Amphineurus (Rhamphoneurus) nullus Alexander, 1967

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

3.3.19. Amphineurus (Rhamphoneurus) nullus Alexander, 1967

Amphineurus (Rhamphoneurus) nullus Alexander, 1967: 492 (description); Alexander, 1968: fig. 11 (wing), fig. 16 (male terminalia).

Material examined.

Holotype: ♂, Chile, Chiloé Is., Aulen, Duhatao [41°58′S 74°02′W], 6/ 8-II-1952, Peña, Holotype 9620 (USNM) [part of specimen pinned and part in slide prepared by C.P. Alexander]. Allotype: 1 ♀, Chile, Chiloé Is., Aulen, Duhatao [41°58′S 74°02′W], 6/ 8-II-1952, Peña (USNM). - Additional material: CHILE. 1 ♂ and 2 [sex unknown], Osorno, Bahia Mansa [40°35′S 73°44′W], South of Pucotrihue, 12-IV-1968, Peña (USNM) ; 1 ♂, Pucotrihue [40°32′S 73°42′W], 10-60 m, 12-III-1955, Peña (USNM); 1 [sex unknown], Osorno, Pucotrihue [40°32′S 73°42′W], 10/ 12-IV-1968, Peña (USNM); 1 ♂, Chiloé Is., Aucar [42°9′S 73°30′W], 15-I-1952, Peña (USNM)*; 1 ♂, Chiloé Is., Aulen [42°2′S 74°1′W], 8-II-1952, L.P. Guzman (USNM)*; 1 ♂, Pucotrihue [40°35′S 73°44′W], 10-60 m, 12-III-1955, Peña (USNM)*; 1 [sex unknown], Chiloé Is., Chepu [42°2′S 74°1′W], 14-II-1952, Peña (USNM)*; 1 [sex unknown], Chiloé Is., Chepu [42°2′S 74°1′W], 4/ 6-IV-1952, Peña (USNM)*; 1 ♂, Osorno, Bahia Mansa [40°35′S 73°44′W], South of Pucotrihue, 12-IV-1968, Peña (USNM) *.

Diagnosis.

The species is distinguished by absence of markings near R2, cross-vein m-cu attached to M3+4 and length of r-m twice length of basal deflection of R5. Furthermore, the species has distinctive male terminalia with a curved sheath of aedeagus, both mesal lobes with folded tips and branches of clasper of gonostylus of similar sizes. The species further distinguished also by the combination of sheath of aedeagus with small markings and male tergite IX pigmented. Furthermore, females of this species have the thickest cercus of the subgenus.

Redescription.

Wing length 6.32 mm, width 1.76 mm. - Coloration: General coloration brownish-yellow. Rostrum and palpus dark brown. First segment of antenna yellow, remainding segments dark yellow. Head grayish brown. Eyes black. Thorax brownish yellow, pleura brownish-yellow. Scutum without stripes. Halter yellow. Coxae and legs yellow. Abdomen brown. - Head (dorsal view Fig. 24B , ventral view Fig. 24A ): Head wide, rostrum bifurcated with long appendices, first palpal segment longer than dilated terminal segment; scape as thick as pedicel, terminal flagellomere longer than penultimate. - Thorax (lateral view Fig. 24E , dorsal view Fig. 24F ): Anatergite shorter than katatergite. Halter with dilated knob. Wing (Fig. 24D ) clear, without distinct markings; veins near fork of bM (Fig. 24C ) visible; R2 partially faded; crossvein r-m longer than basal deflection of R5; M1+2 about same length of M1+2; R2+3+4 longer than R2+3. - Female terminalia (Fig. 24H ): Female tergite X longer than tergite IX, tergite IX wider. Cercus thick, longer than hypoginial valves, slightly curved dorsad. - Male terminalia (Fig. 24G ): Male tergite IX darkened on posterior margin, with V-shaped median notch. Ventral branch of gonocoxite expanded in distal section. Dorsal branch of gonocoxite half-length of ventral branch. Lobe of gonostylus with round lobule; lobule longer than wide, longer than half length of lobe of gonostylus, wider than stem. Clasper of gonostylus with similarly shaped branches: lateral branch nearly oval: medial branch distally flattened, narrowed at margin. Mesal lobes of gonocoxite asymmetrical, both hook-shaped; left mesal lobe narrower. Sheath of aedeagus angulated, darkened only at tip.

Remarks.

This species resembles A. (R.) falcatus sp. nov. but differs mainly in the attachment of m-cu, shape of male tergite IX, prescutum and left mesal lobe.

Figures

Figure 24. Amphineurus (Rhamphoneurus) nullus Alexander. 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.