Epeorus is widely distributed in the Holarctic, northern portion of the Neotropical, Palaearctic, and Oriental regions (Kluge 2004). In tropical Southeast Asia, species of this genus have been reported and described by Braasch (1990, 2011), Braasch and Boonsoong (2010), Braasch and Soldán (1979, 1984c), and Webb and McCafferty (2006). Nguyen and Bae (2004a) provided larval descriptions and a key to six species of Vietnamese Epeorus ; this was the first comprehensive taxonomic study of the larvae of Epeorus from tropical Southeast Asia. The first record of Epeorus in Thailand is of Epeorus aculeatus Braasch (1990) from Doi Inthanon National Park, Chiang Mai province. Recently, the first Thai imago of Epeorus aculeatus was described by Webb and McCafferty (2006) from Chiang Mai province. Originally, Epeorus unicornutus was recorded from Himalayas (Braasch 2006b) although it had been already collected in Thailand December 1987/1998 from the river Nam Lang, Soppong / Pangmapa, Mae Hong Son province (Braasch, unpublished). Currently, seven species of Epeorus are known from Thailand (Braasch and Boonsoong 2010).

Braasch and Boonsoong 2010: 13-17, Figs 53–68.

Unknown.

Egg chorion of Epeorus khayengensis very smooth without any peculiar structure (Fig. 5A), 2-3 micropyles visible in the equatorial area (Fig. 5B).

Huai Khayeng stream (Thong Pha Phum district, Kanchanaburi province).

The larva of Epeorus khayengensis (Fig. 9D) can be distinguished from that of othercongeners by abdominal terga 2–9 without long acute median spine on posterior margin, but bearing long hair-like setae.

The larva of Epeorus khayengensis inhabits tropical headwater streams approximately 210 m in alt. The streams range between 6–7 m in width and 10–11 cm in depth. The water temperature ranges between 22–25°C, pH between 6.35–7.15, total dissolved solids are between 27–34 mg/L, and conductivity is between 41–53 µS/cm. The larvae are found in eroded areas of streams where moderately flowing over cobble and sandy bottom.

Braasch and Boonsoong (2010) described this species from Thailand based on nymphal specimens, and deposited them in the Zoological Museum, Kasetsart University (ZMKU), Bangkok. The adults of Epeorus khayengensis are unknown.

Braasch 2006b: 80, 82, Figs 1–8.

Unknown.

Unknown.

Nam Thob Ranger Station, Phu Luang Wildlife Sanctuary, Nam Thob stream (Loei province).

The larva of Epeorus unicornutus can be distinguished from that of other congeners by the combination of the following characters: abdominal terga 2-9 each with single, prominent, acute median spine and with a row of short spines on posterior margin, tergum 10 with short spines and hair-like setae on posterior margin.

Larvae of Epeorus unicornutus are found in headwater streams shaded under tree canopies in mountainous areas (alt 330 m) where the streams are 10–12 m wide and 10–15 cm in depth. The water temperature ranges between 22–23°C, pH between 7.0–7.2, total dissolved solids range between 18–20 mg/L, and conductivity between 28–30 µS/cm. The larvae are found underneath stones in fast flowing reaches of the streams. The coarse mineral substrate consists of boulder (60%), cobble (30%), gravel and coarse sand (10%), and abundant fallen leaves. Epeorus unicornutus is found under minimally disturbed conditions of Nam Thob streams, Loei province.

Braasch (2006b) described this species based on larval specimens from River Indravati near Dalaghat 1, 200 m, Nepal, Himalayas. In this study, this species were found from northern and northeastern parts of Thailand. This species is different from other known species of the genus Epeorus by abdominal terga 2-9 each with single, prominent, and acute median spine.

Braasch and Soldán 1984c: 113–114, Figs 35–44; Nguyen and Bae 2004a: 102–104, Figs 1–6.

Unknown.

Unknown.

Khun Kon Waterfall (Chiang Rai province).

