Grammia behrii (Stretch)

Ferguson, Douglas C. & Schmidt, Christian, 2007, Taxonomic review of the Grammia nevadensis species group (Lepidoptera: Arctiidae) with descriptions of`two new species, Zootaxa 1405, pp. 39-49 : 46-48

Grammia behrii (Stretch) , revised status

( Figs. 1 e, 2, 4)

Arctia behrii Stretch, 1872 , Zygaenidae and Bombycidae of North America, p. 75, pl. 13, figs 11, 12. Type locality: “Downieville [Sierra County], California.” [Type lost?]

Arctia shastaensis French, 1889 . Canadian Entomologist 21: 35, 162. New Synonomy

Type locality: Upper Soda Springs, Siskiyou County, near Mt. Shasta [California]. [Location of types unknown]

Grammia behrii was essentially a “lost species” since the time of its original description in the sense that it was not recognized or accepted as a distinct taxon until now. Although it is one of the largest and most colourful of the western Grammia species, it was relegated to the synonymy of nevadensis by Stretch himself (1873: 238) only a year after he described it, when he concluded that he had been mistaken in thinking it different from nevadensis . There it remained for more than 125 years. The name shastaensis ( French, 1889a) , which was proposed for the same taxon, suffered a similar fate, except that it was mistakenly listed as a junior synonym of G. o r n a t a, and it is here transferred to the synonymy of G. behrii . The name shastaensis was inadvertently omitted in Ferguson & Opler (2006). The reason why behrii was misunderstood is simply that so few have been collected that such a species was not known to exist; also, western species of Grammia have never been adequately or comprehensively studied.

Most specimens of G. behrii are easily recognized by the very wide, complete antemedial band on the forewing, all­black thorax, intense, bright, wing colouring, and reduced black spots on the hindwing ( Fig. 1 e). The forewing markings are ochre yellow on a nearly black background, and the hindwing is intense pinkishred or yellow. The nominate form occurs in northern California and western Oregon from about Point Reyes to Portland, but most specimens we examined are from southwestern Oregon, Trinity and Siskiyou counties, California, and the western foothills of the Sierras in the northern half of California. Remarkably few have been collected. Individuals from G. b e h r i i populations in Los Angeles, Kern, and Riverside counties in southern California are slightly smaller with less saturated colouration, but with much the same wing pattern and genitalic structure.

Redescription. Head and thorax entirely dark brown, almost black (one male from Point Reyes has a hint of pale striping on the thorax). Male antennae dark brown, the branches with a tinge of yellowish; longest branches 4 to 5 x longer than intersegmental (flagellomere) distance. Female antennae slightly biserrate, less so than in G. nevadensis . Underside of body mostly blackish, except that vestiture of coxae and femora usually at least partly yellow; and legs also may be marked with yellow; abdomen above concolourous with hindwing ground colour, with middorsal and lateral segmental black spots, of which the dorsal ones may merge into a solid stripe; underside of abdomen black with transverse, segmental, yellowish bands. Anal tuft black or mixed black and yellowish. Forewing black, with the usual pattern of light bands typical of the nevadensis complex, except that their colour is bright ochreous yellow, at least in fresh specimens; and the antemedial band may be exceptionally wide, up to 5 mm. The medial band may be missing or reduced to one or more small spots at or near the position of the discal spot in other moths. The antemedial, medial (if present) and postmedial bands commonly cross the postcubital to inner margin, but the basal band, as in most species, never does. Fringes blackish, yellow tipped. "Posterior wings rose, inclining to orange,” exactly as Stretch said, although a few (about 10% of those examined) have yellow hindwings that are nearly the same colour as the bands of the forewing. Black markings of hindwing nearly always reduced, commonly to just three spots near the outer margin plus a variable amount of narrow, irregular blackish border along outer margin, especially toward apex; spots of hindwing absent altogether in two examples before me (a male and female). Fringe of hindwing yellowish. Undersurfaces of wings as above but colours washed out, markings more diffuse, and with width of antemedial band further exaggerated. Wing markings similar among the sexes, with females exhibiting brighter, more saturated colours. Length of forewing: male, 17­20 mm (n = 11); female, 20 mm (n = 1).

