Himaloconnus klapperichianus (Franz)

Jałoszyński, Paweł, 2020, Himaloconnus Franz and Nogunius gen. n. of Japan (Coleoptera: Staphylinidae Scydmaeninae), Zootaxa 4822 (3), pp. 334-360 : 337

Himaloconnus klapperichianus (Franz)

Euconnus (Himaloconnus) klapperichianus Franz, 1985: 97 .

Himaloconnus klapperichianus (Franz) , implied, by elevation of Himaloconnus to genus ( Jałoszyński 2016b).

Diagnosis. Body slender, uniformly light brown; each eye in male composed of 23 ommatidia; pronotal base lacking pits; setae on elytra much shorter than those on pronotum; punctures on head, pronotum and elytra fine, inconspicuous; endophallus with elongate median tubular structure distinctly expanded in proximal region to form a large vesicle.

Remarks. Himaloconnus klapperichianus klapperichianus will be redescribed together with Oriental and Himalayan species of the genus (Jałoszyński, in prep.). It is one of two Himaloconnus species known to occur in Taiwan. The other species, H. alishanensis , has distinctly larger adults reaching ∼ 1.5 mm, and their pigmentation is not uniform but clearly bicolored: the head and partly the pronotum are nearly black, remaining body parts are brown.

Specimens collected in the Ryukyu Archipelago, i.e., on Ishigaki-jima and Iriomote-jima of the Yaeyama group, on Okinawa-jima and on Amami-Ôshima, do not differ from the holotype of H. klapperichianus in male genital structures and externally differ only in minor characters. The aedeagus among the Rykyuan specimens shows some degree of variability in the shape of the apical region and sclerotization of endophallic elements, and this variability was observed even within a sample of specimens collected on the same mountain on Ishigaki-jima, and even on the same collecting spot. It is not possible to distinguish populations that inhabit Taiwan, Yaeyama, Okinawa-jima and Amami-Ôshima using male genital characters. However, specimens from each of these localities differ in body length, and males have different proportions of the length of eye in relation to the length of temple in dorsal view, and different diameters of ommatidia (even though the number of ommatidia is the same in all specimens). The relative length of eye in the largest studied sample from the Yaeyama seems to be a stable, constant character. Putatively, I place these geographically isolated populations as subspecies of H. klapperichianus . Genetic study and possible discoveries of Himaloconnus on other islands between Taiwan and Kyushu may verify this view. As the currently known disjunctions are relatively strong (sea barriers, lack of forests on some islands of the Ryukyu Archipelago that otherwise could serve as intermediary steps in dispersal), and morphological differences between the studied populations are small but distinct, the present state of knowledge supports the decision to treat them as subspecies.