Pachylaella Berlese, 1916 (Macrochelidae)

MAŠÁN, PETER & HALLIDAY, BRUCE, 2014, Review of the mite family Pachylaelapidae (Acari: Mesostigmata), Zootaxa 3776 (1), pp. 1-66 : 52

Genus Pachylaella Berlese, 1916 (Macrochelidae)

Pachylaella Berlese, 1916b: 152 . Type species Pachylaella robustissima Berlese, 1916 , by original designation.

Notes. The genus Pachylaella was proposed by Berlese (1916b) with Pachylaella robustissima as type species, and placed in the family Pachylaelapidae . There are four slides and seven adult specimens (three females, four males) of this species in the Berlese Acaroteca, viz. 182/9 (type) and 182/6–8, all from the dung beetle Atheucus sp. in La Plata, Argentina, but only one female specimen is in suitable condition for examination (on slide 182/6). Pachylaella robustissima does not appear to be a member of the family Pachylaelapidae . The sternal shield has three pairs of setae; there is a pair of small circular metasternal platelets separate from the sternal shield; the epigynal shield is tongue-shaped, not enlarged posteriorly, and bears only one pair of genital setae; the anal shield is subcircular, enlarged anteriorly, almost adjacent to the epigynal shield, and appears to have some ventral setae on its surface. Pachylaella could be classified in the family Macrochelidae rather than the Pachylaelapidae . The ventral idiosoma of P. robustissima resembles some species of Holostaspella Berlese, 1903 . In addition, the peritremes of P. robustissima are looped posteriorly, and join the stigma posteriorly, which is a specific character typical of most of the known macrochelid genera. Unfortunately, some important characters on the chelicerae were obscure and not visible in the available material.