Male: Body pubescence mostly sparse, not concealing cuticula at pronotum, elytra and abdomen. Denser white hairs forming dithered pattern viewed as oblique stripe (or oblique spot) before the middle and oblique stripe (or divided into a pair of separated spots on each elytron) behind the middle; background of elytral pubescence consisting of intermixed white and brownish yellow or yellowish brown hairs. Distal part of eyes comparatively narrow. Lobes of protarsomere 3 relatively narrow, narrowed towards apex. Apical tarsomere longer than tarsomeres 2 and 3 combined. Aedeagus at apical half with lateral emarginations, with preapical obtuse angles protruding outwards. Apex of aedeagus angulate ore forming rounded apical tip. Lateral lobes of tegmen not widened at apex, posterior process of tegmen more or less elongate.
Frontal carinae widely separated, occasionally look like wide elevated plate. Metatarsomeres 2 and 3 combined about 1/2 as long as metatarsomere 1.
Female: known only by nominative subspecies (see description of X. arnoldii arnoldii)
Type locality: Central Kazakhstan, Akmola Region, Temirtau Distr., right bank of Tersakan River, Kokshetau mt. (about 50°05'N, 62°28'E).
Distribution: Central Kazakhstan (Akmola reg., Kokshetau mt.), South Kazakhstan (Priaral`ye, Kyzylorda reg., Kumsagys env.).