Lacinipolia vicina (Grote, 1874)
OR : Malheur Co.
Namorf, 2637 ft
June 14, 2007, L. G. Crabo.
Specimen courtesy of LGCC
Photograph copyright: Merrill A. Peterson
Lacinipolia vicina is a medium-sized gray moth (FW length 14 - 16 mm) with a pattern of crisp lines and spots that include a long basal dash, a long pointed claviform spot, and a light yellow and black mark near the anal angle in combination with a white hindwing with dark veins that flies in dry forests during the summer. The forewing is relatively long and has a pointed apex. It is mottled medium-dark gray. The basal area is light whitish gray anterior to a black basal dash. A thin brown or red-brown area abuts the anterior claviform spot across the median area. The cell medial to the reniform spot is dark gray in some specimens. A patch of gray that is slightly lighter than the ground is present in the anterior subterminal area below the dark costa and at the apex in the terminal area. The rest of the terminal area is dark gray. The basal, antemedial, and postmedial lines are gray, partially double filled with the ground color or slightly paler gray. The basal line is curved, evident anterior to the basal dash. The antemedial line is faint, angled toward the outer margin and weakly excurved with apex at the base of the claviform spot when visible, usually most evident on the costa and at the fold. The median line is dark gray, angled from the costa to the medial reniform spot and absent on the posterior wing. The postmedial line is weakly scalloped, is nearly straight lateral to the reniform spot, then angled toward the base with a prominent pale-filled concave segment in the fold. The subterminal line is pale gray except pale yellow in the fold, moderately irregular with a weak W-mark to the outer margin on veins M3 and CuA2. It is preceded by a series of black lines or long wedges that are absent near the costa and longest on the mid-wing and in the fold. A dark gray to diffuse black spot is present in the adjacent terminal area, extending into the fringe. The terminal line is black, thin. The fringe is dark gray with a light weakly checkered base. The orbicular and reniform spots are outlined in black and gray, darkest along the medial and lateral orbicular spot and the medial and inferior reniform spot. The orbicular spot is ovoid, tilted toward the base anteriorly, filled with light gray peripherally and the ground color to light gray centrally. The reniform spot lacks a dark outline laterally, is asymetrically kidney-shaped with a longer posterior end, and is filled like the orbicular spot. The claviform spot is black, long, always spanning the median area, with straight edges and a pointed tip, filled with the ground color or black in a few specimens. The hindwing is pearly white in males, pearly light gray in females, with a dark gray marginal band that is thin in males except wider along the veins and wider in females. The veins are black near the margin and white at the base. The discal spot and thin terminal line are dark gray and the fringe is white with a light gray base in males; white with a dark gray base in females. The head and thorax are hoary medium to dark gray with a black transverse line on the distal collar and dark edges on the tegulae. The eyes are covered with fine hairs. The male antenna is biserrate.
This species can recognized by the combination of medium-gray forewing, long pointed claviform spot, light yellow and black mark on the anal angle, and white hindwing with black distal veins and limited dark shading that appears to clump around the ends of the veins. Lacinipolia vicina is very close to some forms of Lacinipolia pensilis in superficial appearance and can be very difficult to separate without resorting to dissection. In general, L. vicina is larger than L. pensilis, has a more pointed apex, and is less variable in color and pattern. The claviform spot of L. vicina is always long and pointed, reaching the postmedial line. That of L. pensilis can have this appearance but is often shorter or less pointed. Red-brown color in the median area is restricted to the area near the claviform spot in L. vicina but is often more extensive in L. pensilis. The hindwing color of L. vicina is whiter with more of a sheen than in L. pensilis, dark on the veins is usually restricted to near the outer margin, and the marginal shading is less extensive and is usually clumped near the ends of the veins. In L. pensilis the wing becomes gradually darker and the shading is more diffuse without extending proximally around the veins. In females, the hindwing is pearly light gray in L. vicina and darker gray without a sheen in L. pensilis. Lacinipolia vicina usually flies slightly earlier in the year than L. pensilis and has a shorter flight season. It is also more restricted to dry open forest and shrublands, while L. pensilis is found in a variety of habitats from wetter forest to open steppe. The juxta of the male genitalia, the area through which the aedeagus emerges, differs between these species. This usually requires dissection to be observed by can be seen in fresh material by spreading apart the valves. That of L. vicina is bordered on each side by a large flat plate that is covered with long straight spines that point dorsad, while that of L. pensilis has patches of curved spines lateral to the opening.
Lacinipolia vicina is less likely to be confused with other moths. Lacinipolia longiclava, a species that is restricted to western Montana in our area, has a long claviform spot but is smaller than L. vicina, paler gray and tan, and has pale streaks in the fold that L. vicina lacks.
This species is widely distributed throughout most of North America in drier, relatively open habitats. In the Pacific Northwest, it is most common in oak savanna and oak woodlands at low elevations west of the Cascades, and in juniper woodlands at middle elevations east of the Cascades. It occurs occasionally in coastal rainforests, mixed hardwood forests, and mixed hardwood-conifer forests west of the Cascades, spruce-fir forests along the summit of the Cascades, and in open ponderosa pine forests and dry sagebrush steppe east of the Cascades, but is uncommon to rare in these latter habitats.
Lacinipolia vicina is widespread east of the Cascade Mountains in our region. It occurs as far north as south-central British Columbia and as far east as southeastern Idaho. Its range is restricted to western Oregon west of the Cascades. It is often absent from open steppe habitats, although it occurs commonly around the edges of our interior basins.
The range of this species extends east to the Atlantic Coast. It is most common and widespread in the West where it occurs from the southern Canadian Prairie Provinces and British Columbia to southern New Mexico, Arizona, and California. In the east it occurs from southern Canada about as far south as the Ohio River.
This species is a climbing cutworm that feeds on various kinds of herbaceous vegetation, particularly in the families Asteraceae and Fabaceae.
Adults of L. vicina fly during the summer, most commonly during late June and July. Some specimens have been found as early as late May and as late as September. It is nocturnal and comes to lights.