Platychauliodes pusillus (McLachlan)

Liu, Xingyue, Price, Ben W., Hayashi, Fumio & Yang, Ding, 2011, Revision of the fishfly genus Platychauliodes Esben-Petersen (Megaloptera: Corydalidae) endemic to South Africa, Zootaxa 2909, pp. 1-13 : 7-9

Platychauliodes pusillus (McLachlan)

( Figures 3–4 , 24–31 )

Chauliodes pusillus McLachlan, 1867: 231 . Type locality: Unknown.

Chauliodes tenuis McLachlan, 1869: 38 . Type locality: South Africa (Knysna). syn. nov. Platychauliodes woodi Barnard, 1931: 177 . Type locality: South Africa (Oudebosch, Cederberg). syn. nov.

Diagnosis. This is a small species, which is characterized by the filiform antennae, the 5 or 6-branched Rs, and the male tenth sternum with median plate separated into a pair of narrowly spoon-like lobes and a pair of long accessory processes laterally.

Description. Male. Body length 12.0– 18.8 mm; forewing length 17.2–23.0 mm, hindwing length 15.4–20.3 mm.

Head yellowish brown, vertex medially with raised longitudinal scars yellow. Compound eyes blackish brown; ocelli widely separated, pale yellow, medially margined blackish brown. Antenna filiform, yellowish brown. Mouthparts brown, with maxillary and labial palpi much darker.

Thorax yellowish brown, much darker on meso- and metanota. Legs yellow, with dense yellowish setae; extreme apices of tibiae and entire tarsi brown, tarsal claws reddish brown. Wings hyaline, pterostigmatic area narrowly elongated, pale grayish brown. Forewings with numerous indistinct brownish spots along longitudinal veins. Hindwings immaculate. Veins pale yellow, but brownish in distal half, also with brownish sections in dark markings and costal crossveins of forewings. Rs ( Fig. 3 ) 5 or 6-branched; M 2-branched.

Abdomen dark brown with venter yellowish brown. Ninth tergum ( Figs. 24, 26 ) subquadrate in dorsal view, with anterior and posterior margins truncate. Ninth sternum ( Figs. 25–26 ) short, posteriorly bearing a subtriangular membranous lobe. Tenth tergum ( Figs. 24–27 ) nearly as long as 2/3 of ninth tergum, obliquely directed dorsad and slightly flattened; in lateral view anterior portion strongly inflated ventrad, bearing numerous spinous setae, posterior half gradually narrowed, leaving an acutely pointed tip; in dorsal view posterior half feebly curved inward. Tenth sternum ( Figs. 25–28 ) short, nearly as long as ninth tergum, strongly sclerotized with short lateral arms; median plate medially separated into a pair of narrowly spoon-like, distally produced lobes, each of which laterally bears a long and clavate process, obliquely producing dorsad at subdistal portion. Anus ( Figs. 25–27 ) slightly sclerotized ventrad, medially with a broad rectangular sclerotized area in ventral view. A pair of short setose lobes presented beneath anus.

Female. Body length 21.9–25.6 mm; forewing length 26.9–29.8 mm, hindwing length 24.2–25.7 mm.

Rs ( Fig. 4 ) 5 or 6-branched in forewings but 5-branched in hindwings.

Eighth sternum ( Figs. 29–30 ) subtrapezoidal in ventral view, posteriorly bearing a triangular membranous lobe. Ninth gonocoxite ( Fig. 29 ) broadly foliate, with obtuse tip. Tenth tergum ( Figs. 29, 31 ) short, acutely produced posteriad, with strongly inflated cercus laterally.

Type material. Holotype 3, SOUTH AFRICA: “ Chauliodes pusillus McL[achlan] (Type)/McLachlan Coll. B.M.1938-674./ pusillus McL[achlan]./ Holotype ” (NHM).

