Polyplocia nebulosa, Gonçalves, Inês C. & Peters, Janice G., 2016

Gonçalves, Inês C. & Peters, Janice G., 2016, A new species of Polyplocia Lestage from Malaysia with comments on the genus (Ephemeroptera, Euthyplociidae, Euthyplociinae), Zootaxa 4184 (3), pp. 553-560 : 554-558

Polyplocia nebulosa sp. nov. Gonçalves & Peters

Diagnosis. 1) Wings with longitudinal veins light brown and cross veins brown, cross veins with narrow dark brown clouds and margins tinged with brown ( Figs. 2 and 5 ); 2) Sterna II-IX with a pair of blackish brown anterolateral marks ( Figs. 12 ); 3) Penes broad, T-shaped, fused, with medial groove extending from apex to half length of penes; large laterally projecting lobes apically rounded with a small dorsolateral spine; basal outer margin of each lobe sclerotized ( Figs. 7–10 ); 4) Styliger plate short and straight, not projected posteriorly; 5) Eggs 265– 267 µ m in length and 170–186 µ m in width, barrel shaped, without polar caps or other attachment structures, with one visible micropyle and chorion forming an irregular mesh with raised ridges, mesh size from 3.8–8 µ m ( Figs. 13–14 ).

Male Imago —Length (mm): Body = 13–17; Forewings = 13–16; Hind wings = 6–8.

Head: Yellowish shaded with black between lateral ocelli; eyes black; ocelli yellowish white surrounded by black ring. Antennae covered by brown shade.

Thorax: Pronotum yellowish, translucent, shaded with black; yellowish brown laterally; about as long as wide, trapezoidal in shape with a membranous elevated ridge on posterior margin ( Fig. 6 ). Meso- and metanota yellowish brown, parascutellum yellowish; posterior margin of metanotum shaded with black. Prosternum with median crest divided into two oblique ridges forming a wide triangle with the posterior margin.

Wings: Membrane translucent, longitudinal veins light brown, cross veins darker brown with narrow dark brown clouds; margins of wings tinged brown ( Figs. 2 and 5 ). Vein C of forewings brown with small spines along entire length; fork of MA slightly distal to or on same level as fork of Rs; ICu reaching CuP, second parallel intercalary present ( Figs. 1–2 ). Hind wings with C folding over Sc forming a groove to effect coupling with forewings; vein R1 rising from base of wing; MP forked; anal region with several long veinlets directed toward margin ( Figs. 3 and 5 ).

Legs: Yellowish. Coxae of fore and median legs shaded with black, hind coxae sometimes with light black shading; apex of femora tinged with black, darker on forefemora. Forelegs with basal half of femora possessing spines on outer margin; apex of tibiae with black mark, tibiae covered with short spines. Tarsal claws similar, both somewhat pointed ( Fig. 4 ).

Abdomen: Yellowish. Terga shaded with brown except for medial longitudinal line extending from terga I–X; a pair of pale, apical, submedial drop-shaped spots on terga II-IX, and paler more distal sublateral marks on terga II– X, pale marks large on terga II–V ( Fig. 11 ). Sterna II–IX with a pair of anterolateral blackish brown marks ( Fig. 12 ). Caudal filaments yellowish with light black shading, with short setae on terminal filament and shorter lateral setae on cerci. Genitalia: Styliger plate yellowish brown, short, straight, not projecting posteriorly ( Fig. 7 ). Forceps yellowish, outer margin rugose with yellowish brown shading; distal portion with scattered short setae, particularly on apex ( Figs. 7–9 ). Penes yellowish, T-shaped, broad, fused, with medial groove extending from apex to half length of penes; each penis lobe rounded apically and strongly curved laterally with a long, lateral projection and a small dorsolateral spine; basal outer margin of each lobe sclerotized ( Figs. 7–10 ).

Variations: In some male imagos deposited at PERC, distomedial marks were not always visible on abdominal terga II–III. In others, these marks were indistinct and blended with the pale color of the posterior margin. Three males had deformed penes, with apical lobes collapsed; on these the genitalia had dried in such a way that the dorsal spines could be seen in ventral view.

Female Subimago —Length (mm): Body = about 18 (abdomen curved); Forewings = 18; Hind wings = 6.

Color pattern similar to male imago. Head with remnants of mandibular tusks. Posterior margin of pronotum not elevated; shading on abdomen darker. Fore and hind legs missing. Subanal plate short, truncate. Caudal filaments dark brown.