Male genitalia ( Fig. 3 ). Basically of the nevadensis type but differing from others of that group in having a somewhat more elongate vinculum and valve, and a broader juxta. The vesica is scobinate, with individual spinules larger than those of nevadensis .

Female genitalia. Not examined.

Types. The type material of behrii is apparently lost. There are no specimens among the only remaining Stretch types in the California Academy of Sciences, San Francisco. However, the original description and Stretch’s drawings of the male ( Fig. 2 ) and female are unmistakable. The type material apparently consisted of two males and two females; Fig. 2 is a reproduction of the male illustrated by Stretch (1872: pl. 3, fig. 12) from Downieville, California. There are no known existing behrii types from Stretch’s material, and to ensure the stability of the name and to avoid further confusion with other nevadensis group species, a male specimen from the vicinity of the type locality bearing the following labels is designated as neotype, and is deposited in CNC:

“ USA, California, / Jackson Cr[eek]., Plumas Co[unty]. / 39 50’N 120 39’W, 5400’ / 28 August 2000 / J. Troubridge Leg.”

“Disctn. # / CS­3241”

“ NEOTYPE / Arctia behrii / Stretch 1872 / B.C. Schmidt 2006”

Distribution. Behrii occurs as two separate populations, one from northern CA to northwest OR and west­central ID, the second population in Los Angeles, Kern, and Riverside counties, CA. California. San Francisco Co.: A specimen from San Bruno Mountain, San Francisco appears to be this species. Marin Co.: Pt. Reyes Station (W.R. Bauer). Sierra Co.: Downieville (types). Plumas Co.: Jackson Creek (J. Troubridge); Quincy, 4 mi. WSW of Platina, 2700’ (D.F. Hardwick). Trinity Co.: Norse Butte; 4 mi. S Buckhorn Summit, 4550’; Hyampum; Ruth (R. Spaldoni). Siskiyou Co.: Hornbrook; 3 mi. NE of Mt. Shasta, 5300’. Lake Co.: Clear Lake. Los Angeles Co.: Mint Canyon; Lancaster; Juniper Hills, Mojave Desert (D.C. Henne); Portal Ridge. Kern Co.: Tehachapi; Lebec; Greenhorn Mtns., Oak Flat Lookout (J.P. & K.B.S. Donahue). Riverside Co.: San Jacinto Mtns., W slope (D. Wikle). Oregon. Klamath Co.: 10 mi. S Klamath Falls, reared from sweet clover (F.P.Larson). Multnomah Co.: Portland. Josephine Co.: Eight Dollar Mtn. Rd., (J. Troubridge). Idaho. Boise Co.: 13 mi. NE Garden Valley.

Flight Period. Late August to late September, but single specimens as early as 3 August (Trinity Co.) and as late as 10 October (Pt. Reyes).

Figures

FIGURE 1. Adult males of the Grammia nevadensis species group, a) G. n. nevadensis (Winnemuca, Humboldt Co., NV); b) G. n. superba (Victoria, Vancouver Is., BC); c) G. n. geneura (Estes Park, Larimer Co., CO); d) G. n. gibsoni (Burstall dunes, SK); e) G. behrii (Eight Dollar Mtn., Josephine Co., OR); f) G. i n c o r r u p t a (Comanche Natl. Grassland, Baca Co., CO); g) G. williamsii (Jenner, AB); h) G. eureka (HOLOTYPE, Eureka, Juab Co., UT); i) G. bowmani (PARATYPE, Black Ridge, Mesa Co., CO).

FIGURE 2. Reproduction of illustration accompanying original description of Arctia behrii male (Stretch 1872, pg. 75, plate 3 fig 12).

FIGURES 3 – 8. Male genitalia Grammia nevadensis group species; caudoventral aspect of genital capsule (a) and aedeagus with vesica everted, right lateral aspect. 3) G. nevadensis superba (Oliver, BC), 4) G. behrii (Kern Co., CA), 5) G. incorrupta (Pima Co., AZ), 6) G. williamsii (Jenner, AB), 7) G. eureka (PARATYPE, Eureka, UT), 8) G. bowmani (PARATYPE, Mesa Co., CO).