Neochauliodes subfasciatus ( Westwood, 1848 )

Liu, Xingyue, Hayashi, Fumio & Yang, Ding, 2010, Revision of the fishfly genus Neochauliodes van der Weele (Megaloptera: Corydalidae) from India and adjacent regions of South Asia, Zootaxa 2692, pp. 33-50 : 44-45

Neochauliodes subfasciatus ( Westwood, 1848)

( Figures 6 , 30–34 )

Chauliodes subfasciatus Westwood, 1848: 70 . Type locality: Bangladesh (Sylhet).

Diagnosis. This species is characterized by the broad median transverse markings in both fore and hindwings. Males are distinguished by a posteriorly widened tenth tergum and the narrowly elongate median plate of the tenth sternum with concaved tip. Female ninth gonocoxite much broader than tenth tergum, acutely produced posteriad.

Male. Body length 15–19 mm; forewing length 23–27 mm, hindwing length 20–23 mm.

Head dark, except clypeus which is yellowish brown ( Fig. 6 ). Compound eyes grayish brown, ocelli pale yellow, medially margined in black. Antennae blackish brown. Mouthparts yellowish brown, mandibles with distal 1/3 reddish brown.

Thorax dark. Legs dark with short, dense brownish setae; tarsal claws reddish brown. Wing ( Fig. 6 ) background colour hyaline, with wide, dark bands medially and at distal margin; pterostigmata short, pale. Forewing proximally with several small, isolated brown spots in intercostals cellules; a subtriangular hyaline area formed by proximal and median markings; distally with several isolated small spots and a short stripe distally to pterostigmatic area, and with distal and posterior margin brownish throughout. Hindwing similarly patterned, but almost immaculate proximally, only with a few brownish spots sometimes. Veins brown but pale yellow on hyaline areas. Rs five to seven-branched, smoothly directed and feebly curved posteriad; three crossveins between R1 and Rs.

Abdomen black. Ninth tergum ( Fig. 30 ) subtrapezoidal in lateral view, slightly narrowed and produced anteroventrad. Tenth tergum ( Figs 30, 32 ) in lateral view subtrapezoidal, obliquely directed ventrad, slightly widened posteriad, posterodorsal corner distinctly prominent; narrow in dorsal view, inner portion not inflated, bearing several rows of brushy setae and several spinous setae, the latter confined to the apex. Tenth sternum ( Figs 30–31 ) strongly sclerotized, lateral arms short and ovoid, connected with median plate by narrow strap, median plate in ventral view subtrapezoidal, narrowly elongate, with concaved tip, anteriorly incised V-shaped; median plate in lateral view straightly directed, slender, with feebly pointed tip.

Female. Body length 17–19 mm; forewing length 26–29 mm, hindwing length 23–26 mm.

Eighth sternum ( Figs 33–34 ) subtrapezoidal in lateral view, with rounded convex posterior margin in ventral view. Tenth tergum ( Fig. 33 ) short and stout, subtriangular in lateral view. Ninth gonocoxite ( Fig. 33 ) much broader than tenth tergum, acutely produced posteriad, a small stylus present at its tip.

Type material. Lectotype ɗ, BANGLADESH: “Silhet[= Sylhet]/Saunders [Coll.]/ Chauliodes subfasciatus West. Cab. or. Ent., pl. 34, fig. 5/ Chauliodes subfasciatus Westwood ɗ D.E. Kimmins det. 1969 LECTOTYPE / subfasciatus Westwood ” (NHM). Paralectotype 1ɗ, BANGLADESH: “Silhet/ C. subfasciatus Silhet / PARALECTOTYPE / Neochauliodes subfasciatus Westw [ood]. det v[an]d[er] Weele 1907 ” (NHM).

Additional material. 1Ψ, without collecting label (NHM); 1Ψ, BANGLADESH: Sylhet ( IRSNB); 3ɗ, Caty [untraceable locality], 12.VI.1998 (EUM).

Distribution. Bangladesh (Sylhet).

Remarks. This species is currently known only from Bangladesh. The broad median transverse markings on the wings suggest affinity between this species and N. obscurus . The female ninth gonocoxite retains the trace of gonostylus, which is a typical plesiomorphic character and rarely present in Neochauliodes . Only one female with well preserved genitalia was present among the type series. Two additional specimens of N.

subfasciatus were located in NHM and IRSNB. The three male specimens in EUM, on which the present description of the male genitalia is based, possess wing patterns similar to the types of N. subfasciatus , but are larger than the two male types in body size. Moreover, their collecting site (Caty) is ambiguous, even though it is probably that the location is somewhere in northern India or its adjacent regions because we found the specimens of several Indian corydalid species with same collecting site and date in the same collection. Consequently, the current identification of the three male specimens in EUM as N. subfasciatus is somewhat tentative. Further clarification will be made when the male genitalia of the Bangladeshi specimens are examined.

Figures

FIGURES 1 – 7. Habitus images of Neochauliodes spp. 1. N. fletcheri Kimmins, holotype male; 2. N. indicus (van der Weele), paralectotype male; 3. N. nepalensis sp. nov., holotype male; 4. N. obscurus van der Weele, holotype female; 5. N. simplex (Walker), lectotype male; 6. N. subfasciatus (Westwood), lectotype male; 7. N. truncatus Kimmins, holotype male. Scale bars = 5.0 mm.

FIGURES 30 – 34. Neochauliodes subfasciatus (Westwood). 30. Male genitalia, lateral view; 31. Male tenth sternum, ventral view; 32. Male tenth tergum, dorsal view; 33. Female genitalia, lateral view; 34. Female eighth sternum, ventral view. Scale bars = 1.0 mm.