Niphta acus Pivar, 2021

Pivar, Robert J., Sinclair, Bradley J. & Moulton, John K., 2021, Revision of the genus Niphta (Diptera, Thaumaleidae) Theischinger of South America, with descriptions of nine new species and a new immature morphotype, ZooKeys 1063, pp. 49-104 : 49

publication ID	https://dx.doi.org/10.3897/zookeys.1063.71180
publication LSID	lsid:zoobank.org:pub:2792B13C-D577-416C-B83D-1C8043701C78
persistent identifier	https://treatment.plazi.org/id/4E68FECD-24B7-4E34-9F20-0F8FCC80EDBD
taxon LSID	lsid:zoobank.org:act:4E68FECD-24B7-4E34-9F20-0F8FCC80EDBD
treatment provided by	ZooKeys by Pensoft
scientific name	Niphta acus Pivar
status	sp. nov.

Treatment

Niphta acus Pivar sp. nov.

Figs 2A View Figure 2 , 3A View Figure 3 , 4A View Figure 4 , 13A, B View Figure 13 , 14C View Figure 14 , 15C View Figure 15 , 16C View Figure 16 , 17C View Figure 17 , 18C View Figure 18 , 19C View Figure 19 , 20A, B View Figure 20 , 25 View Figure 25 , 27C View Figure 27

Type material.

Holotype: ♂, glued to point with abdomen in glycerine microvial pinned beneath, labelled: "Chile: Region VIII ( Bío Bío)/ Rte. Q-61, Estero Agua/ Blanca, 8.xii.2016/ 37°46'30.8"S 71°42'03.9"W / elev. 552 m, vegetation near/ splash zones, J.K. Moulton &/ R.J. Pivar"; "HOLOTYPE/ Niphta / Niphta acus / Pivar [red label]" (CNC). Allotype: ♀, same label data as holotype (CNC). Paratypes: Chile: Region RM (Santiago): Quebrada el Cinco Mil, 17.xii.2016, 33°31'30.4"S 70°13'52.6"W, elev. 1308 m, creek, J.K. Moulton & R.J. Pivar (3♀*); Region V ( Valparaíso): Rte. 60, 18.xii.2016, 32°54'31.3"S 70°18'21.5"W, elev. 1423 m, creek, J.K. Moulton & R.J. Pivar (2♂); Region VIII ( Bío Bío): Rte. N-55, 16.xii.2016, 36°55'02.7"S 71°25'49.6"W, elev. 1449 m, roadside seep, J.K. Moulton & R.J. Pivar (25♂); same label data as previous except, collected from rockface (8 larvae*, 5 pupae*, 8 pupal exuviae); Rte. Q-61, Estero Agua Blanca, 8.xii.2016, 37°46'30.8"S 71°42'03.9"W, elev. 552 m, vegetation near splash zones, J.K. Moulton & R.J. Pivar (41♂, 10♀*, 1 larva*); Rte. Q-61, 8.xii.2016, 37°48'34.7"S 71°40'30.0"W, elev. 390 m, roadside seep, J.K. Moulton & R.J. Pivar (2♂, 1♀*).

Recognition.

Niphta acus is recognised by the bifurcated apex of the gonostylus and the strongly apically tapered parameres, giving the appearance of a needle-like tip.

Description.

Male. n = 71.

Length 1.6-2.5 mm.

Colouration (Fig. 4A View Figure 4 ). Head dull, blackish brown; pronotum and postpronotum dark brown; postpronotal lobe brown with dark brown markings, light brown around anterior spiracle; prescutum, mesoscutum and pleura shiny, blackish brown; scutellum and mediotergite shiny, blackish brown; katepisternum dark brown with blackish brown markings, remaining pteropleuron mainly blackish brown with dispersed markings of brown to light brown; base of halter black, knob creamy yellow; legs greyish brown, apex of tarsi darker; abdomen blackish brown; terminalia concolourous with abdomen.

Head. Eyes above antennae broadly joined, with small triangular frons visible above antennae; frons with three to five strong setae. Flagellomeres 1-3 subquadrate, with flagellomere 1 expanded, 3 × as wide as next segment, equal to lengths of 2 and 3 combined; flagellomeres 4-10 cylindrical, becoming progressively thinner and elongate. Vertex with black setae of uniform length, with longer, black orbital setae.

