How to Manage Pests
UC Pest Management Guidelines
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Tomato
Tomato Russet Mite
Scientific name: Aculops lycopersici
(Reviewed 1/08, updated 1/08)
In this Guideline:
DESCRIPTION OF THE PEST
Russet mites are so small that a 14X hand lens is needed to see them. Because of their size, these mites are rarely noticed until plants are damaged. By this time, there may be hundreds of yellowish, conical-shaped mites on the green leaves immediately above the damaged bronzed leaves.
DAMAGE
Russet mites remove cell contents from leaves, stems, and fruit cells. Usually starting near the ground, infestations of this mite progress up the plant and lower leaves
dry out, giving the plant an unhealthy appearance. The color of the stems and leaves frequently becomes
greasy bronze or russet colored. If not controlled, this pest can kill plants.
MANAGEMENT
Monitor and treat for these mites if damage is occurring.
Organically Acceptable Methods
Mined sulfur dust or sprays are acceptable on organically certified produce.
Monitoring and Treatment Decisions
Look for bronzing on lower leaves and stems, then check damaged leaves and the green leaves immediately above them for mites. Damage is typically first observed when green fruit reaches 1 inch (5 cm); rarely is it first observed after more than 25% of the fruit are ripe. Determine the extent of each infested area in the field by examining leaves and stems for bronzing, and mark the boundaries of the infested areas. Check these areas again in 2 or 3 days to see if they are increasing in size. Immediate treatment is necessary when damage symptoms begin to spread.
Common name Amount/Acre** R.E.I.+ P.H.I.+
(trade name) (hours) (days)
The following materials are listed in order of usefulness in an IPM program, taking into account efficacy and impact on natural enemies and honey bees. When choosing a pesticide, also consider information relating to environmental impact. Not all registered pesticides are listed. Always read label of product being used.
A. SULFUR DUST# Label rates 24 0
...OR...
WETTABLE SULFUR# Label rates 24 0
MODE OF ACTION: Unknown. An inorganic insecticide.
COMMENTS: Check CCOF guidelines regarding the suitability of the specific product for use on organically certified crops. Thorough coverage is required; ground application preferred. Do not apply when temperatures are in excess of 90°F or during a heavy dew or fog. Avoid drift.
B. ABAMECTIN*
(Agri-Mek) 0.15 EC 8–16 oz 12 7
MODE OF ACTION GROUP NUMBER1: 6
COMMENTS: Also effective against leafminers and tomato pinworm; does not harm beneficials. Do not exceed 48 fl oz/acre/season.
** See label for dilution rates.
+ Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment until harvest can take place. In some cases the R.E.I. exceeds the P.H.I. The longer of these two intervals is the minimum time that must elapse before harvest may take place.
# 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). For additional information, see their Web site at
http://www.irac-online.org/.
The above info is from California UC Davis
They only recommend sulfer dust and abamectin to treat russet mites on tomato crops at 8-16 ounces per acre with a 1 hour R.E.I. and a 7 day P.H.I.
REI=time to wait before entering the garden after spraying
PHI=time to wait before harvesting a treated crop
