Procloeon (P.) kottagudiensis Balasubramanian and Muthukatturaja, 2022

Muthukatturaja, Marimuthu & Balasubramanian, Chellaiah, 2022, A new record and new species of Procloeon (Procloeon) Bengtsson, 1915 (Ephemeroptera: Baetidae) from the Western Ghats, peninsular India, Zootaxa 5094 (2), pp. 321-330 : 322-328

Procloeon (P.) kottagudiensis Balasubramanian and Muthukatturaja sp. nov.

( Figs 1–36 )

Type material ( ZSI). Holotype: male imago (Reg.No. SRC/ ZSI-I/E 616) (reared from mature nymph), INDIA, Kottagudi stream, Kuragani, Theni District , Tamil Nadu state, 30-II- 2021, 800 m a.s.l, (10°04’576” N, 77°15’1100” E), colls. Balasubramanian & Muthukatturaja . Paratypes: 2 female imagoes (reared from mature nymph) (Reg.No. SRC/ ZSI-I/E 616) and 2 mature nymphs (Reg.No. SRC/ ZSI-I/E 617), same data as holotype, colls. Balasubramanian & Muthukatturaja .

Other material examined ( ZMTC). 5 male (Reg.No. ZMTC-79) and 5 female imagoes (Reg.No. ZMTC-80),, and 10 mature nymphs (Reg.No. ZMTC-81), INDIA, Kottagudi stream, Kuragani, Theni District , Tamil Nadu state, 30- II- 2021, 800 m a.s.l, (10°04’576” N, 77°15’1100” E), colls. Balasubramanian & Muthukatturaja. 15 mature nymphs (Reg.No. ZMTC-82) from Bison valley, Idukki District , Kerala state, 17-IV- 2021, 882 m a.s.l, (10°00’15” N, 77°06’42” E), colls. Balasubramanian & Muthukatturaja. 40 mature nymphs (Reg.No. ZMTC-83) from Periyavarai stream (Munnar), Idukki district , Kerala state, 29- III- 2021, 1,501 m a.s.l, (10°10’9476” N, 77°05’7512” E), colls. Balasubramanian & Muthukatturaja.

Diagnosis. The larva of Procloeon (P.) kottagudiensis sp. nov. can be distinguished from congeners by the combination of the following diagnostic characters: (i) segment III of labial palp truncate, with sparse stout setae and hair-like setae on dorsal surface; (ii) abdominal tergum VIII with ca. 4 lateral spines; (iii) posterior margin of tergum I with acute spines; (iv) gill VII single without process; (v) paraproct with 7–9 acute spines.

The imago of Procloeon (P.) kottagudiensis sp. nov. can be distinguished from congeners by the combination of the following diagnostic characters: (i) stigmatic area of forewing milky transparent with 8 cross-veins; (ii) longitudinal veins with single crossvein except areas of R and MA with two cross-veins, Sc with three cross-veins; (iii) hind wings approximately five times longer than wide; (iv) costal projection of hind wing located at 1/2 distance from the base, and the longitudinal veins not forked.

Description. Mature Nymph ( Figs. 1–3 ): Body length (excluding cerci) 8.5–9.5 mm in male and female nymphs; cerci 2.5–2.8 mm; median terminal filaments 2.1–2.5 mm; head width 1.0 mm; head length 0.7 mm; antenna length 1.75 mm; labrum width 0.3 mm; labrum length 0.25 mm; compound eye length 0.3 mm; compound eye width 0.25 mm; distance between compound eye 0.3 mm; length of fore femur/ tibia/ tarsi 1.3/ 0.8/ 0.8 mm; length of middle femur/ tibia/ tarsi 1.3/ 0.7/ 0.7 mm; length of hind femur/ tibia/ tarsi 1.5/ 0.7/ 0.8 mm. General body coloration light yellow to brown with dark brown markings.

