Agriculture

Aphids

  • Bean aphid: Aphis fabae
  • Cowpea aphid: Aphis craccivora
  • Green peach aphid: Myzus persicae
  • Pea aphid: Acyrthosiphon pisum
Updated: 06/2018

Tools

PestManage: a decision support tool to view and compare pest management options

Description of the Pest

Aphids are small insects, 0.04 to 0.2 inches (1–5 mm) long that come in a variety of colors. The two most common species encountered on beans are the cowpea aphid and the bean aphid.

  • The adult cowpea aphid has a shiny black body with whitish legs and antennae ending in black tips, while the younger cowpea aphid nymph is a lighter gray.
  • The bean aphid is slightly larger and less shiny than the cowpea aphid. The adult bean aphid is dark purplish-black with light-colored legs, while the younger bean aphid nymph has a slightly reddish tint.
  • The pea aphid is a relatively large (4 mm), green, long-legged aphid.
  • The green peach aphid is dark green to yellow and lacks a waxy covering.

Refer to the photo identification key, Key to the common aphids of cowpeas in California (PDF) for more detailed information.

Damage

Ways that aphids damage plants:

  • Suck plant sap which stunts plants and causes heavily infested leaves to curl
  • Excrete honeydew, a sugary substance that causes sticky, shiny leaves and black sooty mold growth
  • Spread plant diseases (a large number of viruses are vectored by aphids)
  • Inject toxins which can stunt plants

Infestations are frequently localized with heavily infested leaves curled downward.

Management

Assess levels of biological control when evaluating aphid numbers. Frequently, natural enemies prevent aphid infestations from becoming established throughout a field. Temperatures greater than 85°F can slow down increase of pea and green peach aphid numbers.

Biological Control

(View photos to identify natural enemies of aphids)

Common predators of aphids in beans include lady beetles, syrphid flies, and lacewings. Parasitic wasps also attack aphids, turning them into hard, aphid-shaped shells called mummies. Plant field edge habitat that attracts natural enemies and avoid the use of broad-spectrum pesticides known to harm natural enemies.

Organically Acceptable Methods

Planting hedgerows of native California flowering shrubs along field crop edges will enhance natural enemy activity, helping to manage this pest. For more information about planting hedgerows, see Establishing Hedgerows on Farms in California, (PDF) UC ANR publication 8390. Organically approved pesticides are not likely to provide economically viable levels of pest control in dry bean production.

Monitoring and Treatment Decisions

Aphid control in beans is not always necessary. The decision to apply an insecticide for aphids is based mainly on visual inspection and the stage of crop development. Measurable thresholds are not available. Begin inspecting for aphid problems when the crop emerges. Continue monitoring through the vegetative growth and flower bud to bloom stages. Apply an insecticide to seedling plants if they appear to be stressed by aphid populations. Older plants can tolerate low to moderate numbers of aphids.

Pesticides and Natural Enemy Releases

Not all registered pesticides are listed. The following are ranked by their IPM value, with the most effective and least harmful to natural enemies, honey bees, and the environment listed at the top of the table. When choosing a pesticide, consider information related to water and air quality, resistance management, and the pesticide's properties and application timing. Use PestManage to compare summarized management options for different pests in the same crop. Always carefully read the label of the product being used and take all necessary precautions when handling pesticides.

Rank Active ingredient Example trade name Group Group Order MoA 1 Amount per acre REI (hours) ‡ PHI (days) ‡ Comments Selectivity 2 Bees 3 Predatory mites 4 Predators 5 Parasitoids 5 Residue duration 6 Leaching(fish) 7 Adsorbed runoff(fish) 8 Solution runoff(fish) 9 Leaching(human) 10 Solution runoff(human) 11 Last updated 12
F
Leverage 360 Application Timing Varies (See UC IPM Pest Management Guidelines and Label) 8

3A/4A

2.4–2.8 fl oz 12 7 Highly toxic to bees. Review and follow... broad 13 I high high high long — — — — — 08/2024
H
Bifenture EC Application Timing Varies (See UC IPM Pest Management Guidelines and Label) 8

3A

2.1–6.4 fl oz 12 14 — broad 13 I high high high long intermediate low extra high very low intermediate 08/2024
E
Brigadier Application Timing Varies (See UC IPM Pest Management Guidelines and Label) 8

3A/4A

3.8–5.6 fl oz 12 14 Review and follow the California neonico... broad 13 I high high high long — — — — — 08/2024
C
Dimethoate 2.67 EC Application Timing Varies (See UC IPM Pest Management Guidelines and Label) 8

1B

0.75–1.5 pt 48 0 Do not feed sprayed vines to livestock.... broad I high high high long very low low low intermediate high 08/2024
A
Sivanto prime Application Timing Varies (See UC IPM Pest Management Guidelines and Label) 8