The larva of Epeorus martinus can be distinguished by the following characteristics: pairs of moderately long acute submedian spines on the abdominal terga 1-9, large but narrow gill 1 forming a sucking disc and gill 7 being unfolded.

Epeorus martinus larvae are found in mountain streams with a moderate current, at an elevation of 300–2800 m (Nguyen and Bae 2004a).

Webb and McCafferty (2008) did not recognize the subgenera of Epeorus (e.g. Belovius, Iron). However, we hold on the validity of subgenus Belovius and Iron within genus Epeorus (Boonsoong & Braasch, 2010). Therefore, we propose Iron martinus Braasch & Soldán, 1984 = Epeorus (Iron) martinus Braasch & Soldán, 1984

Braasch and Boonsoong (2010) have described new species sub nom. “Epeorus (Iron) longitibius Nguyen & Bae, 2004 (questionable)”: 20–22 (Figs 83–98). The deposition of the female larva is in ZMKU (80% alcohol).

Unknown.

Unknown.

Region of Doi Inthanon (Chiang Mai province); alt 2000 m, III 1999; bottom sample (leg. R. Braasch).

In contrast tothe larva of Epeorus longitibius with foretibiae 1.2 × length of forefemora, Epeorus thailandensis has foretibia of equal length; forefemur of new species is with a small femoral spot, Epeorus longitibius without such one; the gills 2-6 are quadrangular and gill 7 has a fold in Epeorus thailandensis, but in Epeorus longitibius gills 2-6 are elongated and gill 7 unfolded.

The larvae of Epeorus thailandensis live presumably in high mountain streams with high oxygen concentrations and a faster current where the substrate is mostly stony at an elevation of 2000 m.

Boonsoong and Braasch (2010) misidentified this species as Iron longitibius Nguyen & Bae, 2004 (questionable). In this study, we have re-checked them and found , then we re-identified it as a new species, Epeorus (Iron) thailandensis. The new species is different from the larva of Iron longitibius by characters within length of foretibia, femoral spot, and gill shape of gills 2–7. In this observation, we propose as the new species.

Braasch 1990: 7–9, Figs 1–8; Nguyen and Bae 2004a: 19–21, Figs 1–6.

Webb and McCafferty 2006: 65–68, M, Figs 1–5.

Unknown.

Mae Chaem district, Doi Inthanon NP (Chiang Mai province); Braasch (1990) recorded Epeorus aculeatus from Doi Inthanon National Park, Chiang Mai province.

The larva of Epeorus aculeatuscan be distinguished from that of othercongeners by abdominal terga 2-9 (Fig. 1A) each bearing a pair of long, acute, submedian spines on its posterior margin, and with a median dark brown spot on femoral surface.

The larva of Epeorus aculeatus occurs in headwater streams between 600–740 m alt in Thailand and high mountain streams between 1, 400-2, 800 m in Vietnam (Nguyen and Bae 2004a). The larvae are mostly found under rocks in fast flowing reaches of the streams. The substrate consists of mixed sand/gravel and larger stones such as boulders and cobble.

Braasch (1990) described this species based on larval specimens. Then, Webb and McCafferty (2006) described the male imago of Epeorus aculeatus based on reared Thai specimens from Doi Suthep NP, Chiangmai province. This species is different from other known species of the genus Epeorus by each bearing a pair of long, acute, submedian spines on its posterior margin.

Braasch and Soldán 1979: 266, 270, Figs 15–22; Nguyen and Bae 2004a: 21–22, Figs 7–12.

Unknown.

Unknown.

Tak province, highway 1090, km 64.5, mountain creek, riffle and run habitats; limy, gravel; leaf packs, wood, secondary forest; 750 m asl, c 16°30'N, 99°00'E; 14.1.2009 (leg. Freitag).

The larva of Epeorus bifurcatus can be distinguished from that of itscongeners by pairs of small submedian dorsal tubercles on tergites with acute spines and gill 1 larger than gill 3. In the Figs 7–8 of Nguyen and Bae (2004a) some characters (the femoral spot, the rim of hairs of the hind margin of head and pronotum) are not described. Furthermore, according to our material, the head of the type species is smoothly trapezoid without markings in anterior median half, however, the head is transversely ellipsoid with a broad dark band between its front and hind margins.

