Brachypoda Kramer, 1875

Smith, Ian M., Cook, David R. & Gerecke, Reinhard, 2015, Revision of the status of some genus-level water mite taxa in the families Pionidae Thor, 1900, Aturidae Thor, 1900, and Nudomideopsidae Smith, 1990 (Acari: Hydrachnidiae), Zootaxa 3919 (1), pp. 111-156 : 146-147

Genus Brachypoda Kramer, 1875

Brachypoda (Brachypoda) : Cook, 1974a, p. 339, figs. 1431, 1434, 1439. Brachypoda (Brachypoda) : Cook, 1975, pp. 279–281, figs. 1–7 Brachypoda: Smith, 1977 , p. 958, figs. 10–17.

Brachypoda: Wainstein, 1980 , pp. 213–215, figs. 758–765.

Brachypoda (Brachypoda) : Cook, 1981, p. 98, figs. 25, 26, 28, 29, 32. Brachypoda (in part): Smith & Cook, 1991, pp. 553, 577.

Brachypoda (in part): Smith et al., 2001, pp. 581, 614, fig. 162. Brachypoda (in part): Smith et al., 2010, pp. 523, 555, fig. 15.162.

Diagnosis. Larva (modified from Smith 1977b, 1984 and based upon larvae of B. cornipes Habeeb ): Character states of Brachypoda -like mites. Third coxal plate with medial coxal apodeme present and transverse muscle attachment scar present. Posterior edge of third coxal plate bearing prominent lobed projection. Excretory pore plate much larger than excretory pore and nearly triangular in shape, bearing setae ps1, ps2, and h2 posterolaterally with ps2 displaced anteriorly and medially. Numbers of setae on leg segments as follows: ITi 8 (seta Ti10 absent); ITa 11 (setae Ta8 and Ta14 absent); IITa 11 (setae Ta8 and Ta14 absent).

Adults (modified from Cook 1974a, 1975): Character states of Brachypoda -like mites. Dorsal shield of males with a slight bulge posterior to midlength bearing two enlarged glandularia with extremely long associated setae. Ventral shield of males bearing a pronounced ridge extending anterolaterally from genital field. Fourth coxal plate with opening for insertion of fourth leg bearing condyles; lacking a ridge extending posteriorly from region of insertion of fourth legs. Genital field bearing three pairs of acetabula; genital field of males located well anterior to posterior edge of ventral shield and relatively compact, with acetabula not extending laterally beyond level of insertion of fourth leg and without a patch of long setae immediately lateral to acetabula. Excretory pore borne on dorsal shield near posterior edge. Fourth leg of males with genu bearing a patch of spatulate setae distoventrally and a distal projection that extends well beyond level of insertion of tibia, tibia slightly bowed and bearing a row of swimming setae posteriorly, and tarsus slightly expanded distally and bearing modified claw socket with highly modified claws. Pedipalp femur bearing a distoventral projection and tibia bearing a thick seta on a ventral projection.

Type species. Brachypoda paradoxa Lebert = Brachypoda versicolor (Müller) .

Species included. Brachypoda versicolor (Müller) (Europe) , B. cornipes Habeeb (North America), B. ichikawai Imamura ( Japan) , B. japonensis (Tuzovskij) ( Japan) , B. nipponica Imamura ( Japan) , B. rossica Pešić & Semenchencko ( Russia) .

Distribution. Holarctic (North America, Eurasia).

Discussion. Cook (1974a, 1975, 1981) employed a broad concept of Brachypoda including four subgenera. This arrangement was followed by Smith (1977b, 1984), Smith & Cook (1991), Smith et al. (2001, 2010), and Pešić & Semenchenko (2014). We are here proposing a restricted concept of the genus Brachypoda including only species previously allocated to the nominate subgenus. The other three taxa previously regarded as subgenera of Brachypoda are here either elevated to full generic status or allocated as subgenera to another of the newly recognized full genera. We consider the name Eubrachypoda Tuzovskij, 2004 to be a synonym of Brachypoda (sensu stricto).

Wainstein (1980) described larvae of a species of Brachypoda identified as B. versicolor (Müller) . These larvae reportedly differ from those of B. cornipes Habeeb in that the third coxal plate lacks both a transverse muscle attachment scar and a prominent lobed projection on the posterior edge. In addition, the excretory pore plate, though nearly triangular and much larger than the excretory pore, bears only setae ps1 and ps2, with setae h2 located in soft integument posterolateral to the plate. Finally, the tibia of the first and second legs bears only 10, rather than 11, setae. These differences are numerous and substantial and if the larvae described by Wainstein can be confirmed to be those of B. versicolor then either the larval diagnosis for Brachypoda will have to be amended accordingly or consideration will have to be given to further revision of this genus.