Afronurus rainulfiana (Braasch, 1990)

Wongyam, Anuntaya, Sartori, Michel & Boonsoong, Boonsatien, 2023, Unravelling the diversity of the genus Afronurus Lestage, 1924 (Ephemeroptera, Heptageniidae) in Thailand, ZooKeys 1176, pp. 55-78 : 55

Afronurus rainulfiana (Braasch, 1990)

Figs 9A-E , 10A-E , 11A-C , 12A-C

Cinygmina rainulfiana Braasch, 1990: 8, figs 9-12, original description (male and female imago, nymph).

Afronurus rainulfiana - Boonsoong and Braasch 2013: 87.

Material examined.

3 nymphs, Thailand, Kanchanaburi Prov., Huai Kha Yeng , 14°36'20.98"N, 98°34'39.8"E, 937 m, 31.I.2019, W. Anuntaya leg. (ZMKU); 12 nymphs, Narathiwat Prov., Klong Aika Ding, 5°47'45.8988"N, 101°50'5.4996"E, 56 m, 22.IV.2018, W. Anuntaya leg. (ZMKU); 1 nymph, Phetchaburi Prov., Huai Mae Kamoei, 12°58'41.4984"N, 99°34'55.401"E, 119 m, 24.II.2019, W. Anuntaya leg. (ZMKU); 4 nymphs, Ranong Prov., Klong Phon Rang, 9°53'39.4002"N, 98°38'28.8996"E, 10 m, 20.IV.2018, B. Boonsoong leg. (ZMKU); 13 nymphs, Ratchaburi Prov., Bo Klueng, 13°31'27.3612"N, 99°14'39.3606"E, 180 m, 24.XI.2018, W. Anuntaya leg. (ZMKU) .

Description.

Nymph. See Braasch (1990: 8, figs 9-12, 18.1-18.3).

Adult. Female imago (in alcohol, Fig. 11 ). Head brown with black round eyes. Thorax. Mesonotum brown with pale mark at the middle area, anterior part with dark brown heart-shaped marks. Wings transparent; forewing base area of vein thick and dark brown, RS and MP forked basally, MA forked at the middle; hindwings asymmetrical, 1.6 × longer than width, RA and MA adjacent at basal of wing (Fig. 11C ). Abdomen. Dorsally brown marked with yellow, tergites II-V with single pair of circular sub-median marks and another pair of circular posterolateral marks; on tergite V the sub-median mark is fused to form a large square mark, tergites VI and VII with one pair of longitudinal marks each and tergite X pale on anterior part (Fig. 11A ); subgenital plate concave at tip; subanal plate extending as triangle-shaped projection and emarginate at tip (Fig. 11B ).

Egg.

Chorionic surface of egg with dense pKCTs on each pole and eKCTs (Fig. 12A ). Equatorial and subequatorial areas with eKCTs and micropyle beside eKCTs (Fig. 12C ); area between pKCTs and eKCTs with distinct small tubercles (Fig. 12B ), areas of two poles of pKTCs ~ 0.5 × that of the whole egg (Fig. 12A ).

Remarks.

Nymph of Afronurus rainulfiana is distinguishable from congeners by the combination of the following characteristics: anterior margin of head with four distinct pale spots (Fig. 9C ), lateral surface of the eyes with a large bright triangular spot, and area between eyes with two pairs of circular marks, each mark linked with one straight line. Abdomen tergites II-VII with two pairs of circular markings on sub-median and posterolateral areas (Fig. 9A ), pair on sub-median areas fused on tergite V, all markings combined in tergites VIII and IX, and tergite X brown without markings (Fig. 9B ). Sternites without markings (Fig. 9C ). Gill V (Fig. 10A ) and gill VI (Fig. 10B ) obliquely rounded, triangular, with apical projection, gill VII narrowly lanceolate (Fig. 10C ). Pattern of hind femur as shown in Figs 9E , 10D . Bristles on the dorsal face of the hind femur both blunt and pointed (Fig. 10E ). The imago can also be distinguished by the pattern on its abdomen (Fig. 11A ).

Habitat.

Afronurus rainulfiana was described only as a nymph by Braasch (1990) from Saraburi province and then subsequently by Boonsoong and Braasch (2013) in Mae Sot Distinct, Tak province. In this study, A. rainulfiana was found in 20 localities in six provinces. The nymphs attach to the undersides of the cobbles submerged in running water. We reported the female characteristics. The male adults of A. rainulfiana are still unknown.

Distribution.

Kanchanaburi, Narathiwat, Phetchaburi, Ranong, Saraburi and Tak provinces (Fig. 18 ).

Figures

Figure 9. Afronurus rainulfiana (Braasch, 1990), larval morphology A female habitus B tergites I-X D sternites III-X C head E hind leg. Scale bars: 1 mm.

Figure 10. Afronurus rainulfiana (Braasch, 1990), larval morphology A gill V B gill VI C gill VII D bristles on the dorsal face of the hind femur E enlargement of bristles on basal part. Scale bars: 1 mm (A-D); 0.25 mm (E).

Figure 11. Afronurus rainulfiana (Braasch, 1990), female imaginal morphology A tergites I-X B anal plate C fore wing and hind wing. Scale bars: 1 mm.

Figure 12. Afronurus rainulfiana (Braasch, 1990), SEMs of egg morphology A general outline of egg B chorion surface between polar KCT (pKCT) and equatorial KCT (eKCT) C micropyle (M) and enlargement of eKCTs. Scale bars: 50 μm (A); 10 μm (B); 10 μm (C).

Figure 18. Distribution map of the genus Afronurus in Thailand.