A guide to Oribatid Identification for the ABMI: - Royal Alberta Museum

Almanac of Alberta Oribatida 2.3 13 January 2013Supercohort Mixonomatides (RAM 99000134)Comments: In Alberta, the Mixonomatides (aka Mixonomata Grandjean, 1969 (ITIS 733331)) isrepresented by one record of an Epilohmannia species from near Lethbridge (49.48 N,112.54’ W) (Osler et al. 2008) and two superfamilies of box mites, i.e. mites with the abilityto withdrawal their legs into their body and fold their aspis over the opening and thusresemble a closed box, a closed pocket knife, or a plant seed. The technical term for thismorphological-behavioural defence is ptychoidy. The three superfamilies ofMixonomatides are distinguished in the Key to Major Groups. Below, the species in eachsuperfamily of box mites, Euphthiracaroidea and Phthiracaroidea, are keyed.Euphthiracaroidea Jacot, 1930 (ITIS 733348)(Return to Key to Major Groups)Comments: Euphthiracaroid mites generally have their apparent anal and genital plates (actuallyusually fused ano-adanal and genito-aggenital plates) meeting at an angle and thusappearing knife-like and complementing the metaphorical pocket-knife image.Phthiracaroid mites have the plates in this region broad and more or less flattened in a more‘box-like’ manner. In addition to taxa known from Alberta, the key below includes thegenus Maerkelotritia Hammer, 1967 because it seems likely that M. alaskensis Hammer,1967 and other species known from BC may eventually be discovered here.7. Key to families & genera of Euphthiracaroidea potentially in Alberta1. Anal plates discrete, not fused to adanal region (Fig. 7.1A); genital plates also free or fused toaggenital region; notogastral integument usually smooth, uniformly shiny in reflected light....................................................................................................................... Oribotritiidae (2)- Genital region covered by a single genital-aggenital plate (Fig. 7.1B); anal region with a singleanal-adanal plate; hinge-like interlocking triangles on anterior and sometimes posterior ofanal region on midline; notogaster often pitted or sculptured (at least anteriorly), usually notshiny......................................................................................................... Euphthiracaridae (4)40