Rhoenanthus (Rhoenanthus) distafurcus Bae & McCafferty, 1991

Kwanboon, Sedtawut, Sartori, Michel & Boonsoong, Boonsatien, 2021, Behningiidae and Potamanthidae (Insecta, Ephemeroptera) in Thailand, ZooKeys 1067, pp. 57-82 : 57

Rhoenanthus (Rhoenanthus) distafurcus Bae & McCafferty, 1991

Figures 10E , 11D , 14 , 15

Materials examined.

1 larva, Thailand, Kanchanaburi province, Sai Yok district, Pueng Wahn Resort , 14°12'08.9"N, 99°03'36.0"E, 15.X.2015, B. Boonsoong leg ; 2 larvae, Ratchaburi province, Suan Phueng district, Pha Chi river , 13°30'57.3"N, 99°20'40.1"E, 19.IX.2016, B. Boonsoong leg ; 1 larva, Nan province, Bo Kluea district, Sapan waterfall, 19°11'25.8"N, 101°11'56.3"E, 800 m, 28.XI.2020, B. Boonsoong leg.

Diagnosis.

The larvae of Rhoennanthus distafurcus can be distinguished from those of other Rhoenanthus (Rhoenanthus) species based on the following characteristics: i) subapical spine of the mandibular tusk well developed laterally (Fig. 10E ), with a simple, short spine, ii) 16-20 medial rounded setae on mandibular tusk (Fig. 10E ) iii) length of the mandibular tusks ca 1.7-1.9 × length of head, iv) length of foretibiae ca 1.19-1.25 × length of the forefemora and about 2.5-2.8 × length of the foretarsi, (v) leg with colour marking as in Fig. 11D, and vi ) lack of bipectinated setae on the mandible ( Soldan T and Putz M 2000).

Distribution.

Kanchanaburi, Ratchaburi, and Nan provinces.

Remark.

Bae and McCafferty (1991) described R. distafurcus based on imaginal specimens from Thailand, India, and Vietnam. The larva of R. distafurcus was described by Soldan T and Putz M (2000) based on specimens from Vietnam. In Thailand, a male adult of this species was found in Khao Yai National Park ( Bae and McCafferty 1991). In the present study, larval specimens of this species were found in western and northern Thailand.

Figures

Figure 10. Larval morphology (head and mandibular tusk) A Potamanthus formosus Eaton, 1892 B Rhoenanthus magnificus Ulmer, 1920 C R. obscurus Navas, 1922 D angle measurement of mandibular tusk E R. distafurcus Bae & McCafferty, 1991 F R. speciosus Eaton, 1881.

Figure 11. Larval morphology (foreleg) A Potamanthus formosus Eaton, 1892 B Rhoenanthus magnificus Ulmer, 1920 C R. obscurus Navas, 1922 D R. distafurcus Bae & McCafferty, 1991 E R. speciosus Eaton, 1881. Scale bar: 1 mm.

Figure 14. Distribution map of the family Potamanthidae in Thailand.

Figure 15. The COI phylogenetic construction based on the maximum likelihood (ML) analysis of family Potamanthidae in Thailand.