Female Imago —Length (mm): Body = about 18 (abdomen curved); Forewings = 17; Hind wings = 7.

Color pattern similar to male imago. Head without remnants of nymphal tusks. Posterior margin of pronotum not elevated. Wings as in male imago, with more long intercalaries on forewings: a pair between R3/R4+5, one between MA1/IMA, a pair between MA2/MP1 as well as shorter intercalary between IMP/MP2. Forelegs missing. Brown shading on abdomen darker. Subanal plate short, truncate. Caudal filaments missing.

Variations: Presence of additional intercalary veins varied on the left and right wing on the single female described, evidence for intraspecific variation in this species. This may be true for the genus as a whole.

Eggs (described from female subimago)—Measurements (µ m): Length = 265–267; Width = 170–186; Mesh = 3.8–8. Barrel-shaped, without polar caps or other attachment structures, one visible micropyle, chorion forming an irregular mesh with raised ridges ( Figs. 13–14 ).

Possible Nymph —Length (mm): Female—Body = 19; Male—Body = 14. Nymphs are tentatively associated based on the color on abdominal sterna and shape of nymphal male genitalia.

Head: Brown with light black shading along lateral branches of epicranial suture, posterior to median ocellus and anterior to lateral ocelli, area between lateral ocelli slightly lighter. Clypeus projected anteriorly. Eyes black, ocelli white with inner margin black. Antennae with scape, pedicel and base of flagellum brown, flagellum yellow distally; antennae longer than mandibular tusks ( Fig. 16 ).

Mouthparts: Labrum ( Fig. 19 ): brown; lateral margins divergent, anterior margin with median shallow emargination; labrum with longitudinal sub-basal row of long setae, a median subapical row of short dense setae, and bordered with simple setae, setae dense on anterior margin. Mandibles ( Figs. 16–17 ): yellowish brown, tusks brown and incisors and molae dark brown; tusks long, sickle shaped, apex truncate, length more than 2x that of head; several long slender setae on margins, rows of setae forming a filtering network on inner margin; dorsal surface covered with small spine-like setae; larger spine-like setae on distal half ( Fig. 17 ); left mandible: 4 denticles on outer and 3 on inner incisors; prostheca short, truncate, broader apically; right mandible: 4 denticles on outer and 2 on inner incisors; prostheca absent. Maxillae: palpi with 3rd segment about 2.6x longer than 2nd segment, 3rd segment long, at least 6x longer than wide; palpi with many long setae, particularly on 2nd and 3rd segments. Labium ( Fig. 21 ): glossae and paraglossae densely covered with setae ventrally; glossae drop shaped, ventral; paraglossae meet above glossae; palpi with long simple setae, mostly on outer margins; 3rd segment with several short strong setae dorsally, much broader and about 1.5 x longer than 2nd segment, acutely rounded apically. Hypopharynx: lingua cordiform with deep medial emargination distally; distal margin with short simple setae; superlingua with dense long setae on distal and inner lateral areas.

Thorax: Brown with black markings on pro- and mesonota. Pronotum with anterolateral corners projected beyond posterior border of eyes, not reaching half its length; lateral flanges pale, translucent and forming an acute apical projection subequal in size to anterolateral projections ( Fig. 16 ). Metanotum yellowish brown.

Legs: Yellowish brown; tarsal claws without denticles. Fore and middle legs with a row of spine-like setae on inner and outer margins of femora; distoventral surface of hind femora with area covered by short setae. Foreleg ( Fig. 16 ): tibia with apical projection short, less than half length of tarsus; margins of projection bordered with strong setae; tarsi with apical projection shorter than claw; apex of tarsi and its projection densely covered by short setae. Middle leg: apex of tibia with short projection; area around projection and inner margin of tarsi with dense concentration of short plumose setae; patello-tibial suture present.

Abdomen ( Fig. 15 ): Yellow, heavily shaded with black, except for a medial longitudinal line, on terga I–X and paler submedial markings as in male. Sterna yellowish, with a pair of anterolateral black marks, one on each corner. Gills purplish gray, gills I bifurcated, vestigial, dorsal portion longer and wider than ventral portion ( Fig. 20 ); gills II–VII long, longer than 1.5x length of subjacent abdominal segment, narrow, lanceolate, fringed; dorsal and ventral portions of same length. Cerci and median filament whitish yellow, shaded with black on base, paler toward apex; setae at annulations.

