Potato, sweet-Spider mite

Tetranychus spp.

Pest description and crop damage Several species of spider mite are common in the Pacific Northwest. Frequently, infestations include a mixture of spider mite species. Adult mites are about 0.06 inch long, have four pair of legs, are greenish to pink or cream color, and have various-size black spots on the body. Under warm conditions, spider mites move rapidly within the colony area. Damaged leaves become somewhat stippled on the upper surface and may turn brown or bronze with heavy damage. The undersurface of leaves may have a grayish cast due to webbing. Wilting, leaf deformity, tissue death, and abscission all may take place.

Management-chemical control: HOME USE

  • azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
  • bifenthrin
  • insecticidal soap-May require several applications. Some formulations are OMRI-listed for organic use.
  • plant-derived essential oils (such as clove or rosemary)-These have some efficacy against spider mites. Some formulations are OMRI-listed for organic use.
  • sulfur

Management-chemical control: COMMERCIAL USE

  • abamectin (Agri-Mek) at 0.009 to 0.019 lb ai/a. PHI 14 days. REI 12 hr. Do not exceed 0.019 lb ai/a per year. Retreatment interval 7 days.
  • bifenazate (Acramite 4SC) at 0.5 to 0.75 lb ai/a. PHI 14 days. REI 12 hr. Retreatment interval 14 days.
  • bifenthrin/zeta-cypermethrin (Hero) at 0.1 lb ai/a. PHI 21 days. REI 12 hr. Retreatment interval 21 days. Do not exceed 0.45 lb ai/a per season. Limit 2 applications.
  • fenpyroxymate (Miteus) at 0.11 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval 14 days. Do not exceed 0.21 lb ai/a per season. Limit 2 treatments.
  • lambda-cyhalothrin (Warrior II) at 0.03 lb ai/a. PHI 7 days. REI 24 hr. Retreatment interval 7 days. Do not exceed 0.13 lb ai/a per year.
  • lambda-cyhalothrin/thiamethoxam (Endigo ZC) at 0.07 lb ai/a (Suppression only). PHI 14 days. REI 24 hr. Minimum interval between applications 7 days. Do not exceed 0.094 lb ai/a of thiamethoxam or 0.12 lb ai/a per season. Do not follow a foliar application of thiamethoxam following an in-furrow or soil application or seed treatment of thiamethoxam.
  • propyleneglycol monolaurate (Acaritouch) at 12 to 25 oz/100 gal of formulated product. PHI 1 day. REI 4 hr