Epeorus (Epeorus) aculeatus Braasch, 1990

Boonsoong, Boonsatien & Braasch, Dietrich, 2013, Heptageniidae (Insecta, Ephemeroptera) of Thailand, ZooKeys 272, pp. 61-93 : 67

Epeorus (Epeorus) aculeatus Braasch, 1990 Fig. 1A

Epeorus aculeatus Braasch, 1990: 7-9, Figs 1-8. (orig.)

Epeorus (Epeorus) aculeatus Braasch, 1990 (comb.)

Larva.

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

Adult.

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

Eggs.

Unknown.

Distribution.

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

Diagnosis.

The larva of Epeorus aculeatus can 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.

Habitat and biology.

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.

Remarks.

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.