Nguyen and Bae (2004a) noted that the larva of Epeorus bifurcatus occur in mountain streams ranging between 200–600 m. They were found on the underside of stones in fast flowing sections of the streams.

Braasch and Soldán (1979) described this species based on larval specimens and original descriptions are written in Germany. Then, Nguyen and Bae (2004a) described the larva of Epeorus bifurcatus in English based on specimens from northern Vietnam, near the holotype locality.

Braasch and Boonsoong 2010: 17–19, Figs 69–82.

Unknown.

Unknown.

Doi Inthanon NP (Chiang Mai province).

This species resembles Epeorus bifurcatus however, the larva of Epeorus inthanonensis has paired tubercles on the terga which are more rounded than in Epeorus bifurcatus; they lack spines and gill 1 is smaller than gills 2–6.

Braasch and Boonsoong (2010) noted that the larva of Epeorus inthanonensis wasfound in small mountain streams ranging between 800–2000 m.

This species was described by Braasch and Boonsoong (2010). This species resembles Epeorus bifurcatus however, the larva has paired tubercles on the terga which are more rounded than in Epeorus bifurcatus.

The genus Rhithrogena is the most diverse in the Holarctic, with numerous species also in the Palaearctic Asia. However, it seems to be under-representedinSoutheast Asia. Braasch and Boonsoong (2009) described Rhithrogena siamensis Braasch & Boonsoong, 2009 from northern Thailand, this species also occurs in the northeastern and western parts of Thailand. Only two further species of the genus can be found in this area: Rhithrogena parva Ulmer, 1939 from Taiwan (Ulmer 1912) and Rhithrogena diehliana Braasch & Soldán, 1986 from Sumatra (Braasch and Soldán 1986c).

Braasch and Boonsoong 2009: 39–43, Figs 32–47.

Braasch and Boonsoong 2009: 38-39, M, Figs 19–30; F, Fig. 31.

Eggs. General shape ovoid. One of the poles terminates with large knob-terminated coiled threads (KCTs) (Fig. 5C), the whole chorion is covered with uniform granules and scattered with small loose KCTs, with a large micropyle on the equatorial plane (Fig. 5D).

Mae Hong Son province, Chiang Mai province, Chiang Rai province, Loei province.

The larva of Rhithrogena siamensis resembles Rhithrogena (Tumungula) unica Zhou & Peters, 2004 but differs in mouthparts structure and gill 1, with Rhithrogena siamensis being pointed-crenulate and having longer plica which are more bluntly rounded, whereas that of Rhithrogena (Tumungula) unica has a few angular crenulations and a shorter, more strongly rounded plica.

Rhithrogena siamensis larvae cling to rock surfaces in medium- to fast-flowing water. Collections over most of the year revealed that the flight season at altitudes of 600 m was mainly during March/April, just before the beginning of the monsoon rains in May.

Only one species of Rhithrogena was identified in our study as being distributed thoughout Thailand. They live in a rapid current of stream.

The Southeast Asian genus Trichogenia was established by Braasch and Soldán (1988) from Vietnam. Four species of Trichogenia are present in the Oriental region (Webb et al. 2006). Onlyone species, so far, is found in northern and northeastern Thai streams.

Braasch and Soldán 1988: 119-124, Figs 1–13.

Unknown.

Unknown.

Doi Suthep, Chiang Mai province; Loei province; Soppong, Mae Hong Son province.

Trichogenia maxillaris can be differentiated from congeners by the following combination of characteristics: gill lamellae 2–7, long, narrow and sharply pointed; base of outer canines of mandibles without dense lateral brush of setae; supracoxal sclerites short. The other Trichogenia species have gill lamellae 5-7 rounded with a pointed apex, base of outer canines of mandibles with dense lateral brush of setae, and supracoxal sclerites long and pointed.

