Greenhouse ornamentals-Thrips

Greenhouse thrips (Heliothrips haemorrhoidalis)

Pest description and crop damage The insects are very small with fringed wings. Monitoring is usually made by visual inspection for the thrips or their damage. Their damage is usually evident as a scraping of the epidermal layers of the plant leaf. Thrips are vectors of a serious disease. Tomato Spotted Wilt Virus (TMSV) and Impatiens Necrotic Wilt Virus (INSV) can have devastating consequences in susceptible crops.

Biology and life history They tend to prefer very tight spaces and are particularly attracted to flowers with pollen.

Scouting and thresholds Thrips can be very difficult insects to detect. Use blue or yellow sticky traps to assess infestation and control efforts. An aggregation pheromone for thrips, Thripline ams, is available for monitoring.

Management-biological control

When there is potential for vectoring disease and/or low tolerance for direct damage from thrips, biological control may be inappropriate as a tactic. There must be some tolerance for a pest in order to sustain biological control organisms. Where viruses are not a factor or damage tolerance higher, biological control may provide several benefits, including pesticide resistance management, improved worker safety, and reduced re-entry intervals.

Management-biological control

Natural enemies include:

  • minute pirate bug, Orius insidiosus
  • predatory mites, Typhlodromips (Amblyseius) swirskii; Iphesius degenerans; Neoseiulus (Amblyseius) cucumeris; Neoseiulus barkeri
  • predatory thrips, Thripobius semiluteus
  • soil-dwelling predatory mite, Hypoaspis miles-Feeds on pupal stage in soil.

Management-chemical control

  • abamectin (Avid 0.15EC) at 0.009 lb ai/100 gal (8 fl oz). REI 12 hr. Suppression.
  • 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)
  • acetamiprid (Tristar 30SG) at 0.75 to 1.5 lb ai/100 gal (4 to 8 oz). REI 12 hr.
  • azadiractin (Azahar)-Some formulations are OMRI-listed for organic use.
  • Beauvaria bassiana (Botanigard, Mycotrol, Naturalis L)-Some formulations are OMRI-listed for organic use.
  • bifenthrin (Talstar) at 0.168 to 0.335 lb ai/1,000 sq ft. REI 12 hr. Restricted use pesticide.
  • canola/pyrethrins (EB Stone, Earth-tone, Worryfree)-Some formulations are OMRI-listed for organic use.
  • chlorfenapyr (Pylon) at 0.08 to 0.16 lb ai/100 gal. REI 12 hr.
  • cyantraniliprole (Mainspring) at 0.013 to 0.1 lb ai/100 gal. REI 4 hr.
  • cyfluthrin (Decathlon) at 1.9 oz/100 gal. REI 12 hr.
  • dinotefuran (Safari 20SG) at 0.1 to 0.2 lb ai/1,000 ft sq; 0.05 to 0.1 lb ai/100 gal. REI 12 hr.
  • flonicamid (Aria) at 0.067 to 0.09 lb ai/100 gal. REI 12 hr.
  • flupyradifurone (Altus) at 10.5 to 14 fl oz/a. REI 4 hr.
  • garlic oil/powder (Allityn)-Some formulations are OMRI-listed for organic use.
  • GS-omega/kappa (Spear Biological Insecticide) at 0.138 to 1 lb ai/a. PHI 0 days. REI 4 hr. Do not exceed 2 lb ai/a per year.
  • imidacloprid (Marathon II) at 0.027 oz ai /100 gal foliar. REI 12 hr. Drench and irrigation permitted.
  • Isaria fumosoroseus (PFR 97) at 0.175 to 3.5 lb ai/100 gal foliar. REI 4 hr.
  • kaolin (Surround WP)-Some formulations are OMRI-listed for organic use.
  • lambda-cyhalothrin (Scimitar GC) at 0.013 to 0.043 lb ai /100 gal. REI 24 hr.
  • Metarhizium anisopliae strain F52 (Met52 EC)
  • 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)-Some formulations are OMRI-listed for organic use.
  • novaluron (Pedestal) at 0.039 to 0.052 oz ai/100 gal. REI 12 hr.
  • oil of rosemary/peppermint (Ecotec for WA only)-Some formulations are OMRI-listed for organic use.
  • pyrethrins/piperonyl butoxide
  • pyridalyl (Overture 35) at 0.175 lb ai/100 gallonsgal. REI 12 hr.
  • pyrifluquinazon (Rycar) at 0.034 to 0.045 lb ai/100 gal. REI 12 hr. Limit 2 treatments per crop.
  • pyriproxyfen (Distance) at 0.041 to 0.054 lb ai/100 gal (6 to 8 fl oz) foliar. REI 12 hr.
  • s-kinoprene (Enstar AQ) at 0.012 to 0.024 lb ai/10,000 sq ft. REI 4 hr.
  • soybean oil (Golden Oil Spray)-Some formulations are OMRI-listed for organic use.
  • spinosad (Entrust) at 0.047 to 0.078 lb ai/100 gal. OMRI-listed for organic use.
  • 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.
  • tolfenpyrad (Hachi-Hachi) at 0.14 to 0.33 lb ai /100 gal. REI 12 hr.