Etymology. nebulosa (latin) meaning “a cloud“ or “mist“ in allusion to the brown tinge on margins of wings.

Type material. Holotype: Malaysia, Sabah, Sungai Moyog, tributary 8 miles East of Penampang , 01.X.1978, G.F. Edmunds col., 1 male imago ( FAMU)[approximate coordinates 5°55'N / 116°09'E] ; Paratypes: same data, 2 male imagos ( FAMU) 11 male imagos ( PERC); Malaysia, Sabah, Sungai Moyog, 3 miles East of Penampung , 29.IX.1978, G.F. Edmunds col. , 1 female subimago (FAMU) [approximate coordinates 5°55'N/116°07'E]; same data, 1 female imago ( PERC).

Additional material. Polyplocia nebulosa sp. nov. possible nymph: Malaysia, Sabah, Borneo stream 1 km S. of Poring Hot Springs, CL 2023, 02.VIII.1985, J.T. & D.A. Polhemus col., 7 nymphs ( PERC) [approximate coordinates 5°54'N / 116°09'E] ; Malaysia, Sabah, Borneo, Samalang River , 7 km S. of Ranau, CL 2026, 03.VII.1985, J.T. & D.A. Polhemus col., 3 nymphs ( PERC) [approximate coordinates 6°02'N / 116°42'E]. Polyplocia vitalisi type : Tonkin, 08.IV.1920, Vitalis de Salvaza, 1 male imago ( IRSNB). Polyplocia campylociella : Sarawak, 2 males, Lestage Collection ( IRSNB) ; Sarawak, Mt. Penrissen , 3.000 ft, Dr. E. Mjöberg, 1 female, Lestage Collection ( IRSNB) . Polyplocia orientalis : Vietnam, Lam Dong Prov., Bao Loc, Da Mre stream, 450 (alt.), 22.III.2002, V.V. Nguyen & D.H. Hoang col., 1 nymph ( DZRJ). Polyplocia spp. : Thailand, Phrae Province, Wieng Ko Sai National Park, Namtok Mae Koeng Luang , 350 m, 17o58’N / 99 o35’E, L-295, 14.III.2002, R.W. Sites, Vitheepradit, Kirawanich, G. W. Courtney col., 3 female imagos , 1 female nymph (FAMU); Thailand, Phayao Province, Doi Luang National Park, Nam Tok Cham Pa Thong , 620 m, 19o13’N / 99o4’E, 17.III.2002, R.W. Sites, Vitheepradit, Kirawanich, G.W. Courtney col., 10 nymphs, both sexes ( FAMU) ; Thailand, Nan Province, Doi Phu Ka National Park, Nam Tok Sila Phet , 400 m 19o05’N / 100o56’E, L-292, 13.III.2002, R.W. Sites, Vitheepradit, Kirawanich, G.W. Courtney col., 1 young nymph ( FAMU) ; Thailand, Chiang Mai Province, Doi Suthep-Pui National Park, Huai Kaew above Monthathan , 800 m, 18o49’N / 98o55’E, 15.III.2002, G.W. Courtney col., 2 young nymphs ( FAMU) ; Thailand, Chiang Rai Province, Doi Luang National Park, Namtok Pu Kaeng , 540 m, 19o26’N / 99o42’E, 17.III.2002, G.W. Courtney col., 5 nymphs, both sexes ( FAMU) ;

Figures

FIGURES 1 – 12. Male of Polyplocia nebulosa sp. nov.: 1 and 2 — Forewings; 3 and 5 — Hind wings; 4 — Tarsal claws of foreleg; 6 — View of head and pronotum, arrows show elevated ridge; 7 — Genitalia, ventral view; 8 — Genitalia, dorsal view; 9 — Detail of penes, ventral view; 10 — Detail of penes, dorsal view; 11 — Abdominal color pattern, dorsal; 12 — Abdominal color pattern, ventral.

FIGURES 13 – 14. Eggs of subimago of Polyplocia nebulosa sp. nov.: 13 — Overall appearance; 14 — Detail of chorionic ultrasculpture.

FIGURES 15 – 21. Possible nymph of Polyplocia nebulosa sp. nov.: 15 — Abdomen; 16 — Head and prothorax; 17 — Detail of tusks and distribution of spine-like setae; 18 — Detail of foretibia; 19 — Labrum, dorsal view; 20 — Gill I; 21 — Labium, ventral view.