Hypoprepia lampyroides Palting & Ferguson

Palting, John Douglas, Ferguson, Douglas C. & Moore, Wendy, 2018, A new species of Hypoprepia from the mountains of central Arizona (Lepidoptera, Erebidae, Arctiinae, Lithosiini), ZooKeys 788, pp. 19-38 : 23-29

Hypoprepia lampyroides Palting & Ferguson sp. n. Figs 1-2, 3-4, 5, 8, 9-10, 13-14, 18, 19

Type material.

Holotype ♂. Arizona:, [Apache Co.], White Mountains, Greer, 8,200 ft., 4-5 July 1988, R.H. Leuschner [USNM]. Paratypes 32♂ 3♀. Arizona: Santa Cruz Co., 8.5 mi. SE of Patagonia, Harshaw Canyon, 4,850 ft., 24 July 1998, D.E. Bowman, 1♀ [DEBC]; 29♂ 2♀, Greenlee Co., Blue Ridge Primitive Wilderness, US Hwy 191, vicinity of Rose Peak, 33°26'N 109°22'W, 8084 ft., 19 June 2017 [specimens distributed between JDPC (8♂), UAIC (6♂), CNC (5♂ 1♀), USNM (8♂ 1♀), UNAM (2♂), and RBNC (1♀)]. Mexico: 10 mi. W. of El Salto, Durango, 9,000 ft, 13 June 1964, J.E.H. Martin, 1♂ [CNC]; 2♂, Sonora, Mesa del Campanero, Barranca El Salto, elevation 6561', Municipio de Yecora,, 2 July 2013, J. Palting [JDPC, UNAM].

Etymology.

The specific epithet lampyroides means "like Lampyra " referring to this species’ remarkable mimicry of a sympatric lampyrid beetle species, as discussed below.

Diagnosis.

Hypoprepia lampyroides (Figs 1-5) occurs sympatrically with H. inculta (Figure 6) and is easily distinguishable externally by its larger size; unmarked blackish forewings; brighter more extensively pink hindwings; somewhat different palpi; and different male antennae that more nearly resemble those of H. cadaverosa. The antenna differs structurally from that of H. inculta (Figure 7), which exhibit squarish, closely set segments (flagellomeres) with little space between them. The laminae of the antennal segments of H. lampyroides (Figure 8) are conspicuously raised, tapered, and appear farther apart when viewed laterally. The antenna of H. lampyroides is more like that of H. cadaverosa , a species that it does not otherwise resemble.

Internally, the male H. lampyroides (Figs 9-10) differs from H. inculta (Figs 11-12) in the form of the spinose cornutus on the dorsal vesica chamber, which is apically elongated in H. lampyroides versus sawblade-like in H. inculta . Hypoprepia lampyroides males always have three well-developed spinose cornuti (Figure 10), whereas the left ventrolateral cornutus (adjacent to the ductus) is often missing or reduced in H. inculta (Figure 12). The shape of the valve and tegumen is stouter and less elongate than in H. inculta . In females, the corpus bursae is globose (Figure 13) versus irregularly elongate in H. inculta (Figure 14), with four instead of three signa, the right-ventral signa possessing smaller spines than the corresponding right-ventral signa in H. inculta .

Description.

Sexes similar externally (Figs 3-4), but females with pink area on dorsal hindwing not quite as extensive, and with boundary between pink part and dark outer border more diffuse. Head. Vestiture of frons and vertex dark grey; labial palpus dark grey, upturned, slightly larger and longer than that of H. inculta , terminal (3rd) segment 1.25 × longer than 2nd; eye large, protuberant, more clearly exceeding a half sphere than those of the other Hypoprepia species; male antenna blackish, laminate, densely clothed with short setae beneath and with a few longer setae protruding sublaterally along the sides; female antenna simple, flagelliform.

Thorax. Dark brown or dark gray except for the tegula, which is mostly bright pink, matching basal spot of forewing; patagium blackish; legs entirely blackish or dark gray.

Abdomen. Vestiture gray, flushed with pink basally and terminally, ventrum entirely blackish or dark gray, except for some pink scales at distal end ( H. inculta also may have a pink-tipped abdomen); ventral sternite A8 of males with reinforced, sclerotized rim-like anterior margin, but no pockets, coremata or androconial setae are visible on segments A7-A8. In females, pleurite of A7 with membranous but thick pockets, appearing somewhat rugose and more heavily sclerotized than surrounding integument. Forewing. Uniformly dark brown to charcoal gray, appearing blackish, unmarked except for a pink spot at base next to thorax, and lacking the pale streak on basal half of cubital vein seen in many H. inculta ; male forewing length 17-20 mm, mean 17.5 mm (n = 6); female average forewing length 15.8 mm (n = 2) (usually 12-15 mm for both sexes of H. inculta ). Hindwing. Hindwing pink, with a uniform, dark-gray costal and outer margin, ending just before anal angle; fringes gray to dark brown; ventrum of both wings similar to dorsum but slightly paler, and with more diffuse boundaries between pink and gray areas. Male genitalia (Figs 9-10) Generally similar to those of H. inculta ; uncus cylindrical, flattened slightly laterally, oval in cross section, 8.8 × longer than wide; apex formed by slightly ventrally-curved, fine spine; basal two thirds with sparse, latero-basally directed setae; tegumen well-defined, rounded quadrate and dorsoventrally flattened with a slight constriction at juncture with vinculum; dorsal surface convex and bubble-like on either side of midline, densely covered in setal sockets distally; valve without clasper or process, slightly constricted basally, distal half rounded triangular, apex a rounded point, with short, broad somewhat spine-like setae along distal third of costal margin; sacculus not differentiated from remainder of valve, with a slight sub-basal, setose bulge; juxta indistinct, forming a dorsally emarginate rounded-rectangular transverse plate, approximately 4 × wider than long; phallus a straight, simple cylinder, 2.5 × longer than wide, coecum lacking; vesica consisting of three adjoining, globose chambers, the phallus appearing more or less as a tripartite club when vesica expanded; ventral chamber adjacent to ductus ejaculatorius, with additional lobe-like diverticulum, and with a spinose crest-like patch apically; laterodorsal chambers also with spinose crests. Female genitalia. (Figure 13) Papillae anales broadly diamond-shaped, sparsely setose; anterior and posterior apophysis relatively short, approximately equal in length to width of papillae; postvaginal aree with triangular scerlotization; ductus bursae short and broad, 1.5 × wider than long, highly flattened dorsoventrally and recurved ventrally; corpus bursae relatively small and globose, diameter 1.5-2 × width of ductus; signa consisting of two pairs of spinose straps, situated laterally near junction of ductus; cervix bursae situated right caudo-laterally and recurving left across ventral side of ductus.

