Amphineurus (Rhamphoneurus) triangularis, 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

3.3.26. Amphineurus (Rhamphoneurus) triangularis sp. nov.

Material examined.

Holotype: ♂, Chile, Chiloé Is., Chepu [42°2′S 74°1′W], 8-II-1952, Peña (USNM)*. Paratypes: 1 ♀, Chile, Chiloé Is., Dalcahue [42°22′S 73°39′W], 1/ 4-IV-1968, Peña (USNM); 1 ♂, Chile, Chiloé Is., Chepu [42°2′S 74°1′W], 10/ 14-II-1952, Peña (USNM)*. - Additional material: CHILE. 2 ♂ and 1 [sex unknown], Pucotrihue [40°32′S 73°42′W], 60 m, 10-III-1955, Peña (USNM) ; 1 ♂, 1 ♀ and 1 [sex unknown], Llanquihue, Carelmapu [41°44′S 73°40′W], Canal Chacao, 18-III-1957, Peña (USNM); 1 [sex unknown], Chiloé Is., Chepu [42°2′S 74°1′W], 8-II-1952, Peña (USNM).

Etymology.

The word Amphineurus triangularis is Latin for “triangular”. This name references the triangular shape of the spur of sheath of aedeagus.

Diagnosis.

This species is distinguished by only a dark spot near R2 and M1+2 as long as the basal deflection of M1. Furthermore, this species is characterized by male terminalia with sheath of aedeagus with a triangular spur, tip of both mesal lobes bent horizontally, straightened lateral branch of clasper of gonostylus and cercus uniformly wide and abruptly angled dorsad.

Description.

Wing length 5.76 mm, width 1.74 mm. - Coloration: General coloration brownish yellow. Rostrum and palpus dark brown. First segment of antenna yellowish brown, remainding segments brown. Head brown. Eye black. Thorax brownish yellow, pleura pale. Scutum with one black stripe. Halter dark yellow with knob yellowish brown. Coxae yellow and legs brown. Abdomen yellowish brown. - Head (dorsal view Fig. 31B , ventral view Fig. 31A ): Rostrum bifurcated with long appendices; first palpal segment shorter than terminal segment; scape thinner than pedicel; terminal flagellomere longer than penultimate. - Thorax (lateral view Fig. 31E , dorsal view Fig. 31F ): Division line of laterotergite almost vertical, anatergite as tall as katatergite. Halter with dilated knob. Wing (Fig. 31D ) almost clear of markings, except marking on R2; veins near fork of bM (Fig. 31C ) faded; M1+2 as long as basal deflection of M1; R2+3+4 longer than R2+3; basal deflection of R5 shorter than R2+3. - Female terminalia (Fig. 31H ): Female tergite IX shorter, wider than tergite X; cercus bent at right angle. Hypogynial valve slender and longer than cercus. - Male terminalia (Fig. 31G ): Male tergite IX slightly darkened along posterior margin, with wide V-shaped median notch. Ventral branch of gonocoxite slightly sinuous, with concentration of setae on distal tip. Dorsal branch of gonocoxite shorter than half-length of ventral branch, slightly inclined medially. Lobe of gonostylus with rounded lobule; lobule longer than wide, longer than half-length of lobe of gonostylus, narrower than stem. Clasper of gonostylus with differently shaped branches: lateral branch straight; medial branch curved. Mesal lobes of gonocoxite asymmetrical; left mesal lobe curved; right mesal lobe short with sideways projection. Sheath of aedeagus straight with triangular projection, darkened near tip.

Remarks.

Some specimens of this new species were previously identified by C.P. Alexander as A. (R.) insanus Alexander and some as A. (R.) glabristylatus Alexander. This species resembles A. (R.) podenasi sp. nov. but differs mainly in the length of M1+2 and R2+3+4, shape of cercus and ventral branch of gonocoxite.

Figures

Figure 31. Amphineurus (Rhamphoneurus) triangularis 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); H female terminalia (dorsal view). - Abbreviations: aed sh, sheath of aedeagus; anatg, anatergite; anepm, anepimeron; anepst, anepisternum; aprn, anteropronotum; cer, cercus; cgonst, clasper of gonostylus; cx, coxa; goncx, gonocoxite; hlt, halter; hyp val, hypogynial valve; 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; st, sternite; tg, tergite; t 9, male tergite IX.