Labiobaetis numeratus ( Müller-Liebenau, 1984 ) Muller-Liebenau, 1984

Shi, Weifang & Tong, Xiaoli, 2014, The genus Labiobaetis (Ephemeroptera: Baetidae) in China, with description of a new species, Zootaxa 3815 (3), pp. 397-408 : 404-405

Labiobaetis numeratus ( Müller-Liebenau, 1984) n. comb.

( Figs. 24–27 )

Baetis numeratus: Müller-Liebenau, 1984: 268 ;

Labiobaetis numeratus: McCafferty & Waltz, 1995: 21 ; Pseudocloeon numeratum: Lugo-Ortiz et al, 1999 : 25

Specimens examined. China, Guangdong Province: 1 nymph on slide and 1 nymph, Wuhua County, Shuanghua Town, near Junying Hydropower Station (23.75°N, 115.85°E, alt. 241m), 14-xi-2011, coll. Shi Weifang; Hainan Province: 1 nymph on slide and 2 nymphs, Baisha County, Yinggeling National Nature Reserve, Daoyin (18.99°N, 109.58°E), 5-xii-2005, coll. Yao Haiyuan; 1 nymph on slide, Wanning City, Nanqiao Town, Taiyang River (18.68°N, 110.15°E), 23-iv-2011, coll. Shi Weifang.

Distribution. China (Guangdong, Hainan), Malaysia.

Remarks. L. numeratus (Müller-Liebenau) is closely similar to L. ordinatus (Müller-Liebenau & Hubbard) from Sri Lanka in mouthpart structure because both possess a quite distinctive characteristic within the Oriental species, i.e. having a distinct protuberance between incisor base and molar region on right mandible ( Fig. 24 ). However, the color pattern of pronotum and abdomen ( Fig. 25–27 ), the shape of posterior marginal spines on abdominal terga can be used for differentiating these two species. Similar protuberance on right mandible also exists in Australian genus Offadens Lugo-Ortiz & McCafferty (Lugo-Ortiz & McCafferty 1998) , however, it can be distinguished from Offadens by (1) the right mandible with robust prostheca, whereas in Offadens it is slender or forked ( Webb & Suter 2011); (2) terminal segment of maxillary palpus with a slightly concave near apex (vs. terminal segment without any concave or notch in Offadens ) and (3) femur with rudimentary villopore, in contrast to the villopore being entirely absent in Offadens which means it can not be considered to belong to the Baetis complex of genera ( Lugo-Ortiz & McCafferty 1998).

Figures

FIGURES 24 – 27. Labiobaetis numeratus (Müller-Liebenau) 24, right mandible; 25, pronotum; 26, color pattern of abdomen (left: sterna; right: terga); 27, habitus of male nymph.