Pacific Northwest Insect Management Handbook

Greenhouse ornamentals-Spider mite

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Image related to Greenhouse ornamentals-Spider mite
Tetranychus unknown
© Ken Gray Insect Image Collection

Including

Twospotted spider mite (Tetranychus urticae)

Pest description and crop damage Several species of spider mites can cause damage in deciduous ornamentals. The appearance of these mites varies with the species, although all are 0.02 inch or smaller. Adults and nymphs can be yellowish, greenish, or reddish-brown, depending on the species. Mites damage plants by feeding on leaves, which causes stippling, bronzing, and possibly leaf drop. The reduction in photosynthesis causes loss of vigor.

Biology and life history Most mite species share a similar life cycle. The majority of twospotted mites overwinter as adult females. Mites become active in the spring. There may be eight to ten overlapping generations per year.

Scouting and thresholds Observe the leaves for mites and webbing and check for the number of pest and predator mites.

Management-biological control

Natural enemies include:

  • minute pirate bugs, Orius spp.
  • predatory lady beetle, Stetorus spp.
  • predatory midge, Felitiella
  • predatory mites, Neoseiulus californicus, N. fallacies, Amblyseius hibisci, Phytoseiulus persimilis, P. macrophililis, P. longipes (Metaseiulus), Galendromus occidentalis