4D

7–10.5 fl oz 12 7 — narrow I — — — — very low low low very low low 08/2024
D
Admire Pro Application Timing Varies (See UC IPM Pest Management Guidelines and Label) 8

4A

1.2 fl oz 12 7 Review and follow the California neonico... narrow I — — high short to moderate — — — — — 08/2024
D
Admire Pro Application Timing Varies (See UC IPM Pest Management Guidelines and Label) 8

4A

7–10.5 fl oz 12 21 Review and follow the California neonico... narrow I — — high short to moderate — — — — — 08/2024
G
Warrior II Application Timing Varies (See UC IPM Pest Management Guidelines and Label) 8

3A

1.28–1.92 fl oz 24 21 Do not graze livestock in treated areas... broad I high high high long intermediate low extra high low high 08/2024
B
Fyfanon ULV-AG Application Timing Varies (See UC IPM Pest Management Guidelines and Label) 8

1B

8 fl oz 12 1 Do not graze livestock in treated areas... broad I moderate high high moderate high intermediate extra high very low very low 08/2024
A
Cruiser 5FS Application Timing Varies (See UC IPM Pest Management Guidelines and Label) 8

4A

1.28 fl oz per 100 lbs seed 12 N/A Review and follow the California neonico... narrow I — — moderate short very low very low low high high 08/2024
I
Mustang Maxx Application Timing Varies (See UC IPM Pest Management Guidelines and Label) 8

3A

3.2–4.0 fl oz 12 21 — broad 13 I high moderate moderate moderate intermediate low extra high low high 08/2024
—
No information.
I
Do not apply or allow to drift to plants that are flowering including weeds. Do not allow pesticide to contaminate water accessible to bees including puddles.
II
Do not apply or allow to drift to plants that are flowering including weeds, except when the application is made between sunset and midnight if allowed by the pesticide label and regulations. Do not allow pesticide to contaminate water accessible to bees including puddles.
III
No bee precaution, except when required by the pesticide label or regulations.
  • ‡ a b Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without personal protective equipment. Preharvest interval (PHI) is the number of days from treatment to harvest. In some cases, the REI exceeds the PHI. The longer of the two intervals is the minimum time that must elapse before harvest.
  • 1 ↩ Group numbers for insecticides and miticides are assigned by the Insecticide Resistance Action Committee (IRAC). Insecticides with unknown modes of action are assigned mode-of-action group numbers (MoAs) that begin with UN. Rotate pesticides 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; insecticides with a 1B group number should be alternated with insecticides that have a group number other than 1B.
  • 2 ↩ Range of insect and mite groups affected by a pesticide. Broad means the pesticide affects most groups of insects and mites; narrow means the pesticide affects only a few specific groups.
  • 3 ↩ Risk of harm to honey bees. For more information, see Bee Precaution Pesticide Ratings.
  • 4 ↩ Risk of harm to predatory mites. Toxicities are generally to western predatory mite, Galendromus occidentalis. Where differences have been measured in toxicity of the pesticide-resistant strain versus the native strain, these are listed as pesticide-resistant strain or native strain.
  • 5 a b Risk of harm to parasitoids and general predators. Toxicities are averages of reported effects and should be used only as a general guide. Actual toxicity of a specific insecticide depends on factors including the application rate, environmental conditions, and the life stage and species of a parasitoid or predator.
  • 6 ↩ Length of time residue affects natural enemies. Short means hours to days; moderate means days to 2 weeks; and long means many weeks or months.
  • 7 ↩ Risk of harm to fish from leaching, based on USDA Natural Resources Conservation Service Windows Pesticide Screening Tool (WIN-PST).
  • 8 ↩ Risk of harm to fish from adsorbed runoff, based on USDA Natural Resources Conservation Service Windows Pesticide Screening Tool (WIN-PST).
  • 9 ↩ Risk of harm to fish from solution runoff, based on USDA Natural Resources Conservation Service Windows Pesticide Screening Tool (WIN-PST).
  • 10 ↩ Risk of harm to humans from leaching, based on USDA Natural Resources Conservation Service Windows Pesticide Screening Tool (WIN-PST).
  • 11 ↩ Risk of harm to humans from solution runoff, based on USDA Natural Resources Conservation Service Windows Pesticide Screening Tool (WIN-PST).
  • 12 ↩ Date information was last updated in the UC IPM Pest Management Guidelines.
  • 13 a b c d Harmful mostly to predatory mites rather than pest mites. May cause increase in spider mite numbers.

Important Links

UC Peer Reviewed Logo

UC IPM Pest Management Guidelines: Dry Beans
UC ANR Publication 3446

R.F. Long (emeritus), UC Cooperative Extension Yolo County

P.B. Goodell (emeritus), UC IPM and Kearney Agricultural Research and Extension Center, Parlier

Acknowledgement for Contributions to Invertebrates

L.D. Godfrey, Entomology, UC Davis

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