Iphidonopsis -Zerconopsis (Lindquist and Evans, 1965)

Makarova, Olga L., Marchenko, Irina I. & Lindquist, Evert E., 2021, Distribution, habitats, and redescription of the rare mite species Iphidonopsis sculptus Gwiazdowicz, 2004 (Mesostigmata: Ascidae), Zootaxa 4952 (3), pp. 448-464 : 462

Iphidonopsis -Zerconopsis relations

Members of Iphidonopsis much resemble those of Zerconopsis species but in contrast to the latter lack in particular paddle-formed setae on the dorsal shield and females have an anal (not ventrianal) shield, bearing only the three circumanal setae. Based on out-group comparisons with other genera of Arctoseiinae , both of these characteristics may be considered as initial, plesiomorphic conditions. Nevertheless, the genus Iphidonopsis seems to be an advanced derivate of Zerconopsis (probably of the mycophilous michaeli -group) in secondarily losing the paddleshaped form of certain dorsal setae as well as reducing the size of the ventrianal shield, leaving opisthogastric setae on soft cuticle. Both of these tendencies are already found among species of Zerconopsis . Thus, Z. apodius Karg, 1969 has only one pair of paddle-like dorsal setae (Z 5) “remaining” from eight pairs that are possible among other genus members (eight pairs of such modified dorsal setae were revealed in a new undescribed Zerconopsis species from North America and Europe). Moreover, another new species of Zerconopsis from California has only one pair of opisthogastric setae on the ventrianal shield while other members bear two to six pairs of setae in addition to the circumanal setae. Similar to species of the michaeli -group of Zerconopsis , adults of Iphidonopsis have a rigid and expansive dorsal shield with extremely complex ornamental structure, relatively reduced and anteriorly rounded female ventrianal/ anal shield, and legs I–II reinforced by tuberculate setal sockets. As advanced features of Iphidonopsis within Zerconopsis , we consider the simplification of paddle-shaped dorsal setae, diminution of the ventrianal shield to a broad anal shield in female, and presence of an apomorphically elongated spermatodactyl in the males. Both Iphidonopsis and michaeli -group members of Zerconopsis inhabit bracket fungi, sometimes together.