Potamanthus huoshanensis Wu, 1987

Li, Wen-Juan & Zhou, Chang-Fa, 2022, A detailed comparison of two species in the genus Potamanthus Pictet, 1843 from China (Ephemeroptera, Potamanthidae), ZooKeys 1125, pp. 193-205 : 193

publication ID	https://dx.doi.org/10.3897/zookeys.1125.89219
publication LSID	lsid:zoobank.org:pub:DF876772-5BBC-40E9-ACD0-AABD6D910471
persistent identifier	https://treatment.plazi.org/id/70800F60-A37D-58A5-B55A-20F3E9996412
treatment provided by	ZooKeys by Pensoft
scientific name	Potamanthus huoshanensis Wu, 1987
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Treatment

Potamanthus (Patamanthus) huoshanensis Wu, 1987b: 421. figs 1-5. Types: nymph, male and female, from Anhui, China.

Potamanthus (Patamanthus) huoshanensis : Bae and McCafferty 1991: 49. figs 15, 95, 113, 126, 139 (nymph, male and female); Ishiwata 2001: 58; Zhou 2013: 202; Zhou et al. 2015: 252.

Potamanthus huoshanensis : Wu et al. 1991: 111. fig. 2 (egg); You and Gui 1995: 116. fig. 123 (male and female).

Distribution.

China (Anhui Province); Japan (Yokkaichi city, Lake Biwa).

Description.

see Wu (1987b) and Bae and McCafferty (1991).

Diagnosis.

This species resembles Potamanthus luteus in the main characters of both the adults and the nymphs, which can be differentiated only by very fine structures (Table 1 View Table 1 ). In the nymph, the labrum of P. huoshanensis is slightly narrower than that of P. luteus (Fig. 3A, B View Figure 3 ); the mandibular tusks are indistinctly shorter than in P. luteus , and this can be seen in nymphal dorsal views (Figs 2A, B, E, F View Figure 2 , 3E-H View Figure 3 ); the maxillary palpi of both species are similar but different in their length ratio: the ratio in the former species is 1.0: 0.6: 1.0, whereas that of the latter species is 1.0: 0.7: 1.3 (Fig. 3I-L View Figure 3 ). The two species have a very similar hypopharynx and labia (Fig. 3C, D, M, N View Figure 3 ). Although the color pattern of examined P. huoshanensis has fainted and is pale, the leg lengths are different in the two species: ratio of forefemora: tibiae: tarsi = 1.0: 0.7: 0.6 in P. huoshanensis and 1.0: 0.8: 0.6 in P. luteus , the former having slightly shorter forelegs and tibiae (Fig. 2I, L View Figure 2 ). But the midlegs, hindlegs and their claws are very similar (Fig. 2D, H, J, K, M, N View Figure 2 ).

Males of the two species can be easily separated: (1) the pigments of the crossveins of the forewings of P. huoshanensis are almost invisible, but they are clear on the forewings of P. luteus (Figs 4A, C View Figure 4 , 5E, G View Figure 5 ); (2) the costal projection of the hindwings are slightly blunter in P. huoshanensis than in P. luteus (Fig. 5F, H View Figure 5 ); (3) the compound eyes of P. huoshanensis are almost contiguous but they are clearly separated in P. luteus (Fig. 5A, C View Figure 5 ); (4) both the lateral and inner extended lobes of the penis of P. huoshanensis are slightly smaller than those of P. luteus (Fig. 6C-E, H-J View Figure 6 ); (5) the penes of P. huoshanensis are slightly shorter than those of P. luteus : the subgenital plate of P. huoshanensis almost covers the base of the penial lobes but the penes of P. luteus are longer, with the whole penes completely visible in ventral view (Fig. 6A, B, F, G View Figure 6 ); (6) the subgenital plate of P. huoshanensis has a shallow median emargination, whereas that of P. luteus has a clear V-shaped cleft (Fig. 6A-D, F-I View Figure 6 ); (7) the forking point of the MA in the P. huoshanensis forewings is more distal than that of P. luteus , with the ratio of MA: MA1 = 1.0: 0.7 in the former species and 1.0: 0.9 in the latter (Fig. 5E, G View Figure 5 ); (8) the foretibiae of P. huoshanensis are shorter than in P. luteus , with the ratio forefemora: tibiae: tarsi = 1.0: 1.3: 1.6 in P. huoshanensis and 1.0: 1.6: 1.5 in P. luteus (Fig. 4A, C View Figure 4 ).

The females of the two species can differentiated by their wing color and the shape of the hindwings, like in the males (Fig. 4B, D View Figure 4 ). The compound eyes of female P. luteus are slightly smaller than those of P. huoshanensis (Fig. 5B, D View Figure 5 ), but the subgenital plates are very similar (Fig. 7 View Figure 7 ).

Although the color of the P. huoshanensis material is not clear, the original description of Wu (1987b) and our specimens clearly show that the males, females and nymphs of this species do not have dots on their abdominal terga. In contrast, all stages of P. luteus have a pair of dark dots on the abdominal terga (Fig. 4C-D View Figure 4 ). In addition, P. luteus has a longitudinal median reddish band on the abdomen (Fig. 4C-D View Figure 4 ).

The differences between the two species are listed in Table 1 View Table 1 .