Apamea apamiformis

Distinguished from other Apamea species by the white-scaled concave border of the reniform spot on the forewing. The dimorphic coloration (dark and light forms) is a notable feature. In the Upper Midwest, larvae are identified by their presence within wild rice florets and grain heads, and their resemblance to rice grains. Adults may be confused with other cutworm moths in the genus Apamea, which are notoriously difficult to separate based on appearance alone.

Adults have a wingspan of approximately 39 mm (1.5 in). Forewings show two distinct color morphs: a dark form and a light form. The reniform spot is dark with distinctive white scales along its concave border facing the outer wing margin. Hindwings and body coloration correspond to the forewing morph. Larvae are grub-like and may be mistaken for rice grains during harvest.

Associated with wetlands and aquatic environments where wild rice (Zizania spp.) grows. Adults are attracted to light and nectar sources, particularly common milkweed flowers. Larval habitat is restricted to the flowering heads and stalks of wild rice plants.

North America: primarily in the Upper Midwest and eastern Canada. Documented from Wisconsin, New York, Minnesota, Manitoba, and Saskatchewan. Populations in Maryland are imperiled, Indiana critically imperiled, and New Jersey vulnerable.

Adults active June to August, with timing varying by location. Egg laying occurs late June/early July to early August. Larvae overwinter in soil or rice stalks from September through spring. Pupation occurs mid-spring with emergence following.

Adults feed on nectar, specifically observed on common milkweed (Asclepias syriaca) flowers. Larvae feed exclusively on wild rice (Zizania spp.): initially consuming the ovary of the host floret, then maturing grain in flower heads from third instar onward.

• Zizania spp. - larval host plantWild rice; eggs laid in florets, larvae feed on ovary and maturing grain
• Asclepias syriaca - adult nectar sourceCommon milkweed

Eggs laid in wild rice florets (late June–early August). Eggs hatch in 8–9 days. First–second instar larvae consume floret ovary, then balloon on silk threads to new florets. Third–sixth/seventh instars feed on maturing grain in flower heads. Late instars (September) burrow into soil or rice stalks to overwinter. Spring emergence, feeding, and molt to eighth instar, followed by pupation. Adults emerge June–August.

Newly hatched larvae produce silk threads for ballooning dispersal between wild rice florets. Late instar larvae construct overwintering shelters by boring into rice stalks or burying in soil. Adults are nocturnal and attracted to light.

Specialist herbivore of wild rice. As a significant consumer of wild rice grain, it influences seed production and plant fitness in both natural and cultivated stands. Serves as prey for generalist predators in wetland ecosystems.

Major economic pest of cultivated wild rice in Minnesota and the Upper Midwest, considered the most serious insect pest of this crop. Larval infestation reduces yield and grain quality. Larvae may be harvested with rice and mistaken for grain, affecting product quality. Conservation concern exists for peripheral populations (Maryland, Indiana, New Jersey).

• Other Apamea speciesCutworm moths in this genus are notoriously difficult to identify due to individual variation and overlapping morphology; A. apamiformis distinguished by reniform spot pattern and association with wild rice habitat

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Bug Eric: National Moth Week Recap for Colorado Springs