Thorax. Mesoscutum with prominent antealar ridge, bearing thee pronounced setae. Scutum clothed dorsally in short, black setulae; notopleural, supra-alar and postsutural setae long, black. Pteropleuron bare. All legs with tarsi simple.

Wing. Wing length: 1.8-2.5 mm. Dark, infuscate throughout, apex somewhat narrowed; C fringed in small setulae, with a few microtrichia scattered throughout; posterior wing margin with closely spaced fringe of microtrichia; Sc incomplete; R1 and R1(+R2+3) with three weakenings or depigmented gaps, first slightly beyond R2+3, second and third closely approximated, near C; microtrichia of R1(+R2+3) confined to base near humeral crossvein, remaining veins bare; R flexed into cell br; R2+3 distinct, situated in basal third of R1(+R2+3); bend in R4+5 gentle; R4+5 and M1 running parallel toward margin; M1 straight; M2 with gentle bend in apical third; M4 with slight bend.

Abdomen. Abdominal sternite 1 narrow, spectacle-shaped; sternite 2 reduced to slender median sclerite, a few setae restricted to laterad on posterior third and medially beneath sclerite; sternites 3-7 rectangular, lacking distinct sclerites, setae restricted to posterior two-thirds; sternite 8 strongly reduced, anterior margin well sclerotised, arched slightly into preceding segment, lacking setae.

Terminalia (Figs 2A View Figure 2 , 3A View Figure 3 ). Epandrium quadrate in ventral view, posterior margin rounded with large, medial indentation; long, extending well beyond gonostyli; without lobes or projections. Gonocoxites conical, one-third longer than wide, anterior margin rounded, expanded dorsally behind gonocoxal plate, nearly meeting medially, extended anteriorly toward sternite 8; posterior inner margin produced into rounded projection, outer margin without notch; inner margin densely setose. Gonostylus short, three-quarters length of cercus, strongly curved laterally throughout; widest at base, tapered toward bifurcated apex; outer margin bearing laterally directed setae. Parameres fused at gonocoxal apodeme, widest at point of fusion; extended beyond cerci; forming canal-like structure, flattened apically, tapered to off-centre sharp point (occasionally specimens with broken apex). Gonocoxal plate well sclerotised; tongue-like plate extended anteroventrally; hollow medially, pitcher plant-like; gonocoxal apodeme with secondary structure comprising three arms fused medially, running along interior of paramere canal, flaring into three or four filaments, projected ventrally at apex, with pair of lateral flanges near point of fusion. Cercus large, prominent; subquadrate; projected posteriorly; situated within epandrial indentation.

Female. n = 15.

Similar to male except as follows: Terminalia (Fig. 13A, B View Figure 13 ). Hypogynial valve not projecting beyond tergite 9; posterior margin deeply emarginated in ventral view, nearly dividing sternite in half, forming two subtriangular lobes; lobes densely setose. Tergite 9 subtriangular in lateral view, 3 × as wide as tergite 8, lacking lateral projections; posterior margin heavily sclerotised at base of cerci. Sternite 9 (genital fork) slender, Y-shaped anteriorly and posteriorly; lateral arms extended slightly beyond hypogynial valve, divergent toward apex. Hypoproct sclerotised, narrow. Cercus rounded, projected posteroventrally; bearing numerous setae.

Pupa. n = 8 (Figs 14C View Figure 14 , 15C View Figure 15 , 16C View Figure 16 ).

Length 3.0-4.0 mm.

Colouration. Brown; with black spot above eye in developing adult.

Head. Maxillary sheath short, posteromedially directed; gently tapered toward truncate apex; apices of palpi separated medially. Three short, slender setae above black spot over eye.

Thorax. Width nearly subequal to abdomen at widest point. Foreleg sheath projecting straight, slightly longer than wing sheaths, reaching posterior margin of sternite 2; anterior half of midleg visible anterior to wing sheath, then hidden behind foreleg, slightly shorter than foreleg; hind leg concealed behind wing sheath, only apex visible between apex of foreleg and wing sheath, shorter than foreleg. Wing sheaths not reaching posterior margin of abdominal sternite 2; large tubercle at base bearing pair of short, slender setae. Respiratory organ short and squat, much shorter than maxillary sheath, broadest subapically; bulbous; spiracular openings encircling apex; stalk wide, emerging from small tubercle. Tubercle situated posterodorsally to respiratory organ, rounded, projected slightly laterally; apex nearly touching or touching respiratory organ. Tubercle situated posterolaterally to respiratory organ crenulate, projected slightly anteriorly. Ridge located anteroventrally to respiratory organ with single, thin midlateral seta; mesothorax with group of four short, slender dorsocentral setae near ridge; single seta on humeral lobe.

