Raphia frater Grote

Schmidt, B. Christian & Anweiler, Gary G., 2014, Taxonomy and biogeography of the Nearctic Raphia Huebner (Lepidoptera, Noctuidae, Raphiinae), ZooKeys 421, pp. 91-113 : 100-102

Raphia frater Grote

Diagnosis.

Despite variation in adult facies and lack of a particular diagnostic trait, Raphia frater is recognizable by the combination of a broad, rounded forewing, often conspicuous antemedial and postmedial band, obsolete medial band (rarely faint), an orbicular, reniform and usually also a claviform stigma that are clearly outlined, black shading in the anal angle of the hindwing, and the conspicuously bipectinate male antennae. Pseudopanthea palata (Grote) and Colocasia Ochsenheimer species share some superficial similarities with Raphia frater , but attention to the above-stated characters relative to those in Pseudopanthea McDunnough and Colocasia Ochsenheimer will provide an easy diagnosis of this unique species.

Description.

Head - Male antennae bipectinate, anterior rami 3 × longer than segment length, posterior rami 3.3 × longer; female antennae simple; eyes round, with short, sparse interfacetal setae, visible only at high magnification; labial palpus with second segment clothed in long strap-like scales ventrally; third segment 0.6 × length of second segment (when denuded) and smoothly scaled; occiput and frons with mix of grey and black scales, frons with transverse line of black scales; frons rounded and moderately protuberant when denuded. Thorax - vestiture dark grey to yellowish grey, thoracic collar sometimes contrastingly darker than dorsum; tarsi smoothly scaled, with transverse bands of black and light to dark grey; tibia with similar scaling but with faint or indistinct banding; femur with long, shaggy hair-like scales. Abdomen - lacking specialized secondary sexual structures such as coremata; vestiture of smooth, short grey scales; small, rounded dorsal tufts on segments A3, A4 and A5, consisting of densely set spatulate scales. Forewing - ground colour varies from a dark charcoal grey to pale yellowish ochre; antemedial band a parallel-sided, double black line, varying from slightly irregular and rounded to nearly linear, acute, and angled at the cubital vein; medial band obsolete, usually reduced to a black bar or two diffuse lines at costa adjacent to reniform stigma, but band sometimes visible as a faint, diffuse black line extending from bottom of reniform stigma to anal margin; postmedial band a single black line, sinuate and slightly sagittate at veins (often faint or absent in ssp. coloradensis and elbea), expanding to diffuse black patch at costa; orbicular stigma paler than ground colour, with black border and often with a diffuse dark pupil (orbicular often absent entirely in ssp. coloradensis and elbea); reniform stigma paler than ground colour, with a black border (border often lacking in coloradensis and elbea) and a diffuse black central crescent; subterminal band absent, faint, or diffusely sagittate with paler distal edging; terminal area often darker grey than subterminal area. Average size is greatest in subspecies frater, while abrupta and piazzi are smallest; forewing length varies from 16.2 mm and 18.5 mm in male and female Raphia frater frater to 13.7 mm and 15.2 mm in male and female Raphia frater abrupta , respectively. Hindwing - ground colour varying from white, white and dusted with fuscous grey (ssp. frater, coloradensis, elbea, cinderella, piazzi), or entirely pale fuscous grey (ssp. abrupta), females with more fuscous than males; crescentic discal spot diffuse or absent; postmedial band faint or absent, although nearly always with a contiguous diffuse black patch at anal angle. Male genitalia ( Fig. 5 ) - uncus slightly compressed dorsoventrally, with slight medial bulge, apex blunt; valva tapering more or less evenly to a rounded point, sacculus poorly differentiated from remaining valva; ampulla long and flattened, 0.7 × length of valva width, projecting mesially; aedeagus stout and sausage shaped, 2.1 × longer than wide; vesica a simple kidney-shaped, unarmed chamber equal in length to aedeagus, tapering gradually into ductus. Female genitalia ( Fig. 5 ) - bursa copulatrix membranous, lacking apparent differential sclerotization, including ostium, ante- and postvaginal plate; ductus bursae a simple rugose tube, 3.3 × longer than diameter, connecting subbasally to corpus bursae; corpus bursae a simple kidney-shaped chamber, slighter wider over apical two-thirds; ductus seminalis arising from basal end of corpus bursae, caudad of ductus bursae; papillae anales short, bluntly rounded, with a broadly joined base, with two types of unusual, modified setae: 1) a dense band of thin, evenly curved setae arising from base of papillae and curving up to caudal margin, outer surface of lobe virtually encircled by a dense setal crown; and 2) highly modified thick, spatulate setae densely set along caudal margin of lobe. Immature stages - larva described by Thaxter (1883) based on eastern specimens, and by Dyar (1894) from Yosemite, California (possibly referable to Raphia frater cinderella ). Illustrations in McCabe (1991) (head capsule and mandible), Wagner (2005) and Wagner et al. (2011). Mature larva stout, tapered only slightly anteriorly, bluish green to apple green with a slightly translucent quality, pinacula yellow, a dorsal transverse yellow band on A1, A5 and A8 extends to just above spiracle; T2 with short horn-like process middorsally, reddish with yellow base; these bands with whitish anterior border, those on A5 and A8 partially bordered with reddish orange; prolegs green, anal prolegs with yellow and reddish orange; head whitish green, usually retracted into T1, ocelli black, labrum whitish; total length 40 to 30 mm. Thaxter (1883) states that male larvae are more slender and smaller. Cocoon tough and firm, incorporating debris; pupa cylindrical with a rounded abdomen, cremaster short but broad and thick, lacking hooks. Eggs laid in small clusters or overlapping in linear groups; early instars much more elongate ‘semi-loopers’ with A3 and A4 prolegs reduced ( Wagner et al. 2011). Larvae rest along midrib of leaf underside. Comparison among larvae of Californian Raphia frater (Dyar, 1894), Raphia frater frater , Raphia frater abrupta and Raphia frater elbea indicate no discernible differences among these subspecies.

