Sunflower Production Field Guide - Your "Home Page"

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pumpkin. Palestriped fl ea beetles are considered an
important pest of commercially grown vegetables in
some areas of the U.S. Recently, palestriped fl ea beetles
have been observed delaying regrowth of alfalfa
and also were observed feeding on soybean seedlings
in eastern South Dakota.
Damage: Palestriped fl ea beetles chew on the cotyledons,
leaves and hypocotyls of sunfl ower seedlings,
causing them to wilt and die. Injured leaves become
riddled with holes, giving them a “lacey” appearance
(Figure 29). The sunfl ower plant is most sensitive to
palestriped fl ea beetle injury from seedling emergence
(V-E) through the four-leaf stage (V-4). Signifi cant
stand losses may result from heavy feeding injury by
the palestriped fl ea beetles.
■ Figure 29. Damaged sunfl ower leaves by
palestriped fl ea beetle. (Michael Catangui, SDSU)
Scouting Method: Surveys may be accomplished by
using yellow sticky cards placed close to the ground
(Figure 30). Sampling seedlings for beetles also can
aid in estimating populations and feeding injury
levels. Palestriped fl ea beetles move very fast and are
hard to count directly on the seedlings or catch with
an insect net.
Economic Threshold: Control is recommended when
20 percent of the seedling stand is injured and at risk
to loss due to palestriped fl ea beetle feeding. This economic
threshold is a guideline based on published hail
injury data that predicts potential yield loss relative to
seedling stand loss.
Management: Palestriped fl ea beetles are hard to
control with chemical insecticides; research has shown
that treatments may provide up to 75 percent control
of adults.
■ Figure 30. Yellow sticky trap for monitoring
palestriped fl ea beetles. (Michael Catangui, SDSU)