Trichogenia maxillaris larvae occur in small mountain streams. To date, only a few Trichogenia specimens have been collected in Thai streams. This species appears to be a sensitive indicator because larvae were found exclusively in forest stream areas.

Only one species of Trichogenia (Trichogenia maxillaries) was reported from Thailand. The larva of this species was described by Braasch and Soldán (1988). The adults are unknown.

Three species of Notacanthurus are described from the Himalayas (Braasch 1980, 1986). The Thai species Notacanthurus baei Braasch & Boonsoong, 2009was collected and described from the northern part of country.

Braasch and Boonsoong 2009: 34–38, Figs 1–18.

Unknown. Its prospective penis (Fig. 14, Braasch 1986) is quite unlike the bilobed penes of the Himalayan Notocanthurus (Figs 4-8, Braasch 1986).

Chorionic pattern of geometrically arranged small KCTs covering the entire egg surface (Fig. 6A) and interspersed among crenulated granules, folded surface of the chorion, many microgranules densely scattered all over the surface of the chorion, large micropyles on equatorial plane (Fig. 6B).

Mae Hong Son province, Mae Chaem district, Doi Inthanon NP, Doi Suthep NP (Chiang Mai province)

Larvae of Notacanthurus baei are easily identified by having a dorsal median abdominal ridge on tergites 1-9 and denticles on the claws. Larvae of the Indian species Notocanthurus edentatus Braasch, 1986 have no dorsal ridges on the abdomen (Braasch 1986); however, all Himalayan species of Notacanthurus key out by the absence of denticles on the claws. Its prospective penis (Fig. 14, Braasch 1986) is quite unlike the bilobed penes of the Himalayan Nothacanthurus (Figs 4–8, Braasch 1986)” and is expected to be a simple, not bilobed, penis in the male imago.

Nothacanthurus baei larvae inhabit small streams and brooks. Larvae were usually found together with those of Asionurus species.

Braasch and Boonsoong (2009) described only one species of Nothacanthurus from Thailand. The adults of Nothacanthurus baei are unknown.

Thalerosphyrus occurs from China through Southeast Asia to India. This genus is originally described from tropical Southeast Asia. Thalerosphyrus sinuosus Navás, 1933seems to be widely distributed in Thailand and adjacent countries (Nguyen and Bae 2004b). Larvae of Thalerosphyrus are usually the dominant heptageniids in Thai streams as well as those of Afronurus.

Braasch and Soldán 1984b: 203–205 (sub name Thalerosphyrus siamensis Dang, 1967, Figs 5–20v, 26)

Navás 1933: 70, F, fig. 80; Ulmer 1939: 551–555, M&F, Figs 118–128; Braasch and Soldán 1984b: 201–206, Figs 1–8, M, 25.

KCTs randomly scattered laterally and concentrated at both poles, although larger and numerous at the pole (Fig. 6C). Rounded tubercles are scattered all over the surface of the chorion (Fig. 6D). Five – six micropyles located on equatorial plane.

Widely distributed in many parts of Thai streams.

The combination of having a distinctly thickened anterior margin of the head capsule, long posterolateral spines on the abdomen, acutely pointed supracoxal spurs, and well-developed lamellae on gills 1 will distinguish Thalerosphyrus from other Ecdyonurinae genera. Within Thalerosphyrus is a ‘sinuosus’ group of species with larvae having the above-mentioned combination, having in both sexes of adults “costal and subcostal fields with two indistict umbra-brown spots, the first at the beginning of pterostigmatic region, the second directly to the wing tip” (Navás 1933) and a ‘determinatus’ group, having larvae with short posterolateral spines; however, both sexes of adults have umbra-brown tinged costal and subcostal fields on forewings. In general, the species differentiation in the genus (Thalerosphyrus ‘sinuosus’ group) is unsatisfying and requires verification. The larva of Thalerosphyrus sinuosus can be differentiated by the combination of the following characters: gill 3 of rounded shape is much less wide than that of Thalerosphyrus vietnamensis (Dang, 1967) and while in Thalerosphyrus flowersi (Venkataraman and Sivaramakrishnan 1987) the inner side of gill 1 has a straight margin, that of Thalerosphyrus vietnamensis (=Thalerosphyrus sinuosus?) is slightly concave.

