How to Manage Pests

UC Pest Management Guidelines

Citrus

Citrus Thrips

Scientific Name: Scirtothrips citri

(Reviewed 2/17, updated 2/17)

In this Guideline:


Description of the Pest

Adult citrus thrips are small, orange-yellow insects with fringed wings. During spring and summer, females lay about 25 eggs in new leaf tissue, young fruit, or green twigs; in fall, overwintering eggs are laid mostly in the last growth flush of the season. Overwintered eggs hatch in March about the time of the new spring growth. First-instar larvae are very small, whereas second-instar larvae are about the size of adults, spindle-shaped, and wingless. They feed actively on tender leaves and fruit, especially under the sepals of young fruit. Third- and fourth-instar (propupa and pupa) thrips do not feed and complete development on the ground or in the crevices of trees. When adults emerge, they move actively around the tree foliage.

Citrus thrips do not develop below 58°F (14°C). They can produce 8 to 12 generations during the year if the weather is favorable.

When monitoring citrus thrips, you must be able to distinguish them from flower thrips, which feed on flower parts but do not damage citrus. Shortly after petal fall, immature flower thrips can be seen moving around young fruit, but they soon pupate and adults disperse to other plants, consequently they are only concentrated in citrus orchards for a short period in spring. For more information on distinguishing citrus thrips from other thrips, see UC ANR Publication 3303, Integrated Pest Management for Citrus, 3rd edition.

Damage

Citrus thrips is of greatest economic importance on San Joaquin navel oranges and mandarins, desert citrus, and coastal lemons. On fruit, the citrus thrips punctures epidermal cells, leaving scabby, grayish or silvery scars on the rind. Second-instar larvae do the most damage because they feed mainly under the sepals of young fruit and are larger than first instars. As fruit grow, damaged rind tissue moves outward from beneath the sepals as a conspicuous ring of scarred tissue. Fruit are most susceptible to scarring from shortly after petal fall until they are about 1.5 inch (3.7 cm) in diameter. Thrips damage is higher on fruit located on the outside canopy where fruit is also susceptible to wind damage and sunburn.

Management

Citrus thrips numbers can vary greatly from year to year. Monitor to determine if a pesticide application is needed in a particular year. Navel oranges are more susceptible to damage than are Valencia oranges, which often do not require a pesticide application.

Treatment of young, nonbearing trees in a grove is not recommended except in severe cases. Although the citrus foliage is often heavily damaged by citrus thrips, healthy trees can withstand the damage and frequent pesticide applications can lead to the development of insecticide resistance, making control of thrips on fruit more difficult in later years.

Citrus thrips is less of a problem in orchards that receive minimal broad-spectrum pesticide applications than in orchards that are heavily treated. Because of pesticide-induced hormoligosis (i.e. stimulation of thrips reproduction), thrips numbers tend to increase after sprays with organophosphates, carbamates, pyrethroids, foliar neonicotinoids, and the miticide pyridaben (Nexter).

Biological Control

A number of natural enemies attack citrus thrips, including the predaceous mite Euseius tularensis, spiders, lacewings, dustywings, and minute pirate bugs. Some controversy exists regarding the degree of citrus thrips control afforded by E. tularensis populations; they provide some control but are also a very good "indicator" species, giving an indication of the level of general natural enemies present in an orchard. Citrus thrips numbers are worsened when broad-spectrum pesticides are used, probably because of both a reduction in natural enemy levels and pesticide-induced hormoligosis (increased rate of development or reproduction due to stressor).

In some years, when citrus thrips densities are excessively high, no amount of E. tularensis or other natural enemies in combination with selective pesticides can keep citrus thrips below an economic threshold.

Organically Acceptable Methods

Use biological control, sprays of the Entrust formulation of spinosad with an organically approved oil, or Veratran D applied with molasses or sugar bait in organically managed orchards.

