Sunflower Production Field Guide - Your "Home Page"

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Quick Reference Guide to Major Sunfl ower Insects
The information presented on this page is designed to be a quick reference for growers, crop consultants, fi eld scouts and
others. Since this information is very brief, the user should refer to the following pages for more detailed data on life cycles,
damage, descriptions, etc.
Insects Description Occurrence, Injury and Economic Threshold (ET)
Cutworms Dirty gray to gray brown. ET – 1 per square foot or 25 percent to 30 percent stand
(several species) Grublike larva, 0.25 to 1.5 inches in length. reduction. Appear in early spring when plants are in the
seedling stage, chewing them at or slightly above ground.
Palestriped Adult: 1/8 inch long and shiny black, with two white ET – 20 percent of the seedling stand is injured and at risk
Flea Beetle stripes on the back. The hind legs are enlarged and to loss due to palestriped fl ea beetle feeding. Scout for
modifi ed for jumping. fl ea beetles by visually estimating population on seedlings
or using yellow sticky cards placed close to the ground.
Sunfl ower Beetle Adult: reddish-brown head, cream back with three ET – 1 to 2/seedling (adults), or 10 to 15/seedling
dark stripes on each wing cover. Body 0.25 to 0.5 (larvae). Adults appear in early June, larvae shortly
inch long. Larva: yellowish green, humpbacked in thereafter. Both adults and larvae chew large holes
appearance, 0.35 inch in length. in leaves.
Sunfl ower Adult: wingspread 0.63 to 0.75 inch, gray brown ET – none. First generation adults appear in late May to
Bud Moth with two dark transverse bands on forewings. mid-June. Second generation adults appear in midsummer.
Larva: Cream-colored body (0.33 to 0.4 inch) with Larvae from fi rst generation damage terminals and stalks,
a brown head. whereas second generation larvae feed in receptacle area.
Longhorned Adult: pale gray and 5/8 inch (6 to 11 mm) in No scouting method or ET has been developed. Adults are
Beetle (Dectes) length, with long gray and black banded antennae. present from late June through August. Larvae tunnel and
Larvae: yellowish with fl eshy protuberances on the feed in the petioles and stem pith and girdle the base of
fi rst seven abdominal segments (1/3 to 1/2 inch) plants. Stalks often break at the point of larval girdling.
Sunfl ower Stem Adult: small (0.19 inch long) weevil with a ET – 1 adult/3 plants in late June to early July. Adults
Weevil gray-brown background and white dots on the back. appear in mid to late June, with larvae in stalks from
early July to late summer.
Thistle Caterpillar Adult: wingspread of 2 inches, upper wing surface brown ET – 25 percent defoliation, provided that most of the
(Painted Lady with red and orange mottling and white and black spots. larvae still are less than 1.25 inches in length. Adults
Butterfl y) Larva: brown to black, spiny, with a pale yellow stripe appear in early to mid-June, with larvae appearing
on each side, 1.25 to 1.5 inches in length. shortly thereafter. Larvae chew holes in leaves.
Sunfl ower Midge Adult: small (0.07 inch), tan, gnatlike insect. ET – none. Adult emergence begins in early July. Larvae
Larva: cream or yellowish, 0.09 inch long, tapered at feed around head margin and at the base of the seeds,
front and rear. causing shrinkage and distortion of heads.
Sunfl ower Seed Adults: the red sunfl ower seed weevil is about 0.12 ET – generally 8 to 14 adult red sunfl ower weevils per head
Weevils inch long and rusty in color. The gray sunfl ower seed (oil) and one per head (confectionery). Adults appear in
weevil is about 0.14 inch long and gray in color. late June to early July. Treat for red sunfl ower seed weevil
Larvae: both species are cream-colored, legless and at R5.1 to R5.4. Larvae feed in seeds from mid to late
C-shaped. summer.
Sunfl ower Moth Adult: body is 0.38 inch long, with 0.75 inch ET – 1 to 2 adults/5 plants at onset of bloom. Adults are
wingspread. Color is buff to gray. Larva: brown head migratory and usually appear in early to mid-July. Larvae
capsule with alternate dark and light lines running
longitudinally, 0.75 inch in length.
tunnel in seeds from late July to late August.
Banded Sunfl ower Adult: small 0.25-inch straw-colored moth with brown ET – See banded sunfl ower moth section for egg or adult
Moth triangular area on forewing. Larva: in early growth sampling methods for determining ET. Sampling should be
stage, off-white, changing to red and then green color conducted in the late bud stage (R-3), usually during midat
maturity, 0.44 inch in length. July. Adults appear about mid-July to mid-August. Larvae
present in heads from mid-July to mid-September.
Lygus Bug Adult: small (0.2 inch in length), cryptically colored ET - for CONFECTION SUNFLOWERS ONLY –
insects with a distinctive yellow triangle or “V” on 1 Lygus bug per 9 heads. Two insecticide sprays are
the wings and vary in color from pale green to dark recommended: one application at the onset of pollen shed
brown. Nymph (immature stages): usually green and or 10 percent bloom, followed by a second treatment
similar in appearance to the adults, but lack wings. 7 days later.
Sunfl ower Adult: metallic, black, 0.25-inch long body with a long ET – none. Adults appear in mid to late July and create
Headclipping “snout.” Larvae: 0.25 inch in length. feeding punctures around stalk just below the heads.
Weevil Heads drop off.
NOTE: The insects discussed above are listed in the order that they likely are to occur throughout the growing season; however, the various insects
may or may not appear, depending upon overwintering survival and environmental conditions as the season progresses. The table is intended
simply as a guide to when fi elds should be checked for possible presence of the various insects known to infest sunfl owers.