Biology and distribution. Raphia frater occurs in virtually all wooded or shrubby habitats of the boreal region since the larval hosts form a dominant part of most non-coniferous forest types. It can be one of the most common late spring noctuids in aspen-dominated boreal forests of central Canada. In the West it becomes increasingly more restricted to riparian areas, particularly major river systems in drier regions of the Pacific Northwest and the desert of the Southwest. Raphia frater has a nearly transcontinental distribution, absent only from the arctic and most of the subarctic. The records from northern subarctic Labrador are surprising, but are based on three CNC specimens from two localities, so the data appear to be authentic. Handfield (2011) cites records from the northeast shore of the St. Lawrence, but the species is not known from Newfoundland. The range is essentially continuous south to northern Mexico, although very spotty throughout the Atlantic states, and spotty or absent in the central to southern Appalachians. Nominal Raphia frater frater occurs across the boreal region south to the northeastern States, southern Great Lakes region, and northern Rockies / Pacific Northwest; Raphia frater abrupta occurs from the Great Plains southward to eastern Texas and eastward to the Atlantic seaboard; Raphia frater coloradensis occurs from western California to the eastern slope of the Rockies; Raphia frater elbea occurs from at least southeastern Utah through Arizona, southwestern New Mexico and into Mexico; Raphia frater cinderella is restricted to western and central California; and Raphia frater piazzi occurs from the Edwards Plateau into southern Texas. Raphia frater is univoltine across the boreal region and most of the west, with peak flight activity from late May to July. It is bivoltine in the eastern U.S., flying mostly in April to May, and July to August. In the Deep South, Raphia frater abrupta has three abundance peaks: March, May and a smaller flight (partial third brood?) in September ( Brou 2014). Larvae are most common from late July to mid-August in Canada ( Prentice 1962).

Figures

Figure 5. Genitalia of Raphia frater. a female (Konza Prairie Biol. Stn., Riley Co., KS; leg. Metlevski), with inset showing apical spatulate setae and subapical dense setal crown of papillae anales b male vesica c male genital capsule (Pitchfork Ranch, Grant Co., NM; leg. C. Ferris); note magnification difference between sexes.