Biology and distribution.

The brown eggs of H. lampyroides (Figure 16) were laid in small clusters inside a vial containing a piece of paper, and under magnification exhibit the "hammered copper" surface texture typical of lithosiine ova. These hatched after 14 days, the larvae being light yellowish initially then darkening as they fed. The larval stages are basically dark brown and unmarked throughout their development. Like other Hypoprepia (and other members of the subtribe Cisthenini) the larvae lack true verrucae ( Bendib and Minet 1999) and instead have structures technically known as panniculae ( Stehr 1987) with just one or two, stiff, black setae emerging from each (Figs 17-19). The larva is similar to H. inculta , which is also predominantly brown with black setae, while H. cadaverosa , reared by JDP at the same time as H. lampyroides , are marked with bright yellow bands (Figure 20). The larval mandible, dissected (Figure 21), shows the enlarged molar region found in other lithosiines. This feature has been suggested as a synapomorphy for the Lithosiini ( Bendib and Minet 1999) and is believed to be related to their lichen diet. The larvae fed successfully on a mixed population of lichens obtained by shaving bark off oak trees, and developed through six instars into a caterpillar large enough to pupate. Unfortunately, lab conditions failed to yield a successful pupation, and the larvae eventually died. It is likely that H. lampyroides over-winter as a fully mature larva, pupating in the spring and emerging in early summer.

The striking resemblance of this moth at rest (Figs 1-2) to a common southwest species of firefly, Ellychnia corrusca Linnaeus, 1767 ( Coleoptera : Lampyridae ) (Figure 23), points to them being part of a mimicry ring, which also includes another common montane beetle, Discodon bipunctatum Schaeffer, 1908 ( Coleoptera : Cantharidae ) (Figure 22). Ellychnia corrusca was common during the day in the Rose Peak area, and the bright pink markings on its pronotal region closely match the pink markings at the base of the forewing in H. lampyroides , likely affording the resting moths protection should a bird or other predator come upon them. Lampyrids are known to be chemically protected and distasteful to birds, but unlike most familiar nocturnal fireflies, Ellychnia lacks an abdominal light and is primarily diurnal. Research on sequestration of lichen polyphenolic compounds by other lithosiine arctiids ( Hesbacher et al. 1995, Conner 2009, Scott et al. 2014) suggests that H. lampyroides itself has some chemical protection, thus the mimicry between these organisms is likely Mullerian. H. inculta is also likely part of this mimicry ring, although with its smaller size, dull pink markings, and grey wing color, it is a much less dramatic match to Ellychnia than H. lampyroides .

Hypoprepia lampyroides is known from over 30 specimens collected in Arizona, two specimens from Yecora, Sonora, Mexico and one from Durango, Mexico (Figure 24).

Remarks.

When examining the nearest relatives of H. lampyroides , Ferguson found that H. inculta from the southwestern United States is indistinguishable from the type material of H. muelleri Dyar, described from the vicinity of Mexico City, H. muelleri tends to have darker, more grayish hindwings, although in some H. inculta from Arizona they are equally grayish. Such a difference by itself is hardly significant. Unfortunately, fresh collected material of H. muelleri was not available for molecular analysis, but Ferguson’s conclusion based on his examination of the type material results in the following taxonomic change: Hypoprepia muelleri Dyar, = Hypoprepia inculta Henry Edwards, syn. n. This extends the known range of H. inculta from as far north as Utah to the vicinity of Mexico City. H. muelleri had previously been the only member of the genus found exclusively in Mexico.

Ferguson found the Durango, Mexico specimen of H. lampyroides among unidentified arctiids from the Canadian National Collection. The region of El Salto, Durango, where it was collected, is mesic, conifer-dominated forest similar to that around Greer, Rose Peak, and Yecora, Sonora. The Harshaw specimen, a female, was collected by Don Bowman of Golden, Colorado and sent to Ferguson for identification. The Harshaw region is rather dry mid-elevation oak woodland/mesquite grassland, very unlike where all the other specimens of this moth have been collected.