Thalerosphyrus sinuosus larvae (Fig. 9F) are one of the most widespread mayfly species in Thailand. The larvae are found underneath stones in slow-flowing reaches of streams (water velocity approximately 3-7 cm/sec, water depth ranges between 7–17 cm). The larvae cling to submerged boulders and cobbles. Because they feed by grazing on diatoms, algae and detritus on stream rocks, they prefer rocky substrates in fairly clear to silty sediments.

Only one species of Thalerosphyrus (Thalerosphyrus sinuosus) was identified from Thailand and this species widely distributed in Thai streams. The larva and adults of this species were adequately described by Braasch and Soldán (1984b) and Navás (1933).

The heptageniid mayfly genus Compsoneuria was reviewed by Webb et al. (2006). Eleven species were revised from Afro-tropical and Oriental regions. Compsoneuria larvae were found abundantly in lowland rivers on mainland Southeast Asia. There are three species of Compsoneuria mayflies reported from Thailand (Braasch 1990; Braasch 2006a; Braasch and Boonsoong 2010). Compsoneuria larvae occur among submerged vascular plants or roots.

Ulmer 1939: 672, Figs 440–448, 449–454; Braasch and Soldán 1986b: 42–46, Figs 14.1–14.14.

Ulmer 1939: 564, M, Figs 145–149, 152; F, 151; Fs, 150; Braasch and Soldán 1986b: 42–44, M, Figs 5-9.

Chorionic surface characterized by granular matrix, large KCTs randomly scattered on entire egg surface (Fig. 7A), small micropyles visible on equatorial plane (Fig. 7B).

Mae Hong Son province, Chiang Mai province, Trat province.

Compsoneuria thienemanni is recognised by having gills 2-6 without emarginations and gill 7 leaf-like and pointed apically; pale dots and marks on abdomen as shown in Fig. 3I.

Compsoneuria thienemanni larvae (Fig. 9C) are found abundantly in the large rivers at lower altitudes where it is encountered clinging to floating submerged water plants. A few male specimens of Compsoneuria thienemanni were found in the mountainous region of Mae Hong Son province.

The larva and adults of this species were described by Ulmer (1939) and Braasch and Soldán (1986b). The larvae of this species are found abundantly in the low-gradient streams and large rivers in Thailand.

Braasch and Boonsoong 2010: 9–11, Figs 31–45.

Adult. Braasch and Boonsoong 2010: 7–9, M, Figs 19, 21–25, 27–30; F, Figs 20, 26.

Unknown.

Nam Lang River, Soppong (Mae Hong Son province).

Larva without emarginations on gills 2–6, gill 7 lanceolate and rounded apically, pale dots and marks on abdomen as on Fig. 3K.

Both Compsoneuria thienemanni and Compsoneuria langensis larvaeare mainly found attached to floating water plants or thick pads of green algae.

Braasch and Boonsoong (2010) described this species from Thailand based on larval and imaginal specimens. The larva of this species is different from other known species by gills 2–6 without emarginations, gill 7 lanceolate and rounded apically.

A brief comment on the appropriate placement of Compsoneuria (Siamoneuria) kovaci in Braasch and Boonsoong (2010) is required. Larval diagnosis of Compsoneuria(Siamoneuria) is in contradiction to that of Compsoneuria, namely in lacking the combination of long, sharply pointed supracoxal spurs, black spotting on the head capsule and femora, and narrow, apically pointed glossae. Siamoneuria cannot belong in the genus Compsoneuria but probably deserves its own status; it appears to be a morphospecies whose characters are not in accordance with other known genera. For a final definition, important missing details of mouthparts and eggs should be included. For now, we see it as a species as "INCERTAE SEDIS" (Braasch and Boonsoong 2010). So, further studies and more specimens are needed to clear taxonomic of this species.

Larva. Braasch 2006a: 50–51, Figs 9–21.

