Description of a new relict eriophyoid mite, Loboquintus subsquamatus n. gen. & n. sp. (Eriophyoidea, Phytoptidae, Pentasetacini) based on confocal microscopy, SEM, COI barcoding and novel CLSM anatomy of internal genitalia.

A new pentasetacine mite Loboquintus subsquamatus n. gen. & n. sp. was found living under scale-like leaves of 2-3 years old twigs of Cupressus sempervirens in Montenegro. This mite species possesses a number of morphological features (uncommon teardrop-shaped body, traits of prosoma, atypical primitive anatomy of the genital apparatus and morphological traits of immatures) which clearly distinguish it from all other known eriophyoids. Adults of L. subsquamatus have seta vi situated on the anterior margin of a uniquely elongate lingua-like thin frontal lobe, three pits on the posterior prodorsal shield margin, a remarkable tube-like structure in the basal part of gnathosoma, a complicated three-layered epigynium, spermathecae directed antero-laterad, short spermathecal tubes and setae eu suppressed in males and possibly expressed in females. External genitalia of males and females of L. subsquamatus are fundamentally similar. Hypothesized remnants of coxisterna III or IV (forming a postgenital plate) are remarkably distinct in males. Two new morphometrical variables are proposed to supplement the CLSM protocol for description of internal genitalia of eriophyoids proposed by Chetverikov et al. (Zootaxa 3560:41-60, 2012b): (a) the length of ventral projection of the transvers genital apodeme and (b) the length of the posterior (=postspermathecal) part of the longitudinal bridge which in L. subsquamatus is remarkably long, whereas in many other eriophyoids it is reduced.