Noctuidae - Psaphidinae - Grotellini




Grotella soror Barnes and McDunnough 1912

Grotella soror Barnes and McDunnough, 1912, Canad. Ent., 44: 19.

Diagnosis: The forewing of Grotella soror is slightly off-white. The postmedial line is single consisting of irregular dots and dashes and there are no traces of any orange band following the postmedial line. The basal line is represented by a small black dot on the forewing costa. The antemedial line is a series of irregular dots and lines and is slightly convex outward. The orbicular mark is absent and the reniform mark is a minute black dot. A large, quadrate dark patch exists in the median area along the costa. A triangle of three black dots exists near the forewing costa between the postmedial line and the outer margin. In addition there are two elongate, double dark patches in the middle of the subterminal region, one on the outer side of the postmedial line and the other near the outer margin. A series of black dots occurs along the outer margin, although the strength of these dots is variable is are never as strong as in the other four species of the species group. The hindwing is strongly suffused with dull black, although the inner half of the wing may be distincly lighter than the outer half. A triangular projection is present along the saccular margin of male valve. This projection is slightly hooked and not straight as in binda and tricolor. The juxta has a bulbous out-pocketing that is absent or barely hinted at in binda and tricolor. The vesica has a ventral diverticulum (in the orientation of the figure). The dorsal group of large spine-like cornuti are larger than in either binda or tricolor and the outer edges of the larger spines have serrate edges. The female appendix bursae is rounded, not quadrate as in binda and tricolor and is not distinctly separate from the corpus bursae. The ductus bursae is broadly joined with the corpus bursae and appendix bursae in what appears to be large swollen region dorsal (behind in the orientation of the figure) behind the appendix bursae.

Adults have been collected in August.

Distribution: This species is known only from Pima and Santa Cruz Counties in southern Arizona. The amount of dark suffusion of the hindwing is variable; the hindwing in some specimens is completely suffused with dark brown-black, but in others the inner half of the hindwing is distinctly lighter than the outer half.

Identification Quality: Excellent

Larva: Unknown

Foodplants: Unknown


Grotella soror

Grotella soror is most likely to be confused with binda. The postmedial line is single in both species and the no orange band is present following it. On the whole the black forewing markings of binda are larger and much more regular than those of soror. The best character separating the two species is the triangle of three dots in the subterminal region near the costa of soror. Only two dots occur in this region in binda. In addition the two dots found in the middle of the subterminal region of soror are completely absent in binda. The hindwing of binda is mostly white, although the apex and costal margin may be shaded with dull gray. The hindwing of soror, in contrast, is almost entirely suffused with dull brown-black.

Similar Species

Grotella binda