Description of the Pest
Green peach aphid is among the most common aphid species found on peppers. It may be present at any time throughout the year but is most common from March through May and September through November. Generally its color is pale green, although at times individuals may be present that are pinkish. During cool weather, individuals are usually more deeply pigmented. Both winged and wingless forms of the green peach aphid have prominent cornicles on the abdomen that are markedly swollen and clublike in appearance. The frontal tubercles at the base of the antennae are very prominent and are convergent. Winged forms of the green peach aphid have a distinct dark patch near the tip of the abdomen; wingless forms lack this dark patch.
Damage
The green peach aphid transmits a number of destructive viruses in pepper including pepper potyviruses and cucumber mosaic cucumovirus. In addition, it can also damage the plant by sucking plant sap. Damaging levels are characterized by large numbers of aphids found on the underside of leaves. Extensive feeding causes plants to turn yellow and the leaves to curl downward and inward from the edges. Honeydew produced by the aphids can be a problem, especially on fresh market peppers. Aphid damage is most prominent on newer, younger leaves in the center of the plant.
Management
Biological and cultural controls can be useful for limiting damage from this aphid. For instance, removing old crop debris from the field will reduce sources of virus and thereby its transmission by aphids, and using reflective mulches early in the season will repel aphids from young plants. Heavy infestations on seedling and young plants may require treatment with insecticides.
Biological Control
The green peach aphid is attacked by a number of common predators, including lacewings, lady beetles, syrphid flies, and parasites, including the parasitic wasps Lysiphlebus testaceipes, Aphidius matricariae, Aphelinus semiflavus, and Diaeretiella rapae, and is susceptible to the fungus disease, Entomophthora spp., that commonly attacks aphids. Aphid sampling should always include an evaluation of the presence and activity of natural enemies.
Cultural Control
An important factor in reducing virus spread is good field sanitation, especially the chopping or discing of crop debris immediately after harvest and destruction of alternate host plants. While field sanitation helps control the incidence and spread of viruses transmitted by green peach aphid, it does little to control the aphid itself. The spread of the virus within a geographical area can be reduced by not planting peppers near other pepper fields.
If peppers are planted near large areas of rangeland, it may not be possible to prevent the influx of green peach aphid. Studies have shown, however, that aluminum foil or silver reflective plastic mulches can be effective in repelling aphids from plants.
Organically Acceptable Methods
Biological and cultural controls and sprays of insecticidal soap (potassium salts of fatty acids) or pyrethrin are acceptable for use on organically certified crops.
Monitoring and Treatment Decisions
Set out sticky traps before planting and check traps weekly for green peach aphids, along with thrips, tomato psyllid, and whiteflies. Be sure to replace traps as needed. When aphids are observed on traps, start monitoring pepper plants to determine population levels. Treatment thresholds for green peach aphid are not well established. Heavy populations can do extensive damage, particularly on seedlings or young plants. If seedlings or young plants show signs of stress because of aphid feeding, consider an insecticide application. If green peach aphids have been a problem in the past, apply imidacloprid at planting.
