Euchromius ocellea is one of the few micromoths that I had previously made the effort to identify, primarily because they are, when seen up close, quite the spectacular moth. And the sheer number of them (as there were during the ‘3rd Night of Moth Week’) make them a little harder to ignore than other micros. In Europe and Africa where they are native, they are known to migrate in vast numbers, flights which can cross the English Channel and even the Mediterranean Sea. These migration happen to a lesser extent in North America “…but their abundance is wildly erratic, as though they sporadically emigrate in large numbers…” Powell/Opler, “Moths of Western North America”; 2009.
This beautiful little member of the family Crambidae, “which is called the “necklace veneer” in England, is a widespread Palaearctic species thought to have been native in the Mediterranean region. It has been imported worldwide and reached western North America in the nineteenth century, even Hawaii by 1882. This is one of the most widespread moths in the western United States, often seen at lights, and sometimes incredibly abundant. For example more than 2,000 were caught in an 8-watt blacklight trap in weedy grassland on tiny Santa Barbara Island, 25 miles from the nearest other land.” Powell/Opler, “Moths of Western North America”; 2009.
Description– “ The FW (8–10.5 mm) is elongate, tan sprinkled with black scales, and has two parallel, ochreous yellow, transverse bands beyond midwing, enclosing a whitish streak and bordered by gray. There is a row of golden metallic spots preceded by black bars along the termen from below the apex to the tornus, like the jewels of a necklace. The HW is white.” Powell/Opler, “Moths of Western North America”; 2009.
Similar species– “In E. californicalis, the forewing bands are placed at a slightly different angle to the costa than in E. ocelleus, and the terminal line dots are bordered proximally by a wide white strip, whereas E. ocelleus has a narrow white strip bordering the terminal line dots.” Species Euchromius ocellea – Hodges#5454 – BugGuide.Net
Habitat– Grasslands, lawns, disturbed ground, and agricultural areas.
Range– Introduced species with a cosmopolitan range; “Georgia and Florida to California(1); in the west, occurs north to Oregon, Washington and North Dakota. (2), (3); Wisconsin and Kentucky; Ontario, Canada.” Species Euchromius ocellea – Hodges#5454 – BugGuide.Net; found region wide in the PNW.
Eats– According to BugGuide “Larvae feed on corn roots. Previous reports of feeding on grain products and dried vegetation are erroneous per Hahn Capps in proceedings of U.S. National Museum, 1967.” Species Euchromius ocellea – Hodges#5454 – BugGuide.Net; however Powell/Opler, in “Moths of Western North America”; 2009, say “The larvae are dead-leaf feeders, including Asteraceae and dry thatch, and must do well on Mediterranean annual grasses in the Pacific states…”, and I usually find them near grassy areas.
Eaten by– Presumably a host for parasitoids in Hymenoptera and Diptera, and probably preyed upon by insectivores of all classes, but I can find nothing specific for this species.
Adults active– April into October
Life cycle– Oddly, I can find nothing specific for this species, but based on the length of their flight season I would guess they are multivoltine, and based on how early in the year they start flying I would guess that they overwinter as pupae in diapause.
Etymology of names– Euchromius is from the Greek words for ‘well colored’, referring to the bright pigmentation of many members of this genus. The specific epithet ocellea is from the Latin for ‘little eye’, and refers to the metallic spots at the end of the forewing.