Comment on the proposed designation of a neotype for the nominal species Chionobas chryxus Doubleday, 1849 (currently Oeneis chryxus; Insecta, Lepidoptera, NYMPHALIDAE) (Case 3495)

There is clear evidence that there are two separate species throughout the Rocky Mountains. I personally collected altacordillera in Alberta at Nigel Pass and Highwood Pass. Charles Harp and Steve Kohler collected numerous altacordillera in Montana, the former’s specimens now in the University of Colorado museum. Specimens in that museum show both species fly together in the Wind River Mts. of Wyoming. Paul M. Thompson and David Threatful collected altacordillera at Gott Peak in British Columbia, and Norbert Kondla found it on Mt. Spieker. In NE Nevada altacordillera occurs in the Snake Range, while the other species has been found in the Egan Range. The two species are sympatric at 20 known locations throughout the Rocky Mountains. And I recently (Scott, 2008) found that larvae of altacordillera (including two subspecies from Washington and Ontario) have a different coloration and usually have a dashed heart-band on larvae, compared to the species depicted in the original chryxus painting which has a solid heart-band. No known butterfly has subspecies with oviposition behaviour as different as these two Oeneis taxa have. The problem here is that it takes time for people to learn how to identify new similar taxa, and not all lepidopterists have acquired those skills. Difficulty of identification is nothing new: four species of Phyciodes (NYMPHALIDAE) and seven of Celastrina (LYCAENIDAE) are now known in eastern United States, up from two and one a few decades ago, and most lepidopterists still cannot identify those. Females are not as good as males for identification in Oeneis chryxus-group species: O. nevadensis and O. macouni females are almost identical while the males are very different, and O. alberta females often resemble O. ‘chryxus’ females.

The ICZN governs nomenclature, not taxa, so squabbling about limits of taxa is largely irrelevant. It is enough to state that the people who have carefully studied these taxa think there are several taxa in Alberta, and a neotype is needed because the lectotype has dubious taxon identity and disputable locality.

I had thought that the proposed chryxus neotype would be acceptable to other lepidopterists, as it comes from the Alberta location that people generally cite as the type locality, and it matches the phenotype of the original painting. Surely it is preferable to stabilise nomenclature before a large body of literature using confused names accumulates, rather than after. However, from a biological viewpoint, the optimal neotype should come from an area where the biology of both species has been well studied (Colorado), and the biology of these butterflies is little known in Alberta. I was informed that the Commission can render an Opinion on this case in multiple ways, so to satisfy the doubters and permit an optimal neotype, the best way would be for the Commission not to designate a neotype, and either merely affirm that the wording of Articles 72.4.1 and 72.4.1.1 of the Code is not a mistake, or make no decision at all on the case. As written, Article 72.4.1.1 is numbered and indented as subservient to 72.4.1; therefore 72.4.1.1 allows one to consider specimens not mentioned in the original publication as part of the type series, only if those specimens belong to the taxon defined by the original publication. This interpretation prevents the worst calamity that can befall a lectotype (a lectotype that proves to belong to a taxon different from that defined in the original publication), therefore the writing in the 4th edition of the Code is a considerable improvement over the 3rd edition. When this case was reviewed prior to publication, two Commissioners agreed with this restrictive interpretation of Articles 72.4.1 and 72.4.1.1, which with Article 86.3 invalidates the lectotype, and wrote that I could just designate a neotype without petitioning the Commission. So the absence of an Opinion on this case would satisfy doubters and would permit an optimal neotype, although a statement that the wording is not a mistake would contribute to John Calhoun’s request for clarification of this Article.

Even if the original male chryxus were found, it would be considered merely a useless paralectotype by anyone who thinks the lectotype is valid. Also, Article 73.1 clearly confirms that the male illustrated in the original publication is the holotype, and Article 73.1.2 states that evidence outside the work may be taken into account to help identify that specimen – any other conspecific specimens found would be paratypes, not syntypes.

Additional reference

Scott, J.A. 2008. Early stages of Oeneis calais altacordillera Scott (plate V). Pp. 25–29, pl. 5 and pl. 5 continued, in Scott, J. & Fisher, M.S. Geographic variation and new taxa of western North American butterflies, especially from Colorado. Papilio (New Series), 18:1–72.