Other material. SOUTH AFRICA: Western Cape Province: 33, C[ape].P[rovince]., Kaaiman’s [= Kaaimans] River, 6 km E of George [33°59'S, 22°33'E], I.1936, H.G. Wood ( SAM, SAM-MEG-A 000017); 23, Palmiet River [33°43'S, 19°02'E], XII.1932, H.G. Wood ( SAM, SAM-MEG-A 000049); 1Ƥ, Grootvadersbosch [33°58'S, 20°39'E], X.1985, A.J. Prins ( SAM, SAM-MEG-A 000055); 13 (paralectotype of P. w o o d i, present designation), Cedarbergen [= Cederberg, 34°06'S, 19°01'E], 4000 ft, I.1930, K.H. Barnard ( SAM, SAM-MEG- A000016); 13, Meirings Poort [= Meiringspoort], Spitzkop [= Spitskop, 33°55'S, 23°07'E], I.1935, Museum Staff ( SAM, SAM-MEG-A 000015); 431Ƥ, R[ivier] Sonder End [= Riviersonderend], Oudebosch [34°09'S, 19°54'E], I.1933, H.G. Wood (331Ƥ in SAM, SAM-MEG-A 000072 and 13 in NHM); 13, R[ivier] Sonder End [= Riviersonderend], Oudebosch, I.1934, Museum Staff ( SAM); 13 (lectotype of P. woodi , present designation), Caledon, Oudebosch, 1500 ft, I.1919, K.H. Barnard ( SAM, SAM-MEG-A 000012); 1Ƥ, Montague Pass [33°52'S, 22°27'E], I.1940, Museum Staff ( SAM, SAM-MEG-A 000039); 1ex, “Afrique [P.A.] Delalande/Afrique Australe [= South Africa], [P.A.] Delalande, Museum Paris/sp. nov./ Chauliodes tenuis McLachlan , det. v[an] d[er] Weele, 1908” ( MNHN); 1Ƥ (holotype of C. tenuis ), S[outh] Afr[ica], Knysna [34°02'S, 23°04'E] (NHM); 13, Keurboom R[iver]. [33°52'S, 23°17'E], 3.I.1922, Chas. K. Brain (NHM); 1Ƥ, Witte River [33°38'25''S, 19°6'45''E], 3.II.1996 ( AMGS, WCR 154 A); 1Ƥ, Witte River [33°40'0''S, 19°7'30''E], 1.II.1996 ( AMGS, WCR 146 E); 23, Buffels River near J Schmids [33°58'50''S, 23°27'28''E], 17.I.2008 ( AMGS, TSR 0 11 A); 43, Upper Matjies [33°58'51''S, 23°27'28.1''E], 27.I.2009 ( AMGS, TSR 527 A); 133Ƥ, Upper Buffels River [33°58'57''S, 23°28'43.9''E], 27.I.2009 ( AMGS, TSR 539 A); 13, Lower Salt River [33°58'28''S, 23°31'19.7''E], 25.I.2009 ( AMGS, TSR 520 B); 23, Salt River [33°58”S, 23°33”E], 29.XI.2000 ( AMGS, SCR 258 B); 431Ƥ, Salt River, 25.I.2006 ( AMGS, SCR 358 A and SCR 358 B); 133, de Vasselot Reserve [33°58”S, 23°33”E], 7.XII.2006 ( AMGS, SCR 385 A); 432Ƥ, Upper Bobbejaans River [33°53'47''S, 23°33'19.5''E], 30.I.2009 ( AMGS, TSR 559 A and TSR 560 A); 633Ƥ, Upper Groot River West [33°54'46''S, 23°34'37.1''E], 30.I.2009 ( AMGS, TSR 561 M and TSR 562 A); 33, Lower Bloukrans River [33°57'21''S, 23°38'19''E], 22.I.2009 ( AMGS, TSR 499 A); 231Ƥ, Upper Bloukrans River Tributary [33°55'4''S, 23°38'20''E], 24.I.2009 ( AMGS, TSR 523 A); 531Ƥ, Lower Buffels River confluence [33°59'8''S, 23°38'20''E], 27.I.2009 ( AMGS, TSR 532 A); 23, Lower Groot River West [33°57'21''S, 23°38'19''E], 15.IV.2009 ( AMGS, TSR 629 A); Eastern Cape Province: 23, Lower Groot River West [33°55'59''S, 23°43'45.6''E], 15.IV.2009 ( AMGS, TSR 627 A); 23, Lower Lottering River [33°58'24''S, 23°44'50.5''E], 21.I.2009 ( AMGS, TSR 522 A); 13, Upper Elandsbos River [33°55'57''S, 23°46'58''E], 21.I.2009 ( AMGS, TSR 478 A); 23, Upper Storms River Tributary [33°56'57''S, 23°54'55''E], 20.I.2009 ( AMGS, TSR 454 A); 13, Upper Elands River [33°58'18''S, 24°3'51.1''E], 17.I.2009 ( AMGS, TSR 447 A); 13, Lower Elands River [34°1'3''S, 24°3'39.1''E], 17.I.2009 ( AMGS, TSR 448 A).

Distribution. South Africa (Western Cape Province and western margin of the Eastern Cape Province).

Remarks. The identity of this species is clarified. Based on the examination of the primary types of P. pusillus and P. woodi , we considered these species conspecific since the male genitalia in their types are identical. Although the holotype of P. t e n u i s is a female (mistaken for male by Kimmins, 1970), the body-size and the branching number of Rs clearly show that it is identical to P. pusillus . Therefore, we treat P. t e n u i s (originally Chauliodes tenuis ) and P. woodi as the junior synonyms of P. pusillus .

This species appears to be closely related to P. t h o r n e i by the similar male genitalia with tenth tergum acutely pointed posteriorly and with tenth sternum separated into a pair of spoon-like lobes that bear a pair of accessory processes laterally. However, P. pusillus can be easily separated from P. thornei by the small body-size (forewing length 17.2–23.0 mm in male and 26.9–29.8 mm in female), the 5 or 6-branched Rs, and the narrow lobes and accessory processes of the male tenth sternum. In P. thornei , the forewing length ranges around 26.0 mm in male and over 34.0 mm in female, the Rs is 6 or 7-branched, and the lobes and accessory processes of the male tenth sternum is much broader and shortened.

Figures

FIGURES 1 – 6. Habitus images of Platychauliodes spp. 1. P. c a p e n s i s Barnard, lectotype male; 2. same, female; 3. P. pusillus (McLachlan), holotype male; 4. same, female; 5. P. t h o r n e i Barnard, lectotype male; 6. same, paralectotype female.

FIGURES 24 – 31. Platychauliodes pusillus (McLachlan). 24. Male genitalia, dorsal view; 25. Male genitalia, ventral view; 26. Male genitalia, lateral view; 27. Male genitalia, caudal view. 28. Male tenth sternum, ventral view; 29. Female genitalia, lateral view; 30. Female eighth sternum, ventral view; 31. Female genitalia, dorsal view. Scale bars = 1.0 mm.