Head: coloration light brown; vertex with paired dark brown stripes medially.Antennae pale yellow, longer than width of head; labrum ( Fig. 4 ) with submarginal stout setae laterally; margin of labrum with median W-shaped incision; anterior margin with row of long feathered setae and long fringed setae; right mandible ( Fig. 5 ) with more than 7 blunt denticles on incisors; 8 denticles on prostheca and cluster of hair-like setae between prostheca and mola; left mandible ( Fig. 6 ) with 9 blunt denticles on incisors, 8 denticles on prostheca and cluster of hair-like setae between prostheca and mola; apex of maxilla ( Fig. 7 ) with 3 prominent dentisetae and numerous stout monopectinate setae; galea-lacinia with 2–3 long hair-like setae at surface; palp 3-segmented; segment III ca. 0.8×length of segment I, conical, and with scattered hair-like setae; lingua and superlingua of hypopharynx ( Fig. 8 ) with hair-like setae on anterior margin; labium ( Fig. 9 ) with V-shaped glossae slightly narrower than paraglossae, with row of stout marginal setae; paraglossae with row of stout marginal setae and few stout setae on dorsal surface; labial palp 3-segmented; segment III truncate, with sparse stout setae and hair-like setae on dorsal surface.

Thorax: terga yellowish-brown; sterna white with dark brown markings near the base of legs. Legs ( Fig. 10 ): light yellow; femur with 2 rows of stout monopectinate setae on inner margin and without stout apical setae; outer margin of femur with few hair-like setae; tibiae light brown, with 2 rows of stout setae on inner margin; tarsi light brown, with scattered hair-like setae dorsally and 2 rows of stout setae on inner margin; claws ( Fig. 11 ) light brown, relatively long, ca. 0.37×length of tarsi, and with two rows of minute denticles progressively larger distally.

Abdomen: tergum I ( Fig. 20 ) light yellow with irregular brown markings; terga II, III and V ( Fig. 21 ) with single triangular dark brown spot medially and irregular brown markings laterally; terga IV, VII and VIII somewhat pale; tergum VI pale brown to dark brown, with single paired distinct oblique streaks; terga ( Fig. 16 ) with row of alternatively arranged long and small spines on posterior margin; tergum I with acute teeth on posterior margin ( Fig. 20 ); posterior margin of tergum X straight ( Fig. 19 ), with row of 11–13 acute spines; terga VIII and IX with ca. four and eight lateral spines respectively ( Fig. 18 ); sterna white with brown stripes laterally ( Fig. 17 ); sternum IX with dark brown stripe along lateral and anterior margins; paraprocts ( Fig. 15 ) with 7–9 acute spines on distal half; Gills ( Figs 12–14 ) pale brown with well-developed dark brown tracheae; gills I–VI bilamellate; dorsal lamella small; gill VII unilamellate. Caudal filaments: ca. 0.35×length of the body; ca. 1/2 basal part light yellow to brown and remaining distal part with dark brown bands; segments 4–6 narrow; paracercus with a row of long hair-like setae on inner and outer margins ( Fig. 22 ); cerci with a row of long hair-like setae on inner margin ( Fig. 23 ).

Male Imago ( Fig. 24 ): Body length (excluding cerci) 5.7–6.3 mm; cerci 11.7–12.1 mm; head width 0.8 mm; head length 0.5 mm; antenna 1ength 0.7 mm; compound eye length 0.4 mm; compound eye width 0.4 mm; distance between compound eye 0.0 mm; length of fore femur/ tibia/ tarsi 1.2/ 1.5/ 1.7 mm; length of middle femur/ tibia/ tarsi 1.1/ 0.8/ 0.8 mm; length of hind femur/ tibia/ tarsi 1.1/ 0.8/ 0.8 mm; forewing length 5.3 mm; forewing width 2.1 mm; hindwing length 0.8 mm; hindwing width 0.15 mm. General body coloration yellowish brown to pale yellow.

Head: vertex pale yellow with paired dark brown stripes medially; compound eyes turbinate; dorsal eyes pale brown; ventral eyes pale grey; ocelli pale yellow; scape and pedicel of antennae paler; flagellum pale grey.

Thorax: prothorax pale brown; mesothorax pale yellow, with single paired chestnut brown vertical stripes medially; sterna pale yellow ( Fig. 29 ). Legs ( Figs. 36–36 ): femur pale yellow, tibia and tarsi pale yellow to translucent; claws brown basally. Wings: forewings ( Fig. 30 ) transparent, membrane hyaline and veins darker; stigmatic area milky transparent with 8 cross-veins; longitudinal veins with single crossvein except areas of R and MA with two cross-veins, Sc with three cross-veins; hindwings ( Figs. 31 & 32 ) narrow and slender, approximately five times longer than wide, distal margin rounded, and with two longitudinal veins; apex of costal projection acute, located at 1/2 of distance from base to margin.

