Grammia blakei, (GROTE)

Schmidt, B. Christian, 2009, Taxonomic revision of the genus Grammia Rambur (Lepidoptera: Noctuidae: Arctiinae), Zoological Journal of the Linnean Society 156 (3), pp. 507-597 : 560-562

GRAMMIA BLAKEI (GROTE) ( FIGS 32, 66 , 91 , 125 )

Arctia blakei Grote, 1864d: 523 , pl. 5, fig. 2. Apantesis blakei (Grote) ; Franclemont, 1983: 117 Grammia blakei (Grote) ; Ferguson & Opler, 2006: 10.

Type material: Described from a single female, type number 7684 [ ANSP, not examined]. The type locality is ‘ Colorado Territory’ [ CO, USA] .

Diagnosis: Grammia blakei somewhat resembles small, pale G. nevadensis or G. williamsii , but the pale whitish-buff antennae and presence of a forewing basal dash along the anal vein will almost invariably distinguish G. blakei specimens. Internally, the male vesica is unusually distinctive; the basal chamber is relatively large, and the distal chamber is smaller than the medial chamber (larger than or equal to medial chamber in other G. nevadensis group species). Grammia blakei flies relatively early in the spring (occasionally with a second, late summer flight), overlapping partially with the start of the flight of G. williamsii in the northern Great Plains, whereas sympatric G. nevadensis populations do not fly until late summer/early autumn.

Description: Head – vestiture of palps and frons pale buff, vertex black, pale buff laterally; eyes reduced mean maximum diameter 5.68 ¥ 10 - 1 mm (N = 6 males), gena exposed adjacent to lateral eye margin; male antennae strongly bipectinate, rami averaging 5.75 ¥ 10 - 1 mm, 3.9¥ longer than intersegmental distance (N = 6); dorsal scales of antenna predominantly pale buff; female antennae strongly biserrate to slightly bipectinate. Thorax – Vestiture black with broad, pale buff borders on vertex, patagia, and tegulae; black thorax form absent; pale buff ventrally, central tuft yellowish buff, black laterally; legs predominantly pale buff, coxa and tibia pale buff and black. Abdomen – Dorsal ground colour pale yellow to yellowish orange, pale buff near apex; medial and lateral markings black; pale buff ventrally, lateral black markings often reduced in males, expanded in females and often converging laterally into broad black band. Forewing – Mean forewing length 13.8 mm (N = 6 males); ground colour dark chocolate brown to black; banding pattern pale buff, moderately developed; basal band extending to postcubital or reduced to costal wedge, antemedial band usually present, most often as costal wedge and band below postcubital; medial band well developed, extending caudally beyond postcubital; postmedial band well developed, curving slightly basad near costa; subterminal band well developed; anal dash usually present; cubital vein sometimes pale-lined near postcubital stripe, especially in females; fringe entirely pale buff, or with dark scales near tornus; basal 7/8 of costa lined pale buff; sexes similar. Hindwing – Ground colour pale yellow, rarely orange, brighter in females; markings well developed, dark brown to black; antemedial spot near anal margin usually streaked basad; medial spot prominent, postmedial and subterminal spots prominent and often confluent; females with relatively reduced markings; ventrally with similar pattern and duller ground colour. Male genitalia – Distal portion of valve gradually tapering to rounded apex; clasper and median ridge moderately developed; uncus broad-based, process evenly tapered to point; juxta wider than long; aedeagus with dorsad curve at 2/3 distance beyond base; vesica with relatively large basal chamber, medial and distal chamber small and equal in size, equally scobinate, spinules relatively large. Female genitalia – Ductus bursae unsclerotized; basal half of ductus bursae widened considerably, about half the diameter of corpus bursae; corpus bursae more or less globose and relatively small, two¥ width of ostium bursae; signum 1 rounded-triangular in shape, larger than signa 4; signa coarsely scobinate; appendix bursae with broad, angled elbow, not evenly tapered; posterior apophysis slightly longer than length of papillae anales.

Biology: Adult collection dates range from late May to early September, and in some years there is a partial second generation in the southern parts of the range (Ferguson, cited as in lit. in Byers, 1988). In the northern Great Plains, the species is univoltine, the larvae aestivating in mid summer, feeding again in autumn, then diapausing ( Byers, 1988). Peak flight activity is from late May to early June, with a few MT records for August. KS records are for mid July to early September. Grammia blakei is primarily a low- elevation, Great Plains grassland species, and can be abundant in sparsely vegetated, sandy prairie, including overgrazed native pastures ( Byers, 1988). It also occurs at higher elevations, with records from 9200′ in CO and 6500′ (near treeline) in south-western AB. Adults are primarily diurnal, and rarely come to light ( Byers, 1988; B. C. Schmidt, unpubl. data). Males are active in late afternoon (B. C. Schmidt, unpubl. data), and mating occurs during the first hour of darkness ( Byers, 1988). Byers (1989) described trapping techniques using virgin females, and males apparently approach calling females by crawling, as traps that were not placed directly on the ground caught few or no males. Larvae feed on Antennaria dimorpha (Asteraceae) , Koeleria cristata , Poa sandbergii , Stipa comata , Agropyron smithii , Eurotia lanata , Bouteloua gracilis (Poaceae) , and Carex spp. (Cyperaceae) , and in captivity will also accept a variety of monocot and dicot crop plants ( Byers, 1988). Larvae are occasionally abundant enough to cause significant damage to spring wheat, reaching numbers of up to 100 larvae m-2 ( Byers, 1988).

Distribution: Occurs from the southern prairie provinces south to TX, and west CO ( Fig. 125 ). Essentially a Great Plains species and contrary to Byers (1988), it is not known from southern BC and CA. Ferguson et al. (2000) recorded it as far south as AZ and NM.