Braasch 2006a: 49–51, M, Figs 1–8.

Unknown.

Nam Lang river, Soppong, Mae Hong Son province,

Larva is conspicuous due to emarginations on gills 2–6, gill 7 being narrowly lanceolate, the head without markings, and the body with paired paramedian spots on tergites 5–8, large median spot on 9, and three distantly arranged small spots at anterior margin of tergite 10.

The habitat of the single larva found was submerged roots of a tree standing at the river bank.

Three species of Asionurus mayflies have been reported from the Oriental region (Braasch 2011; Braasch and Soldán 1986a; Braasch and Soldán 1986b). Only Asionurus primus Braasch & Soldán, 1986 was collected and reported from northern Thailand. The identity of Vietnamese specimens of Asionurus primus (Braasch and Soldán 1986a) with those of northern Thailand (Sangpradub et al. 2002) is probable but needs confirmation by reared males from Vietnam.

Braasch and Soldán 1986a: 155–158, Figs 1–13.

Braasch and Boonsoong 2010: 5–7, M, Figs 14–17; F, Fig. 18.

General shape ovoid, both poles with large KCTs densely arranged (Fig. 7C), many microgranules densely scattered all over the surface of the chorion, macrogranules on equatorial plane (Fig. 7D), border well-defined by a thickened rim beset with tubercles, 5–6 micropyles on equatorial plane.

Chaiyaphum province, Mae Hong Son province, Chiang Mai province.

Asionurus primus differs from Asionurus ulmeri (Braasch and Soldán 1986a) by shorter and more pointed wings of hypopharynx and gill 7 with bulging anterior portion and acutely shaped apically. In Asionurus ulmeri the wings of hypopharynx are longer and have rounded ends whereas gill 7 is narrow and long and hardly extended anterioriorly.

Asionurus primus larvae (Fig. 9B) are often the most abundant in small mountain streams of Thailand. Larvae live beneath rocks and debris. They were found together mostly with those of Notacanthurus baei. Larval habitat preference is similar to that of larvae of Notacanthurus baei.

Only one species of Asionurus (Asionurus primus) was identified from Thailand. The larva and adults of this species was described by Braasch and Soldán (1986a) and Braasch and Boonsoong (2010). The larva of this species found in small mountain streams of Thailand.

Genus Rhithrogeniella is unique in having scaled caudal filaments with special arrangements of stout bristles and finer setae in the proximal portion; distal portion segments bear longer, stiffer setae and at articulations short bristles alternate with fine setae. These characters are similarly expressed in several Nixe spp. from Taiwan (Kang and Yang 1994). In view of the similarity in egg structure Rhithrogeniella is recently often identified as Nixe Flowers, 1980. However, Ulmer(1939) published Rhithrogeniella ornata from Sundaland which clearly has priority over Nixe Flowers, 1980.

Ulmer 1939: 575–576, M, Figs 165–166, 169; Ms, fig. 170, 173–174; F, Figs 171–172; Fs, Figs 167–168.

Soldán and Braasch 1986: 203–210, Figs 1–18.

Soldán and Braasch 1986: 203 (F), 206, 210 (Ms, Figs 19–22); Braasch 1990: 11–12, M, Figs 17.1–17.4.

Egg ovoid, chorionic surface with mesh-like reticular ridges of a hexagonal structure, evenly covered with KCTs (Fig. 8A), micropyle slightly oval with inconspicuous marginal rim, 1–2 small micropyles visible on the equatorial area (Fig. 8B).

Chiang Mai province, Chaiyaphum province.

The larvae of Rhithrogena tonkinensis can be distinguished from those of other genera of Heptageniidae by the following combination of characters: the head is approximately as broad as the pronotum, without a median emargination and marginal bristles and by the presence of interfacing setae on the caudal filaments (Soldán and Braasch 1986). The latter are provided at rings with rather stout spines regularly alternating with fine setae. Segments of filaments are “scaled”. Larvae of the other Southeast Asian species Rhithrogeniella ornata Ulmer, 1939 are unknown.

