How to Manage Pests

UC Pest Management Guidelines


Tomato (Potato) Psyllid

Scientific name: Bactericera cockerelli

(Reviewed 12/09, updated 11/12, pesticides updated 6/16)

In this Guideline:


The adult psyllid is a small insect (about 1/8 inch or 3 mm) that resembles a cicada. The adults have white or yellowish markings on the thorax, clear wings, and lines on the abdomen between segments. The tiny eggs are laid on stalks, most commonly on the underside of leaves and along leaf margins, and are best seen with the use of a hand lens. Initially white, they turn a pink color a few hours after they are laid.

Nymphs hatch from eggs in 4 to 15 days and have scalelike, flattened, oval, yellowish green to orangish bodies with red eyes and three pairs of short legs. Older nymphs are greenish and fringed with hairs and have wing buds, which make them easy to distinguish from whitefly nymphs. They develop through five stages (instars) in 2 to 3 weeks before becoming winged adults. Nymphs feed most often on the underside of leaves.

Tomato psyllids have an extensive range of acceptable hosts, but solanaceous plants (tomatoes, potatoes, nightshades) are preferred.


Psyllids have the potential to rapidly build up large populations on peppers. The nymphs, and possibly the adults, inject a toxin while feeding on the foliage, which can cause transplants to die. In larger, pre-flowering plants it can cause stunting, chlorosis, and curling of the leaves. This can lead to either no fruit production or overproduction of very small, non-commercial grade fruit. Collectively, these symptoms are known as psyllid yellows.

In coastal and San Joaquin Valley growing areas they are also known to transmit Candidatus Liberibacter solanacearum, a pathogen of solanaceous crops,which amplifies psyllid feeding damage.

In addition to direct feeding damage, psyllids produce large amounts of honeydew, which often causes sooty mold to colonize. This can result in significant crop losses if the fruit becomes unmarketable. Unlike aphid honeydew, which is a liquid, psyllid honeydew is white and powdery. The powdery deposits must be removed to make the fruit marketable.


Management strategies are aimed at preventing the development of large populations in the field when fruit is present. An application of imidacloprid at planting is an important component of tomato psyllid management. Monitoring fields by inspecting plants as well as the use of sticky traps is essential to detecting a population before it can become established and will help determine the need for in-season foliar treatments.

Biological Control

While predators and parasites may attack psyllids, most parasites attack too late in the psyllid life cycle to stop crop loss and biological control does not appear to be a promising control strategy in the field.

Organically Acceptable Methods

Sprays of the Entrust formulation of spinosad are acceptable for use on organically certified produce.

Monitoring and Treatment Decisions

Monitor fields to determine the need for in-season treatments. Where psyllids occur, place yellow sticky cards near the tops of plants growing at the field margins to monitor psyllid movement. Place the traps on adjustable poles so the height of the traps can be modified with plant growth. If tomato psyllids are caught in traps, examine the foliage of pepper plants located at the field margins for eggs and nymphs. If more than five psyllids per plant are found, treat. Be sure to alternate treatment materials to help prevent the development of insecticide resistance.

Consider treating with imidacloprid at planting if psyllids are present. It is very important not to use carbamates (Sevin, Lannate, Vydate) for the control of other pests as these materials actually promote the development of psyllid populations.

Common name Amount per acre** REI‡ PHI‡
(Example trade name)   (hours) (days)

Calculate impact of pesticide on air quality
Bee precaution pesticide ratings
The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least harmful to natural enemies, honey bees, and the environment are at the top of the table. When choosing a pesticide, consider information relating to air and water quality, resistance management, and the pesticide's properties and application timing. Not all registered pesticides are listed. Always read the label of the product being used.
  (Admire Pro –soil) 7–10.5 fl oz 12 21
  COMMENTS: For a direct-seeded crop apply at planting as a side dress, through drip irrigation, or over the top as seedlings emerge. For transplanted peppers, apply at planting either through drip irrigation or as a soil application. Does not harm most natural enemies. To reduce the potential for the development of resistance, avoid the use of neonicotinoids both as a soil and a foliar application on the same crop. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging.
  (Agri-Mek SC)* 1.75–3.5 fl oz 12 7
  COMMENTS: Do not apply at less than 7-day interval. Do not exceed 48 fl oz/acre per growing season. Do not apply in less than 20 gal water/acre. Do not make more than two sequential applications. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging.
  (Knack) 8–10 fl oz 12 1
  COMMENTS: An insect growth regulator that is not harmful to most natural enemies.
  (Movento) 4.0–5.0 fl oz 24 1
  COMMENTS: Minimum interval between applications is 7 days and maximum allowed per season is 10 fl oz.
  (Oberon 2SC) 7.0–8.5 fl oz 12 1
  COMMENTS: Do not exceed three applications per crop or make applications at less than 7-day intervals.
  (Entrust)# 1.25–2.5 oz 4 1
  (Success) 4–8 fl oz 4 1
  COMMENTS: Do not exceed 29 fl oz of Success or 9 oz of Entrust/acre per crop. Toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging.
** See label for dilution rates.
# Acceptable for use on organically certified produce.
Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (PHI) 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.
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).



[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
J. Aguiar, UC Cooperative Extension, Riverside County

Acknowledgment for contributions to Insects and Mites:
W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier
W. E. Chaney, 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, Kearney Agricultural Center, Parlier

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