Resistance

Citrus thrips has a history of rapidly developing resistance to chemicals that are used repeatedly and frequently for its control. For example, resistance to dimethoate and formetanate hydrochloride (Carzol) has developed in a number of citrus thrips populations in the San Joaquin and Coachella valleys; beta-cyfluthrin (Baythroid), fenpropathrin (Danitol), spinosad (Success), and spinetoram (Delegate) resistance has appeared in several groves in Kern County. Although citrus thrips disperse a good deal, citrus thrips resistance problems are often localized. Thus, resistance problems are most likely to occur in groves where insecticides with the same mode of action were repeatedly applied to control citrus thrips.

With the limited number of pesticides available for control of citrus thrips now and in the foreseeable future, it is wise to monitor citrus thrips levels carefully and limit pesticide applications only to populations that are causing or are expected to cause significant levels of fruit scarring. It is also important to time and apply pesticides optimally so that reapplications are not required. Do not apply pesticides just to prevent foliar damage.

Selectivity

The botanical insecticide sabadilla (Veratran D) and spinetoram (Delegate), spinosad (Success or Entrust) and abamectin (Agri-Mek, etc.) are relatively nontoxic to beneficial insects and mites.

The broad-spectrum organophosphate (dimethoate), carbamate (formetanate hydrochloride–Carzol), and pyrethroids (beta-cyfluthrin–Baythroid, fenpropathrin–Danitol) insecticides are toxic and fairly persistent against both beneficial mites and beneficial insects and disrupt biological control.

Monitoring

Check young fruit for immature thrips and monitor the undersurface of inside foliage for predaceous mites. Monitor from petal fall until fruit is greater than 1.5 inches in diameter. For oranges, the monitoring time is about 6 to 8 weeks in spring. For lemons, monitor June through October.

Monitoring Fruit for Citrus Thrips

Select trees that are three to four rows in from the outside edge of the block. Sample 25 young fruit from each corner of the block for a total of 100 fruit. Take only one to two healthy, dark green fruit from outside, sunny branches of each tree. Look for thrips on the stem end of the fruit under the calyx. Count fruit as infested only if it has one or more wingless first-or second-instar nymphs (ignore pupae and adults). Record the total fruit infested with immature citrus thrips and calculate the percentage of infested fruit (example form(PDF)available online). On very susceptible varieties, such as San Joaquin Valley navels, monitor fruit at least twice a week after petal fall, and continue monitoring as long assusceptible fruit is on the tree.

Monitoring Predatory Mites

Examine the underside of twenty 5-leaf terminals with fully expanded leaves from shady areas of the canopy (a total of 100 leaves), and count the number of adult predatory mites. Calculate and record the average number of predatory mites per leaf (example formPDF). A minimum of 0.5 predatory mites per leaf is needed to assist with biological control of citrus thrips.

Treatment Decisions

Treatment thresholds vary by growing region, cultivar, beneficial mite numbers, and the type of miticide that will be applied. A significant factor affecting threshold levels is whether the orchard is sheltered from wind damage (lower threshold) or has a history of outside fruit scarring from seasonal winds (higher threshold). As fruit get larger, treatment thresholds go up. Less susceptible varieties, such as Valencia oranges, may not require monitoring or pesticide applications.

Sabadilla (Veratran D), spinetoram (Delegate), spinosad (Entrust, Success), or abamectin (Agri-Mek, etc.) are recommended to avoid severe mortality of natural enemies. Sabadilla is a stomach poison that contains sugar as a bait and must be consumed by the thrips in order to be effective. Add an additional 1 to 2 gallons/acre of molasses or 5 to 10 lbs/acre of sugar for best results. When an application of sabadilla, spinetoram, spinosad, or abamectin is planned, beneficial mite numbers are considered significant if you have more than 0.5 predators per leaf. Just after petal fall, treatment thresholds are as follows:

  • Valencia oranges: 10% of fruit sampled with one or more immature citrus thrips and few predators present, or 20% infested in the presence of significant levels of beneficial mites. Raise these thresholds as fruit grow.
  • Navel oranges: 5% of fruit sample infested and few predators present, or 10% infested with significant levels of beneficial mites. Raise these thresholds as fruit grow.

