Neoperla leptacantha, 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 : 23-24

Neoperla leptacantha sp. n.

( Figs. 8‐11 , 103‐105 )

Material examined. Holotype ♂, paratype ♀, from Vietnam, Cao Bang, Ba Be National Park, junction Lake Ba Be Road and ethnic village trail, 18 May 1995, D. Currie, J. Swann, ROM 956068 ( ROM).

Paratypes: Vietnam: Nghe An, Coa Cuong, Con River , 2 June 1995, B. Hubley, J. Swann, ROM 956148 , 3 ♂ ( ROM) . Tuyen Quang, Pac Ban , 25 May 1996, D. Currie, D.C. Darling, J. Swann, ROM 963078 , 1 ♂ pinned ( IEBR). Tuyen Quang, Pac Ban, Gam River , 21 May 1996, D. Currie, D.C. Darling, J. Swann, ROM 963002 , 1 ♂ ( ROM) .

Adult habitus. Biocellate. Head yellow brown with small dark ocellar spot. Pronotum pale with indistinct rugosities. Wings pale amber with slightly darker veins; costal area pale. Legs pale but tibiae darker at knee.

Male. Forewing length 9.5‐10.5 mm. Tergum 7 process triangular with blunt tip margined by 5‐6 spines. Mesal sclerite of tergum 8 a low mound with small sensilla basiconica patch near front of sclerite and sparse, short dark bristle patches anterolateral and posterior to sensilla basiconica patch. Tergum 9 with mesal and lateral sensilla basiconica patches on low mounds. Hemitergal processes short, straight and slanted inward ( Fig. 8 ). Aedeagal tube slender but wider at base, lightly sclerotized, and armed with minute spinules on most of surface ( Fig. 9 ). Aedeagal sac longer than tube and unarmed along ventrobasal margin to near midlength; dorsobasal patch reduced to a few, mostly mesal spinules clearly removed from tube apex; major dorsal sac armature consists of two irregular, crowded rows beginning before ventral armature; largest spines along both margins straight and peg shaped ( Fig. 9 ). No armature occurs on apical third of sac.

Putative Female. Forewing length 11.5 mm. Subgenital plate unproduced, set off from posterior margin of sternum 8 by slight emarginations ( Fig. 10 ). Vagina long and slender with a patch of brown setae lining dorsal wall around base of spermatheca. Spermatheca long, coiled and lined rather completely with brown setae, but lining is incomplete particularly in basal area ( Fig. 11 ).

Egg. Outline oval. Length ca. 0.29 mm, width ca. 0.15 mm. Collar sessile, width ca. 0.065 mm; collar margined by an irregular row of poorly defined cells; rim smooth, narrow and slightly flanged ( Figs. 103‐ 105 ). Chorion striate, striae moderately wide with ca. 14 visible in lateral aspect; sulci about half as wide as striae and densely punctate with ca. 3‐4 rows of punctures. Striae slightly notched around micropyles; micropyles set on long, low mounds. Lid small but covered with prominent follicle cell impressions; FCIs densely punctate with ca. 65 or more punctures present in each cell; walls of cells smooth and moderately thick.

Larva. Unknown.

Etymology. The species name refers to the small, slender spines of the aedeagal sac.

Diagnosis. The aedeagus and external male genitalia of this species are similar to those of N. cavaleriei and N. gordonae . It differs from these and other members of the complex in having the dorsobasal spine patch reduced to a few minute spinules restricted to a sparse, irregular, mesal grouping discreetly removed from the tube apex, and in having the ventral armature absent from the basal third of the sac. In addition, the largest sac armature consists primarily of straight, peg shaped spines mixed with small cultriform shaped spines. The female and egg (if correctly associated) are also of the same general types as found in N. cavaleriei and N. gordonae but the egg in particular, differs in having relatively prominent FCIs on the lid, and is more similar to the egg of N. clara . These species (except N. clara ) cooccur at the Ba Be National Park sites in Cao Bang province.

Figures

Figs. 8‐11. Neoperla leptacantha. 8. Male terminalia, 9. Aedeagus, 10. Female terminalia, 11. 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.