Hydroporus polaris Fall 1923
Hydroporus polaris Fall, 1923 Fall (1923: 92) described this species from two males and one female from Bernard Harbour (Nunavut, Canada, ca. 68.788 N 114.82 W; square 9 in Fig. 13). In the same work Fall (1923: 93) described Hydroporus subvirescens after specimens collected at Cape Collinson (Alask...
| Main Authors: | , , |
|---|---|
| Format: | Other/Unknown Material |
| Language: | unknown |
| Published: |
2012
|
| Subjects: | |
| Online Access: | https://zenodo.org/record/5914741 https://doi.org/10.5281/zenodo.5914741 |
| Summary: | Hydroporus polaris Fall, 1923 Fall (1923: 92) described this species from two males and one female from Bernard Harbour (Nunavut, Canada, ca. 68.788 N 114.82 W; square 9 in Fig. 13). In the same work Fall (1923: 93) described Hydroporus subvirescens after specimens collected at Cape Collinson (Alaska, USA, ca. 69.986 N 144.861 W; square 8 in Fig. 13). He provided for this taxon the following features: "with evident viridi-aeneous surface lustre" on the elytra and a "distinctly alutaceous and dull" upper surface. Additionally, he wrote: "Front tarsi of male moderately dilated, its anterior claw not appreciably different from the posterior." We have studied the male holotype and the female paratype of H. polaris as well as the male holotype of H. subvirescens (all in CNC). To our great surprise, the holotype of H. polaris has a "distinctly alutaceous and dull" upper surface with a well visible metallic sheen on the elytra (sic!), while the holotype of H. subvirescens has a shiny (although reticulate) surface and does not show any metallic sheen. In addition, both male holotypes have the anterior protarsal claws clearly strongly curved near the base and in the more distal part straight. While the appearance of the shape of the protarsal claws depends somewhat on their orientation and can be misinterpreted, this is not true of the reticulation and sheen of the dorsal surface. Thus, we must assume that either Fall himself or any person who dealt with these types after Fall has mixed up both holotypes by mistake. But we made yet another interesting observation: the dull appearance and the metallic sheen can be easily removed mechanically, for instance by means of a brush with hard hairs (tested in a very small area of the elytra). We agree with Larson et al. (2000: 348) who have synonymised H. subvirescens with H. polaris. One of the main differences between H. polaris and H. acutangulus is the reticulation which is present in males and females of the former on the entire upper and ventral surface, while only present ... |
|---|