Niphta Theischinger, 1986

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

Genus Niphta Theischinger

Niphta Theischinger, 1986: 314. Type-species: Niphta bickeli Theischinger (original designation).

Diagnosis.

Niphta is characterised as follows: presence of a distinct antealar ridge; proepisternal setae absent; microtrichia of R1(+R2+3) confined to base near humeral crossvein; R2+3 crossvein situated closer to apex of R1(+R2+3) than to origin of R4+5; R1 and R1(+R2+3) with three weakenings or depigmented gaps; R4+5 often with arch not strongly produced; basal spur of CuA absent; gonocoxites broad, not much longer than wide; hypandrium absent; gonocoxal plate extended posterodorsally forming a medial process; parameres fused medially, emerging from gonocoxal plate complex.

Redescription.

Adult. Eye bridge broad, comprising more than five facets. Scutum clothed in both short and long setae; scutellum with row of long, black marginal setae. Supra-alar region produced into distinct antealar ridge (Fig. 9H ); ridge with setae. Proepisternal setae absent. Wing tip narrowly rounded; membrane lacking macrotrichia; C with sparse macrotrichia, more so on remaining wing margin; Sc incomplete; microtrichia of R1(+R2+3) confined to base near humeral crossvein; R2+3 crossvein situated closer to origin of R4+5 than to apex of R1(+R2+3); R1 and R1(+R2+3) with three weakenings or depigmented gaps; R4+5 often with arch not strongly produced; R4+5 and M1 running parallel toward margin; M1 straight; M2 with gentle bend in apical third; M4 with slight bend; CuA angulate near base; basal spur of CuA absent. Male Terminalia: Hypandrium absent. Gonocoxites broad, not much longer than wide; gonocoxal plate extended posterodorsally, forming medial process, acting as aedeagal guide; parameres fused medially, emerging from gonocoxal plate complex.

Distribution.

Chile and Australia.

Species groups.

Prior to this study, only five described species of Niphta were known from all regions and few phylogenetic affinities had been discussed. Theischinger (1986) suggested that the Australian N. farecta Theischinger was more closely allied to the Chilean N. nudipennis (Edwards) than the other Australian species. With the additional nine species described herein, it is now possible to better assess relationships based upon morphology. Species groups are proposed below for the genus Niphta .

The N. bickeli group: This group is characterised by the following features: broad gonocoxites extending to the posterior epandrial margin and lacking projections; long gonostyli; parameres fused medially, then separating into two arms that do not project anteriorly; a pair of apodemes from base of parameres extend to posterior margin of epandrium, on either side of the anus; cerci inconspicuous, thinly sclerotised and unpigmented; females lack projection at base of hypogynial valves. This group is greyish black in colouration. Additionally, immatures of N. collessi Theischinger lack ventral adhesive structures and protuberances on the larval head capsule ( Sinclair 2000); these are tentatively seen as important characters uniting this species group until further Australian immatures are discovered and accurately associated with the adults (see discussion below comparing Niphta immatures). The N. bickeli group is found in Australia and includes the following species: N. bickeli Theischinger, N. collessi , and N. farecta .

The N. halteralis group: This group is characterised by the following features: gonocoxites extending to midpoint of epandrium, lacking pointed projections; short and narrow gonostyli; parameres fused throughout; prominent cerci projecting anteriorly, extending well beyond posterior epandrial margin; females lack projection at base of hypogynial valves. This group is darkly coloured, mostly black and grey. Immature stages have ventral adhesive structures, are collected from rocky substrates and larval head capsules have many protuberances. The N. halteralis group is known from Chile and includes the following species: N. acus sp. nov., N. downesi sp. nov., N. halteralis (Edwards), and N. mapuche sp. nov.

The N. nudipennis group: This group is characterised by the following features: gonocoxites extending, at most, to midpoint of epandrium, and bearing pointed projections; broad, short gonostyli cheliform or finger-like; parameres fused medially. separated into two arms that project anteriorly and may be flexed or extended; cerci small, projecting anteroventrally; females possess distinct blunt or pointed projection at base of hypogynial valves; sternite 8 highly modified (genital fork and lateral arms); Female sternite 9 greatly expanded and heavily sclerotised, presumably reflecting the highly modified male genitalia. This group tends to be lighter in colouration. Immature stages have ventral adhesive structure, are collected from vegetation in splash zones, and larval head capsules have many protuberances. The N. nudipennis group is known from Chile and includes: N. bifurcata sp. nov., N. bispinosa sp. nov., N. brunnea sp. nov., N. courtneyi sp. nov., N. daniellae sp. nov., N. eurydactyla sp. nov. and N. nudipennis .

Figures

Figure 9. Adult lateral habitus micrographs of the Niphta nudipennis group A N. bifurcata sp. nov. (♂) B N. brunnea sp. nov. (♂) C N. courtneyi sp. nov. (♀), abdomen dissected D N. daniellae sp. nov. (♂) E N. eurydactyla sp. nov. (♂) F N. bispinosa sp. nov. (♂), abdomen dissected G N. nudipennis (♂) H N. courtneyi sp. nov. (♂), inset with arrow indicating antealar ridge. Scale bars: 1.0 mm.