Neoperla clara, 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 : 20-21

Neoperla clara sp. n.

( Figs. 1‐5 , 91‐93 )

Material examined. Holotype ♂ and 2 ♀ paratypes from Vietnam, Dac Lac, Yok Don National Park , ca. 2 km SE Ban Don, 12 ° 53’ N, 107 ° 48’ E, 31 May 1997, D.C. Darling, D. Currie, A. Guidotti, ROM 974019 ( ROM).

Adult habitus. Biocellate. Head pale with obscure pale brown ocellar spot. Pronotum pale with obscure rugosities; median suture and margins pale brown ( Fig. 1 ). Wing membrane transparent, veins pale amber. Legs pale, tibiae with dark spot at knee.

Male. Forewing length 10 mm. Triangular process of tergum 7 rounded at apex and margined with spines. Median sclerite of tergum 8 a narrow, flattened bar, slightly expanded near anterior margin and without sensilla basiconica. Tergum 9 with lateral sensilla basiconica patches on low humps, median patch absent. Hemitergal processes long, slender and directed inward ( Fig. 2 ). Aedeagal tube well sclerotized on dorsal and ventral margin but membranous laterally; lateral tube membrane covered throughout with small spinules, dorsal tube surface with a mesal patch of small triangular spines near apex, but much of surface bears low, wide spinules which appear as groups of short lines ( Fig. 3 ). Sac about as long as tube and armed rather uniformly over at least basal half with small spines; sac not fully everted, but a group of somewhat larger spines organized as an irregular double row for ca. 7 pairs, and continuing as a single row of progressively smaller spines for ca. 15 additional spines, occurs beyond midlength of sac ( Fig. 3 ).

Putative Female. Forewing length 11.5‐12.5 mm. Subgenital plate not produced; posteromesal margin of sternum 8 recessed slightly ( Fig. 4 ). Vagina slender, spermathecal stalk long, coiled and lined for almost entire length with brown spines; spermatheca coiled and bearing a single accessory gland near apex ( Fig. 5 ).

Egg. Length ca. 0.31 mm, width ca. 0.15 mm. Collar not distinctly stalked, but slightly constricted at base; width ca. 0.08 mm at rim ( Figs. 91‐93 ). Sides of collar with a single irregular row of poorly formed cells; rim narrow and slightly flanged overlapping cell row. Chorion striate with ca. 14 wide striae and ca. 13 narrow sulci visible in lateral aspect; sulci with three irregular rows of pores near collar and lid. Follicle cell impressions on lid distinct but becoming less so near apex; cells have thick, smooth walls and floors are punctate. Striae join marginal row of FCIs on lid and collar. Micropyles subequatorial in position and with slender, elongate sperm guides set in sulci.

Larva. Unknown.

Etymology. The species name refers to the transparent, or clear, wing membrane.

Diagnosis. The aedeagus of this species bears a general resemblance to that of N. gordonae Stark and N. cavaleriei but the tube of those species is more fully sclerotized and lacks the extensive lateral spinule patch and dorsoapical spine patch found on the tube of N. clara . The species appears to be more closely related to N. daklak , a small dark species collected at the same locality. The aedeagal tube of that species is similar but the sac armature has more variably sized spines forming the basolateral patch and this is separated from the tube armature by a narrow bare ring. In addition, the sac of that species lacks the larger spines found beyond midlength, the 9 th tergum has a median sensilla patch and the 8 th mesal sclerite is larger and more triangular in outline.

Figures

Figs. 1‐5. Neoperla clara. 1. Head and pronotum, 2. Male terminalia, 3. Aedeagus, 4. Female terminalia, 5. Vagina and spermatheca.

Figs. 88‐93. Egg micrographs. 88‐90. N. cavaleriei. 88. Egg, 89. Collar, 90. Lid. 91‐93. N. clara. 91. Egg, 92. Collar, 93. Lid.