Abdomen. Subcylindrical, strongly tapered at caudal segment. Spiracles weakly developed, not projected or distinctly visible. Tergites 1-8 rectangular, without ridges; bearing pair of slender lateral setae above lateral margins and pair of slender dorsolateral setae. Tergite 9 rounded, posterior with dorsolateral ridges bearing pair of lateral setae and hind margin emarginated; projection directed posteriorly in lateral view. Sternites 3-8 rectangular, without row of faint setulae along anterior margin; lateral margins crenulate, bearing a few thin, short setae. Sternites 3 and 4 bearing pair of small lateral adhesive structures, sternite 5 bearing pair of large lateral adhesive structures on lateral margin. Caudal sternite subquadrate, with pair of posteriorly projected medial lobes; posterior margin with pair of medial ridges, curved dorsally forming small, dorsally projected tubercle in lateral view; without distinct caudal hooks.

Larva. n = 8 (Figs 17C View Figure 17 , 18C View Figure 18 , 19C View Figure 19 , 20A, B View Figure 20 ).

Length of final instar 6.2-6.7 mm.

Colouration. Head capsule usually black or dark brown, sometimes black with light brown markings. Body mottled with various shades of grey and brown.

Head capsule (Fig. 20A, B View Figure 20 ). Two large, circular eye spots, elevated on tubercle; antenna on largest tubercle, with three finger-like processes; with five pairs of tubercles outside of ecdysial lines (not including antennal and ocular tubercle), two outermost tubercles bifurcate; single tubercle between ecdysial line, bi- or trifurcate; 15 pairs of unbranched setae; five pairs of sensory pits (13, 14, 18, 20, 21), sensory pit 13 above antennal tubercle.

Thorax. Prothorax with pair of anterodorsolateral protuberances bare; anterolateral protuberances with one long and two short setae; spiracular protuberance bearing two protuberances, inner protuberance with pair of setae, outer with single seta; pair of midlateral setae below anterolateral protuberance; three closely approximated setae near base of prothoracic leg ( Keilin’s organ). Mesothorax and metathorax with pair of dorsolateral protuberances bearing pair of closely approximated setae, one thickened, one slender; mesothorax with additional seta beneath protuberance; lateral protuberance on both segments bearing four setae; one long seta slightly ventral to lateral protuberance; three mid-ventrolateral setae directed ventrally. Prothorax bearing proleg, posterior half with rectangular adhesive structure; meso- and metathoracic sternites with rectangular adhesive structures.

Abdomen. Sternites 1-7 modified into circular, suction cup-like adhesive structures; sternite 8 with quadrate adhesive structure, extending over sternite 9; sternite 9 smooth, bearing anal proleg. Tergites 1-7 with single anterolateral protuberance on each side with single seta, and pair of posterodorsolateral protuberances, each bearing two closely approximated short, thin setae; lateral adhesive structure swelling bearing four setae, two lateral, two basal; additional single seta located anterior to lateral swelling. Segment 8 with dorsolateral protuberance on either side of posterior spiracular plate, each bearing pair of small setae; lateral protuberance with three setae; single short ventrolateral seta; ventral surface bearing pair of setae. Posterior spiracular plate with sclerite encircling procerci; procercus shorter than length of spiracular plate, bearing four setae, two thick, two slender; without cone-like protuberance on either side of procerci. Terminal segment with anterior dorsal protuberance bare; pair of posterior lateral protuberances with pair of setae; five lateral setae; two pairs of long setae on posterior margin, above pair of anal papillae; ventral sternite bearing single pair of setae.

Additional material examined.

Known only from the type series.

Distribution.

Known from the south-central Andes of Chile (Fig. 24A View Figure 24 ); this species includes the northern-most record for Niphta in South America.

Etymology.

The species name is from the Latin acu (needle, pin) in allusion to the needle-like tip of the paramere.

Bionomics.

This species was collected at higher elevations than any other species in this publication. Larvae and pupae have ventral adhesive structures and were collected only from rocky substrates (Fig. 25 View Figure 25 ). All immatures were collected from the margin of waterfalls, where water flow was quite slow.