Noctuidae - Agaristinae

 

 

Psychomorpha epimenis (Drury)

Phalaena Noctua epimenis Drury, 1782, Illustrations of Natural History, 3:39 (index), pl. 29, fig. 2.

Psychomorpha euryrhoda Hampson, 1910, Catalogue of the Lepidoptera Phalaenae in the British Museum, 9:425, pl. 146, fig. 7.  NEW SYNONYMY

Diagnosis: Psychomorpha epimenis is a distinctive species and is unlikely to be confused with any other North American noctuid. The body, forewing, and hindwing are jet, velvety black. The forewing has a large light yellow, vertically elongate patch at the position of the postmedial line. This patch is notched on its inner side by the lower part of the reniform mark. The reniform mark is otherwise indistinguishable from the black of the forewing as are all of the other forewing markings, although the orbicular and reniform marks and the antemedial line may be visible as slightly darker black markings is the wing is seen in the right light. The lower halves of the basal, median, and subterminal areas are lightly dusted with metallic blue scales, although the reflective scales are normally only seen if the specimen is viewed at an angle and the specimen is fresh. The ventral surface of the forewing is also black, but the yellow patch extends through the cell and the orbicular and reniform marks form two distinct black bars. The black inner margin may have a slightly orange-bronze reflection. The inner two-thirds of the dorsal hindwing is black and the outer third is orange, red-orange, or yellow-orange with a broad, black outer margin. The black outer margin is slightly dusted with reflective blue scales, again seen at the correct angle. The ventral hindwing is similar except the blue reflective scales along the black outer margin are much stronger than they are dorsally.

Distribution: Psychomorpha epimenis is widely distributed in the eastern half of the United States, but is not yet known from Canada. The northeastern boundary of epimenis appears to be in southern New England and southern New York and across Pennsylvania, Indiana, Illinois, and southern Minnesota. In the east the species extends as far south as south-central Florida, and throughout most of the states of the Deep South. The western boundary of the species is on the eastern edge of the Great Plains, occurring in eastern Nebraska, Kansas, and Oklahoma. Psychomorpha epimenis occurs in the eastern half of Texas as well. The most significant within population is the color of the orange patch in the outer third of the hindwing. This patch can be either yellow orange or reddish orange. These two colors form the principle types, but all integrades between the two exist. The reddish-brown color is slightly more typical of males than females, but color is not entirely sex dependent. Significant geographical variation occurs in the size of this patch. The orange patch is significantly larger in South Carolina and most of Florida, occupying one-half to two-thirds of the hindwing. The patch occupies nearly all of the hindwing in some Floridian specimens. Two of these Floridian specimens were the basis of the name euryrhoda.

The adults are spring day fliers and have been collected in late March, April, and May.

Identification Quality: Excellent

Larva: The larva has been described by Crumb (1956) and Riley (1870, 1871). Riley's earlier 1870 paper incorrectly identified the larva as Eudryas unio, a mistake corrected in the 1871 paper. Crumb (1956) simply lists "grape" as a foodplant. Riley (1870, 1871) describes the larva and blue in general, although the blue coloration is not apparent in the preserved material I have seen. Each abdominal segment from one to seven has three vertical brown stripes terminating on each side near the position of seta L3. In addition there is a slightly lighter brown band in each of the intersegmental membranes between abdominal segments. The L3 seta on abdominal segments 1-7 is on a large round, brown pinaculum. Abdominal segment eight is strongly humped and is capped with an orange dorsal patch marked by distinctive brown, round pinacula about the setae D1, D2, SD1, and SD2. Vertical stripes are absent from the prothorax except for a caudal, vertical brown band. All of the setae on the prothorax arise from large, round brown pinacula. The head is orange with the setae sited in large, round brown pinacula. The larva is nearly identical to that of Gerrodes minataea, despite the great superficial differences in the adults. The larva feeds mostly in the terminal buds of the grape vine (Riley, 1870), drawing the leaves together by a weak silken thread. The pupating larva forms an earthen cell or bores in a piece of old, rotten wood.

Foodplants: Riley reared the species from commercial grape, although it is not clear whether the species was Vitis vinifera or Vitis labrusca (Vitaceae).

 

Psychomorpha epimenis

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