Dimethoate, formetanate hydrochloride (Carzol), beta-cyfluthrin (Baythroid), and fenpropathrin (Danitol) are contact poisons and are most effective when applied shortly before the majority of citrus thrips hatch (when 5% or less of the fruit are infested with first instar citrus thrips). On very susceptible varieties, such as San Joaquin Valley navel oranges, monitor fruit at least twice a week after petal fall. Less susceptible varieties such as Valencia oranges may not require a pesticide application. Optimal timing of these contact sprays is usually shortly after petal fall but can be delayed depending on weather and on thrips development. If an application of dimethoate, formetanate hydrochloride, cyfluthrin, or fenpropathrin is planned, the threshold is 1 to 5% infested fruit on navel oranges. Do not apply a pesticide for citrus thrips prebloom or after fruit exceed 1.5 inches in diameter, unless high thrips numbers are present.

Because of the continuous fruiting nature of coastal lemons, a treatment threshold of between 10 to 20% infested fruit is used, depending on whether the orchard is sheltered from wind damage (lower threshold) or has a history of outside fruit scarring from seasonal winds (higher threshold).

When monitoring indicates a pesticide application may be needed, it is essential to properly time and apply the pesticide in order to reduce the need for a second application, and thus reduce the long-term development of resistance. Apply the pesticide using outside coverage (OC) by reducing spray blower wind velocity. Ground application is more effective than air application and 200 gallons per acre is more effective than lower or higher gallonage, except with the sugar or molasses bait treatments using sabadilla. Because of their smaller size, coastal lemon trees receive adequate control with an aerial application. Firm data on optimal gallonage with sugar baits are not available, but some growers believe that lower gallonage is more effective because the bait concentration is increased. Don't apply sabadilla and a sugar bait just before or during periods of heavy dew, fog, or drizzle. Such weather conditions cause the sugar bait to separate from the toxin, rendering the treatment ineffective.

Common name Amount to use REI‡ PHI‡
(Example trade name) (type of coverage)** (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.
 

SELECTIVE

 
A. SABADILLA#
  (Veratran D) 10–15 lb/acre PLUS up to 12 When dry
    1–2 gallons molasses or 5–10 lb sugar in 50–200 gal (OC)    
  RANGE OF ACTIVITY: Pests: narrow (citrus thrips); Natural enemies: predatory thrips
  PERSISTENCE: Pests: short; Natural enemies: short
  COMMENTS: For use on all varieties. Acidify water in the spray tank to a pH of 4.5 before adding sabadilla; use citric acid or other approved acidifying agents. Most effective if substantial numbers of predators such as the predaceous mite Euseius tularensis are present. Sabadilla is a short residual stomach poison; time application of this insecticide to coincide with mid-hatch. Most effective during warm weather; in cool weather thrips don't feed well on bait and it degrades with time. Use higher rates with more dilute applications. Do not combine with fertilizers because this reduces feeding by the thrips on the bait. Ground application at 3 mph with reduced wind velocity so as to achieve outside coverage. Don't apply during periods of heavy dew, fog, or drizzle.
 
B. SPINETORAM
  (Delegate WG) 4–6 oz/acre (OC) 4 1
  RANGE OF ACTIVITY: Pests: narrow (thrips, orangeworms, katydids); Natural enemies: predatory thrips
  PERSISTENCE: Pests: intermediate; Natural enemies: intermediate
  RESISTANCE: Some citrus thrips populations in Kern County.
  MODE-OF-ACTION GROUP NUMBER1: 5
  . . . PLUS . . .
  NARROW RANGE OIL
  (415) 0.25–1% See label When dry
  RANGE OF ACTIVITY: Pests: broad (unprotected stages of insects and mites); Natural enemies: most
  PERSISTENCE: Pests: short; Natural enemies: short
  MODE OF ACTION: Improves translaminar movement and insecticide persistence.
  COMMENTS: For use on all varieties. Do not apply to citrus nurseries or to citrus in greenhouses. Most effective if substantial numbers of predators such as the predaceous mite Euseius tularensis are present. Time application to coincide with early to mid-hatch (see the thresholds listed above). To avoid potential phytotoxicity of oil to the fruit, do not apply 30 days before or after a sulfur application, and do not apply to small fruit (less than 1 inch in diameter) on a day when the ambient temperature has or is expected to exceed 95°F or when the relative humidity has or is expected to drop below 20%. Use ground application at 3 mph with reduced wind velocity so as to achieve outside coverage. Repeated applications will result in citrus thrips resistance. For resistance management purposes, do not apply mode-of-action group 5 insecticides (spinetoram and spinosad) more than twice a year. Do not apply more than a total of 12 oz/acre per crop.
 
