New York Natural Heritage Program
Pin-striped Slug Moth
Monoleuca semifascia (Walker, 1855)
Insects

Identifying Characteristics [-]
This species can be identified from a good image or any specimen. The wingspan ranges from 19-27 mm. The forewing is brown, sometimes reddish brown. The only marking is a narrow, wavy, silvery white to yellowish line above the inner margin (Covell 1984). The larvae (caterpillars) are peach colored with wavy, bright reddish-orange, black, or dark brown vertical striping in three sequences of a four-stripe pattern. The bright reddish-orange stripes are covered with numerous white, stinging hairs.
Pin-striped Slug Moth Images
click to enlarge
The Best Time to See
Adults have been observed in June and into July. The larvae or caterpillar stage typically exists from July to September. In the north, there is only one generation each year. This species is not well studied and therefore the entire life history is not well documented.
J F M A M J J A S O N D
Present Reproducing Larvae present and active
The time of year you would expect to find Pin-striped Slug Moth present (blue shading), reproducing (green shading) and larvae present and active (orange shading) in New York.