Lasionycta leucocycla

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 : 25-26

Lasionycta leucocycla species-group

The L. leucocycla species-group is comprised of 33 species in North America. Males are defined by a cylindrical to slightly laterally compressed uncus tapered to a hook-like apex. Th ose of other species-groups are dorsoventrally flattened and laterally expanded with blunt tips. Females have ovipositor lobes covered by short peg-like cornuti whereas those of other species-groups are covered with hairs. Th e genitalia of most species are closely similar and are of limited use for identification of individual species. They are described in the following paragraphs, with significant features of each species subgroup and species noted subsequently as appropriate.

Males have a simple strap-like valve. Th e costal lobes are variable, small to moderately large. The cucullus is weak to moderate size (0.7–1.4× valve width) separated by a nearly absent to mildly constricted neck. Th e corona of 15–40 curved setae is arranged in a single row, a single row with irregular apical double row, a complete double row, or as an irregular patch up to 4 rows wide. Th e triangular or finger-like digitus is oriented 30–45° ventrad to the valve. The aedeagus is tubular without projections. The vesica is 1.5–2.0× as long as the aedeagus, the basal portion is coiled 360° (dorsad, then anterior, ventrad, and rightward) and its distal portion is gently twisted 180° to project rightward and/or ventrad. Th e 0–6 subbasal cornuti are located on the basal coil and are elongate, comprised of a central spike arising from a smooth cone-shaped base.

In the female, the ductus bursae is cylindrical, slightly expanded anteriorly. The corpus bursae is 1.1–1.6 x as long as the corpus bursae. The corpus bursae is ovoid and focally constricted distal to the appendix origin, about 50 % in most species, but weakly in the L. staudingeri and L. impingens sub-groups. The appendix bursae arises from the dorsal posterior margin of the corpus bursae and extends dorsad and posterior. Its base is slightly expanded and the distal third tapers bluntly following a 90° posterior and slight leftward bend. Th e bursa appears unisaccate in the sub-groups with weak constrictions.

The male antennae are variable in width, ranging from weakly biserrate to broadly bipectinate (1.4–5.4× as wide as the shaft).

The L. leucocycla species-group contains the majority of species in the genus and is significantly larger than the “ L. leucocycla complex” of Lafontaine et al. (1986). They restricted the complex to L. leucocycla and present members of the L. staudingeri subgroup based on ellipsoid eyes and pale hindwings, both characters are likely adaptations to diurnal flight. We divide the species-group into seven sub-groups of similar-appearing species to aid identification, recognizing that this arrangement might not be entirely phylogenetically accurate. In fact, CO1 distance analysis divides the species-group into four major divisions – L. subfuscula (Grote) , L. caesia sp. n. from the L. phoca sub-group, and two larger assemblages ( Fig. 248 ). One of the large DNA groups contains the L. leucocycla and L. perplexa sub-groups plus L. staudingeri and L. subfumosa from the L. staudingeri sub-group. Th e other large assemblage contains the other L. staudingeri sub-group species ( L. lagganata (Barnes & Benjamin) , L. quadrilunata (Grote) , L. dolosa (Barnes & Benjamin)) , the L. promulsa and L. impingens sub-groups, and the remaining members of the L. phoca sub-group. DNA sequences are not available for several species (see Fig. 248 ).

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.