Greenhouse ornamentals-Spider mite

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 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.
  • acephate/fenpropathrin (Valent Tame/Orthene)
  • acequinocyl (Shuttle O) at 6.4 to 12.8 fl oz/a. REI 12 hr.
  • acetamiprid (Transport) perimeter treatment applications.
  • azadirachtin (Azamax) 5 fl oz/10 gal water every 10-14 days.
  • Beauveria bassiana (Mycotrol ESO)-3 quarts/100 gal water, spray to wet but avoid 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 (Quali-Pro Chlorpyrifos) at 0.25 to 0.5 lb ai/100 gal. REI 24 hr. RESTRICTED USE IN OREGON.
  • Chromobacterium (Grandevo)-Application rates based on host plant.
  • cinnamaldehyde (Seican)-Variable rates for first appearance, common and high pressure. .
  • cinnamon oil (Cinnerate) at 13 to 64 fl oz/100 gal, 50 to 210 gallons per acre.
  • citronella (BioMite)-OMRI-listed; 1 to 2 quarts/ 100 gal, 100 to 400 gal/acre.
  • clofentezine (Ovation SC) at 0.0625 lb ai/100 gal. REI 12 hr.
  • clove oil (Nature-cide)
  • corn oil (Circadian Sunrise) at 1 to 3 oz/ gal. Agitate solution throughout application.
  • cyflumetofen (Sultan) at 0.18 lb ai/100 gal. REI 12 hr. Limit 2 treatments.
  • cyhalothrin (Declare)-Specific host differ in application rates
  • 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
  • dicrotophos (Inject-a-cide)-Pines only, use when mites first appear.
  • dimethoate (Dimethoate 400)-Depends on host plant. .
  • esfenvalerate (Onslaught) broadcast or foliar spray at 0.1 to 1.0 fl oz/gal for 1,000 sq ft.
  • etoxazole (Tetrasan 5WDG Miticide) at 0.4 to 0.8 oz ia/100 gal. REI 12 hr.fenbutatin-oxide (Vendex 50W) at 4 to 8 oz ai/100 gal. REI 48 hr. Restricted use pesticide.
  • 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 hrs.
  • 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 of water as a dilute spray.
  • methyl bromide (Meth-o-Gas)mineral oil/petroleum distillate (Biocover LS)
  • naled (Dibrom 8) as vapor treatment.
  • neem oil (Nimbiosys) 1 to 2 pints/acre at 0.5% concentration.
  • peppermint oil (Mantis EC) 1 to 8 pints/100 gal; 1 to 2 fl oz/gallon.
  • permethrin (ProZap)-Requires heavy contact.
  • phosphorous (Mite-Phite) foliar 1 to 3 quarts in a minimum of 20 gallons of water per acre.
  • potassium laurate (numerous labels)-Some formulations are OMRI-listed for organic use.
  • propargite (OMITE-30WS) application 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.
  • soybean oil. (Golden Pest Spray Oil)-Some formulations are OMRI-listed for organic use.
  • spinetoram (XXpire) at 3.5 oz/100 gal; 7 oz/acre.
  • 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.
  • tau-fluvalinate (Mavrik Aquaflow) at 0.063 to 0.156 lb ai/100 gal. REI 12 hr.