Unexpected finding of rare and little known leaf beetle Chrysolina levi (Coleoptera, Chrysomelidae) in West Siberia

The first record of rare and little known leaf beetle Chrysolina levi Okhrimenko, 1990 was registered in the Omsk region (West Siberia). Redescription of male is given because holotype was collected dead and damaged, lacking legs, antennae, head and pronotum. Position of Chrysolina levi inside subgenus Chalcoidea is discussed, its distribution area in Scythian steppe region is now considered as Taman’– Irtysh instead of Pontic.


Introduction
The leaf beetle Chrysolina (Chalcoidea) levi Okhrimenko, 1990 was described from Krasnodar province based on one male and one female only. Moreover, both specimens were collected dead at the base of sagebrush plant. Female lacks legs and antennae almost entirely, male also lacks head and pronotum (Okhrimenko 1990). Thus, the holotype and paratype are both remains of beetles with various damage rate. Therefore the original description of male holotype is very brief, five lines only, but it provides the figure of aedeagus, whereas the original description of female paratype is more detailed. Later, Bieńkowski (2007) collected one more female in Krasnodar province near Kuchugury village, attributed it to this species and made its redescription.
Thus, Ch. levi is the rarest species of Chrysolina described by three specimens only, including the types, and no alive male has been collected so far. Authors of the subsequent keys (Bieńkowski 2007;Warchałowski 2010) had to copy the original, quite sketchy aedeagus drawing from the description of Okhrimenko (1990), while the original drawing based on holotype examination was presented recently by Bieńkowski (2019).
Unexpectedly, Roman and Evgeny Dudko collected one male of this species far away from Krasnodar province in 2015. The new locality in Omsk region is 2800 km eastwards and almost 10 degrees northwards from the type locality. Although a very comprehensive review of the leaf beetle fauna has been completed recently for this region (Moseyko et al. 2018), our record herein proved to be the first not only for Omsk region but also for Siberia.

Material and methods
All measurements were made using an ocular grid mounted on MBS-10 stereomicroscope. Total body length (TL) was measured from the anterior edge of pronotum to the elytral apex, body width was measured in the broadest part of elytra (EW). Redescription is based on the algorithm proposed by Bieńkowski (2011) for species descriptions in the genus Chrysolina.
Elytra. at base slightly wider than pronotum, with weak humeral callus, each elytron 2.3 times longer than wide. EL (elytral length) 4.6 mm. Primary puctures large, form rows that are paired starting with 2nd. Puncture rows partly confused, especially rows 6 and 7, row 1 confused where it goes closer to scutellar row, which consist of 9 punctures. Intervals flat, their punctation fine and sparse, with thin wrinkles, but among fine punctures there are also larger ones, almost of the same size as on pronotum. Marginal stria with large dense punctures. Sutural stria distinct at apical slope. Epipleura inclined outside, visible along entire length. Hind wings developed.
Abdomen. Pygidium with deep longitudinal furrow at 4/5 of entire length. Ventrite 1 broadly margined on anterior edge, covered with small sparse punctures, only anterior intercoxal process covered with large wrinkled punctures. Last ventrite very slightly convex, with slightly incised apex, medially with flat impunctate area slightly depressed apically.
Aedeagus. (Fig. 2) with broad rounded subtriangular apex, its dorsal surface weakly chitinized, lateral curves very slight. Flagellum thin, but not whip-shaped on the apex, slightly curved, produced from apical orifice for 1/3 of its length. Okhrimenko (1992) treated this species as Pontic, endemic to Eisk-Taman' (or Taman' steppe) natural district. This was true for the findings limited by Taman' peninsula. Now it is clear that Ch. levi has wider distribution in West Scythian subre-gion of Scythian steppe region (according to zoogeographic scheme of Emeljanov 1974). The new record in the extreme south-east of Omsk region is evidenced that this species has Taman'-Irtysh distribution (Fig. 3), considering that the saline lands are also common in the adjacent Novosibirsk region and Kazakhstan, where this species could be found.

Discussion
Ch. levi was initially placed by Okhrimenko (1990) in the subgenus Chalcoidea Motschulsky, 1860, although this species has somewhat isolated position lacking several peculiar subgeneral characters. These characters are narrow last maxillary palpomere, similar in both sexes, aedeagus usually "bottle shaped" with narrow long or short apical projection, reddish lateral stripe on elytra (Bieńkowski 2019). In addition, Ch. levi has specific structure of aedeagus and pronotum. Aedeagus shape of Ch. levi (Fig. 2) is very peculiar not only among Chalcoidea but in the whole genus Chrysolina. Lateral impressions of pronotum of this species are deep and narrow (Fig. 1A), while in other representatives of Chalcoidea they are usually shallow, basally widened and covered with coarse punctures (Fig. 1B-D). Okhrimenko (1990) put Ch. levi closer to Ch. hyrcana Weise, 1884 andCh. turgaica (Jacobson, 1910), thought the latter species has very different aedeagus shape. In Chalcoidea, Ch. levi can be put closer to Ch. songarica Gebler, 1843 (= Ch. hyrcana) or to Ch. immarginata (Rybakow, 1884) and Ch. dieckmanni (Mohr, 1966) due to specific structure of pronotum. These species have narrow lateral ridges of pronotum and relatively narrow lateral impressions, although coarse punctures in these impressions are always separate, not fused like in Ch. levi. Peculiar deep furrow-shaped impressions of pronotum provide means to place Ch. levi closer to the representatives of the subgenus Jeanclaudia Mikhailov, 2009, for example, Ch. ordinata Gebler, 1823.