Noctuidae - Agaristinae

 

 

Euscirrhopterus gloveri
(Grote and Robinson)

Euscirrhopterus gloveri Grote and Robinson, 1868, Trans. Amer. Ent. Soc., 2:185.

Hortonius euenemus Dyar, 1926, Insecutor Inscitiae Menstruus, 14:95.

Diagnosis: Euscirrhopterus gloveri and cosyra are not sexually dimorphic as is poeyi. Both the male and the female of gloveri have a gray or gray-brown forewing with a prominent white stripe reaching from the base of the wing, through the cell, and curving upward to the costa just before the wing apex. Most of the rest of the forewing maculation of gloveri is absent. However the orbicular and reniform marks are prominent. The orbicular mark is large and round with an outer black defining line and a dark central dot. The reniform mark is also distinctive, kidney shaped, with an outer black defining line and a slightly darker central vertical line. The dorsal margin of the white band follows the margin of the costa, but is not well defined. The lower margin is roughly triangular. The inner half is approximately straight up to a point nearly midway between the orbicular and reniform marks, then angles upward to the lower margin of the reniform mark. The margin then curves outward to the position of the postmedial line (if it was present) and then upward again to the costa. The only remaining maculation is a series of strong black dashes and dots surrounded by pale areas along the outer margin of the wing. The ventral forewing is yellow-orange except for the gray-brown apex and outer margin. The dark region is widest at the forewing costa, narrowing toward the middle of the wing and then expanding just before the inner margin. The orbicular and reniform marks are prominent dark, round spots. The black dots and dashes of upper side are also present. The hindwing is yellow-orange with a broad gray-brown band along the outer margin. The dark band is interrupted by a diffuse yellow-orange spot just above the anal angle. The vague dark discal spot (showing through from the ventral side) is present. The ventral hindwing is similar to its dorsal surface except the discal dot is much more prominent and a series of curved black dashes is present along the outer margin. A piece of the dark outer band is cut off as a round blotch in the anal angle. The frontal process of gloveri is a large, rectangular, shovel-shaped projection with a tridentate outer margin. The abdomen is yellow-orange except for a large tufted of curled gray-brown scales on the first abdominal tergum. A few gray-brown scales are also found on each succeeding abdominal tergum. The female genitalia are easily separable from those of poeyi as described in the generic description. The corpus bursae is less than the half of the size of poeyi, and is globular, not ovate-elongate. The ductus bursae is about twice and long as wide and is directed caudally. The ductus bursae of poeyi curves dorsally and to the right.

Distribution (See Map on Left): Euscirrhopterus gloveri is common in the southern and central United States. It occurs in Nebraska and Kansas, southward throughout Texas, New Mexico, and Arizona. The species lives in most of Mexico and has been taken as far south as Guatemala. A specimen in the USNM is labeled Mt. Shasta, California. This locality needs to be verified. There is no discernable geographic variation in gloveri. Males are smaller, on average than females. There is little significant variation in this species. The gray-brown of the forewing is slightly variable, tending to be slightly grayer in fresher specimens.

Adults have been collected in July, August, and September.

Identification Quality: Excellent

Larva: The larva and life history of gloveri have been described several times, noteably by Riley (1888) and Crumb (1956). The larva overall is dull white. The most distinctive feature of the larva is a vertical black stripe running from just below the mid-dorsal line to just below the level of the spiracle on each thoracic segment and abdominal segments one through eight. An orange horizontal band runs below the spiracles along the thorax and the first eight abdominal segment. A double orange blotch occurs on the dorsum of these same segments caudal to the vertical black bands. The remainder of each of these segments is irregularly reticulate with brown-black. The dorsum of abdominal segment eighth is a mixture of orange and brown-black spots. The prolegs are darkly sclerotized. The head is orange with brown-black spots. The larva feeds on the leaves of the foodplants. During pupation the larva forms a long tubular structure of dirt and mud. The pupa has the same blade-like frontal process and the process may be used in breaking out of the pupal cell. The larva and pupa are illustrated by Riley (1888).

Foodplants: The cited foodplant is Portulaca oleracea (Purslane) (Portulaceae), a recumbent, slightly fleshy herbaceous plant. Larvae and associated adults in the USNM list Talinum aura. I have not found a species of Talinum by this name, but it may be an abbreviation of Talinum aurantiacum (Portulaceae). Portulaca oleracea is believed to be an introduced weed from the Old World. Several species of Portulaca occur in the range of this species. The species possibly feeds generally in the plant family Portulaceae

 

Euscirrhopterus gloveri

Euscirrhopterus gloveri is easily separable from both cosyra and the females of poeyi. The best character is the shape of the frontal process. The frontal process of gloveri is a large, blade shaped projection with a tridentate outer margin. The frontal processes of both poeyi and cosyra are round rings and are neither blade-shaped, not do they project nearly as far as in gloveri. The width of the front between the eyes is sexually dimorphic in poeyi and cosyra. The front is extremely narrow in the males of poeyi and cosyra, but considerably wider in the females. In contrast the front is wide in both the males and the females of gloveri. The males of poeyi, of course, are very different from their females and from males and females of gloveri and are not an identification problem. The lower margin of the broad white forewing band in the female of poeyi is evenly curved, not angulate as in gloveri. The reniform mark of the female forewing of poeyi is comma-shaped, not kidney-shaped. The reniform and orbicular marks of cosyra are both absent, a feature immediately separating cosyra from gloveri.

Similar Species

Euscirrhopterus poeyi (female)

Euscirrhopterus cosyra