Ctenochauliodes khasianus

Liu, Xingyue, Hayashi, Fumio & Yang, Ding, 2011, Taxonomic notes and updated phylogeny of the fishfly genus Ctenochauliodes van der Weele (Megaloptera: Corydalidae), Zootaxa 2981, pp. 23-35 : 25-27

Ctenochauliodes khasianus (van der Weele), comb. nov.

( Figures 1 , 6–10 )

Neochauliodes khasianus van der Weele, 1909: 259. Type locality: India (Khasi Hills).

Diagnosis. The forewings of this species are densely marked by numerous small brownish spots. The male tenth tergum is twisted apically forming a triangular, somewhat flattened lobe. The male tenth gonocoxite is composed of a pair of bluntly tapered lobes that form nearly equal in length and subtriangular on posterior half of right lobe. Lateral lobes beneath anus feebly developed.

Description. Male. Body length 10 mm; forewing length 22 mm, hindwing length 20 mm.

Head blackish brown with frons black. Compound eyes brown, ocelli yellow. Antenna blackish brown. Mouthparts blackish brown, mandibles with apices reddish brown.

Thorax blackish brown. Legs brown, with short dense yellowish setae; tarsal claws reddish brown. Wings hyaline, slightly tinged pale smoky brown, with a brownish marking over each black nygmata. Forewings with proximal half of costal area pale brown and brownish markings on pterostigmatic areas, and with numerous indistinct small brownish spots throughout. Hindwings much paler than forewings, immaculate except for black nygmata. Rs four to five-branched; three crossveins between R1 and Rs; M two-branched; 1A two-branched.

Abdomen blackish brown with venter much paler. Tenth tergum ( Figs. 6–8 ) claviform, with apex distinctly narrowed and strongly twisted anteroventrad. Tenth gonocoxite ( Figs. 6, 9 ) strongly sclerotized, median plate divided into a pair of asymmetric lobes by a narrow incision; in lateral view median plate distinctly broadened and rounded dorsad and bearing short setae distally; in ventral view lateral arms suboval, median plate concave anteriorly forming a triangular emargination; lobes formed by narrow cleft nearly equal in length but asymmetrical, left lobe slightly incurved on medial surface and rounded apically, right lobe wider, posterior half strongly narrowed into a subtriangular apex. Sclerite ventrally to anus ( Figs. 6, 10 ) indistinct except for tuberculate lateral lobes which are posterolaterally directed.

Female. Unknown.

Type material. Holotype 3, “Khasis [= Khasi Hills, 91°38'E, 25°35'N, in Meghalaya State]. Nat[ive]. Coll[ector]./Cat[alog] No.1./3/ Neochauliodes khasianus Type 1908 Weele/ Type /Coll[ection]. v[an].d[er].Weele leg. 1907 No.6.” ( RMNH).

Distribution. India (Meghalaya).

Remarks. The taxonomic status of this species has remained obscure for more than a century. The male holotype of this species was first identified by van der Weele (1907) as Chauliodes pusillus McLachlan, 1867 , but was moved to the South African genus Platychauliodes by Barnard (1931). Later, van der Weele (1909) used this Indian specimen as the holotype for a new species, Neochauliodes khasianus van der Weele. However, we realized that this species resembles species of Ctenochauliodes with its narrowed wings and strongly pectinate male antennae as shown in the habitus photo of the holotype (van der Weele 1907: Plate 4, Fig. 4 ). Recently, we confirmed our assumption that this species truly belongs to Ctenochauliodes when we re-examined the holotype at the RMNH. Its similarly shaped male tenth gonocoxite appears to place it in close relationships with C. nigrovenosus from China and Vietnam. However, it can be distinguished from the latter species by the male tenth gonocoxite with the right lobe being rapidly narrowed at its apex. In C. nigrovenosus , the right lobe of the male tenth gonocoxite is more gradually narrowed apically.

Figures

FIGURES 1 – 3. Habitus images of Ctenochauliodes spp. 1. C. khasianus (van der Weele), holotype male; 2. C. nigrovenosus (van der Weele), lectotype female; 3. C. nigrovenosus (van der Weele), lectotype male of C. friedrichi Navás. Scale bars = 5.0 mm.

FIGURES 6 – 10. Ctenochauliodes khasianus (van der Weele). 6. Male genitalia, lateral view; 7. Male tenth tergum, dorsal view; 8. Male tenth tergum, ventral view; 9. Male tenth gonocoxite, ventral view; 10. Sclerite beneath anus, ventral view. Gx 10: tenth gonocoxite; S 9: ninth sternum; sa: sclerite beneath anus; T 9 – 10: ninth to tenth tergum. Scale bars = 1.0 mm.

FIGURES 4 – 5. Habitus images of Ctenochauliodes spp. 4. C. nigrovenosus (van der Weele), holotype male of C. forcipatus Kimmins; 5. C. stigmosus sp. nov., holotype male. Scale bars = 5.0 mm.