© EDP Sciences, 2017

1 Introduction

The genus Neomaruina was described by Vaillant (1963) from larvae collected in rapid-flowing streams where they attach to rocky substrates with conspicuous ventral adhesive organs (often termed “suckers”). Initially this was interpreted as evidence of a relationship with the chiefly Neotropical genus Maruina Müller, 1895. However, ventral suckers are also present in the Oriental genus Neotelmatoscopus Tonnoir, 1933 and in the more distantly related taxa Horaiella Tonnoir, 1933 (Psychodidae: Horaiellinae) and Blephariceridae (Duckhouse, 1985; Courtney, 2000). The widely divergent structures of the larvae and adults suggest that ventral adhesive organs in the larvae have evolved at least five times independently within Psychodomorpha s.l. (including Psychodidae, Tanyderidae and Blephariceridae).

Of the three lineages of Psychodinae with ventral suckers in their aquatic larvae, a recent revision is available for Neotelmatoscopus (Curler and Courtney, 2009), while Maruina was last treated in a monograph by Hogue (1973). Duckhouse (1985) reviewed Neomaruina including detailed descriptions of two species and two new combinations; however, several characters of the adult stages have still not been elucidated and no identification key is available.

Five species of Neomaruina are described so far: N. deviata (Tonnoir, 1939) and N. pseudomaxima (Tonnoir, 1939) from the Rwenzori Mountains in Uganda; N. torosa Duckhouse, 1985 and N. stuckenbergi Vaillant, 1963 from the Zomba Plateau in Malawi; and N. usambarica Wagner and Andersen, 2007 from the West Usambara Mountains in Tanzania (Duckhouse, 1985; Tonnoir, 1939; Vaillant, 1963; Wagner and Andersen, 2007, see also Fig. 13). In the present contribution we review the diagnostic characters for all known species of Neomaruina, and describe Neomaruina ghanae n. sp. based on adult specimens collected in Ghana. Further, we provide additional character evidence for N. usambarica Wagner and Andersen, 2007 based on previously unpublished material from Tanzania. An identification key and distribution map for all six described Neomaruina species are presented.

2 Materials and methods

The examined material was collected with nets and Malaise traps during expeditions to Ghana and Tanzania conducted by staff of the Zoological Museum of Bergen (now the University Museum of Bergen) in 1990 and 1991. Prior to examination the specimens were macerated in KOH and mounted on slides in Canada Balsam. For detailed information regarding the localities in Tanzania see Andersen and Johanson (1992).

Measurements are given as ranges followed by the mean when more than 3 specimens were available. All measurements were taken with an ocular micrometer in µm with an accuracy of 4 µm, except wing length which is given in mm with an accuracy of 0.02 mm. Morphological terminology follows Kvifte (2015).

All material is housed in the entomological collection at the University Museum of Bergen, Norway (ZMBN).

3 Results

Neomaruina Vaillant, 1963
Neomaruina Vaillant, 1963: 338. Type species: Neomaruina stuckenbergi Vaillant, 1963, by monotypy.

Diagnostic characters (adult male): Eyebridge constricted, with 2–3 facet rows at base and 3–4 facet rows at middle of body axis; frons and clypeus fused; antenna with 13 flagellomeres; flagellomeres 1–11 symmetrical nodiform with Y-shaped ascoids, flagellomeres 12 and 13 diminutive, globular; labellum dorsoventrally compressed with distal row of digitiform sensilla; anepisternum with dorsal wing-shaped projection; tarsomere 5 with dorsal bilobed projection; male genitalia symmetrical with Y-shaped basiphallus and spatulate distiphallus fused with L-shaped parameres, surstyli shorter than epandrium with distal cluster of 3 or more unstriated, short tenacula.

Remarks. Newly recognized diagnostic characters are listed in italics above. For diagnoses of adult females and immature stages, see Duckhouse (1985).

Neomaruina ghanae n. sp.

(Figs. 1–7)

Type material. Holotype male: Ghana, Eastern Province, Boti Falls, 6.1894° N 0.2175° W, 19.xi.1990, sweep net, leg. J.S. Amakye.

Etymology. Named after the country of origin.

Diagnostic characters. Interocular suture incomplete, basiphallus without median keel and basally without lateral lobes, gonostylus S-shaped, evenly tapering towards apex; surstyli with 3 tenacula.

