Lasionycta mono, Crabo & Lafontaine, 2009

Crabo, Lars & Lafontaine, Donald, 2009, A Revision of Lasionycta Aurivillius (Lepidoptera: Noctuidae) for North America and notes on Eurasian species, with descriptions of 17 new species, 6 new subspecies, a new genus, and two new species of Tricholita Grote, ZooKeys 30 (30), pp. 1-156 : 66

Lasionycta phoca sub-group

The L. phoca sub-group contains seven mostly medium-size (expanse 30–36 mm) species from alpine or subarctic habitats. Most occur in western North America, with two in the Northeast. Th e forewing is gray to brown gray with dark basal, antemedial, and postmedial lines; the orbicular and reniform spots are weakly defined, evident mostly due to pale filling, and the claviform spot is absent; in several species the forewing is mottled with white, blue gray, or yellow. Th e dorsal hindwing is typically dark with a pale fringe. Th e ventral hindwing, often useful for diagnosis, is white to pale gray (rarely brownish gray) with dark chevron- or arrowhead-shaped discal spot, postmedial line, and marginal band. A small species from the Sierra Nevada ( Lasionycta mono sp. n.) with a hindwing resembling species in the L. staudingeri sub-group is associated with this sub-group by the shape of the valve.

The male valve is elongate with a weak to moderate narrowing at the base of the cucullus. The cucullus is fairly stout and similar to those of the L. leucocycla sub-group in shape. The corona is variable, simple with partial double row near the apex in most species, but comprised of several rows in two species. Th e digitus is cylindrical. The female genitalia are similar to those of the L. leucocycla sub-group. Th e corpus bursae is ovoid with a 50 % medial constriction and an appendix bursae of similar size to the corpus bursae. The male antennae are biserrate with triangular individual segments 1.5–2.1× as wide as the central shaft.

Species in this sub-group are among the most diffi cult to identify in the genus. The genitalia are only helpful in a few of the species and the male antennae are generally indistinguishable. Most species resemble each other and several are variable to the point where individuals approach other species in appearance. For this reason, a definitive diagnosis is easiest when series can be examined. Identification is simplified by narrowing the possibilities by locality since no more than three species occur in a region (see Table 1). Th e habitus, especially the ventral hindwing pattern, can then be used for definitive diagnosis. Species status was determined by lack of evidence of intergradation in areas of sympatry together with genital and DNA differences in most cases. Assessment of species limits was most difficult in L. uniformis , a variable widely distributed species with many local forms and several CO1 haplotypes. The rationale for treating it as one species are discussed under L. uniformis .

The CO1 DNA sequences of all phoca sub-group species except L. caesia are similar (that of L. mono is unknown), clustering with those of L. lagganata , L. quadrilunata , and L. dolosa ( Fig. 248 ). Th e sequences of L. caesia , L. brunnea , L. gelida sp. n., L. discolor (Smith) , and L. phoca are fairly uniform, although this could be an artifact of small sample sizes. In contrast, many haplotypes exist for several L. uniformis subspecies which are intermixed with those of the other species in the DNA tree ( Fig. 248 ). Despite this overlap, CO1 distance analysis was useful for determining the number of taxa in a region. For example, comparison of all L. phoca sub-group DNA samples from the Canadian Rocky Mountains identifies two dominant haplotype clusters that correlate with L. u. uniformis and L. brunnea . Similarly, two main haplotypes from the central United States Rocky Mountains correspond to L. discolor and L. uniformis fusca . However, more haplotypes than identifiable species exist in the Pacific Northwest. Two of the haplotypes correspond to L. gelida and L. caesia . Th e other three major clusters are similar but variable and cannot be sorted by appearance to more than one taxon in L. uniformis multicolor .

Figures

Figure 248. Neighbor-joining CO1 tree of the North American Lasionycta leucocycla species-group. Symbols and codes are the same as in Fig. 247. No data is available for Lasionycta carolynae, L. illima, L. leucocycla hampa, L. macleani, L. mono, or L. uniformis handfieldi. The illustrated specimens demonstrate the variation in appearance of the species-group and are scaled to the same size.