Noctuidae - Agaristinae





Alypia disparata H. Edwards

Alypia disparata H. Edwards, 1884, Papilio, 4: 13.

Alypia gracilenta Graef, 1887, Ent. Amer., 3: 42.

Diagnosis: Alypia disparata is the southernmost species of the genus occurring from eastern-central Texas southward through eastern Mexico to the southern reaches of the state of Vera Cruz. This species looks like a version of octomaculata with elongate, pointed forewings. The forewing is black and both the anterior and posterior yellow-white spots are present and roughly of the same shape and size as in octomaculata. Pale blue, metallic patches are present in the forewing but are easily seen only in light reflected at the correct angle. A v-shaped pair of blue patches radiates from the base of the wing, one arm angled to the dorsal edge of the interior yellow-white patch and the other angles to the lower edge. A small light blue band arises from the tornus of the forewing and is directed toward the lower, outer angle of the interior yellow-white patch. A lunulate blue band is found along the inner side of the outer yellow patch and it is sometimes preceded by a small blue dot. All of these blue bands and patches are very difficult to see. The ventral surface of the forewing is identical to the dorsal surface except the blue bands and patches are absent. The male forewing has a well developed sound producing structure as discussed in the generic description. The medial swelling of the costal vein is well developed and a distinct clear patch of the wing membrane is present in all but the very freshest of specimens. This sound producing organ, of course, is absent in the female forewing. The hindwing is black with two pure white patches; a large patch at the base of the wing separated by a black bridge through the discal dot from a smaller exterior white dot. The ventral surface is identical to the dorsal side.

This species presents a geographical mystery. Within Texas the species is divided into two very distinctive populations; a population occurring along the Rio Grande River, but collected most commonly in Cameron County and a more northerly population best represented by specimens from near Kerrville in Kerr County. The northern population is considerably larger than the southern population. The average wing length of the Kerr County population (males and females pooled is 17.43 mm from the base of the wing to its apex. The corresponding average wing length for material for Cameron County along the Rio Grande River is 14.58 mm. A more detailed listing of statistics is given below. In addition the metallic blue, reflective forewing scales are more poorly developed in the southern than the northern population, particularly the v-shaped structre at the base of the wing. I have not seen any specimens from localities located between these two populations. The species may not be present in the intermediate zone, or possibly has just not been collected there. Alternatively two distinct species may be present. I have not detected any significant differences in the male or female genitalia other than size. The Mexican specimens I have seen are all (except for one) like those found in southern Texas. The single exception is the holotype of disparata which was stated to come from "Vera Cruz, Mexico" and collected by William Schaus. This specimen may be mislabeled. Wing length: (Kerr County, Texas, (males) mean = 16.80 mm, standard deviation = 0.81 mm, n = 5; (Kerr County, Texas (females) mean = 18.06 mm, standard deviation = 0.30 mm, n = 5; (Kerr County, Texas pooled (males +females) mean = 17.43 mm, standard deviation = 0.88 mm., n = 10; (Cameron Co., Texas (males) mean = 13.62 mm, standard deviation = 0.56 mm, n = 5; (Cameron County, Texas (females) mean = 15.54 mm, standard deviation = 0.65 mm, n = 5; (Cameron County, Texas pooled (males + females) mean = 14.58 mm, standard deviation = 1.16 mm, n = 10.

Distribution: Alypia disparata occurs in central and southern Texas and down along the the eastern third of Mexico to southern Vera Cruz. The size differences within Texas population is discussed above.

Adults of the central Texas population have been collected in March and April. Adults of the southern Texas population have been taken in April, June, and October.

Identification Quality: Good

Larva: The larva is not known with certainty. However there is a single blown larva in the USNM from Brownsville, Texas (but no other information) and identified as octomaculata. Alypia octomaculata does not occur as far south as Brownsville and the larva is probably the immature of disparata. The larva is similar to that of octomaculata. However, the following differences are present. First the spiracular regions of abdominal segments one through seven lack the orange patches of both octomaculata and langtoni, although orange may be found in the ventral and lower lateral regions. A strong black band runs vertically through the D1, SD1, and spiracles on the mesothorax and metathorax and abdominal segments 1 through 5. This dark line is much stronger than the other vertically running lines. This line, if present, in octomaculata, is not stronger than the other vertical lines.

Foodplants: I have seen adult specimens reared by Roy Kendall from Ampelopsis arborea (Vitaceae) (Pepper Vine), a species in the same genus as Virginia Creeper, a common foodplant of octomaculata.


Alypia disparata

Alypia disparata is sympatric only with octomaculata, octomaculata occurring is northern and central Texas. The elongate, pointed forewing of disparata should almost always separate the two species. There are a number of other distinctive features that may be used to identify disparata. The palpi of disparata are completely brown-black. The palpi of octomaculata (as well as langtoni and wittfeldii) have a large patch of yellow scales on the lower third of the first palpal segment as well as a ring of yellow scales around the apex of the second segment. A patch of yellow scales is present in octomaculata on the anterior margin of the thorax formed by the yellow interior edges of the two patagia. This yellow patch in absent in disparata. The dorsal surface of the abdomen of octomaculata almost always has some white scaling, usually as a line running along the dorsal surface and ending is a white dot on the eighth tergum. The white scaling is variable in development in octomaculata, but is nearly always present. White scaling is always absent in disparata. I have not found any consistent differences between the male genitalia of these two species. The female genitalia differ in three minor, although consistent ways. The caudal ends of the circular sclerite defining the shape of the basket-shaped ostium of octomaculata bend ventrally when meeting the seventh abdominal segment and form a small overhang on each side of the ostium. The caudal ends of disparata, in contrast, do not bend ventrally, but rather meet the seventh abdominal segment in parallel and do not form small overhanging structures. The ductus bursae is about twice as long as wide in disparata, but never greater than one and one-half times as long in octomaculata. Finally the outer sides of the ostium flare outward more strongly in disparata than in octomaculata, a difference evident in the figures if difficult to describe.

Similar Species

Alypia octomaculata