How to Manage Pests

UC Pest Management Guidelines

DAMAGE
Citrus bud mite is primarily a pest of coastal lemons. The mites feed inside the buds, killing them or causing a rosettelike growth of the subsequent foliage and distortion of flowers and fruit, which may or may not reduce yield and/or fruit quality.

MANAGEMENT
Recent research has failed to show any consistent impact from bud mite feeding under current oil treatment regimes, especially in Lisbon lemons. Research has also yet to be done to determine if abamectin plus oil treatments of bud mite are economically justified. To detect bud mites before damage occurs, check buds on green angular twigs from mid-spring to autumn. Collect one bud from each of 50 randomly chosen trees throughout the orchard. Dissect the buds under a microscope or use a 20X hand lens to determine the percent of buds infested with one or more live mites. As an alternative to dissecting buds, bud infestation can be estimated from infested fruit buttons. Collect one green fruit, about 1.25 to 2 inches in diameter, from 50 trees scattered throughout the orchard. Remove the button and record whether the button or the fruit beneath the button is infested with live bud mites. The relationship between fruit and bud infestations is not linear, but a fruit infestation of 15 to 20% indicates a bud infestation of approximately 45 to 50%.

No bud mite threshold has been established; levels as high as 80% bud infestation have failed to cause consistent or predictable economic losses. If a reduction in bud mite populations is desired, apply treatments 2 to 3 months before the bloom that is to be protected.

Common name (trade name)		Amount to Use (type of coverage)**	Minimum Days before Harvest+
A.	FENBUTATIN OXIDE*
	(Vendex) 50W	1-2 lb/acre (LV)	7
	...PLUS...
	NARROW RANGE OIL
	(415, 440)	10 gal/acre (LV)
	RANGE OF ACTIVITY: Narrow (pest mites)
	PERSISTENCE: Short
	COMMENTS: Do not apply during bloom. To help prevent development of resistance, alternate with dilute oil sprays. Potential of phytotoxicity to leaves, especially if applied during hot weather. Caution: Serious hazards are associated with oil treatments to green lemons because of phytotoxicity after sweating; check label for preharvest interval.
B.	ABAMECTIN*
	(Agri-Mek) 0.15 EC	2 oz/100 gal (TDC)	7
	...PLUS...
	NARROW RANGE OIL	1 qt/100 gal (TDC)
	(415, 440)
	RANGE OF ACTIVITY: Narrow (citrus thrips, mites)
	PERSISTENCE: Short
	COMMENTS: For use on all varieties. Apply in 500-1,000 gal/acre.
C.	NARROW RANGE OIL#	1.2-1.4 gal/100 gal (TDC)
	(415, 440)
	RANGE OF ACTIVITY: Broad (unprotected stages of insects and mites)
	PERSISTENCE: Short
	COMMENTS: Can apply either material anytime between March and Nov. Caution: Serious hazards are associated with oil treatments to green lemons because of phytotoxicity after sweating; check label for preharvest interval.
D.	CHLORPYRIFOS*
	(Lorsban) 4E	0.5 pt/100 gal (TDC)	See comments below
	...PLUS...
	NARROW RANGE OIL
	(415, 440)	1.2-1.4 gal/100 gal (TDC)
	RANGE OF ACTIVITY: Broad (insects and beneficial mites)
	PERSISTENCE: Intermediate
	COMMENTS: Addition of chlorpyrifos to dilute oil gives faster control than oil alone, but rate of control for subsequent applications will diminish as resistance develops. It also causes thrips outbreaks, especially if used early season, and may lead to ridging of fruit. Apply this material in Sept-Oct only if several pests, such as citrus rust mite, citrus thrips, and ants, need to be controlled in addition to citrus bud mite. Do not apply chlorpyrifos in combination with spray oil when temperatures are expected to exceed 95°F (85-90°F in coastal areas). Minimum period before harvest is 21 days for up to 7 pt of chlorpyrifos/acre or 35 days for rates above 7 pt/acre. Caution: Serious hazards are associated with oil treatments to green lemons because of phytotoxicity after sweating; check label for preharvest interval.

**	TDC - Thorough distribution coverage uses 500-3,000 gal/acre, but less than thorough coverage (TC).
	LV - Low-volume uses 20-100 gal/acre.
+	Minimum days before harvest takes into account the California restricted entry interval and the federal preharvest interval and lists the longer interval. (See Table 1 Mandatory Intervals Between Application, Reentry and Harvest, and Hazards to Bees.)
*	Permit required from county agricultural commissioner for purchase or use.
#	Acceptable for use on organically grown produce.

PUBLICATION

UC IPM Pest Management Guidelines: Citrus
UC ANR Publication 3441
Insects, Mites, and Snails
E. E. Grafton-Cardwell, Kearney Agricultural Center, Parlier
J. G. Morse, Entomology, UC Riverside
N. V. O’Connell, UC Cooperative Extension, Tulare Co.
P. A. Phillips, UC IPM Program, UC Cooperative Extension, Ventura Co.
C. E. Kallsen, UC Cooperative Extension, Kern Co.
D. R. Haviland, UC Cooperative Extension, Kern Co.
Acknowledgments for contributions to the insect, mite, and snail section:
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
J. Stewart, Pest Management Associates, Exeter, CA
P. Washburn, Washburn & Sons Citrus Pest Control, Riverside, CA

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