Cerconychia sapa, Stark & Sivec, 2007

Stark, Bill P. & Sivec, Ignac, 2007, A Synopsis Of Styloperlidae (Insecta, Plecoptera) With Description Of Cerconychia Sapa, A New Stonefly From Vietnam, Illiesia 3 (2), pp. 10-16 : 11

Cerconychia sapa , sp.n. ( Figs. 1 ‐ 9 )

Material examined. Holotype ♂ and 15 ♂, 28 ♀ paratypes from Vietnam, Loa Cai, Sapa, large waterfall on road from Sapa to Lai Chau, UV light, 8 May 1995, D. Currie, B. Hubley, J. Swann (Royal Ontario Museum 956022), Holotype ( ROM), paratypes ( BPS, IEBR, PMSL, USNM). Additional paratypes: Vietnam, Loa Cai, ca. 12 km along road from Sapa to Lai Chau, 1950 m, 22° 20 ʹ 58.3 ʺ N, 103° 46 ʹ 15.7 ʺ E, Malaise trap, B. Hubley, 1 ♂ ( ROM 992002 ), ( ROM). Vietnam, Cao Bang, Ba Be National Park , jct. road to Ba Be, 19 May 1995, D. Currie, K. Ciruna, J. Whiting, 2 ♂, 2 ♀ ( ROM 956101 ), ( ROM). Vietnam, Sapa, Fan Si Pang Mt. , 1600 m, 22 ‐ 29 April 1995, light trap, 2 ♂, 3 ♀ ( MNB).

Adult habitus. Biocellate. General color pale yellow brown. Head pale over much of occiput but dusky brown behind eyes and along stem of epicranial suture in fully pigmented individuals; stem and Y arms of suture dark brown, frons mostly dark brown ( Fig. 1 ). Pronotum dark brown on anterior and posterior margins of disc; disc pale except for dark rugosities which form an irregular mid lateral band ( Fig. 1 ). Legs brown, without banding. Wings transparent, veins brown.

Male. Forewing length 12 ‐ 17 mm. Basal cercal segment swollen in dorsal aspect, terminating in a long, curved, acute process which projects along inner cercal margin ( Figs. 2, 6 , 7 ); basal segment and process armed asymmetrically along length with numerous (ca. 15 or more) small spines or enlarged sensilla ( Figs. 6 ‐ 7 ); second and sometimes third segment armed with an enlarged dorsal spine ( Figs. 6 ‐ 9 ). Ninth sternum bearing a thick, wide setal brush near anterior margin ( Figs. 3 ‐ 4 ).

Female. Forewing length 20 ‐ 22 mm. Subgenital plate very slightly produced into a short tab with mesal emargination ( Fig. 5 ). Sternum 9 sparsely setose over central area but with a patch of coarse short setae associated with basomesal fold posterior to gonopore. Intersegmental membrane between sterna 9 and 10 with microtrichia. Vagina a membranous sac, wide at base, narrowly rounded at tip, and lightly coated with pale brown spinulae in the wrinkled chamber. Spermatheca long, slender and bearing several slender accessory glands.

Egg. Typical of genus. Ovoid with collar absent and chorion smooth.

Nymph. Unknown.

Etymology. The species name, used as a noun in apposition, is based on the type locality near Sapa.

Diagnosis. Males of this species are distinct from all known Styloperlidae by virtue of the numerous small spines scattered over the dorsum and margin of the basal cercal segment and process. Females have a slightly produced, emarginate subgenital plate similar to that of other Cerconychia ( Uchida & Isobe 1989) , but the forewing length is greater than the 9 ‐ 16 mm composite range given for the Taiwanese species. Cerconychia brunnea Klapálek and C. livida Klapálek are known from Taiwan ( Uchida & Isobe 1989) and C. sinensis Yang & Yang is known from Hainan ( Yang & Yang 1995), thus C. sapa is the first mainland Cerconychia species. The following provisional key, modified from Uchida & Isobe (1989), is offered as an aid for identification of Cerconychia males.

Figures

Figs. 1‐6. Cerconychia sapa structures. 1. Head and pronotum, 2. Male terminalia dorsal, 3. Male terminalia, lateral, 4. Male terminalia, oblique lateral. 5. Female terminalia, ventral.

Figs. 6‐9. Cerconychia sapa SEM photomicrographs. 6. Male right cercus, dorsobasal aspect, 7. Apex of male cercal process, dorsal (tip broken), 8. Male cercal segments 2‐6, dorsal, 9. Male cercal segments 2‐3, dorsal.