C. ABAMECTIN*
  (Agri-Mek SC) 2.25–4.25 fl oz/acre (OC) 12 7
  (Willowood Abamectin 0.15EC) 10–20 fl oz/acre (OC) 12 7
  RANGE OF ACTIVITY: Pests: intermediate (citrus thrips, mites, leafminers); Natural enemies: predatory mites and thrips
  PERSISTENCE: Pests: intermediate; Natural enemies: intermediate
  MODE-OF-ACTION GROUP NUMBER1: 6
  COMMENTS: Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging.
  . . . PLUS . . .
  NARROW RANGE OIL
  (415) 0.25–1% See label When dry
  MODE OF ACTION: Improves translaminar movement and insecticide persistence.
  RANGE OF ACTIVITY: Pests: broad (unprotected stages of insects and mites); Natural enemies: most
  PERSISTENCE: Pests: short; Natural enemies: short
  COMMENTS: For use on all varieties. Apply in 50–250 gal water/acre. Do not apply in citrus nurseries. To avoid potential phytotoxicity of oil to the fruit, do not apply 30 days before or after a sulfur application and do not apply to small fruit (less than 1 inch in diameter) on a day when the ambient temperature has or is expected to exceed 95°F or when the relative humidity has or is expected to drop below 20%. Most effective if substantial numbers of predators such as the predaceous mite, Euseius tularensis, are present. Time application to coincide with early to mid-hatch (see the thresholds listed above). Use ground application at 3 mph with reduced wind velocity so as to achieve outside coverage. Repeated applications will result in citrus thrips resistance. Certain formulations emit high amounts of volatile organic compounds (VOCs); use low-VOC formulations. Regulations affect use for the San Joaquin Valley from May 1 to October 31, 2017. Review the Department of Pesticide Regulation's updated fact sheet.
 
D. CYANTRANILIPROLE
  (Exirel) 20.5 fl oz/acre (OC) 12 1
  RANGE OF ACTIVITY: Pests: psyllids, leafminer, aphids; Natural enemies: none
  PERSISTENCE: Pests: intermediate; Natural enemies: none
  MODE-OF-ACTION GROUP NUMBER1: 28
  . . . PLUS . . .
  NARROW RANGE OIL
  (415) 0.25–1% See label See label
  RANGE OF ACTIVITY: Pests: broad (unprotected stages of insects and mites); Natural enemies: most
  PERSISTENCE: Pests: short; Natural enemies: short
  MODE OF ACTION: Improves translaminar movement and insecticide persistence.
  COMMENTS: Do not make ground applications within 25 feet or air applications within 50 feet of water bodies. Do not exceed 61 oz of Exirel or 0.4 lb a.i./acre of cyantraniliprole-containing products/acre per year. Apply by air in a minimum of 10 gallons/acre.
 
