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How to Manage Pests
UC Pest Management Guidelines
Cole Crops
Flea Beetles
Scientific Names:
Palestriped flea beetle: Systena blanda
Striped flea beetle : Phyllotreta striolata
Western black flea beetle: Phyllotreta pusilla
Western striped flea beetle: Phyllotreta ramosa
(Reviewed 6/07,
updated 6/07)
In this Guideline:
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Flea beetle adults are small (about 0.125 inch or 1 mm long), shiny,
hard beetles with enlarged hind legs that allow them to jump like fleas.
Different species vary in color and markings. Adults do most of the damage;
flea beetle larvae may mine leaves or feed on roots, but this activity is not
of economic concern.
Flea beetles feed on the undersides of leaves, creating small pits or
irregularly shaped holes. Large populations can kill or stunt seedlings. Older
plants rarely suffer economic damage although their older, lower leaves may be
damaged.
Flea beetles occasionally infest cole crop seedlings. They are most
common in spring but can occur any time, especially in fields that are weedy or
surrounded by weeds. Remove weeds along field margins and deeply disk plant
residue in infested fields after harvest. Regular monitoring of seedlings for
these pests will help detect problems and treatment needs.
Organically Acceptable
Methods
Cultural control is acceptable in an organically certified crop.
Insecticidal soaps applied at cotyledon stage may provide partial control.
Monitoring and
Treatment Decisions
Check newly emerged seedlings twice weekly for flea beetle damage until
plants are well established. Relatively low populations can cause economic
damage when plants are in the cotyledon or first-leaf stages. Treat if you find
several damaged rows; spot treatment of outside rows or borders may be
sufficient. Baits are not effective.
If populations are high,
treat infested fields just before thinning to prevent post-thinning damage.
Once plants have 5 leaves they can tolerate several beetles per plant without
damage. Older plants are even more tolerant. One insecticide treatment should
be all that is required.
| Common name |
Amount/Acre |
R.E.I.+ |
P.H.I.+ |
| (trade name) |
|
(hours) |
(days) |
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| When choosing a
pesticide, consider information relating to the impact on natural enemies and
honey bees and environmental
impact.
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| A. |
CARBARYL* |
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(Sevin) 4F or XLR |
1–2 pt |
12 |
3 |
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(Sevin) 80S |
0.67–1.25 lb |
12 |
3 |
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MODE OF ACTION GROUP NUMBER1: 1A
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COMMENTS: For broccoli, Brussels sprouts, cabbage, cauliflower. |
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| B. |
CHLORPYRIFOS |
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(Lorsban) 4E* |
2 pt |
24 |
see comments |
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MODE OF ACTION GROUP
NUMBER1: 1B
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COMMENTS: Preharvest
interval for cauliflower is 3 days, cabbage and broccoli 30 days, and
Brussels sprouts 21 days. Avoid drift and tailwater runoff into surface waters. |
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...or... |
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(Lorsban) 50W |
2 lb |
24 |
21 |
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MODE OF ACTION GROUP
NUMBER1: 1B
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COMMENTS: For
broccoli, Brussels sprouts, cabbage, cauliflower. Avoid drift and tailwater runoff into surface waters. |
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| C. |
DIAZINON* |
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(Diazinon) 50W |
0.5–1 lb |
24 |
see comments |
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(Diazinon) AG 500 |
0.5–1 pt |
24 |
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MODE OF ACTION GROUP
NUMBER1: 1B
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COMMENTS: Avoid drift
and tailwater runoff into surface waters. Preharvest interval is 7 days for
broccoli, Brussels sprouts and cauliflower and 21 days for cabbage. See label for other cole crops. |
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| D. |
ESFENVALERATE* |
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(Asana XL) |
2.4–5.8 fl oz |
12 |
3 |
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MODE OF ACTION GROUP NUMBER1: 3
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COMMENTS: For broccoli, cabbage, and cauliflower. |
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| E. |
INSECTICIDAL SOAP# |
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(M-Pede) |
Label rates |
12 |
0 |
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MODE OF ACTION: A contact fungicide with smothering and barrier effects. |
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COMMENTS: For
broccoli, Brussels sprouts, cabbage, cauliflower. Provides partial control of flea beetles when plants are in the cotyledon stage. |
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| F. |
CRYOLITE |
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(Cryolite) 96W |
8–16 lb |
12 |
7 |
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MODE OF ACTION GROUP
NUMBER1: 9A
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COMMENTS: For use on
broccoli, brussel sprouts, and cauliflower. Must be ingested by the insect.
Apply when early insects are present. Can be used in an insecticide resistance management program. |
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UC IPM Pest Management Guidelines: Cole Crops
UC ANR Publication 3442
Insects
W. E. Chaney, UC Cooperative Extension, Monterey Co.
E. T. Natwick, UC Cooperative Extension, Imperial Co.
Acknowledgments for contributions to the insects section:
W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier
N. C. Toscano, Entomology, UC Riverside
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