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. 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.
  • 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.
  • 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 pesticide.
  • clofentezine (Ovation SC) at 0.0625 lb ai/100 gal. REI 12 hr.
  • cyflumetofen (Sultan) at 0.18 lb ai/100 gal. REI 12 hr. Limit 2 treatments.
  • etoxazole (Tetrasan 5WDG Miticide) at 0.4 to 0.8 oz ia/100 gal. REI 12 hr.
  • fenazaquin (Magus Miticide) at 0.15 to 0.3 lb ai/a. 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.
  • fenproxymate (Akari 5SC) at 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.
  • 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.
  • kaolin (Surround WP)-May leave residue. 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.
  • Metarhizium anisopliae strain F52 (Met52 EC) at 8 to 32 fl oz/100 gal foliar; 40 to 80 fl oz/100 drench. REI 4 hr.
  • methiocarb (Mesurol 75W) at 0.375 to 0.5 lb ai/100 gal. REI 12 hr. Restricted use pesticide.
  • mineral oil/petroleum distillate (Biocover LS)
  • naled (Dibrom 8) as vapor treatment
  • potassium laurate (numerous labels)-Some formulations are OMRI-listed for organic use.
  • propyleneglycol monolaurate (Acaritouch)
  • pyrethrin/piperonyl butoxide
  • pyridaben (Sanmite) at 3 to 4.5 oz ai/100 gal. REI 12 hr.
  • soybean oil (Golden Pest Spray Oil)-Some formulations are OMRI-listed for organic use.
  • 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.