Sunflower XIV
Pale-striped Flea Beetles
Gary L. Hein & Frank B. Peairs
Flea beetle adult.
Pale-striped flea beetle damage is very sporadic in sunflower. Populations tend to build up in alfalfa and dry beans, but little is known of the feeding habits of the larval stage of this insect.
Identification (and life cycle/seasonal history)
The pale striped flea beetle is a dark beetle about 1/6 inch long with two pale white stripes running longitudinally on its back. Flea beetles are quick and difficult to see because they will jump off the plants as you approach them. The pale striped flea beetles overwinter as partially grown larvae in the soil. They begin to feed on roots and root hairs as plants begin to germinate in the spring. Adult flea beetles begin to emerge in June, and they are active over an extended period through the late spring and summer. They begin to feed on bean foliage shortly after emergence.
Plant Response and Damage
Adult feeding results in small shot holes (1/16 to 1/8 inch diameter) on leaves and can cause substantial defoliation to young seedlings. Damage at this stage can result in substantial water loss, leading to stressed plants and stand loss. Older plants will also be damaged, but seldom will significant leaf area be damaged. Larvae feed on the roots and root hairs of plants, but the extent of damage to sunflower is not known.
Management Approaches
While significant pale-striped flea beetle infestations in sunflower are uncommon, the risk is greatest during the seedling stage. Treatments should be based on the need to prevent plant stress and stand loss. Risk will be greater near the previous year’s alfalfa or dry bean fields or where host weeds, such as, poverty weed, bindweed and pigweed are numerous. Later in the season, treatment decisions can be based on percent defoliation and expected yield losses according to the following table.
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Estimated % yield reduction from sunflower defoliation occurring at various growth stages (From North Dakota State University Extension Bulletin 25) |
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Percent Defoliation |
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|
10 |
20 |
30 |
40 |
50 |
60 |
70 |
80 |
90 |
100 |
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Growth Stage |
Expected percent yield loss |
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V-4 to V-5 |
0 |
1 |
2 |
2 |
4 |
4 |
5 |
9 |
14 |
21 |
|
V-9 to V-11 |
0 |
2 |
3 |
4 |
5 |
5 |
7 |
11 |
17 |
24 |
|
R-1 |
2 |
4 |
6 |
6 |
7 |
9 |
16 |
24 |
34 |
47 |
|
R-3 |
2 |
8 |
15 |
19 |
24 |
32 |
44 |
59 |
78 |
99 |
|
R-5 |
1 |
3 |
7 |
10 |
16 |
25 |
37 |
49 |
67 |
90 |
|
R-7 |
0 |
1 |
3 |
7 |
10 |
13 |
16 |
18 |
20 |
22 |
|
R-8 |
0 |
1 |
2 |
3 |
5 |
7 |
8 |
9 |
10 |
11 |
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Product list for Flea beetle: |
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Pesticide |
Product/Acre (Fl oz. or oz. product) |
Preharvest Interval, remarks |
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Asana XLR,1 |
5.8 - 9.6 |
28 days. Do not feed forage or fodder tolivestock. Extremely Hazardous to Bees! |
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Baythroid XLR,1 |
0.8 - 1.6 |
30 days. Extremely Hazardous to Bees! |
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carbaryl1,2 |
See labels |
60 days. 30 days to graze or forage. Extremely Hazardous to Bees! |
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chlorpyrifos 4ER1,2 |
32 oz/A |
42 days. Do not graze. Up to 2 lb preplant. Up to 4.5 lb total AI/yr. Extremely Hazardous to Bees! |
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lambda cyhalothrinR1,2 |
1.92 – 3.20 |
45 days. Do not exceed 0.12 lb total AI/yr. Extremely Hazardous to Bees! |
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Seed Treatment
Cruiser 5FS |
0.25 mg ai/seed |
See label for restrictions/ application instructions. |
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RRestricted use pesticide. 1Labeled for chemigation. 2Generic active ingredient, may be additional formulations. |
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The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies. State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality. |
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Categories: Sunflower, Insects, Flea Beetles
Date: 04/24/2006