Abdomen ( Figs. 26–28 ): terga pale yellow to translucent; terga I–V and ½ of tergum VI translucent; terga II–X with a pale brown posterior marginal line; ½ of tergum VI and terga VII–X pale brown to pale yellow; sternal coloration as in tergum except posterior marginal line absent; pleural margins grayish in color. Genitalia ( Fig. 33 ): forceps pale yellow to translucent, 3-segmented; segment II ca. 3×length of segment I, segment III ca. 0.6×length of segment I; posterior margin of penal plate broadly round with sparse thin setae on the surface. Cerci pale yellow to translucent, ca. 2×length of body.

Female Imago ( Fig. 25 ): Body length (excluding cerci) 5.5–6.0 mm; cerci 13.0– 13.3 mm; head width 0.6 mm; head length 0.4 mm; antennae 1ength 0.9 mm; compound eye length 0.3 mm; compound eye width 0.25 mm; distance between compound eye 0.1 mm; length of fore femur/ tibia/ tarsi 1.1/ 0.8/ 0.8 mm; length of middle femur/ tibia/ tarsi 0.9/ 0.6/ 0.6 mm; length of hind femur/ tibia/ tarsi 0.9/ 0.6/ 0.6 mm; forewing length 5.3 mm; forewing width 2.1 mm; hindwing length 0.8 mm; hindwing width 0.15 mm. General body coloration yellowish brown to pale yellow.

Head: vertex pale yellow with paired dark brown stripes medially; compound eyes black; ocelli pale yellow; scape and pedicel of antennae paler; flagellum pale grey.

Thorax: prothorax pale brown; mesothorax pale yellow, with single paired chestnut brown vertical stripes medially; sterna pale yellow. Legs: coloration as in male imago. Wings: coloration and venation as in male imago.

Abdomen: terga pale yellow to translucent; terga I–VI pale yellow; terga II–X with a pale brown posterior marginal line; tergum VII paler; terga VIII–X pale brown to pale yellow; sternal coloration as in terga except posterior marginal line absent; pleural margins grayish in color. Cerci pale yellow to translucent, ca. 2.2×length of body.

Etymology. The new species P. (P.) kottagudiensis is named after the type locality, Kottagudi stream, Theni District, where the new species was collected.

Distribution. Cardamom Hills, Western Ghats, India.

Habitat. The larvae of Procloeon (P.) kottagudiensis sp. nov. were collected from the pool areas of slow-flowing permanent streams with abundant fallen leaves, marginal roots and macrophytes. Water and air temperatures of the collection site were 23.6 and 26.5ºC respectively (at the time of sampling). The current velocity was approximately 0.1–0.3 m /s. Water depth ranged 10–25 cm. The substratum was composed of mainly boulders, cobbles, pebbles and a significant level of sand and silt.

Figures

FIGURES 1–3. Procloeon (P.) kottagudiensis sp. nov., mature nymph. 1, dorsal view; 2, ventral view; 3, lateral view.

FIGURES 4–9. Procloeon (P.) kottagudiensis sp. nov., mature nymph. Dorsal view: 4, labrum; 5, right mandible; 6, left mandible; 7, maxillae; 8, hypopharynx; 9, labium.

FIGURES 10–15. Procloeon (P.) kottagudiensis sp. nov., mature nymph. Dorsal view: 10, foreleg; 11, tarsal claw; 12, gill I; 13, gill IV; 14, gill VII; 15, paraproct.

FIGURES 16–23. Procloeon (P.) kottagudiensis sp. nov., mature nymph: 16, abdomen (dorsal view); 17, abdomen (ventral view); 18, abdominal segments VIII & IX (dorsal view); 19, abdominal segment X (dorsal view); 20, abdominal tergum I; 21, abdominal tergum V; 22, paracercus, 23, cercus.

FIGURES 24–29. Procloeon (P.) kottagudiensis sp. nov., imago: 24, male imago (dorsal view); 25, female imago (dorsal view); 26, abdomen (dorsal view); 27, abdomen (ventral view); 28, abdomen (lateral view); 29, thoracic sternum.

FIGURES 30–36. Procloeon (P.) kottagudiensis sp. nov., male imago: 30, forewing; 31, hindwing; 32, hindwing enlarged; 33, male genitalia; 34, foreleg; 35, midleg; 36, hindleg.