Molecular variation: Two specimens from a single locality exhibited the same haplotype in the Western lineage, shared with G. williamsii ( Fig. 134 ). Both samples sharing this haplotype originated from adjacent prairie sites in south-eastern AB (Appendix S1).

Remarks: Despite the historical misapplication of the name blakei to both G. williamsii and G. nevadensis , and the cox 1 haplotypes shared with G. williamsii , there are clear morphological and ecological differences amongst all three species; these three species often occur in strict sympatry, G. blakei and G. williamsii often flying at the same time.

GRAMMIA CERVINOIDES (STRECKER) ( FIGS 33, 67 , 126 )

Arctia cervinoides Strecker, 1876: 151 .

Apantesis cervinoides (Strecker) ; Franclemont, 1983: 117.

Grammia cervinoides (Strecker) ; Ferguson & Opler, 2006: 10.

Type material: Male holotype from Mt. Flora , [Clear Creek County], CO, [ USA]. [ FMNH, photograph examined] .

Diagnosis: This day-active species of the alpine zone in the Colorado Rocky Mountains is not likely to be confused with other Grammia species. The small size, reduced eyes, whitish and grey hindwings, and presence of most of the forewing bands are unique.

Description: Head – vestiture of palps and frons pale buff or dark brown, vertex entirely black, or black and pale buff laterally; eyes reduced, mean maximum diameter 4.33 ¥ 10 - 1 mm (N = 3 males), gena exposed adjacent to lateral eye margin; male antennae moderately bipectinate, rami averaging 2.82 ¥ 10 - 1 mm, 1.9¥ longer than intersegmental distance (N = 3); dorsal scales of antenna predominantly dark brown, with scattered buff scales. Thorax – Vestiture black to dark brown with pale buff borders on vertex, patagia, and tegulae; black thorax form absent; pale buff ventrally, central tuft reduced, pale buff; legs predominantly pale buff, coxa and femur dark brown. Abdomen – Dorsal ground colour dull, pale buff, black medial band wide; lateral markings black; pale buff ventrally, lateral black markings black. Forewing – Mean forewing length 11.9 mm (N = 3 males); ground colour dark greyish-brown to black; banding pattern pale buff, moderately developed, bands relatively broad; basal band absent or reduced to costal wedge, antemedial band usually present, extending to postcubital stripe or beyond; medial band well developed, usually extending caudally beyond postcubital; postmedial band well developed, nearly straight or curving slightly basad near costa; slightly angled at vein M 3; subterminal band well developed; anal dash usually present; cubital vein not pale lined; fringe variable, pale buff, dark brown or combination thereof; costa usually finely lined whitish buff; anal margin whitish buff. Veins rarely (two of 15 specimens) white-lined according to Smith (1938a); sexes similar. Hindwing – Ground colour dull whitish buff, often with dusky cast; markings well developed, dark brownish grey, often suffused and with borders indistinct; antemedial spots often streaked basad; medial spot prominent, postmedial and subterminal spots prominent and often confluent; ventrally with similar pattern, overall paler. Male genitalia – Distal portion of valve gradually tapering to rounded apex; clasper and median ridge reduced; uncus broad-based, process evenly tapered to point; juxta 1.5¥ wider than long; aedeagus with dorsad curve at 2/3 distance beyond base; vesica with relatively small basal, medial, and distal chambers; medial and pical chambers coarsely scobinate, spinules relatively large; distal chamber broadly kidney-shaped, resembling nevadensis in this respect. Female genitalia – Not examined.

Biology: Adults are diurnal, and occur in alpine habitat, including rocky slopes. Collection dates are from early to mid July.

Distribution: Occurs above treeline in the Rocky Mountains of CO ( Fig. 126 ).

Molecular variation: Not examined.

Remarks: Grammia cervinoides is the smallest species of Grammia , although small G. quenseli specimens are similar in size. This species has traditionally been treated as being closely related to G. quenseli because of the superficial resemblance in the dusky coloration, small size, and occasional expression of forewing vein lines. The forewing transverse lines, and fore- and hindwing shape suggest a closer relationship to the nevadensis group. The name cervinoides means ‘like cervini ’, referring to another dusky grey, high alpine arctiine, Holoarctia cervini of the European Alps.

Figures

Figure 134. Neighbour-joining tree of Western lineage haplotypes of Grammia species. Multiple symbols per row indicate multiple species and/or samples for a given haplotype. Squares indicate species with haplotype complements primarily or exclusively in the Western lineage, circles indicate predominantly Eastern lineage species. Grammia virgo haplotype VI15 (triangle) is the sole G. virgo haplotype outside of the Virgo lineage.

Figures 64–68. Genitalia of male Grammia, ventral aspect of valve and right lateral aspect of aedeagus (scale bar = 1 mm). 64, Grammia yavapai Schmidt. 65, Grammia favorita (Neum.). 66, Grammia blakei (Grt.). 67, Grammia cervinoides (Stkr.). 68, Grammia fergusoni Schmidt.

Figures 87–95. Genitalia of female Grammia, ventral aspect (scale bar = 1 mm). 87, Grammia nevadensis (G. & R.). 88, Grammia behrii (Stretch). 89, Grammia williamsii (Dodge). 90, Grammia elongata (Stretch). 91, Grammia blakei (Grt.). 92, Grammia fergusoni Schmidt. 93, Grammia ornata (Pack.). 94, Grammia hewletti (B. & McD.). 95, Grammia complicata (Walker).

Figures 120–125. Distribution of examined specimens of Grammia.

Figures 126–131. Distribution of examined specimens of Grammia.