Description

Adult male (n = 1).

Head. Wider than long; vertex about one-fifth of total head length, angular in dorsal view. Dorsal supraocular setae not discernible. Eyebridge (Fig. 1) of 2–4 irregular rows of facets, constricted basally, separated by 6 facet diameters. Interocular suture broadly V-shaped, unsclerotized medially; remnants of interocular spur preserved as internal sclerite of vertex. Setae alveoli on frons forming broadly T-shaped patch, reaching second posterior facet row. Length (in µm) of palp segments: 80, 152, 130, 200; 4th palp segment fully sclerotized. Labellum (Fig. 2) dorsoventrally compressed with three apical digitiform sensilla, one subapical to lateral digitiform sensillum, one dorsolateral and one ventral seta. Antennae (Fig. 3) of specimen incomplete with only up to 9 flagellomeres preserved; scape cylindrical, 96 µm; pedicel elongate ovoid, 80 µm, 0.75× as broad as long; preserved flagellomeres symmetrical nodiform with internode approximately a third of flagellomere length, length (in µm) of preserved flagellomeres 120, 116, 120, 120, 120, 108, 104, 100, 80.

Thorax (Fig. 4). With wing-like dorsal extension of anepisternum barely reaching dorsal suture. Dorsum with large sections laterally and medially bare of seta alveoli. Scutellum with two longitudinal stripes of seta alveoli. Anepimeron triangular with micropilosity only; katepimeron triangular, bare; laterotergite with lateral stripe of seta alveoli at lower third. Metathoracic spiracle with operculum setose.

Legs. All coxae with dorsoventral stripes of seta alveoli, mid coxa also with apical rounded patch of seta. Legs short, less than twice height of coxa; 5th tarsomeres with dorsal apical extensions (Fig. 5).

Wing (Fig. 7). 1.62 mm long, 0.62 mm wide; membrane without pilosity. Area between C and R₁ infuscate; vague infuscations also present at base of R₅, between CuA₁ and CuA₂ and between CuA₂ and C. C with two breaks; basal crossveins reduced; R₅ with outline slightly stronger sclerotized than rest of wing. Radial fork distal of CuA₂ apex, both distal to medial fork. Jugum U-shaped.

Genitalia (Fig. 6). Symmetrical. Hypandrium not discernible. Gonocoxites reniform without apparent parabasal processes; gonocoxal condyles weakly J-shaped, tapering towards middle where they curve anteriorly. Gonostyles acuminate with distal patch of poorly visible sensilla. Aedeagus with basiphallus Y-shaped with medial suture in “stem”, stem weakly sclerotized, spatulate. Distiphallus reduced or fused with parameres. Parameres hammer-shaped with broad end of hammer-head connected to basiphallus, narrow end pointed towards and probably connected with gonocoxal condyles; shaft not recurved, fusing indistinctly at apex with interparameral membrane (of aedeagal origin?); parameral-aedeagal complex reaching beyond apex of gonocoxites. Epandrium slightly longer than broad, sides converging slightly towards apex; with single large ovoid aperture. Surstylus subconical, about length of epandrium, covered in spatulate setae, apically with three tenacula. Tenacula unstriated, blunt; small beak-like projection present ventral to base of tenacula. Proctiger not visible in specimen.

Neomaruina usambarica Wagner and Andersen, 2007
Neomaruina usambarica Wagner and Andersen, 2007: 293.

(Figs. 8–12)

Material examined. Holotype male: Tanzania, Tanga Region, West Usambara Mountains, Mazumbai, 4.813° S 38.504° E, loc F, 5.xi.1990, sweep net, leg. T. Andersen; paratype male: Tanzania, Tanga Region, West Usambara Mountains, Mazumbai, loc. A, 4–12.ii.1991, Malaise trap, leg. T. Andersen; 3 males, Tanzania, Tanga Region, West Usambara Mountains, Mazumbai, Locs G, E & F, 2–6.xi.1990, Malaise trap, leg. T. Andersen.

Diagnostic characters. See key.

Redescription

Adult male (n = 5, if not otherwise stated).

