Lacinipolia acutipennis (Grote, 1880)

Schmidt, B. Christian, 2015, Revision of the Lacinipoliavicina (Grote) complex (Noctuidae, Noctuinae, Eriopygini), ZooKeys 527, pp. 103-126 : 109-111

Taxon classification Animalia Lepidoptera Noctuidae

Lacinipolia acutipennis (Grote, 1880) stat. rev. Figs 28-54, 58, 62, 66, 72

Mamestra acutipennis Grote, 1880: 214.

Mamestra doira Strecker, 1898: 7, syn. rev.

Mamestra ascula Smith, 1905b: 257, syn. rev.

† Polia pensilis ab. indistincta Strand, 1917: 28, unavailable; infrasubspecific name.

Lacinipolia subalba Mustelin, 2000: 13, syn. n.

Type material.

Mamestra acutipennis : type female (BMNH; examined); type locality: Nevada. Mamestra doira : type female (FMNH, examined); type locality: Utah. Mamestra ascula : lectotype male designated by Poole (1982), (AMNH, examined); type locality: Stockton, Utah. Lacinipolia subalba : South rim of Los Peñasquitos Canyon, 76 m, San Diego Co., California (SDNHM).

Diagnosis.

Lacinipolia acutipennis is a western steppe / grassland species that shows considerably greater regional phenotypic variation than others in the Lacinipolia vicina group. In more mesic habitats (including higher elevations) of the Pacific Northwest and central Rocky Mountains Lacinipolia acutipennis is replaced by the very similar Lacinipolia pensilis . The two occur sympatrically in many transitional habitats, mostly dry montane woodlands at moderate elevations. Although phenotypes of Lacinipolia acutipennis from the most arid habitats (e.g., Figs 34-39) can be distinguished from Lacinipolia pensilis with relative ease, many northern Lacinipolia acutipennis populations in the Pacific Northwest are dark, well-marked and very similar to Lacinipolia pensilis , which makes identifying the two very difficult and led previous workers to conclude that they represent the same species. Compounding this difficulty is the lack of conspicuous genitalic differences that are otherwise typical of the genus. Despite the identification difficulties in the Pacific Northwest, other sympatric populations of Lacinipolia acutipennis and Lacinipolia pensilis have clearly different phenotypes. Differences are most pronounced in Great Basin populations ( Lacinipolia pensilis , Figs 25, 27 and Lacinipolia acutipennis , Figs 49-51) and in the northern Rockies/Great Plains (e.g., Montana Lacinipolia pensilis , like those in Figs 23, 24, and Lacinipolia acutipennis , Figs 46-48). The two differ in male genitalia structure as discussed below. These differences, in addition to a minimum 2.5% divergence in DNA barcodes (Fig. 75), show that (at least) two species are involved.

Similar phenotypes of Lacinipolia acutipennis and Lacinipolia pensilis differ in the shape and size of the forewing, which averages more acute and smaller in Lacinipolia acutipennis ; the brown tones of the medial forewing are more muted in Lacinipolia acutipennis compared to Lacinipolia pensilis , giving an overall lower contrast in tone of the medial area with the grey-black antemedial and postmedial areas; the white spot in the anal angle is often more prominent in Lacinipolia acutipennis , particularly in females; the forewing apex has a more contrastingly pale diffuse area that usually extends farther towards the reniform. In the male genitalia of Lacinipolia acutipennis , the spinose crest of the phallus usually has a thin, delicate apically-directed spine (which is sometimes broken off, in which case the spine base is still evident), which is absent in Lacinipolia pensilis ; this thin spine is sometimes absent also in Lacinipolia acutipennis , but in such individuals the entire crest is small and with fewer, smaller cornuti (Fig. 61c) compared to Lacinipolia pensilis (Fig. 62).

Two phenotypes have been recognized as separate species, Lacinipolia doira of the Great Basin (Figs 49-51) and Lacinipolia subalba of southern California (Figs 43-45). Clinal phenotypic variation, lack of diagnostic structural characters, and similarity in DNA barcodes, lead me to treat - doira and - subalba as regional forms.

Distribution and biology.

Lacinipolia acutipennis is a western species common throughout xeric, low elevation habitats of western North America. The core range includes the dry, western portions of the Great Plains, the Great Basin, and the western intermontane valleys north of the Sonoran zone, from southern Saskatchewan and Alberta southward to northern Arizona and New Mexico. Reports from Wisconsin (cited in Forbes 1954), Texas and southern Arizona ( Hampson 1905) are probably misidentifications of Lacinipolia sareta . Crumb’s (1954) records from Nebraska and Kansas are plausible; the easternmost specimens I examined were from Watford City in western North Dakota. In the intermontane valleys west of the Rocky Mountains Lacinipolia acutipennis occurs from southern British Columbia to southern California and northernmost Arizona and New Mexico (Fig. 72). All Pacific Northwest specimens examined from subalpine habitats and from sites west of the Coast Ranges proved to be Lacinipolia pensilis .

The larval description and host plants require clarification since the information given by Crumb (1956) and Godfrey (1972) was probably based on both Lacinipolia acutipennis and Lacinipolia pensilis . The larvae likely are general feeders and may ascend shrubs to feed. Lacinipolia acutipennis flies in late summer with most specimens recorded from mid-August to late September.

Remarks.

The name acutipennis has historically been associated with the taxon Lacinipolia sareta (i.e. Lacinipolia vicina of authors) rather than Lacinipolia pensilis . This apparently stemmed from the fact that historical Lacinipolia acutipennis specimens from western Nevada (the type locality of Lacinipolia acutipennis ) and adjacent northeastern California had been wrongly associated; a series from Truckee, California, examined by Lloyd Martin (and probably others before him, including McDunnough) consists of male Lacinipolia sareta and female Lacinipolia acutipennis , but only the male Lacinipolia sareta were previously dissected. Female Lacinipolia sareta from the northern Sierra Nevada and especially Nevada are considerably paler. Comparison of the type female of Lacinipolia acutipennis to all other Lacinipolia vicina -group taxa occurring in the region of the type locality shows that Lacinipolia acutipennis is a dark female of the low-elevation taxon previously treated as a form of Lacinipolia pensilis .

Variation in the DNA barcodes (Fig. 75) could be indicative of cryptic species, but genitalic structure is highly conserved and phenotypic blending is apparent from regions where adequate samples were available.