Larvae of Rhithrogena tonkinensis (Fig. 9E) occur in relative deep waters (30-40 cm) with slow currents and smaller stones or coarse sand on the bottom. Larvae are good swimmers, but prefer to remain attached to the stone surface rather than swimming (Soldán and Braasch 1986).

The larva and adults of Rhithrogena tonkinensis were adequately described by Soldán and Braasch (1986). Only Rhithrogena tonkinensis found in relative deep waters with slow currents of Thai streams.

The synonymization of Cinygmina with Afronurus is recognized by Wang and McCafferty (2004), Kluge (2004), and Braasch and Freitag (2008). The genus Afronurus includes at least 43 species from the Oriental region (Braasch 1987, 1990, 2005, 2011; Braasch and Boonsoong 2010, Braasch and Soldán 1984a, 1987, Flowers and Pescador 1984, Braasch and Jacobus 2011, Kang and Yang 1994, Kimmins 1937, Nguyen and Bae 2003, Venkataraman and Sivaramakrishnan 1989, Zhou and Zheng 2003). It indicates the complicated situation in determining species of Afronurus in the Oriental; in Southeast Asia many species are known only by larvae, or described as adults with affiliation of larvae from the same locality; the rearing of species and genetic investigations will be the aim of a future research. Afronurus larvae are usually the dominant heptageniid benthic macro-invertebrates in Thai streams. In this study, we propose five described species of the genus Cinygmina Kimmins, 1937 = Afronurus Lestage, 1924.

Braasch and Soldán 1984a: 196–197, 199, Figs 17–31, Vietnam; no record in Thailand.

Braasch and Soldán 1984a: Vietnam; 196–197, 199, M, Figs 14–16; Braasch 1990: 8, Fs & Ms, Thailand.

Unknown.

Ban Nam Tok (Chiang Rai province).

Braasch (1990) reported this species based on male, female and subimago male and female specimens, and the head of a presumed larva of Afronurus cervina without markings; gill 1 somewhat upturned, narrowly banana-shaped (Figs 17–18, Braasch and Soldán 1984).

This species is found to be an inhabitant of fast flowing rivers in Vietnam.

The larva and adults of Afronurus cervina were described by Braasch and Soldán (1984a). Only adults of Afronurus cervina found in Thailand. But, the larva of this species is not found in Thai streams.

Braasch and Soldán 1987: Vietnam; 125, Figs 7.1–7.4.

Braasch and Soldán 1987: 123, 125, 126, M, Figs 8.1–8.3; Braasch 1990: 8 (reported 2 M and 1 F from Thailand).

Unknown.

Nam Tok Ban Du (Chiang Rai province).

Head with blurred spots at forward margin; gill 1 up-turned banana-shape, 3 smoothly triangular gills with obliquely attached projection.

The larvae of Afronurus dama were found in streams of Tam Dao, Song Dan, Vinh Puh province, Vietnam.

Only adults of Afronurus dama were reported from Thailand (Braasch 1990). The larva and adults of Afronurus dama were described by Braasch and Soldán (1987).

Braasch 1990: 8, 10, Figs 13.1–13.4, 14–16.

Unknown.

Unknown.

Mae Sot district (Tak province).

The larva of Afronurus gilliesiana can be distinguished from congeners by the combination of the following characters: head with indistinct spots; gill 1 broadly lanceolate (Fig. 13.1, Braasch 1990); gill 3 widely rounded triangular (Fig. 13.2, Braasch 1990), gill 5 obliquely rounded triangular with small projection (Fig. 13.3, Braasch 1990), and broad asymmetrically oval gill 7 (Fig. 13.4, Braasch 1990).

The larvae of Afronurus gilliesiana were found in headwater streams in northern Thailand.

Only larva of Afronurus gilliesiana was reported from northern part of Thailand (Braasch 1990). The larva of Afronurus gilliesiana were described by Braasch (1990). The adults of Afronurus gilliesiana are unknown.

Braasch and Boonsoong 2010: 1–3, Figs 6–13.

