Laothoe amurensis subsp. selene Zolotuhin, 2018

SYN. & STAT. NOV. Zolotuhin (2018) (STI 21919) distinguished Laothoe selene from Laothoe amurensis and Laothoe [amurensis] sinica based on several minor characters of the habitus and male genitalia, in addition to respective DNA barcode divergences of 2.5% and 1.9-2.3%. In terms of the habitus, L. selene was said to differ in a larger size, the relatively slender but strongly apically broadened forewing, a well-defined pattern of transverse lines and bands, and a forewing antemedial band angled on vein 1A. Examination of four specimens from Yunnan in NHMUK, together with six moths on the BOLD website, showed that while generally true (except for the antemedial band shape, which is straight in most specimens observed), there is nevertheless still overlap in these characters with specimens from Sichuan, Shannxi and the Russian Far East, and all four populations are highly variable. As for Laothoe amurensis sinica (q.v.) differences in the male genitalia are limited to the shape of the juxta (long, as in amurensis) and the form of the cornuti on the phallus vesica. However, the differences in the latter are relatively minor; indeed, Kitching & Cadiou (2000) (STI 18788) commented that there is considerable intraspecific variation in cornuti shape in Laothoe populi, and that in this species, they are at best indicative of subspecies differentiation. The same is considered here to apply to populations of Laothoe amurensis. Regarding the DNA barcode divergence, Řezáč (2018) (STI 21910) commented in his study on Rhodoprasina that in that genus “intraspecific divergences are of the order of 4% [and] differences below 2%, unless supported by conspicuous traits in habitus and the structure of the genitalia, cannot be considered significant, even at subspecies level”. This seems to be generally true of many Smerinthini that do not feed as adults and thus, in the absence of such morphological differences, the respective divergences of 2.5% and 1.9-2.3% from amurensis and sinica would indicate subspecies differentiation at best. Taken together, there is thus no justification for treating Laothoe selene as a species separate from Laothoe amurensis but rather as a subspecies, Laothoe amurensis selene. It is also worth noting that Zolotuhin (2018) (STI 21919) overlooked two DNA barcode sequences in BOLD from Baihuashan, near Beijing, that had been mined from GenBank (KF704584 and KF704585). These form a fourth cluster that is as distinct as are the other three (Laothoe amurensis amurensis, Laothoe amurensis sinica and Laothoe amurensis selene). This further complicates any interpretation of where the boundaries are between these clusters in NE China and Korea. There is also the possibility that the Japanese and Gansu populations are also distinct at subspecies level. Clearly, much further sampling is required before we can fully understand the internal differentiation of Laothoe amurensis in eastern Asia.