Sunflower Moth: Appearance, Territory, Damage and Life Cycle

Latin name: Homoeosoma Ellectellum

Appearances: Silvery-gray snout moths, Homoeosoma ellectellum, wrap their wings tightly when at rest. A few small, darker markings can be found on the wings. Tiny yellow worms hatch from the eggs, feeding mostly on florets and pollen. Sunflower moth caterpillars with older heads have brown or purple stripes and light brown heads.

Host Plants: The sunflower moth is a sporadic pest that attacks sunflowers and other composites like coneflower. Furthermore, their feeding damage may result in infection by Rhizopus, a fungus that causes head rot in plants and requires physical injuries to infect.

Territory: The sunflower moth is a migrating pest that breeds all year in northern Mexico and migrates north with each generation. In North Carolina, they first appear in late June or early July.

Damage Caused: Sunflower moths eat on the seeds and bore into the head, spinning webbing in the process. The caterpillars pupate on the flower head’s webbing or drop from flower heads on silk strands to pupate in soil fissures or under agricultural leftovers.

Sunflower moth larvae that are younger eat mostly florets and pollen. Older larvae tunnel through immature seeds and other components of the head to reach the immature seeds. The fading florets and frass give the sunflower head a trashy aspect as the larvae feed and spin silken threads.

Life Cycle and Habits: In North Dakota and the higher Great Plains, banded sunflower moths have only one generation. In the southern regions, more than one generation is feasible. Adults appear in the field in mid-July and stay until mid-August. Individual moths live for seven to ten days, however due to the extended emergence time, moths are present for roughly eight weeks each season. Although some moths rest in the sunflower field during the day, many are spotted along field edges in vegetation (particularly broadleaf vegetation). Females move onto the field around dusk to lay eggs.

The moths start laying eggs on the bracts of the sunflower heads a week after they emerge. Females prefer to lay their eggs on medium-sized buds rather than smaller or larger buds. At pollen shed and afterwards, only a few eggs are laid on plants. The majority of eggs are laid individually or in tiny clusters on the outer whorl of bracts. On the inner bracts and the underside of the sunflower head, a few eggs are inserted. Eggs remain present until early August, and they hatch five to eight days after they are laid.