Amphineurus (Rhamphoneurus) falcatus, Santos & Santos & Ribeiro, 2022

Santos, Daubian, Santos, Rodrigo dos Reis & Ribeiro, Guilherme Cunha, 2022, Systematics of Amphineurus (Rhamphoneurus Alexander) (Diptera: Tipuloidea: Limoniidae), Arthropod Systematics & amp; Phylogeny 80, pp. 439-494 : 439

3.3.11. Amphineurus (Rhamphoneurus) falcatus sp. nov.

Material examined.

Holotype: ♂, Chile, Osorno , Bahia Mansa [40°35′S 73°44′W], South of Pucotrihue, 12-IV-1968, Peña (USNM) *. Paratypes: 1 [sex unkown]: Chile, Chiloé Is., Aulen [42°2′S 74°1′W], 8-II-1952, L.P. Guzman (USNM); 1 ♂, Chile, Chiloé Is., Aulen [42°2′S 74°1′W], 8-II-1952, Peña (USNM)*; 1 [sex unkown]: Chile, Chiloé Is., Aulen , Duhatao [41°58′S 74°02′W], 6/ 8-II-1952, Peña (USNM) *.

Etymology.

The word Amphineurus falcatus is Latin for "armed with scythes". This name is in reference to the sheath of aedeagus, which resembles a scythe.

Diagnosis.

This species is distinguished by absence of markings near R2 and R2+3+4 longer than R2+3. Furthermore, this species has distinctive male terminalia with a curved sheath of aedeagus, only the right mesal lobe folded, and the longest lobule of the subgenus, as long as the remainder of the lobe of gonostylus.

Description.

Wing length 6.08 mm, width 1.86 mm. - Coloration: General coloration blackish brown. Thorax blackish brown, pleura gray. Scutum without stripes. Halter ochreous. Coxae brownish yellow and legs dark brown. - Head (dorsal view Fig. 17B , ventral view Fig. 17A ): Rostrum bifurcated with short appendices; first palpal segment as long as terminal segment; scape as thick as pedicel; last flagellomere as long as penultimate. - Thorax (lateral view Fig. 17E , dorsal view Fig. 17F ): Division line of laterotergite sinuous and almost vertical; anatergite as tall as katatergite. Halter with long dilated knob; length of knob half-length of stem of halter. Wing (Fig. 17D ) without distinctive markings; veins near fork of bM (Fig. 17C ) visible; R2 faded; r-m shorter than M1+2 and basal deflection of M1; M1+2 shorter than basal deflection of M1; R2+3 at least 2.5 × longer than basal deflection of R5; R2+3+4 longer than R2+3. - Male terminalia (Fig. 17G ): Male tergite IX darkened along posterior margin, with wide V-shaped median notch; posterolateral lobes nearly triangular, obtuse at apex. Ventral branch of gonocoxite expanded on distal tip. Dorsal branch of gonocoxite shorter than half-length of ventral branch. Lobe of gonostylus with rounded lobule; lobule longer than wide, longer than half-length of lobe of gonostylus and wider than stem. Clasper of gonostylus with similarly shaped branches: lateral branch rounded; medial branch oblong. Mesal lobes of gonocoxite asymmetrical; left mesal lobe straightened and pointed; right mesal lobe bent at right angle. Sheath of aedeagus curved, darkened for most of length.

Remarks.

Specimens of this new species were previously identified by C.P. Alexander as A. (R.) nullus Alexander. This species resembles A. (R.) nullus but differs mainly in the attachment of m-cu, shape of male tergite IX, prescutum and left mesal lobe.

Figures

Figure 17. Amphineurus (Rhamphoneurus) falcatus sp. nov. A head (ventral view); B head (dorsal view); C detail of wing; D wing; E thorax (lateral view); F thorax (dorsal view); G male tergite IX (dorsal view) and remainder of male terminalia (lateral view). - Abbreviations: aed sh, sheath of aedeagus; anatg, anatergite; anepm, anepimeron; anepst, anepisternum; aprn, anteropronotum; cgonst, clasper of gonostylus; cx, coxa; goncx, gonocoxite; hlt, halter; k, knob of halter; kepm, katepimeron; kepst, katepisternum; ktg, katatergite; l ms, left mesal lobe of gonocoxite; lgonst; lobe of gonostylus; mr, meron; mtanepst, metanepisternum; mtepm, metepimeron; mtg, mediotergite; mtkepst, metakatepisternum; mtn, metanotum; p, posterior basalare; patg, paratergite; pprn, postpronotum; presct, prescutum; r ms, right mesal lobe of gonocoxite; sct, scutum; sctl, scutellum; t 9, male tergite IX.