Turnip (roots and tops) and rutabaga-Diamondback moth

Plutella xylostella

Pest description, crop damage and life history

See:

Common Pests of Vegetable Crops

Pest monitoring Natural enemies and insecticides applied to control other pests keep the diamondback moth under satisfactory control in most fields, but keep records of diamondback moths as you monitor for other caterpillars. Adult moths frequently migrate from fields being harvested or disked.

Management-biological control

Natural enemies, including an ichneumid wasp and the egg parasite Trichogramma pretiosum, often effectively control diamondback moth in California. Therefore, take into account the level of parasitism when making control decisions. Clearly, Bt is much easier on the beneficial insects, and its use, when needed, helps conserve the beneficial insect complex.

Management-chemical control: HOME USE

• azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
• Bacillus thuringiensis var. kurstaki (Btk)-Do not use on rutabaga. Some formulations are OMRI-listed for organic use.
• bifenthrin
• carbaryl
• cyfluthrin
• insecticidal soap (as a mix with spinosad)-May require several applications. Do not use on rutabaga. Some formulations are OMRI-listed for organic use.
• malathion
• pyrethrins-Some formulations are OMRI-listed for organic use.
• spinosad-Some formulations are OMRI-listed for organic use.
• zeta-cypermethrin

Management-chemical control: COMMERCIAL USE

• Bacillus thuringiensis (Javelin) at 0.12 to 1.5 lb/a. PHI 0 days. REI 4 hr. Acts slowly; may need multiple applications. Add an appropriate spreader-sticker to enhance control. Most effective on small larvae. Some formulations are OMRI-listed for organic use.
• bifenthrin (Brigade WSB) at 0.08 to 0.1 lb ai/a. PHI 21 days. REI 12 hr. Do not exceed 0.5 lb ai/a per season. Retreatment interval 7 days.
• Burkholderia spp. (Venerate XC) at 1 to 4 quarts/a product. PHI 0 days. REI 4 hr. OMRI-listed for organic use.
• Chromobacterium subtsugae (Grandevo) at 0.3 to 0.9 lb ai/a per 100 gal. PHI 0 days. REI 4 hr. OMRI-listed for organic use.
• cyantraniliprole (Exirel) at 0.045 to 0.088 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 5 days. Limit 6 treatments per year. Do not exceed 0.4 lb ai/a per year. Turnip greens only.
• cyfluthrin (Tombstone) at 0.038 to 0.05 lb ai/a. PHI 0 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.2 lb ai/a per season. Turnip greens only.
• emamectin benzoate (Proclaim) at 0.008 to 0.015 lb ai/a. PHI 14 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.09 lb ai/a per season. Turnip greens only.
• indoxacarb (Avaunt) at 0.065 lb ai/a. PHI 3 days. REI 12 hr. Do not exceed 0.26 lb ai/a per crop. Retreatment interval 3 days. Turnip greens only.
• GS-omega/kappa-Hxtx-Hv1a (Spear Lep) at 0.8 lb ai/a. PHI 0 days. REI 4 hr. Do not exceed 2 lb ai/a per year.
• methomyl (Lannate SP) at 0.45 to 0.9 lb ai/a. PHI 10 days. REI 48 hr. Turnip greens only. Do not exceed 3.6 lb ai/a per season.
• permethrin (Loveland Permethrin) at 0.05 to 0.15 lb ai/a. PHI 1 day. REI 12 hr. Do not exceed 0.45 lb ai/a per season. Turnip only.
• spinetoram (Radiant SC) at 0.039 to 0.078 lb ai/a. PHI 3 days. Retreatment interval 7 days. Do not exceed 0.266 lb ai/a per season. Limit 6 treatments per season. Turnip greens only. Do not apply to seedling leafy vegetables grown for transplant within a greenhouse, shade house, or field plot.
• spinosad (Success, Entrust SC) at 0.023 to 0.047 lb ai/a. PHI 1 day. REI 4 hr. Retreatment interval 5 days. Do not exceed 0.45 lb ai/a per season. An adjuvant improves control. Entrust SC is OMRI-listed for organic use.
• zeta-cypermethrin (Mustang) at 0.028 to 0.05 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.3 lb ai/a per year.