Management-chemical control

  • abamectin (Avid 0.15 EC) at 0.005 lb ai/100 gal (4 fl oz). REI 12 hr.
  • acephate (Precise, Orthene TR) at 0.024 lb ai/1,000 sq ft broadcast (0.6 oz). REI 24 hr.
  • acequinocyl (Shuttle O) at 6.4 to 12.8 fl oz/A. REI 12 hr.
  • acetamiprid (Transport) perimeter treatment applications.
  • azadirachtin (Azamax) at 5 fl oz/10 gal water every 10 to14 days.
  • Beauveria bassiana (Mycotrol ESO)-3 quarts/100 gal water, spray to wet but avoid a runoff.
  • bifenazate (Floramite SC) at 0.625 to 0.125 lb ai/100 gal. REI 12 hr.
  • bifenthrin (Talstar) at 0.168 to 0.335 lb ai/1,000 sq ft. REI 12 hr. Restricted use pesticide.
  • Burkholderia spp. (Venerate XC) at 2 to 4 quarts per 100 gal.
  • canola oil (Mighty)-Do not apply more than 2.5 gal/100 sq ft. Do not reapply within 3 days.
  • capsaicin (General Hydroponics) at 0.5 to 1 tsp per gal over 350 sq ft.
  • chlorfenapyr (Pylon) at 0.04 to 0.08 lb ai/100 gal. REI 12 hr.
  • chlorpyrifos (Vulcan) at 1/12 to 1/6 fl oz per gal on 0.5 to 1 pint per 100 gal, no more than 2.8 quarts per acre/year.
  • Chromobacterium (Grandevo)-Rates based on host plant.
  • cinnamaldehyde (Seican)-Variable rates for first appearance, common and high pressure.
  • citronellol (BioMite) at 1 to 2 quarts/100 gal, 100 to 400 gal/A. OMRI-listed for organic use.
  • clofentezine (Ovation SC) at 0.0625 lb ai/100 gal. REI 12 hr.
  • corn oil (Circadian Sunrise) at 1 to 3 oz/gal. Agitate solution throughout the application.
  • cottonseed oil, peppermint oil, geraniol, rosemary oil (Furious) at 22 to 33 fl oz/A or 3 fl oz/gal for 1,000 sq ft. WA only.
  • cyflumetofen (Sultan) at 0.18 lb ai/100 gal. REI 12 hr. Limit 2 treatments.
  • cyhalothrin (Declare)-Specific hosts differ in application rates.
  • DDVP (nuvan fog 5%) use is prohibited on food plants
  • deltamethrin (Suspend SC)-Suppression only; 4 to 8 fl oz/100 gal water.
  • diazinon (Diazinon AG600) at 0.5 fl oz per 3 gal or 12.75 fl oz per 100 gal water.
  • dimethoate (Dimethoate 400)-Depends on the host plant.
  • etoxazole (Tetrasan 5WDG Miticide) at 0.4 to 0.8 oz ai/100 gal. REI 12 hr.
  • fenbutatin-oxide (Vendex 50W) at 4 to 8 oz ai/100 gal. REI 48 hr. Restricted use pesticide.
  • fenbutatin (Meraz, Vendex)-Follow label rates for application.
  • fenpropathrin (Tame 2.4EC) at 0.15 to 0.3 lb ai/A (8 to 16 fl oz). REI 24 hr.
  • fenproximate (Akari 5SC) at 0.053 to 0.079 lb ai/100 gal. REI 12 hr.
  • geraniol (Ecotec Plus) at 1 to 4 fl oz/100 gal. OMRI-listed for organic use. REI 0 hr.
  • gs-omega/kappa-Hxtx-Hv1a (Spear T Liquid)-Application varies by application type.
  • hexythiazox (Hexygon DF) at 0.5 to 1 oz ai/100 gal. REI 12 hr.
  • Isaria fumosoroseus (PRF 97) at 0.175 to 3.5 lb ai/100 gal foliar. REI 4 hr. Some formulations are OMRI-listed for organic use.
  • lambda-cyhalothrin (Scimitar GC) at 0.023 to 0.043 lb ai/100 gal. REI 24 hr.
  • malathion (Malathion 8 Aquamul) 1.0 pint in 100 gal water as a dilute spray.
  • methyl bromide (Meth-o-Gas)
  • mineral oil/petroleum distillate (Biocover LS)
  • naled (Dibrom 8)-Application varies by application type and crop
  • neem oil (Nimbiosys) 1 to 2 pints/A at 0.5% concentration.
  • permethrin (ProZap)-Requires heavy contact.
  • phosphorous acid (Mite-Phite) foliar 1 to 3 quarts in a minimum of 20 gal water/A.
  • potassium laurate (numerous labels)-Some formulations are OMRI-listed for organic use.
  • potassium silicate (Sil-Matrix) for organic production-Use 1 quart per 100 gal for a 0.25 solution
  • propargite (OMITE-30WS)-Rates vary by host plant.
  • propyleneglycol monolaurate (Acaritouch)
  • pyrethrin/piperonyl butoxide
  • pyridaben (Sanmite) at 3 to 4.5 oz ai/100 gal. REI 12 hr.
  • rosemary oil (Tetracurb) 0.25% is preventative, 0.5% for moderate infestation, 1.0% for heavy infestation
  • soybean oil (Golden Pest Spray Oil)-Some formulations are OMRI-listed for organic use.
  • spinetoram (XXpire) at 3.5 oz/100 gal; 7 oz/A.
  • spinosad (Entrust) at 0.047 to 0.156 lb ai/100 gal. OMRI-listed for organic use.
  • spiromesifen (Judo) at 0.032 to 0.125 lb ai/100 gal. REI 12 hr.
  • spirotetramat (Kontos) at 0.027 to 0.053 lb ai /100 gal. REI 24 hr.
  • sulfur (Drexel Suffa) at 2 to 10 pints of this product in 100 gallons of water by ground application or 2 to 20 pints by air
  • tau-fluvalinate (Mavrik Aquaflow) at 0.063 to 0.156 lb ai/100 gal. REI 12 hr.

Kaur, N. (Ed.). 2024 Pacific Northwest Insect Management Handbook.
© Oregon State University.

Use pesticides safely!

  • Wear protective clothing and safety devices as recommended on the label. Bathe or shower after each use.
  • Read the pesticide label—even if you’ve used the pesticide before. Follow closely the instructions on the label (and any other directions you have).
  • Be cautious when you apply pesticides. Know your legal responsibility as a pesticide applicator. You may be liable for injury or damage resulting from pesticide use.

Trade-name products and services are mentioned as illustrations only. This does not mean that the participating Extension Services endorse these products and services or that they intend to discriminate against products and services not mentioned.