Noctuidae - Agaristinae

 

 

Gerrodes minataea Dyar

Gerrodes minataea Dyar, 1912, Proc. U.S. Natl. Mus., 42:72.

Diagnosis: Gerrodes minataea is the largest species of the Agaristinae found in North America north of Mexico. The moth is distinctive. The forewing is wood brown with a strong grayish tinge, particularly along the costa, inner margin, and outer margin. Most of the maculation is obscure. The most distinctive forewing feature is a white stripe along the lower margin of the cubital vein running through the median area. This white stripe is accented on its dorsal margin by a dark rusty-red line which begins near the base and terminates near the position of the postmedial line. Immediately above this line is another rusty-red line, but this line continues upward as the postmedial line to the costal margin. The orbicular, reniform, and claviform marks are absent, as are the basal and antemedial lines. The rusty-red postmedial line is followed by a series of dull white, vague lines. A single darker gray line is following in the terminal region of the wing. The median area is streaked with dull white near the region of the reniform mark, although a reniform mark is absent. The ventral forewing is strikingly different. The basal four-fifths are orange yellow with small red-brown spots marking the orbicular and reniform marks. The outer fifth is red-brown and concolorous with the reniform and orbicular marks. The hindwing above is orange yellow with a broad dark brown outer band. This pattern is repeated on the ventral surface.

Distribution: Gerrodes minataea is a primarily Mexican species that occurs in southern Arizona in the United States and is also known from Guatemala and El Salvador. There is little variability in the species. Females average larger than males.

Identification Quality: Excellent

Larva: The larva is distinctive with a white ground color. Each abdominal segments from one through six have three dorsal-ventral brown bands. The median band is the strongest. This median brown band continues all the way around the segment on abomdinal segments one and two becoming part of a larger, quadrate brown patch on the ventral surface of the segment. The median brown band is interrupted dorsal to the proleg on abdominal segments three through six at about the level of seta L3. Seta L3 on these proleg segments is isolated on a large brown pinaculum. The anterior brown band entirely encircles all abdominal segments one through six, although the band is usually interrupted near the position of seta L2. The posterior brown band is much more restriced than either the median or anterior bands and usually ends near the level of the spiracle. The bands on segment seven are like those on the proleg bearing segments. However, the bands on segment eight are converted to round brown binacula about each of the dorsal and subdorsal setae. The anal shield of segment 10. consists of a dark brown outer trapezoid ring surrouding a dull white center with two dark spots represent the two D1 setae. Only two dark brown bands are present on the prothorax and both terminate dorsal to the large, black spiracle. Each of the prothoracic setae at the level of the spiracle is contained on a large brown pinaculum. The head is dull white with a large dark brown band running laterally across the head between the L1 setae. The P2 setae sits in a large dark brown spot. The A2 and A3 are each contained in large dark brown spot and the two spots are confluent. A large inner mandibular tooth is present. Seta SV1 is present on abdominal segment eight.

Foodplants: There are a series of larvae and an associated adult in the USNM. The foodplant on the label is "grape leaves", presumably a species of Vitis (Vitaceae).

 

Gerrodes minataea

 

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