E. SPIROTETRAMAT
  (Movento) 8–10 fl oz/acre (OC) 24 1
  RANGE OF ACTIVITY: Pests: broad (mites, thrips, leafminers, aphids, armored scales); Natural enemies: predatory mites
  PERSISTENCE: Pests: long; Natural enemies: short (except via leaf or host feeding)
  MODE-OF-ACTION GROUP NUMBER1: 23
  . . . PLUS . . .
  NARROW RANGE OIL
  (415) 0.5–1% See label When dry
  RANGE OF ACTIVITY: Pests: broad (unprotected stages of insects and mites); Natural enemies: most
  PERSISTENCE: Pests: short; Natural enemies: short
  MODE OF ACTION: Contact including smothering; also improves insecticide uptake.
  COMMENTS: For use on all varieties. Most effective if substantial numbers of predators such as the predaceous mite Euseius tularensis are present. Time application to coincide with early to mid-hatch (see the thresholds listed above). To avoid potential phytotoxicity of oil to fruit, do not apply 30 days before or after a sulfur application, and do not apply to small fruit (less than 1 inch in diameter) on a day when the ambient temperature has or is expected to exceed 95°F, or when the relative humidity has or is expected to drop below 20%. Use ground application at 3 mph with reduced wind velocity so as to achieve outside coverage unless the pesticide application is also intended for red scale control, in which case intermediate coverage and 500 or so gpa might be best. Must be applied with oil or an adjuvant to improve penetration. Do not apply before bloom, during bloom, or 10 days after petal fall. Repeated applications will result in citrus thrips resistance. For resistance management purposes, do not apply more than once a year (i.e., do not apply in spring for citrus thrips management and in summer for red scale).
 
F. SPINOSAD
  (Entrust SC)# 4–10 fl oz/acre (OC) 4 1
  (Success) 4–10 fl oz/acre (OC) 4 1
  RANGE OF ACTIVITY: Pests: narrow (thrips, orangeworms, katydids); Natural enemies: predatory thrips
  PERSISTENCE: Pests: intermediate; Natural enemies: intermediate
  RESISTANCE: Some citrus thrips populations in Kern County.
  MODE-OF-ACTION GROUP NUMBER1: 5
  COMMENTS: Toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging.
  . . . PLUS . . .
  NARROW RANGE OIL
  (415) 0.25-1% See label When dry
  RANGE OF ACTIVITY: Pests: broad (unprotected stages of insects and mites); Natural enemies: most
  PERSISTENCE: Pests: short; Natural enemies: short
  MODE OF ACTION: Improves translaminar movement and insecticide persistence.
  COMMENTS: For use on all varieties. Most effective if substantial numbers of predators such as the predaceous mite Euseius tularensis are present. Time application to coincide with early to mid-hatch (see the thresholds listed above). To avoid potential phytotoxicity of oil to the fruit, do not apply 30 days before or after a sulfur application, and do not apply to small fruit (less than 1 inch in diameter) on a day when the ambient temperature has or is expected to exceed 95°F or when the relative humidity has or is expected to drop below 20%. Use ground application at 3 mph with reduced wind velocity so as to achieve outside coverage. Repeated applications will result in citrus thrips resistance. For resistance management purposes, do not apply Mode-of-action group 5 insecticides (spinetoram and spinosad) more than twice a year. Do not apply to citrus nurseries or to citrus in greenhouses.
 
BROAD-SPECTRUM
 
A. BETA-CYFLUTHRIN
  (Baythroid XL)* 6.4 fl oz/acre (OC) 12 0
  RANGE OF ACTIVITY: Pests: broad (many insects); Natural enemies: most
  PERSISTENCE: Pests: intermediate; Natural enemies: intermediate (low rates), long (high rates)
  RESISTANCE: Some citrus thrips populations in the San Joaquin Valley
  MODE-OF-ACTION GROUP NUMBER1: 3A
  COMMENTS: Only a single application may be made per crop season. To reduce the potential for resistance, make a total of only one pyrethroid application (for all pest species) per year or, if feasible, only one application every 2 to 3 years. Do not apply within 25 feet of lakes, reservoirs, rivers, permanent streams, marshes, or natural ponds, estuaries, and commercial fish farm ponds. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging.
 
B. FENPROPATHRIN*
  (Danitol 2.4EC) 21.33 fl oz/acre (OC) 24 1
  RANGE OF ACTIVITY: Pests: broad (many insects and mites); Natural enemies: most
  PERSISTENCE: Pests: intermediate; Natural enemies: long
  RESISTANCE: Some citrus thrips populations in the San Joaquin Valley
  MODE-OF-ACTION GROUP NUMBER1: 3A
  COMMENTS: Apply in 50 to 200 gal water/acre. Use only on citrus trees 3 years or older. To reduce the potential for resistance, make a total of only one pyrethroid application (for all pest species) per year or, if feasible, only one application every 2 to 3 years. Do not apply in the vicinity of aquatic areas. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging.
 
