Bidessodes Regimbart , 1895

Miller, Kelly B., 2017, A review of the Neotropical genus Bidessodes Regimbart, 1895 including description of four new species (Coleoptera, Adephaga, Dytiscidae, Hydroporinae, Bidessini), ZooKeys 658, pp. 9-38 : 11-12

Bidessodes Regimbart, 1895

Bidessodes Régimbart, 1895:76; type species: Bidessodes elongatus Sharp, 1882b:25 by monotypy.

Bidessodes Régimbart, 1900:528; type species: Bidessodes semistriatus Régimbart, 1900:529 by subsequent designation of Young 1969:2; preoccupied by Régimbart 1895:76; Blackwelder 1944:76; Young 1967:82; 1969:2; 1986:219; Biström 1988:7; Nilsson 2016:98.

Bidessus (Bidessodes) , Zimmermann, 1919:61; 1921:200.

Hughbosdineus Spangler, 1981:65 syn. n.

Youngulus Spangler, 1981:69 syn. n.

Bidessodes (Hughbosdineus) , Young, 1986:206; Biström, 1988:7.

Bidessodes (Youngulus) , Young, 1986:207; Biström, 1988:7.

Diagnosis.

Bidessodes are characterized by the following features: (1) a transverse occipital line is absent (e.g. Fig. 1), (2) the anterior clypeal margin is unmodified (Fig. 1), (3) the basal pronotal striae are present (Fig. 1), (4) the basal elytral stria is absent (Fig. 1), (5) the elytral sutural stria is absent (Fig. 1), and (6) the transverse carina across the epipleuron at the humeral angle of the elytron is absent. The genus most similar in general appearance to Bidessodes in Bidessini is Neobidessodes Hendrich and Balke, 2009, a group of species from Australia previously placed in Bidessodes . The main difference between these genera is a series of very fine serrations or denticles along the posterior margins of the abdominal ventrites, present in Bidessodes and absent in Neobidessodes .

Comments.

The genera Hughbosdineus and Youngulus were proposed by Spangler (1981) and relegated to subgenera of Bidessodes by Young (1986). It seems clear, though, that the species were placed in their own genera based on unusual apomorphies rather than clear evidence of phylogenetic isolation. Although there has not been a phylogenetic analysis of the group, these two species appear to be well within the general character-based concept of Bidessodes . There is little justification for continued recognition of three subgenera in Bidessodes , so, Hughbosdineus Spangler, 1981 and Youngulus Spangler, 1981 are each placed as junior synonyms of Bidessodes Régimbart, 1895 (new synonymies).

Key to species of Bidessodes

The following key is modified from Young (1986) and Braga and Ferreira-Jr. (2009). Keys to Bidessodes have been historically based on male attributes. This key is similarly limited. Females of many species are extremely similar and cannot be easily distinguished without association with males. Much of the key requires dissection of male genitalia, and even with the key the best diagnostic method is to dissect male genitalia and compare with descriptions and images of them. Bidessodes fragilis is not keyed given ambiguity about its identity and character combination.