Braasch and Boonsoong 2010: 2–3, M, Figs 1–4; F, fig. 5.

The egg chorion of Afronurus namnaoensis is decorated with granules and two kinds of KCTs: small KCTs concentrated at each pole and much larger oval KCTs located equatorially (Fig. 8C); micropyles have an ovoid to round sperm guide (Fig. 8D), visible in the equatorial area. The micropyle is interposed between adjacent equatorial KCTs.

Phromlaeng stream (Chaiyaphum province); Yakraue stream (Petchabun province); Nam Lang river, Pangmapa/Soppong (Mae Hong Son province); Chiang Mai province.

Male of Afronurus namnaoensis is separated from Vietnamese Afronurus cervina in lacking a median penial cone, by the less deeply notched lobal apex, and titillators curved laterally and in their more medial position. Vietnamese Afronurus dama presents a terminal apex of the penis slightly notched at the inner angles, whereas Afronurus namnaoensis is recognized by somewhat elevated corners on both sides of the apices. Larvae are recognizable by an unmarked forehead, pointed and weakly curved gill 1 and smoothly rounded triangular gill 5 with crosswise projection. Two Vietnamese species, Afronurus meo and Afronurus mnong (Nguyen & Bae, 2003) have gills lacking these projections (Figs 8–10, Figs 18–20, Nguyen and Bae 2003).

Larvae of Afronurus namnaoensis (Fig. 9A) are probably the most abundant species on rocks and stones in Nam Lang River and elsewhere in current waters of northern and northeastern Thailand. These mayflies are an important food source for headwater stream fishes (Cyclocheilichthys apogon, Devario regina, Opsarius pulchellus, and Rasbora rasbora).

Braasch and Boonsoong (2010) described this species from Thailand based on nymphal and imaginal specimens, and deposited them in the ZMKU, Bangkok. The larvae of Afronurus namnaoensis are the most abundant species in current waters of Thai streams.

Braasch 1990: 8, 10, 11, Figs 9–12, Figs 18.1–18.3.

Unknown.

Unknown.

Mae Sot district (Tak province).

The larvae of Afronurus rainulfiana can be distinguished from congeners by the combination of the following characters: head with a distinct pattern of light spots (Fig. 9), a broad banana-shaped gill 1 (Fig. 18.1, Braasch 1990), asymmetrically oval gill 6 with sloping finger-like projection (Fig. 18.2, Braasch 1990) and gill 7 narrowly lanceolate (Fig. 18.3, Braasch 1990).

The larvae of Afronurus rainulfiana were found in headwater streams.

Only larva of Afronurus rainulfiana was reported from northern part of Thailand and was described by Braasch (1990). The adults of Afronurus rainulfiana are unknown.

Wu et al. 1986: 67, Figs 1–10; Zhou and Zheng 2003: 757, Figs 7–10.

You et al. 1981: 4, M & F, Figs 1–13; Zhou and Zheng 2003: 758, Fig. 17.

Unknown.

Ban Nam Tok (Chiang Rai province); Nam Lang river, Soppong, Mae Hong Son province.

This species is unique in the genus because of its abdominal pigmentation: terga pale yellow medially and reddish laterally. The male genitalia have an obvious projection between the two lobes. The larvae of this species are larger and have more pale dots and marks on head and body than those of the other known species (Figs 7, 9, 10, Zhou and Zheng 2003), gill 5 or 6 are provided with a small, thin projection (Fig. 8).

Larvae of Afronurus rubromaculata were the only representatives of Afronurus encountered in the large river Mekong in February 2002 along the Thai-Laos border in the utmost north of Thailand. It is regularly found as a resident together with the dominant Afronurus namnaoensis on stones and rocks in Nam Lang River, altitude 600 m (Braasch 2006). This species is also found in Vietnam.

The larva and adults of Afronurus rubromaculata were adequately described by You et al. (1981), Wu et al. (1986) and Zhou and Zheng (2003). Only larva of Afronurus rubromaculata was reported in Thailand (Braasch and Boonsoong 2010).