Head (Fig. 9). Wider than long; vertex about one third of total head length, rounded. Dorsal supraocular setae not discernible. Eyebridge of 3–4 irregular rows of facets, separated by 5–7 facet diameters. Interocular suture broadly U-shaped, complete; spur developed or undeveloped. Seta alveoli on frons forming broadly T-shaped patch, reaching interocular suture. Length (in µm) of palp segments (n = 5, 3, 2, 2): 76–100, 84; 140–144; 156; 180–216. Labellum flat with four apical digitiform sensilla and two lateral setae. Antennae incomplete in all known specimens; scape cylindrical, slightly wider apically than at base; pedicel globular; flagellomeres 1–5 symmetrical nodiform with internode approximately one third of flagellomere length. Length (in µm) of scape, pedicel and first five flagellomeres (n = 5, 5, 5, 4, 2, 1, 1): 76–100, 88; 72–76, 72; 120–148, 132; 108–128, 120; 112–116; 112; 108.

Thorax. With wing-like dorsal extension of anepisternum short, reaching only two rows of seta alveoli above dorsal suture. Dorsum covered in seta alveoli except two bare mediolateral stripes; bare stripes of dorsum disrupted dorsal to wing base by triangular patch of seta alveoli. Scutellum with two longitudinal stripes of seta alveoli. Anepimeron triangular with sparse coverage of seta alveoli; katepimeron pentagonal, bare; laterotergite with lateral stripe of seta alveoli in lower third. Metathoracic spiracle with operculum setose.

Legs. All coxae with dorsoventral stripes of seta alveoli, mid coxa also with mesoapical rounded patch of seta. Legs not preserved in any specimens.

Wing (Fig. 8). 1.6–1.76, 1.68 mm long; 0.58–0.68, 0.62 mm wide; membrane without pilosity. Area between C and R₁ infuscate. C with two breaks; basal crossveins reduced; R₅ with outline strongly sclerotized. Radial fork distad of CuA₂, both distal to medial fork. Jugum broadly angularly V- to U-shaped.

Genitalia (Figs. 10–12). Symmetrical. Hypandrium fused with parameral sheath and parabasal processes of gonocoxites, with ellipsoid expansion medially. Gonocoxites reniform; gonocoxal condyles well-developed, broad, arched, strongly angular. Gonostyles weakly S-shaped with broadened base (Wagner and Andersen 2007, Fig. 20); apically with row of about 4 digitiform sensilla, subapically with elongate setiform sensillum, ventrally with additional row of setiform short sensilla (Fig. 12). Aedeagus (Fig. 11) with basiphallus Y-shaped with broad distal arms and developed median keel, weakly bilobed at base. Distiphallus reduced or fused with parameres. Parameres L-shaped, recurved halfway towards apex, widened apically, connected by median membrane. Parameral-aedeagal complex reaching level of apex of gonocoxites. Epandrium (Fig. 10) slightly longer than broad, sides converging slightly towards apex, with single large subrectangular aperture. Surstylus club-shaped, slightly shorter than epandrium, covered with elongate setae, apically with three tenacula. Tenacula unstriated, blunt. Proctiger with oval setose epiproct and broad subrectangular hypoproct, both poorly sclerotized.

Key to males of Neomaruina Vaillant

The male of N. pseudomaxima (Tonnoir) is unknown.

Key to females of Neomaruina Vaillant

The females of N. deviata, N. usambarica and N. ghanae are unknown.

Figs. 1–6 Neomaruina ghanae n. sp., adult male. (1) Eyebridge and interocular suture, dorsal view. (2) Labellum, lateral view. (3) Scape, pedicel and basal flagellomeres, lateral view. (4) Thorax, lateral view. (5) Apical tarsomere, lateral view. (6) Terminalia, dorsal view (right gonostylus and surstylus not shown). Abbreviations: dph s – distiphallic spatula, m in – median interruption of interocular suture, par – paramere, sads – subapical digitiform seta of labellum.

Figs. 7–8 Neomaruina spp., adult males, wings. (7) N. ghanae n. sp. (8) N. usambarica Wagner and Andersen.

Figs. 9–12 Neomaruina usambarica Wagner and Andersen, adult male. (9) Head, dorsal view. (10) Epandrium, proctiger and right surstylus, ventral view. (11) Terminalia, dorsal view (right gonostylus, epandrium, proctiger and right surstylus not shown). (12) Gonostylus, ventral view. Abbreviations: dph – distiphallomere; par – paramere.

