Corn, sweet-Spider mite

Several species

Pest description, crop damage and life history


Pest Monitoring Infestations usually begin on lower leaves of plants, then progress upwards. Inspect lowest leaves for stippling and webbing first.

Management-biological control

Spider mite populations are held down in cool conditions early in the season by various predators such as pirate and big-eyed bugs. Predator mites are effective predators of spider mites and are available.

Management-cultural control

Avoid early season applications of broad spectrum insecticides, which will reduce populations of beneficial insects. Spider mite infestations are favored by dry, dusty conditions, so avoid creating these problems and stressing the plants. Mites can be hosed from plants with a strong stream of water. Excessive nitrogen fertilization may cause population buildup.

Management-chemical control: HOME USE

  • azadirachtin (as a mix with pyrethrins)-Some formulations are OMRI-listed for organic use.
  • bifenthrin (often as a mix with zeta-cypermethrin)
  • insecticidal soap-Apply control measures when mites first appear, and repeat application as necessary. Thorough coverage, especially of undersides of leaves, is essential. Some formulations are OMRI-listed for organic use.
  • horticultural oil-Some formulations are OMRI-listed for organic use.
  • plant essential oils (clove, garlic etc.)-Some formulations are OMRI-listed for organic use.
  • sulfur (as a mix with pyrethrins) -Some formulations are OMRI-listed for organic use.

Management-chemical control: COMMERCIAL USE

  • abamectin (Agri-MekSC) at 0.0095 to 0.019 lb ai/A. PHI 7 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.038 lb ai/A per year. Organosilicone surfactant improves translaminar movement.
  • bifenthrin (Capture LFR) at 0.1 lb ai/A. PHI 1 day. REI 12 hr. Do not exceed 0.2 lb ai/A per season.
  • bifenthrin/zeta-cypermethrin (Hero) at 0.04 to 0.1 lb ai/A. PHI 3 days. REI 12 hr. Retreatment interval 3 to 5 days. Do not exceed 0.266 lb ai/A per season.
  • borate complex (Prev-Am) applied as a 0.8% solution. Apply to complete coverage. REI 24 hr. Retreatment interval 7 days. OMRI-listed for organic use
  • Chromobacterium subtsugae (Grandevo) at 0.6 to 0.9 lb ai/A per 100 gal. PHI 0 days. REI 4 hr. OMRI-listed for organic production.
  • hexythiazox (Onager) at 0.094 to 0.188 lb ai/A. PHI 28 days. REI 12 hr. Do not exceed 0.188 lb ai/A per year.
  • Isaria fumosorosea (PFR-97 20% WDG) at 1 to 2 lb/Acre of product. REI 4 hr. Retreatment interval 3 to 10 days. OMRI-listed for organic use.
  • phorate (Thimet 20G) at 0.056 to 0.075 lb ai/1,000 row ft. REI 48 hr (dependent on rainfall; consult label). Apply at planting time or cultivation. Do not exceed 1.3 lb ai/A per year. Limit 1 treatment.
  • propyleneglycol monolaurate (Acaritouch) at 12 to 25 fl oz product per 100 gal. REI 4 hr.
  • propargite (Comite) at 1.6 to 2.4 lb ai/A. PHI 30 days. REI 13 days. Apply before ears form.
  • spiromesifen (Oberon 2SC) at 0.089 to 0.25 lb ai/A. PHI 5 days, depending on end use. REI 12 hr. Retreatment 14 days. Do not exceed 0.27 lb ai/A per season. Limit 2 treatments per year.