Yellow postocular scales:
Europe, North Africa, Asia Minor, Afghanistan and North America. Non-native.
Feeds on Melilotus species (including Melilotus officinalis and Melilotus altissima). These are non-native species of clover.
Coleophora apicialbella is a very similar species native to North America. It is only known from Ohio and Indiana, and the larvae feed on fire pink (Silene virginica). The adults are on average smaller and their forewings have a pronounced reddish sheen. The postocular scales are orange yellow, as opposed to pale yellow in C. trifolii.
Coleophora deauratella is another introduced species and is also very similar, but the postocular scales are dark brown.
Coleophora mayrella is likewise introduced and has dark brown postocular scales. More conspicuously, the portion of the antennae between the thickened base and the white tip has alternating light and dark bands.
C. deauratella and C. mayrella have thicker antenna bases than those of C. trifolii.
(Landry & Wright 1993)
Landry, Jean-François and Barry Wright. 1993. Systematics of the Nearctic species of metallic-green Coleophora (Lepidoptera: Coleophoridae). The Canadian Entomologist 125(3):549-618.