Manulea

Perkins, Philip D., 2011, New species (130) of the hyperdiverse aquatic beetle genus Hydraena Kugelann from Papua New Guinea, and a preliminary analysis of areas of endemism (Coleoptera: Hydraenidae) 2944, Zootaxa 2944 (1), pp. 1-417 : 26

Manulea group

Ten species are included in the Manulea group: H. manulea , H. manuloides , H. thumbelina , H. thumbelipes , H. phainops , H. sepikramuensis , H. decepta , H. intensa , H. trichotarsa , and H. mianminica ( Figs. 22–23 , 26–27 , 30– 31 , 34–35 , 38–39 ). Species placed in this group are small to moderately sized (ca. 1.25 to 1.97 mm), and have a very generalized habitus. The pronotum is usually light brown or testaceous in front of and behind the large piceous fascia (color band ratios varying from ca. 4/17/3 to 6/10/5); in one species ( H. phainops ) the pronotum is entirely piceous, and in one species ( H. decepta ) the pronotum has a macula. This is probably not a natural group, but reasons for transferring species to other groups are not readily apparent. However, one subgroup can be distinguished: the manulea subgroup ( H. manulea , H. manuloides , H. sepikramuensis ), in which the male genitalia are similar in general form and have the left paramere with two groups of setae ( Figs. 24–25, 28 ). In several species of the Manulea group the male protibia has a distinctive cluster of spines near the apex, mounted on a prominence (SEM Figs. 286–287 ), but not all species have this character. The metaventral plaques vary greatly in this 'group', again suggesting that perhaps it is not a natural grouping. The species with the most unusual plaques also have unusual male genitalia.

The female tergite X, gonocoxite, and spermatheca of H. manulea and H. phainops are illustrated ( Figs. 389, 390 ). The tergite X and gonocoxite of these two species are quite similar, whereas the spermathecae differ to a greater degree. More study, including DNA sequencing, is needed to determine if this group is composite.

Members of this group have been collected at a wide elevation range, 10–1800 m, with many intermediate elevation records (maps Figs. 439–442 , 444–449 ). The most widely collected species in the group, H. manulea , has an elevation range of 10–1800 m. Species in this group are typically found in gravel banks of streams and rivers.

Figures

FIGURE 22. Hydraena manulea, holotype, dorsal and lateral habitus, and venter.

FIGURE 23. Hydraena manuloides, holotype, dorsal and lateral habitus, and venter.

FIGURE 26. Hydraena sepikramuensis, holotype, dorsal and lateral habitus, and venter.

FIGURE 27. Hydraena thumbelina, holotype, dorsal and lateral habitus, and venter.

FIGURE 30. Hydraena thumbelipes, holotype, dorsal and lateral habitus, and venter.

FIGURE 31. Hydraena phainops, holotype, dorsal and lateral habitus, and venter.

FIGURE 34. Hydraena intensa, holotype, dorsal and lateral habitus, and venter.

FIGURE 35. Hydraena decepta, holotype, dorsal and lateral habitus, and venter.

FIGURE 38. Hydraena trichotarsa, holotype, dorsal and lateral habitus, and venter.

FIGURE 39. Hydraena mianminica, holotype, dorsal and lateral habitus, and venter.

FIGURES 28–29. Aedeagi of holotypes. 28. H. sepikramuensis. 29. H. thumbelina.

FIGURES 286–291. Scanning electron micrographs of H. thumbelipes.

FIGURES 388–391. Female tergite X, gonocoxite, and spermatheca of Hydraena species.

FIGURES 439–442. Geographical distributions of Hydraena species.

FIGURES 443–446. Geographical distributions of Hydraena species.

FIGURES 447–450. Geographical distributions of Hydraena species.