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(human) 9 | Leaching(human) 10 | Solution runoff(human) 11 | Last updated 12 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
|
Assail 70WP | Application Timing Varies (See UC IPM Pest Management Guidelines and Label) | 8 |
4A |
0.8–1.7 oz | 12 | 7 | Do not make more than 4 applications per... | moderate | — 13 | — 14 | — | moderate | very low | very low | low | very low | low | 06/2016 | ||
|
|
Dimethoate 400 | Application Timing Varies (See UC IPM Pest Management Guidelines and Label) | 8 |
1B |
0.5–0.6 pt | 48 | 0 | Highly toxic to bees; do not spray direc... | broad | high | high | high | long | very low | low | low | intermediate | high | 06/2016 | ||
|
|
Dimethoate E267 | Application Timing Varies (See UC IPM Pest Management Guidelines and Label) | 8 |
1B |
0.75–1 pt | 48 | 0 | Highly toxic to bees; do not spray direc... | broad | high | high | high | long | — | — | — | — | — | 06/2016 | ||
|
|
Beleaf 50 SG | Application Timing Varies (See UC IPM Pest Management Guidelines and Label) | 8 |
29 |
2.8–4.28 oz | 12 | 0 | — | narrow | low | low | low | short | very low | very low | low | low | intermediate | 06/2016 | ||
|
|
Admire Pro | Application Timing Varies (See UC IPM Pest Management Guidelines and Label) | 8 |
4A |
1.3–2.2 fl oz | 12 | 0 | Apply as a foliar application according... | narrow | — | low | low | long | — | — | — | — | — | 06/2016 | ||
|
|
Admire Pro | Application Timing Varies (See UC IPM Pest Management Guidelines and Label) | 8 |
4A |
7–14 fl oz | 12 | 21 | Apply as a soil application according to... | narrow | — | low | low | long | — | — | — | — | — | 06/2016 | ||
| Lannate SP | Application Timing Varies (See UC IPM Pest Management Guidelines and Label) | 8 |
1A |
0.5–1 lb | 48 | 3 | Apply in sufficient water (5–15 gal/acre... | broad | high | high | high | moderate | — | — | — | — | — | 06/2016 | |||
|
|
M-Pede # | Application Timing Varies (See UC IPM Pest Management Guidelines and Label) | 8 |
— |
2.5 oz/gal water | 12 | 0 | Insecticidal soap gives only partial con... | broad | moderate | moderate | moderate | short | low | intermediate | intermediate | very low | low | 06/2016 | ||
|
|
Fulfill | Application Timing Varies (See UC IPM Pest Management Guidelines and Label) | 8 |
9B |
2.75 oz | 12 | 0 | Can be applied either by soil or drip ap... | narrow | low | low | low | short | very low | low | low | intermediate | high | 06/2016 | ||
|
|
PyGanic EC 1.4 II # | Application Timing Varies (See UC IPM Pest Management Guidelines and Label) | 8 |
3A |
16 oz | 12 | 0 | Begin applications when insects first ap... | broad | — | moderate | moderate | short | low | low | high | very low | intermediate | 06/2016 | ||
|
|
Movento | Application Timing Varies (See UC IPM Pest Management Guidelines and Label) | 8 |
23 |
4.0–5.0 fl oz | 24 | 1 | — | narrow | — | — | — | — | low | very low | low | very low | low | 06/2016 | ||
|
|
Actara | Application Timing Varies (See UC IPM Pest Management Guidelines and Label) | 8 |
4A |
2.0–3.0 oz | 12 | 0 | Do not exceed 0.172 lb a.i./acre per sea... | narrow | — 13 | — | moderate | moderate | very low | very low | low | high | high | 06/2016 |
Legend
- ‡ 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.
- * a Permit required from county agricultural commissioner for purchase or use.
- # a b Acceptable for use on certified organic crops. Check with your certifier to confirm before application.
- 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 May cause an increase in spider mite numbers.
- 14 ↩ Acute toxicity is low but reproductive capacity is reduced.
UC IPM Pest Management Guidelines: Peppers
UC ANR Publication 3460
E.T. Natwick (emeritus), UC Cooperative Extension Imperial County
J.T. Trumble, Entomology, UC Riverside
J.L. Aguiar, UC Cooperative Extension Riverside County
Acknowledgement for Contributions to Invertebrates
W.J. Bentley (emeritus), UC IPM and Kearney Agricultural Research and Extension Center, Parlier
W.E. Chaney (emeritus), UC Cooperative Extension Monterey County
R.L. Coviello, UC Cooperative Extension Fresno County
C.F. Fouche, UC Cooperative Extension San Joaquin County
C.G. Summers (emeritus), Entomology, UC Davis and Kearney Agricultural Research and Extension Center, Parlier
