Burnsius communis (Grote, 1872)

Zhang, Jing, Cong, Qian, Shen, Jinhui, Song, Leina & Grishin, Nick V., 2025, Update to: Advancing butterfly systematics through genomic analysis, The Taxonomic Report of the International Lepidoptera Survey 12 (6), pp. 1-36 : 20-21

Subspecies of Burnsius communis (Grote, 1872)

Currently, Burnsius communis (Grote, 1872) (type locality in USA: central Alabama) is partitioned into two subspecies: the nominate, distributed throughout most of the range from Canada to Mexico; and Burnsius communis albescens (Plötz, 1884) (type locality in Mexico), known from the southern parts of the range (e.g., Oaxaca and Veracruz in Mexico). In line with this treatment, B. communis albescens is a confidently supported sister to all other populations (98% bootstrap value) in the nuclear genome tree constructed from more than 10 million positions in autosome protein-coding genes ( Fig. 14a ). However, due to their overall lack of prominent genetic differentiation and continuing gene flow within a species, subspecies do not always stand out as major clades in phylogenetic trees. Accordingly, the clade of B. communis albescens specimens, although supported with 100% ultra-fast bootstrap value ( Minh et al. 2013), is found within the nominate clade in the Z chromosome tree ( Fig. 14b ), likely due to poor phylogenetic resolution (low support for most bifurcations) caused by DNA similarity and gene flow. We note that mitochondrial DNA does not consistently segregate several species of Burnsius Grishin, 2019 (type species Syricthus [sic] communis Grote, 1872 ), such as B. communis , B. albezens Grishin, 2022 (type locality in USA: AZ, Cochise Co.), and B. burnsi Grishin, 2022 (type locality in Mexico: Veracruz), and its utility is equally limited for subspecies delimitation.

Additional sequencing of B. communis specimens across the range revealed that specimens from Stanislaus National Forest in Tuolumne County, California, were partitioned between different clades ( Fig. 14 yellow highlight). While several specimens were in a confidently supported (99%–100% bootstrap value) nuclear genome clade of specimens from the northwestern part of the range, one specimen was in a clade that included more western and southern specimens. This latter specimen was collected at the same locality and on the same day with one of the specimens from the northwestern clade (near Mill Creek Campground , elevation 6525’, GPS 38.312 6, −119.939 8, 21-Jul-2022, W. R. Dempwolf leg.). These specimens were different in size and wing pattern ( Fig. 15h vs. Fig. 15l ). Moreover, a similar scenario was later found for four specimens of the same size from south of Lake Tahoe , El Dorado County , California, with two being in the northwestern clade and two (collected several miles to the east) falling in the southeastern clade ( Fig. 14 orange highlight; Fig. 15j, k, m, n ).

Therefore, the northwestern and southeastern clades represent different taxa. Although it is possible that they are species-level taxa, it is also possible that they may be subspecies that intergrade at certain localities and elevations. Currently, several taxa with similar relationships are treated as subspecies (type localities in parentheses): Hesperia colorado sublima A. Warren & Calhoun, 2015 ( USA: Colorado, Clear Creek Co. ) vs. Hesperia colorado colorado (Scudder, 1874) ( USA: Colorado, Lake Co. ) and Apodemia virgulti dialeucoides J. Emmel, T. Emmel & Pratt, 1998 vs. Apodemia virgulti nigrescens J. Emmel & T. Emmel, 1998 (both USA: California, San Bernardino Co.) ( Pelham 2023). Hence, and due to the lack of prominent genetic differentiation characteristic of species, the new taxa of Burnsius are conservatively described here as subspecies of B. communis , pending more detailed analyses and further studies. Warren (2005) reviewed Oregon populations and also noted phenotypic differences among them.

Figures

Fig. 14. Phylogenetic trees of Burnsius communis specimens constructed from protein-coding regions in: a) the nuclear genome (autosomes), based on 10,128,060 positions, and b) the Z chromosome, based on 303,834 positions. The mitochondrial genome tree is not shown because it does not separate several species of Burnsius. Different subspecies are colored differently: B. communis tenebrunis ssp. n. (green), B. communis altus ssp. n. (magenta), B. communis communis (blue), and B. communis albescens (red). Labels of specimens from different clades collected in El Dorado and Tuolumne Counties, California, are highlighted in orange and yellow, respectively.

Fig. 15. Selected specimens of Burnsius communis in dorsal (left) and ventral (right) views, data in text or below. a–d) Burnsius communis tenebrunis ssp. n.: a–b) types from USA, Oregon, Klamath Co.: a) holotype ♂ NVG-24064E07 and b) paratype ♀ NVG-23058A06 and c–d) non-type ♂♂ from Canada, British Columbia: c) NVG-24012E08 (slightly aberrant) and d) NVG-24012E09. e–f) Burnsius communis communis ♂♂ from Canada, Alberta, E. M. Pike leg. [CNC]: e) NVG-24012E07 Green Is., 18-Aug-1981 and f) NVG-24012E06 Finnegan, 18-Aug-1986. g–k) Burnsius communis altus ssp. n. from USA, California: g–i) Tuolumne Co.: g) holotype ♂ NVG-23057F09 and h–i) paratypes: h) ♀ NVG-23032C12 and i) ♀ NVG- 23032C11 and j–k) El Dorado Co. paratypes: j) ♂ NVG-24012E04 and k) ♂ NVG-24012E05. l–m) Burnsius communis communis specimens sympatric or collected near B. communis altus ssp. n. from USA, California: l) ♀ NVG-23032D01, WRD 22433 Tuolumne Co. (data exactly as NVG-23032C12, see text) and m–n) ♂♂ from El Dorado Co., S of Lake Tahoe, Cold Creek, D. L. Bauer leg., 8-Sep-1988 [MGCL]: m) NVG-23058C05 and n) NVG-23058C06.