Doryodes bistrialis (Geyer, 1832)

Lafontaine, J. Donald & Sullivan, J. Bolling, 2015, A revision of the genus Doryodes Guenee, 1857, with descriptions of six new species (Lepidoptera, Erebidae, Catocalinae, Euclidiini), ZooKeys 527, pp. 3-30 : 9

Taxon classification Animalia Lepidoptera Erebidae

Doryodes bistrialis (Geyer, 1832) Figs 1-3, 33, 43

Agriphila bistrialis Geyer, 1832: 38; pl. 133, figs 775, 776.

Ligia acutaria Herrich-Schäffer, [1852]: 74; pl. 73, fig. 447.

Type material.

Agriphila bistrialis : type lost. Given the difficulty of identifying species of Doryodes from an illustration, and the lack of a type locality for Agriphila bistrialis , we designate a neotype in order to preserve the long-standing identity of the inland species of Doryodes . Neotype ♂, USA, North Carolina, Carteret Co., Croatan National Forest, Sam Hatcher Road, 23 April 2006, J. Bolling Sullivan. BOLD barcode Sample ID: 06-NCCC-932 [USNM].

Ligia acutaria is nominally described from southern Russia, although already in 1852 Herrich-Schäffer suspected it was mislabeled. The type is lost, so to ensure that the current synonymy is maintained, we designate the neotype of Agriphila bistrialis as Neotype of Ligia acutaria also.

Other material examined and distribution.

We have examined material from North Carolina east of the Piedmont, from most of Florida except for the Keys and Panhandle and a single male from a power cut near Grand Bay National Wildlife Refuge, Jackson County, Mississippi. Specimens from Florida, Mississippi and North Carolina are closely similar in appearance, genitalia and barcodes.

Diagnosis.

Superficially, adults usually can be identified by the narrower dark stripe on the forewing and their relatively small size (forewing length: ♂ 13.0-15.5 mm, ♀ 14.5-16.0 mm). Compared to Doryodes spadaria the medial longitudinal stripe on the forewing of Doryodes bistrialis is much narrower and the hindwings are whitish not buff through June emergences. Later in the year, Doryodes spadaria hindwings become more whitish, so wing length and the width of the longitudinal line must be relied upon to distinguish the species, or genital characters must be examined for positive identification. Females of Doryodes bistrialis do not overlap those of Doryodes spadaria in size, females of Doryodes spadaria having a forewing length of 18.0-21.0 mm. The male vesica is also diagnostic in Doryodes bistrialis in that there is a line of smaller cornuti extending along the trunk usually in three patches, whereas in Doryodes spadaria there are two side-by-side cornuti on the basal trunk of the vesica. In Doryodes bistrialis , diverticulum 1 is 2-3 × as long as wide and has a deeply-serrated rooster-comb-like cornutus at the apex; Doryodes spadaria has no diverticulum in this position and the cornuti in the vesica are triangular, sometimes minutely serrated on one side. Doryodes bistrialis can be distinguished from Doryodes fusselli by the shape of diverticulum 1, which is rounded in Doryodes fusselli and about as long as wide; also the apex of the vesica in Doryodes bistrialis is symmetrical with a triangular cornutus on a pouch on each side (diverticula 4 and 5). Doryodes bistrialis can be distinguished from Doryodes reineckei and Doryodes latistriga by the wing pattern and by size and from Doryodes broui by the characters of the vesica. Along the Gulf Coast Doryodes bistrialis could be confused with Doryodes broui and Doryodes tenuistriga , but characters of the vesica ( Doryodes broui , Fig. 40 and Doryodes tenuistriga , Fig. 42, versus Doryodes bistrialis , Fig. 33) readily distinguish these three species and Doryodes bistrialis occurs farther inland. The female genitalia of Doryodes bistrialis are elongated with a more compact, less differentiated, appendix bursae than in Doryodes spadaria .

Distribution and biology.

Doryodes bistrialis , unlike all other species in the genus, occurs mainly inland away from coastal salt marshes. It occurs in pine savannas where wiregrass ( Aristida stricta ), the presumed food plant, is abundant. It has only been recorded in North Carolina, Mississippi and Florida, and it follows the distribution of the presumed foodplant, Aristida stricta . The species is on the wing from April through October in North Carolina, and throughout the year in Florida. The species appears to be associated with wiregrass, but we were unable to successfully rear it on cut grasses. Eggs should be placed on potted Aristida and larvae monitored to determine their preference for the grass or detritus in the base of the grass clump. In North Carolina the savannas are usually a half mile or more inland from coastal marshes and extend westward into the Sandhills adjacent to the piedmont. It is possible that the salt marsh species and the wiregrass species could occur in the same or very close areas where coastal marshes penetrate inland but we did not find such areas.