Neoperla tamdao Cao & Bae

Cao, Thi Kim Thu, Ham, Soon Ah & Bae, Yeon Jae, 2007, Description of three new species of Neoperla (Plecoptera: Perlidae) and a historical review of tropical Southeast Asian Perlidae, Zootaxa 1453, pp. 41-54 : 43-44

Neoperla tamdao Cao & Bae sp. nov.

( Figs. 7–15 )

Description. Male body length 12.6 mm; antennae 10.2 mm; forewings 13.3 mm; hindwings 11.7 mm. General body color pale yellow with dark brown markings.

Head ( Fig. 7 ) dark brown medially, pigment extending from anterior of frons to occiput. Ocelli set forward to middle of compound eyes; ocellar area dark brown. A pair of light spots present between ocelli and compound eyes. Anterior edge of frons and large areas posterior to compound eyes pale yellow. Antennae generally dark brown; scape pale yellow. Maxillary and labial palpi dark brown. Pronotum pale yellow, with symmetrical dark brown rugosities, posteriorly narrowed, flared to anterolateral angular corners. Wings ( Figs. 8, 9 ) hyaline; veins brown; forewing Rs with 3 branches; C–Sc with 18 crossveins. Hindwing 3A unforked. Legs relatively long; tibiae, tarsi, and distal part of femora dark brown.

Abdomen pale yellow in membranous areas and brown in sclerotized areas; tergum VII ( Fig. 10 ) strongly sclerotized in almost entire area and posteriorly with paired submedian lobes; submedian lobes each with 4–5 spinules terminally; terga VIII–IX ( Fig. 10 ) sclerotized anterolaterally and membranous posteromedially; tergum VIII with submedian patches of ca. 10 spinules; tergum IX strongly swollen, with submedian patches of ca. 14 spinules and a few long hairs anteriorly. Hemiterga ( Fig. 10 ) strongly sclerotized, medial lobe with scattered spinules, anteriorly directed processes slighly curved and extending over half of tergum IX. Aedeagus tube ( Figs. 12, 13 ) ca. 1.0 mm long, plump (length ca. 3x width), and largely membranous. In lateral view ( Fig. 12 ), everted sac with fingerlike lobes; each lobe with dark spinules. In dorsal view ( Fig. 13 ), bulb weakly sclerotized, slightly swollen at middle. Sac with lateral groups of conical spinules, forming a V–shaped patch of dark spinules from dorsal view. Cerci simple, brown.

Female body length 17.0– 19.8 mm; antennae 12.2–13.9 mm; forewings 18.3–20.5 mm; hindwings 16.5– 18.6 mm. Female much larger than male. Sterna I–V pale yellow; sterna VI–X brown; sternum VIII ( Fig. 11 ) weakly sclerotized in posteromedian area; subgenital plate ( Fig. 11 ) without lobes. Vagina ( Fig. 14 ) sac– shaped, large, and very expansible; upper folds and front of attachment of receptacle distinctly sclerotized; marginal parts soft, irregularly folded and wrinkled; spermathecal stalk ca. 0.5x length of vaginal sac.

Nymph. Unknown.

Egg. Egg ( Fig. 15 ) stout and oval, 0.40 mm long and 0.29 mm wide. Chorion smooth. Collar narrow, with flanged margin. Anchor attached inside collar. Micropyles in upper third; orifices sessile.

Type material. Holotype: ɗ (SWU–PLE–19, aedeagus dissected), Vietnam, Vinh Phuc Prov., Tam Dao NP, Thac Bac, alt. 700 m, 16.iv.2002, DHH & VVN [SWU–AIC]. Paratypes: 2 ɗ (SWU–PLE–20, ɗ aedeagus dissected) & 3 Ψ (SWU–PLE–21, Ψ vagina dissected), same data as holotype [SWU–AIC]. Other Material. ɗ (SWU–PLE–22), Vietnam, Ha Tinh Prov., Huong Son, Son Kim, 9.v.2004, Thi Kim Thu Cao; ɗ, Quang Nam Prov., Phuoc Son, LoXo Pass, alt. 1000m, 1.v.2005, Hoang Vu Tru.

Etymology. The specific name, tamdao (noun), refers to the holotype locality of this species.

Diagnosis. The male adults of Neoperla tamdao sp. nov. have paired submedian lobes on the 7th abdominal tergum and the female adults have relatively large and expansible vagina, which may suggest a close affinity with the borneensis – subgroup of the montivaga– group. The male adult of N. tamdao is similar to that of N. harina Navás (in Zwick 1986a) in general body shape, but can be distinguished by distinct head markings ( Fig. 7 ) and the everted sac lacking protrusions. The female adult can be distinguished by the shape of the vagina that is sclerotized and wrinkled marginally ( Fig. 14 ).

Habitat and biology. Adults of N. tamdao were collected from stream sides of small to medium–sized (4–30 m wide) mountain streams (alt. 290–1000 m) in northern and central Vietnam. The streams were 50 to 100% canopied by evergreen trees such as bamboo and ficus and the substrate consisted of boulder (40%), cobble (30%), gravel (15%), coarse sand (15%), and abundant fallen leaves. The adults were collected from late March to May.

Distribution. Northern and central Vietnam.

Remarks. The male and female adults of N. tamdao were collected simultaneously from the habitat site and no other neoperlids were found at that time. In addition, the complete agreement in head markings between the male and female adults substantiate this conspecificity.

Figures

FIGURES 7 – 15. Neoperla tamdao sp. nov. (7) Male head and pronotum. Scale bar = 0.5 mm. (8 & 9) Male right forewing and hindwing. Scale bar = 2 mm. (10) Male dorsal terminalia. Scale bar = 0.5 mm. (11) Female ventral terminalia. Scale bar = 0.5 mm. (12 & 13) Everted lateral and dorsal aedeagus. Scale bar = 0.5 mm. (14) Female vagina. Scale bar = 0.2 mm. (15) Lateral egg. Scale bar = 0.1 mm. Micropyles arrowed.