Neoperla idella, Stark & Sivec, 2008

Stark, Bill P. & Sivec, Ignac, 2008, New Species And Records Of Neoperla (Plecoptera: Perlidae) From Vietnam, Illiesia 4 (3), pp. 19-54 : 31-32

Neoperla idella sp. n.

( Figs. 34‐39 , 100‐102 )

Material examined. Holotype ♂ and 1 ♂, 1 ♀ paratype from 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 ( ROM). Additional paratypes: Vietnam, Gia Lai, An Khe District , Tram Lap , Azun River , 2 km NW on trail from forestry building, 14 ° 27’ N, 108 ° 33’ E, 23 June 1996, D. Currie, J. Swann, ROM 961084 , 1 ♂ ( IEBR). Vietnam, Lao Cai, Muong Hoa , tributary of Ho River , 15 km E Sapa, 926 m, 10 May 1995, D. Currie, B. Hubley, J. Swann, ROM 956033 , 1 ♂, 1 ♀ ( ROM)

Adult habitus. Biocellate. Head with a dark spot covering ocelli and another near anterior margin of frons. Pronotum pale brown with darker rugosities; anterior and posterior margins and median suture dark brown ( Fig. 34 ). Wing membrane pale amber, veins darker. Femora pale brown, tibiae dark brown at knee and along outer margins.

Male. Forewing length 11.5 mm. Tergum 7 process a rounded plateau, truncate on posterior margin and sprinkled with sensilla basiconica. Process of tergum 8 tongue shaped, erect and armed on anterodorsal margin with small spines. Tergum 9 without sensilla patches ( Fig. 35 ). Hemitergal processes strongly bent and upturned at midlength. Aedeagal tube slender, relatively straight and armed with minute spinules on dorsal and lateral surfaces ( Fig. 36 ). Aedeagal sac about half as long as tube and armed along dorsoapical margin with a double row of 4‐7 cultriform spines ( Figs. 36‐37 ); most of apical half of sac covered with smaller spines.

Female. Forewing length 13‐14 mm. Subgenital plate a short, bilobed, tongue shaped process; notch about as wide as lobes ( Fig. 38 ). Vagina long and slender with small sclerites clustered around spermathecal stalk ( Fig. 39 ). Spermathecal stalk short, spermatheca sausage shaped, curved at midlength and hooked at apex; a single accessory gland occurs subapically.

Egg. Barrel shaped. Length ca. 0.35 mm, width ca. 0.21 mm. Collar sessile, width ca. 0.12 mm; collar margined by an irregular row of triangular cells; rim smooth and thin ( Figs. 100‐102 ). Chorion striate, striae thin and closely packed with ca. 43 visible in lateral aspect; sulci absent. Primary striae connect to collar cells and to meshwork at margin of lid; each pair of primary striae form a longitudinal unit containing a pair of secondary striae. Lid ringed by an irregular row of deep pits; ca. 11‐13 pits visible in lateral aspect; lid covered with obscure follicle cell impressions containing fine punctations; FCIs only evident for marginal rows adjacent to pits. Micropyles subequatorial and without sperm guides.

Larva. Unknown.

Etymology. The species name is from the Greek word ideo, meaning “distinctive”, referring to the unusually armed male aedeagal sac.

Diagnosis. The aedeagus of this species is reminiscent of that of N. laotica Zwick but in that species the large spines are on the venter of the sac and the tube is less sclerotized ( Zwick 1988). In addition the tergal lobes of the two species are quite different with N. idella having a plateau type tergum 7 and N. laotica having a triangular tergum 7 process. The male paratype from Lao Cai has four pairs of cultriform spines on the aedeagal sac whereas the holotype and male paratypes from Gia Lai have seven pairs of spines.

Figures

Figs. 34‐39. Neoperla idella. 34. Head and pronotum. 35. Male terminalia. 36. Aedeagus. 37. Aedeagal sac, dorsal. 38. Female terminalia. 39. Vagina and spermatheca.

Figs. 100‐105. Egg micrographs. 100‐102. N. idella. 100. Egg, 101. Collar, 102. Lid. 103‐105. N. leptacantha. 103. Egg, 104. Collar, 105. Lid.