Thymelicus lineola
Identification: Tiny—FW 0.5". Sexes similar below. Above: FW and HW bright, deep orange with narrow dark margins. Male has a very narrow dark stigma paralleling the outer edge of the inner FW. Antennae are relatively short, with blunt tips (unlike the curved, pointed tips of other skippers). Below: FW and HW unmarked. FW pale orange, HW noticeably more grayish or greenish. Similar skippers: Swarthy is dark above, with pale veining on HW below. Least is even smaller, with rounded wings. Delaware is brighter orange overall (especially when fresh), with prominent black cell-end bars and black veining above. Tawny-edged is pale brown on HW below, contrasting with orange on leading edge of FW, and HW often has a faint spotband.
NJ Status and Distribution: Nonnative resident. As its name implies, the "Euro" is an alien species, native to Eurasia. It was first seen in NJ in the late 1950s and has since colonized the entire state. It is widespread and fairly common in northern NJ, becoming much less so in the south.
Habitat: Any kind of open area with tall grasses. Readily visits garden flowers.
Flight Period: Early June—early July. Extreme dates: North Jersey 5/20—7/14; South Jersey 5/19—7/25.
Caterpillar Food Plants: Timothy (Phleum pratense), Orchard Grass (Dactylis glomerata).
Overwintering Stage: Egg with developed 1st-instar caterpillar inside.
Good Locations: Crystal Springs CP, Schooley’s Mountain CP, Big Brook Park, Flatbrookville, Delaware Water Gap NRA, Estell Manor Road, Lummis Ponds Preserve.
Comments: This is one of only two non-native species of butterfly in NJ (the other is Cabbage White).