C. FORMETANATE*
  (Carzol SP) 1–1.25 lb/acre (OC) 216 (9 days) See comments
  RANGE OF ACTIVITY: Pests: broad (many insects); Natural enemies: most
  PERSISTENCE: Pests: intermediate; Natural enemies: long, unless washed off
  RESISTANCE: Some citrus thrips populations
  MODE-OF-ACTION GROUP NUMBER1: 1A
  COMMENTS: For use on oranges, lemons, limes, tangerines, tangelos, and grapefruit. Apply at the beginning of hatch; less effective if resistance has developed. Do not apply after fruit reach a diameter of one inch. If unharvested grapefruit and Valencia oranges are present from the previous crop, an application may be made to the new crop. However, a preharvest interval of 30 days must be observed for the unharvested crop. Ground application at 3 mph with reduced wind velocity so as to achieve outside coverage. Toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging.
 
D. DIMETHOATE
  (Dimethoate 400) 0.5–1.5 pt/acre in 100 gal (OC) 336 (14 days) 15
    . . . or . . .    
    in 20 gal (A)    
  RANGE OF ACTIVITY: Pests: broad (many insects); Natural enemies: most
  PERSISTENCE: Pests: intermediate; Natural enemies: intermediate
  RESISTANCE: Some citrus thrips populations
  MODE-OF-ACTION GROUP NUMBER1: 1B
  COMMENTS: For use on oranges, grapefruit, lemons, tangerines. No more than two applications on mature fruit. Apply at the beginning of hatch. Less effective if resistance has developed. Ground application at 3 mph with reduced wind velocity so as to achieve outside coverage. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging.
    . . . or . . .    
  (Dimethoate 2.67) 0.75–1.5 pt in 100 gal; 3 pt/acre maximum (OC) 336 (14 days) 15
    . . . or . . .    
    in 5–10 gal (A)    
  COMMENTS: For use on oranges, grapefruit, lemons, tangerines. No more than two applications on mature fruit. Apply at the beginning of hatch. Less effective if resistance has developed. Ground application at 3 mph with reduced wind velocity so as to achieve outside coverage. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging.
 
** A - Aircraft applications 5 to 20 gal/acre
  OC - Outside coverage uses 100 to 250 gal water/acre.
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.
# Acceptable for use on organically grown produce.
* Permit required from county agricultural commissioner for purchase or use.
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).

IMPORTANT LINKS

[Precautions]

PUBLICATION

[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Citrus
UC ANR Publication 3441

Insects, Mites, and Snails

E. E. Grafton-Cardwell, Entomology, UC Riverside and Kearney Agricultural Center, Parlier
J. G. Morse, Entomology, UC Riverside
N. V. O'Connell, UC Cooperative Extension, Tulare County
P. A. Phillips (emeritus), UC IPM Program, UC Cooperative Extension, Ventura County
C. E. Kallsen, UC Cooperative Extension, Kern County
D. R. Haviland, UC Cooperative Extension, Kern County

Acknowledgments for contributions to Insect, Mites, and Snails:
J. Barcinas, E.S.I., Corona, CA
R. Dunn, Badger Farming Co., Exeter, CA
J. Gorden, Pest Management Associates, Exeter, CA
H. Griffiths, E.S.I., Corona, CA
D. Machlitt, Consulting Entomology Services, Moorpark, CA
C. Musgrove, retired entomologist, Riverside, CA
K. Olsen, S & J Ranch, Pinedale, CA
T. Roberts, E.S.I., Corona, CA
T. Shea, UC Cooperative Extension, Riverside County
J. Stewart, Pest Management Associates, Exeter, CA
P. Washburn, Washburn & Sons Citrus Pest Control, Riverside, CA

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