Grotella binda Barnes 1907
Grotella binda Barnes, 1907, Can. Ent., 39: 93.
Diagnosis: Grotella binda is white with the forewing maculation represented by a series of black dots. The basal line consists of a single black dot on the forewing costa. The antemedial line is an irregular, vaguely convex, line of black dots. The reniform mark is present and in most specimens distinct, always more distinct than the black costal mark opposite it. The postmedial line is an irregular line of black dots, the line curving in below the reniform mark. The strongest component of the postmedial line is a elongate dot along the costal margin. The subterminal line consists solely of two dots, one along the costal margin and the other just below it. There is a series of strong terminal, quadrate dots along the outer margin of the wing. The hindwing is white, but strongly shaded with gray at the apex and along the outer margin. The saccular margin of the male valve has a triangular process in common with Grotella tricolor and soror. However this process is thin and straight and the apex is not recurved as in soror. The triangular projection is located much nearer the apex of the valve in tricolor than in binda. The vesica has the two spine groups separate and no ventral (in the orientation of the figure) diverticulum exists as in soror. The female appendix bursa is quadrate as in tricolor, but is bent at its junction with the corpus bursae and is oriented laterally. The appendix bursae of tricolor, in contrast, is not bent and points caudally.
Adults have been collection in August and September.
Distribution: Grotella binda occurs throughout most of the southwestern United States. The species is found in southwestern Texas, from scattered locations in New Mexico, and most of southern and central Arizona. It has also been collected in San Bernardino and Riverside counties in southern California. No significant geographic variation is visible in the species. Within populations variation exists in the intensity of the black forewing markings. The amount of dark gray in the hindwing is also variable is both species, but on the average more dark gray suffusion is found in females than males.
Identification Quality: Excellent
This species might be confused with blanchardi, but binda is a smaller species. The reniform mark so prominent in binda is absent in blanchardi or represented at most by a minute, vague gray dot. The antemdial line of blanchardi is produced into a triangle at the black spot located in the position of the orbicular mark. Indeed this black spot may be the orbicular mark. The postmedial line of blanchardi is nearly straight or evenly curved from the forewing costa to inner margin. The postmedial line of binda, in contrast, curves inward below the reniform mark. The hindwing postmedial line of blanchardi is usually present and distinctive, but is absent in binda. Grotella binda might also be confused with Grotella soror. The most distinctive difference consists of the dark dots between the forewing postmedial line and the outer margin. There are only two black dots in binda and both of these dots are near the forewing costa. In contrast the black markings of soror are much more extensive. A series of three black spots is present near the costal margin, but none of these three dots is on the costa. Two dots are located along the outer edge of the postmedial line and the third points inwardly from near the terminal line. Two further dark, bilobed, elongate markings occur in the middle of the subterminal region, one along the postmedial line and the second near the outer wing margin. Grotella binda can be immediately separated from tricolor and margueritaria by the single, not double, forewing postmedial line. This species could conceivably be confused with sampita, however its maculation is much more complex than that of sampita (compare the color plates) and the white of sampita has a silvery tinge absent in binda.