Neoperla mnong Stark, 1987

Stark, Bill P. & Sivec, Ignac, 2008, New Species And Records Of Neoperla (Plecoptera: Perlidae) From Vietnam, Illiesia 4 (3), pp. 19-54 : 33-34

Neoperla mnong Stark

( Figs. 40‐44 , 106 )

Javanita costalis Navás, 1932:925 . Secondary homonym of Formosina costalis Klapálek ( Zwick 1988)

Neoperla mnong Stark, 1987:48 . Holotype ♂ ( California Academy of Sciences ). Di Linh, Vietnam

Neoperla angustilobata Zwick, 1988:404 . Holotype ♀ (Muséum National d’Histoire Naturelle), New Synonymy

Material examined. Vietnam: Gia Lai, An Khe District, Tram Lap, Azun River , 2 km NW on trail from forestry building, 14 ° 27’ N, 108 ° 33’E, 17 June 1996, D. Currie, J. Swann, ROM 961056 , 4 ♂, 1 ♀ ( ROM, BPS) . Same site, 23 June 1996, D. Currie, J. Swann, ROM 961084 , 1 ♂ ( IEBR) . Gia Lai, An Khe District, Tram Lap, Azun River , 3 km NE on trail from forestry building, 21 June 1996, D. Currie, J. Swann, ROM 961076 , 1 ♂ ( ROM) . Gia Lai, An Khe District, Dacklest River, 5.2 km NE Tram Lap on forest road, 14 ° 24’ N, 108 ° 33’ E, 15 June 1996, D. Currie, J. Swann, ROM 961047 , 4 ♂ ( ROM) . Gia Lai, An Khe District, Tram Lap , near pond and coffee plantation, 14 June 1996, UV light, 14 ° 26’ N, 108 ° 33’ E, B. Hubley, D. Currie, J. Swann, ROM 961045 , 2 ♂ ( ROM) . Gia Lai, An Khe District, 6.5 km NE Tram Lap , forest road, 19 June 1996, D. Currie, J. Swann, ROM 961061 , 1 ♀ ( ROM) . Nghe An, ca. 25 km SW Con Cuong, Khe Moi Forestry Camp, tributary Khe Moi River , 4 June 1995, B. Hubley, J. Swann, ROM 956158 , 1 ♀ ( ROM) .

Remarks. This species was first described as Javanita costalis , by Navás (1932) from a female specimen and later described as a new species from a male specimen by Stark (1987). Zwick (1988) recognized J. costalis as a secondary homonym of Formosina costalis Klapálek after both species were transferred to Neoperla ( Sivec & Zwick 1987) , and proposed N. angustilobata as a replacement for N. costalis, sensu Navás. The conspecificity of N. mnong and N. angustilobata was suggested when N. mnong females were associated in this study.

Adult habitus. Biocellate. Head mostly yellow but small area of brown pigment over ocelli often with distinct anteromesal notch; frons usually marked with an additional dark area near anterior margin ( Fig. 40 ). Pronotum pale brown with slightly darker rugosities. Wings pale, veins amber. Femora and tibiae pale but a little darker at the knee.

Male. Forewing length 12‐13 mm. Described by Stark (1987) but illustrations of the aedeagus and external genitalia are presented in Figs. 41‐42 to aid in recognition of this species.

Female. Forewing length 15‐16 mm. Subgenital plate produced as a small notched tab; notch U‐ shaped and about as wide as lateral lobes of plate ( Fig. 43 ). Vagina longer than wide and swollen in posterior half ( Fig. 44 ). Spermathecal stalk short; spermatheca slender, curled, hooked on apex and without internal spinous lining.

Egg. Pear shaped. Length ca. 0.33 mm, width ca. 0.23 mm. Collar wide and not distinctly stalked; sides with vertical ribs extending onto egg body, and with an irregular cell row; rim not flanged ( Fig. 106 ). Chorion appearing relatively smooth but covered throughout with minute, shallow pits.

Diagnosis. This species is a member of a complex which includes N. diehli Sivec , a species known from Sumatra ( Zwick & Sivec 1985), N. yao Stark , a species which also occurs at sites in Gia Lai Province, N. han Stark , a species described from Hong Kong ( Stark 1987), and N. hubleyi , described above from several Vietnamese sites. The aedeagal Y‐ lobes for N. diehli , N. mnong , N. han and N. hubleyi are similar in having short arms supporting spiny apices, but those of N. han and N. hubleyi have a longer basal stalk, and those of N. diehli are more basally located and less spherical than in N. mnong . Females of N. mnong and N. yao have similar, bilobed subgenital plates and color patterns, but differ in egg collar morphology. The eggs of the latter species have stalked collars whereas those of N. mnong are unstalked.

Figures

Figs. 40‐44. Neoperla mnong. 40. Head and pronotum, 41. Male terminalia, 42. Aedeagus, 43. Female terminalia, 44. Vagina and spermatheca.

Figs. 106‐111. Egg micrographs. 106. N. mnong. 106. Egg, 107‐108. N. tamdao. 107. Egg, 108. Collar. 109‐111. N. nebulosa. 109. Egg, 110. Collar, 111. Lid.