ventral margin shallowly emarginated, setulae uniform in size, evenly distributed except extreme lateral margins, in lateral view ( Fig. 39View FIGURES 38 ‒ 42) broadly bar-like, dorsal third tapered to anterodorsal corner, ventral margin truncate; cercal cavity elliptical, cerci in posterior view ( Fig. 38View FIGURES 38 ‒ 42) semihemispherical, in lateral view ( Fig. 39View FIGURES 38 ‒ 42) narrowly oval, with dorsal and ventral apices rounded; surstylar plate (fused surstyli) in posterior view ( Fig. 38View FIGURES 38 ‒ 42) wider than high, octagonal, ventromedially with narrow, deep cleft, in lateral view ( Fig. 39View FIGURES 38 ‒ 42) robustly bar-like, elongate, apices truncate, very slightly tapered from base to apex; aedeagus in lateral view ( Fig. 42View FIGURES 38 ‒ 42) robustly L-shaped, base wide, basal margin truncate, with a narrow projection from posterior corner, apical arm of L tapered to point, in ventral view ( Fig. 41View FIGURES 38 ‒ 42) more or less U-shaped, basal portion deeply developed, width of gap between extended arms subequal to length of base, extended arms shallowly sinuous; phallapodeme generally reduced, in lateral view ( Fig. 42View FIGURES 38 ‒ 42) L-shaped with one arm of L much wider than other arm, in ventral view ( Fig. 41View FIGURES 38 ‒ 42) shallowly arched, with a medial, short, parallel-sided truncate projection; gonite in lateral view ( Fig. 42View FIGURES 38 ‒ 42) irregularly triangular, with narrow, dorsally oriented projection, a shorter anterior, narrow, tapered projection, and a short, wide, truncate posterior projection, in ventral view ( Fig. 41View FIGURES 38 ‒ 42) longer than wide, curved basally toward phallapodeme; sternite 5 in lateral view ( Fig. 42View FIGURES 38 ‒ 42) irregularly bar-like and one corner projected perpendicular to plane, in ventral view ( Fig. 40View FIGURES 38 ‒ 42) wider than long, pentagonal, anterior and lateral margins irregularly quadrate, posterior margin with deep, wide, V-shaped emargination.

Type material. The holotype male of Limnellia vounitis  is labeled “ VENEZUELA. Bocon, Ande, La Cristalina, 2500 m., Subparanamo, M.G. Paoletti Feb 1987 ex: rotten wood [,] HOLOTYPE ♂ / Limnellia vounitis  Costa, Savaris, Marinoni & Mathis USNM [red]”. The holotype is glued in a paper triangle, is in average condition (some fungi on this specimen; abdomen removed and dissected, parts in an attached microvial), and is deposited in the USNM. The single female paratype ( USNM) has the same date and locality label as the holotype  .

Type locality. Venezuela. Trujillo: Bocon, La Cristalina (Andes; 0 9 ° 14.7′N, 70 ° 19.1′W; 2500 m).GoogleMaps 

Distribution. Neotropical: Venezuela (Trujillo, Fig. 48View FIGURE 48).

Etymology. The species epithet, vounitis  , is a Latinized, masculine noun from the modern Greek word, “voynítès” (βουνíτης), and means “dweller on the hills”, referring to the Andes Mountains of Venezuela where the type series was collected.

Remarks. Unlike other brachypterous species of Limnellia  , this species has several modifications that are apparently related with its brachyptery, such as the compact thorax and reduced size of the halters. There is also the complete loss of ocelli and ocellar setae, which may also be related with brachyptery and is a synapomorphy that is shared with the other new species being described in this paper.

Some external features of this species, such as the shape of the head, especially the widely arched, vertically elongated, and protrudent face, led us to initially associate this species with the tribe Dagini, perhaps related to the wheeleri species group within the genus Physemops Cresson. Structures  of the male terminalia, however, reveal this species to be in the genus Limnellia  , which belongs in the tribe Scatellini  . Even within Limnellia  , this is an anomalous species, given its very compact body, reduced halters, a general reduction of setae and setulae, the conspicuous brachyptery, and the complete loss of ocelli and ocellar setae. The indication of the structure showed in Figs. 40–42View FIGURES 38 ‒ 42 as sternite 5 is also tentative. This sternite is in close proximity to internal structures of the male terminalia and is apparently located within the abdomen. In our specimen, we cannot determine for sure the presence of a sternite 5 in addiction of this structure. Thus we hesitate to suggest that this is another structure since in Limnellia  species the hypandrium and gonites are usually fused as a single, united structure.

According to the collector, the type series was found on rotting wood. This niche, combined with the site being at a high elevation, is typical for some flies with reduced wings and it has apparently exerted evolutionary pressure for such. Other aspects of the life history, such as the immature stages, are unknown, although the collection site suggests that this species may be saprophytic.

USNM

Smithsonian Institution, National Museum of Natural History

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Ephydridae

Genus

Limnellia