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 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 (neem oil)-Some formulations are OMRI-listed for organic use.
  • 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.
  • mineral oil-Some formulations are OMRI-listed for organic use.
  • plant essential oils (clove, garlic etc.)-Some formulations are OMRI-listed for organic use.
  • sulfur-Some formulations are OMRI-listed for organic use.

Management-chemical control: COMMERCIAL USE

  • borate complex (Prev-Am) applied as a 0.8% solution. Apply to complete coverage. REI 12 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 0.078 to 0.188 lb ai/a. PHI 28 days. REI 12 hr. Do not exceed 0.188 lb ai/a per year.
  • phorate (Thimet 20G) at 0.056 to 0.075 lb ai/1,000 row ft. REI 48 hr. Apply at planting time or cultivation. Do not exceed 1.3 lb ai/a per year. Limit 1 treatment.
  • oxydemeton methyl (MSR Spray Concentrate) at 0.375 to 0.5 lb ai. PHI 26 days. REI 13 days. Retreatment interval 7 days. Do not exceed two applications per year.
  • propargite (Comite) at 1.6 to 2.4 lb ai/a. PHI 30 days. REI 14 days. Apply before ears form.
  • spiromesifen (Oberon 2SC) at 0.089 to 0.25 lb ai/a. PHI 5 days. REI 12 hr. Retreatment 14 days. Do not exceed 0.27 lb ai/a per season. Limit 2 treatments per year.