How to Manage Pests

UC Pest Management Guidelines

Peppers

Flea Beetles

Scientific names:
Palestriped flea beetle: Systena blanda
Potato flea beetle: Epitrix cucumeris
Western potato flea beetle: Epitrix subcrinita
Striped flea beetle: Phyllotreta striolata
Western black flea beetle: Phyllotreta pusilla
Western striped flea beetle: Phyllotreta ramosa
...and other species

(Reviewed 12/09, updated 12/09)

In this Guideline:


DESCRIPTION OF THE PESTS

Flea beetle adults are small (about 0.125 inch long), shiny, hard beetles with enlarged hind legs that allow them to jump. Different species vary in color and markings. Larvae live primarily in the soil, although larvae in a few of the species may mine leaves or plant stems. Larvae are pale yellow to white with short legs and dark, hard heads. Older larvae may resemble small wireworms.

DAMAGE

Adult flea beetles feed on the undersides of leaves leaving small pits or irregularly shaped holes on the leaves. Large populations can kill or stunt seedlings. Older plants rarely suffer economic damage, although their older, lower leaves may be damaged. Adults do most of the damage. Most flea beetle larvae feed on roots, but this activity is not usually of economic concern in peppers.

MANAGEMENT

Flea beetles are common seedling pests, and monitoring newly emerged seedlings is critical for detecting a damaging population. Weed control around the field and using transplants also help to minimize damage by these pests.

Cultural Control

Remove weeds along field margins and deeply disc plant residue in infested fields after harvest. Pay particular attention to cruciferous (Brassicaceae) weeds and crops such as canola, which are common hosts from which beetles can migrate into pepper fields. Transplanting peppers usually avoids the problem unless beetle populations are extremely high.

Organically Acceptable Methods

Cultural controls and sprays of pyrethrin are acceptable for use on organically certified produce.

Monitoring and Treatment Decisions

Check newly emerged seedlings or recently planted transplants for flea beetle damage at least twice weekly until plants are well established. Relatively low populations can cause economic damage when plants are in the cotyledon or first-leaf stages. Once plants have five leaves they can tolerate several beetles per plant without damage. Older plants are even more tolerant. Seedling pepper plants and young transplants do not tolerate flea beetle damage well, and they may be killed if the weather is especially hot, dry, and windy. Damage is generally greater to seedlings than to transplants.

Monitor for flea beetles soon after transplanting or after plants emerge. Treat for flea beetles when small holes show on seedlings or on new transplants. The percentage of plants affected and forecast weather conditions will indicate the need to treat. Once established, plants can overcome moderate flea beetle feeding. If flea beetles are migrating to the pepper field, spot treatment of outside rows or borders may be sufficient. Baits are not effective. One insecticide treatment is usually all that is required.

Common name Amount per acre** R.E.I.+ P.H.I.+
(trade name)   (hours) (days)

  Calculate impact of pesticide on air quality
The following materials are listed in order of usefulness in an IPM program. When choosing a pesticide, consider information relating to impact on natural enemies and pollinators and environmental impact. Not all registered pesticides are listed. Always read the label of the product being used.
 
A. ESFENVALERATE*
  (Asana XL) 5.8–9.6 fl oz 12 7
  MODE-OF-ACTION GROUP NUMBER1: 3
  COMMENTS: Do not exceed 0.35 lb a.i./acre per season. Do not use this product if leafminers are present; it is destructive of their parasites.
 
B. DINOTEFURAN
  (Venom) 3–4 oz (foliar);
5–6 oz (soil)
12 see comments
  MODE-OF-ACTION GROUP NUMBER1: 4A
  COMMENTS: Preharvest interval for foliar application is one day; for soil applications it is 21 days.
 
C. PERMETHRIN*
  (Ambush 25W) 6.4–12.8 oz 12 3
  (Pounce 25WP) 6.4–12.8 oz 12 3
  MODE-OF-ACTION GROUP NUMBER1: 3
  COMMENTS: For use on bell peppers only. Do not apply more than 1.6 lb a.i./acre per season. Do not use this product if leafminers are present; it is destructive of their parasites.
 
D. CARBARYL*
  (Sevin 4F or XLR Plus) 0.5–1 qt 12 3
  MODE-OF-ACTION GROUP NUMBER1: 1A
  COMMENTS: Thorough coverage is important. Do not use if psyllids are present.
 
E. ENDOSULFAN*
  (Thionex 3EC) 0.66–1.33 qt 48 4
  (Thionex 50WP) 1 lb 48 4
  MODE-OF-ACTION GROUP NUMBER1: 2A
  COMMENTS: Do not make more than 2 applications per year.
 
F. PYRETHRIN#
  (PyGanic EC) 16 oz 12 0
  MODE-OF-ACTION GROUP NUMBER1: 3
  COMMENTS: Begin applications when insects first appear; do not wait until the plants are heavily infested. Apply in sufficient water for thorough coverage of the plants. Apply at intervals of 7 days or less. Repeat as necessary to maintain control.
 
** See label for dilution rates.
+ Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.
* Permit required from county agricultural commissioner for purchase or use.
# Acceptable for use on organically grown produce.
1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action Group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a Group number of 1B; chemicals with a 1B Group number should be alternated with chemicals that have a Group number other than 1B. Mode-of-action Group numbers are assigned by IRAC (Insecticide Resistance Action Committee). For additional information, see their Web site at www.irac-online.org.

[Precautions]

PUBLICATION

[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Peppers
UC ANR Publication 3460

Insects and Mites

E. T. Natwick, UC Cooperative Extension, Imperial County
J. T. Trumble, Entomology, UC Riverside
Jose Aguiar, UC Cooperative Extension, Riverside County
Acknowledgment for contributions to Insects and Mites:
W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier
R. L. Coviello, UC Cooperative Extension, Fresno County
C. G. Summers, Kearney Agricultural Center, Parlier
W. E. Chaney, UC Cooperative Extension, Monterey County
C. F. Fouche, UC Cooperative Extension, San Joaquin County

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