4 Discussion

Neomaruina shares with Psychoda Latreille, Rhipidopsychoda Vaillant and Epacretron Quate the modified labellum with apical peg-like sensilla, which was suggested by both Quate (1959) and Vaillant (1990, 1991) to be a character of high phylogenetic value. Both Duckhouse (1985) and Vaillant (1990, 1991) considered Neomaruina and Psychoda to be closely related, which was also corroborated by the results of a quantitative phylogenetic analysis by Cordeiro (2013). The characters observed in the present study are in agreement with Cordeiro (2013), although e.g. the variable extent of the interocular suture in Neomaruina shows that the loss of this suture in Psychoda is not a unique apomorphy for the genus.

Our results come from examination of Malaise trap and sweep net collections from large expeditions to Ghana and Tanzania in the early 1990s, which yielded several hundred psychodid specimens. Still, only a very limited number of Neomaruina specimens were found, as was also the case for Tonnoir (1939) and Wagner and Andersen (2007). We deem it likely that the highly specialized larvae make the adults more localized and their abundances more difficult to assess by generalized collection methods. Probably more targeted, microhabitat-based sampling like that of B.R. Stuckenberg, which yielded the 12 specimens described by Duckhouse (1985), will prove a more fruitful approach for collecting Neomaruina in the future.

The centre of diversity for Neomaruina appears to be in the East African mountain ranges, with species described from the Zomba Plateau (Malawi), the Rwenzori Mountains (Uganda) and the West Usambara Mountains (Tanzania) (Fig. 13). However, our description of a new species from Boti falls in Ghana (approximately 300 m.a.s.l.), as well as the low abundances in non-targeted collection material, suggests that the genus may be overlooked elsewhere in the Afrotropical region.

Fig. 13 Map of Africa showing the distribution of the Neomaruina species. Boti falls, Ghana: N. ghanae n. sp.; West Usambara Mountains, Tanzania: N. usambarica Wagner and Andersen; Zomba Plateau, Malawi: N. torosa Duckhouse, N. stuckenbergi Vaillant; Rwenzori Mountains, Uganda: N. deviata (Tonnoir), N. pseudomaxima (Tonnoir).

Acknowledgements

The holotype of N. ghanae was collected by Dr. Joseph S. Amakye, IAB, Accra. Gladys Ramirez made most of the slide preparations. We are indebted to Rüdiger Wagner for access to his collection, and to Greg Curler for illuminating discussions on the ventral suckers in psychodomorph larvae. Greg Curler and two anonymous reviewers provided very useful feedback on an earlier version of the manuscript.

References

All Figures

Figs. 1–6 Neomaruina ghanae n. sp., adult male. (1) Eyebridge and interocular suture, dorsal view. (2) Labellum, lateral view. (3) Scape, pedicel and basal flagellomeres, lateral view. (4) Thorax, lateral view. (5) Apical tarsomere, lateral view. (6) Terminalia, dorsal view (right gonostylus and surstylus not shown). Abbreviations: dph s – distiphallic spatula, m in – median interruption of interocular suture, par – paramere, sads – subapical digitiform seta of labellum.

In the text

	Figs. 7–8 Neomaruina spp., adult males, wings. (7) N. ghanae n. sp. (8) N. usambarica Wagner and Andersen.
In the text

	Figs. 9–12 Neomaruina usambarica Wagner and Andersen, adult male. (9) Head, dorsal view. (10) Epandrium, proctiger and right surstylus, ventral view. (11) Terminalia, dorsal view (right gonostylus, epandrium, proctiger and right surstylus not shown). (12) Gonostylus, ventral view. Abbreviations: dph – distiphallomere; par – paramere.
In the text

	Fig. 13 Map of Africa showing the distribution of the Neomaruina species. Boti falls, Ghana: N. ghanae n. sp.; West Usambara Mountains, Tanzania: N. usambarica Wagner and Andersen; Zomba Plateau, Malawi: N. torosa Duckhouse, N. stuckenbergi Vaillant; Rwenzori Mountains, Uganda: N. deviata (Tonnoir), N. pseudomaxima (Tonnoir).
In the text