Carabdytes Balke, Hendrich & Wewalka, 1992

Balke, Michael, Hájek, Jiří & Hendrich, Lars, 2017, Generic reclassification of species formerly included in Rhantus Dejean (Coleoptera, Dytiscidae, Colymbetinae), Zootaxa 4258 (1), pp. 91-100 : 93

Carabdytes Balke, Hendrich & Wewalka, 1992

Carabdytes Balke, Hendrich & Wewalka, 1992: 94 ; type species: Carabdytes upin Balke, Hendrich & Wewalka, 1992 by original designation.

Diagnosis. Medium sized to large (10–16 mm) species. Medial labral emargination deep. Sides of pronotum mostly broadly and distinctly bordered; posterior pronotal angles weakly obtuse. Elytral reticulation usually simple, consisting of fine isodiametric cells but without larger polygonal meshes; double elytral reticulation developed in the New Caledonian C. alutaceus (Fauvel, 1883) n. comb.; in C. guadalcanalensis ( Balke, 1998) n. comb. reticulation composed of large polygonal meshes. Setae on parameres apically acute, not modified to trumpet-shaped “suction” setae ( Balke 1990).

Position. Sister group of Meridiorhantus n. gen. as described below ( Fig. 1 ).

Species composition. Altogether 10 species occurring on Pacific Islands one of which has two subspecies:

Carabdytes alutaceus (Fauvel, 1883) n. comb., New Caledonia.

Carabdytes guadalcanalensis ( Balke, 1998) n. comb., Solomon Islands: Guadalcanal ( Fig. 2 B).

Carabdytes monteithi ( Balke, Wewalka, Alarie & Ribera, 2007) n. comb., New Caledonia.

Carabdytes novaecaledoniae (J. Balfour-Browne, 1944) n. comb., New Caledonia ( Fig. 2 C).

Carabdytes oceanicus ( Balke, 1993b) n. comb., Hawaii.

Carabdytes pacificus (Boisduval, 1835) n. comb., Hawaii.

Notes: This species and the former were not included in Morinière et al. (2016). They are morphologically however very similar to C. pseudopacificus ( Balke 1993b) which leads us to conclude that they belong to this clade as well.

Carabdytes plantaris (Sharp, 1882) n. comb., New Zealand ( Fig. 2 D).

Notes: This species was not included in Moriniere et al. (2016). Subsequently we obtained DNA sequence data of one specimen and placed it in this clade (M. Balke et al., unpublished data).

Carabdytes poellerbauerae ( Balke, Wewalka, Alarie & Ribera, 2007) n. comb., New Caledonia.

Carabdytes pseudopacificus ( Balke, 1993b) n. comb., Hawaii.

Carabdytes upin Balke, Hendrich & Wewalka, 1992

C. upin tindige Skale, Tänzler, Hendrich & Balke, 2012 , Indonesia: West Papua . C. upin upin Balke, Hendrich & Wewalka, 1992 , Indonesia: Papua ; Papua New Guinea ( Fig. 3A ).

Figures

FIGURE 1. Phylogenetic reconstruction of Colymbetinae relationships using different methods of phylogenetic inference (Bayesian, Maximum Likelihood, Parsimony, figure modified from Morinière et al. 2016 which contains more details on analytical procedures); node support for major backbone nodes indicated with asterisks: black meaning strong support, lighter shades of grey referring to increasingly weaker support. Distribution is coded in colour and ancestral areas were inferred using the software package BioGeoBEARS (details in Morinière et al. 2016). Notes: " R. signatus JFern. " refers to a specimen from Juan Fernandez Archipelago (originally described as R. kuscheli Guignot, 1952).

FIGURE 2. A) Caperhantus cicurius (Fabricius, 1787), 16 mm, Republic of South Africa; B) Carabdytes guadalcanalensis (Balke, 1998), 10.5 mm, Solomon Islands; C) Carabdytes novaecaledoniae (J. Balfour-Browne, 1944), 13 mm, New Caledonia; D) Carabdytes plantaris (Sharp, 1882), 10 mm, New Zealand.

FIGURE 3. A) Carabdytes upin upin (Balke, Hendrich & Wewalka, 1992), 12 mm, Papua New Guinea; B) Meridiorhantus antarcticus (Germain, 1854), 14 mm, Chile; C) Meridiorhantus calidus (Fabricius, 1792), 13 mm, Chile; D) Meridiorhantus validus (Sharp, 1882), 13 mm, Chile.