wavy-lined emerald

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SNR - Unranked

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Wavy-lined emerald is a small, common, widespread, geometer moth. It occurs throughout the United States, Mexico, and southern Canada. The larvae feed on a wide variety of plants but especially plants in the aster (Asteraceae) family. Adults are found from late June through August in open areas with forbs, including prairies, meadows, old fields, and disturbed areas. They are also found in shrublands and open woodlands, but rarely in closed canopy forests with a sparse forb layer.

Adults have a ½″ to 15⁄16″ (13 to 24 mm) wingspan. That is relatively large for an emerald moth (subfamily Geometrinae) but relatively small for a geometer moth (family Geometridae). Size is often given in terms of forewing length. The forewing length of females is 5⁄16″ to ½″ (8.5 to 12.0 mm), with a mean length of 7⁄16″ (10.51 mm). The forewing length of males is ¼″ to 7⁄16″ (7.0 to 10.5 mm), with a mean length of 5⁄16″ (8.67 mm).

The antennae on the male are broadly feather-like with branches along both sides of the shaft (bipectinate) on the basal two-thirds. The extensions taper abruptly beyond the middle and the terminal one-third of the antennae are slender and unbranched. On the female the antennae are slender and unbranched.

The wings are relatively large for the body size. They are rounded, never pointed or angled. They are pale green with a bright pigment that never fades and with no red or brown markings. The antemedial (AM) and postmedial (PM) lines are white and narrow. They are straight or only slightly wavy or toothed. On some individuals, the subterminal (ST) line is visible as a white dot at the end of each vein.

The subcosta (Sc) and radius (R) veins are fused for only a short distance.

The hindwings are the same color and have the same lines as the forewing. Some individuals have a slight outward bulge on the PM line between veins M3 and Cu2.

The abdomen is the same color as the wings, and it has a white longitudinal line down the middle (middorsal).

The caterpillar is small, no more than ⅝″ (1.5 cm) long. The body is brown, black, and white. There is a white oblique line on both sides of each abdominal segment that runs through the breathing pore (spiracle). Each segment of the thorax and abdomen has two elongated protuberances on the upper side, one near each side (subdorsal). The protuberances on abdominal segments 1 through 5 are especially long. Each protuberance has a stiff hair (seta) at the end and numerous much smaller spines. The caterpillar camouflages itself by attaching to the protuberances bits of the plants that it feeds on. With its small size it is best found by scanning Asteraceae flowers for anomalous plant fragments.

Wingspan: ½″ to 15⁄16″ (13 to 24 mm)

Open areas with forbs, including prairies, meadows, old fields, and disturbed areas. Also shrublands and open woodlands.

One generation per year from late June to August in the cool season zone, which includes Minnesota. Two or more generations per year in the transition zone and warm season zone.

Adults are active at night and will come to lights. They rest with their wings spread out and flat.

Partially grown larvae overwinter

A wide variety of plants but especially plants in the aster (Asteraceae) family.

Flower nectar

Sources

4, 21, 27, 29, 30, 75, 82, 83.

The Moths of America North of Mexico Fascicle 18.1. Geometroidea, Geometridae (Part), Geometrinae Douglas C. Ferguson . 1985. The Wedge Entomological Research Foundation.

Common

Synchlora is a large genus of small moths. There are 42 Synchlora species worldwide, 12 species in North America north of Mexico, and just 1 species in Minnesota.

Synchlora aerata wavy-lined emerald moth

Synchlora aerata, wavy-lined emerald moth caterpillars are fairly common in fields, weedy areas, and in my case, tallgrass prairie remnants. The caterpillars disguise themselves by gluing parts of flowers onto their bodies. They're tiny, under half an inch, and often overlooked, because they look like dead parts of a flower.

Adults I've found seem to like hedgerows, or shrubby areas near the prairie.

wavy-lined emerald caterpillar on black-eyed Susan July 11 2021

wavy-lined emerald caterpillar on sweet black-eyed Susan, July 11 2021

Synchlora aerata caterpillar on purple coneflower
7 20 2022 Barnes Prairie

Location: Barnes Prairie, Racine Co. WI

Synchlora aerata caterpillar on purple coneflower 7 20 2022 Barnes Prairie

Location: Barnes Prairie or remnant prairies, Racine Co., Wisconsin

wavy-lined emerald caterpillar on black-eyed Susan July 11 2021