Hydroporus simplex Gordon, 1981

Shaverdo, Helena V., 2006, Revision of the longiusculus-group of the genus Hydroporus Clairville, 1806 (Coleoptera: Dytiscidae), Zootaxa 1170 (1), pp. 27-56 : 54-55

Hydroporus simplex Gordon

Hydroporus simplex Gordon, 1981: 114 (orig. descr.); Larson et al. 2000: 379 (descr.); Nilsson 2001: 159 (cat.).

Type material

Hydroporus simplex : Holotype: ♂ " Pinecrest, Cal \ Tuolumne Co. \ 13–VII–1948 \ P.H. Arnaud ", " Holotype \ Hydroporus simplex \ Robert Gordon" [red], " California Academy \ of Sciences \ Type No. 9839" ( CAS) .

Type locality: USA, California, Tuolumne County, Pinecrest .

In Larson et al. (2000) H. simplex was recognized as a member of the subpubescens ­ group. According to the results of the present work, this group now includes only one species, H. subpubescens . This species is very similar to representatives of the nigellus ­ group, especially to H. tenebrosus ; therefore, distinguishing of the subpubescens ­group is found unnecessary. The subpubescens ­group is omitted, and H. subpubescens is transferred to the nigellus ­group. Nilsson (2001) placed H. simplex in the longiusculusgroup probably because of its slightly angulate metacoxal processes. As shown above, this character is variable in the representatives of the group and alone cannot support placing H. simplex in the longiusculus­ group. Based on my examination of this species I think that it is rather similar to species of the nigellus ­group, especially more similar to H. despectus , than to H. longiusculus and H. pervicinus . It shares with them a single puncture row on the anterior surface of the protibia, the non­produced posterolateral angles of the pronotum, and the median lobe of the aedeagus sinuate in lateral view. Therefore, it is suggested that H. simplex be placed in the nigellus ­group.