Abstract:
The sunflower seed maggot, Neotephritis finalis (Loew), is an emerging pest of
cultivated sunflower throughout the Great Plains sunflower production region. It is a
seed-feeding pest and infests the sunflower plant from late bud stage through the
flowering (Arthur and Campbell 1979). There are two complete generations of this insect
in North Dakota. Adults of first generation emerge during the first week of July and
second generation in the end of the August. During the day, adult maggots occur on
sunflower heads either resting or mating and mated females lay their eggs in the
developing sunflower heads. Larvae of the second generation fall to the ground
overwinter as puparia (Arthur and Campbell 1979).
Crop injury is caused by feeding of the larval stages. After hatching, first instar
larvae start to feed on developing seeds. The magnitude of damage to sunflower seeds by
sunflower seed maggot larvae is largely dependent on the density of larva and stage of
crop development. One larva can cause seed sterility by feeding on 10 or 12 young florets
Mature larvae feeding on older sunflower heads will destroy one to three seeds. Injury to
sunflower can result in a deformed head caused by a creasing and folding toward the
center of the head (Arthur and Campbell 1979)
