Turnip (roots and tops) and rutabaga-Aphid

Includes

Cabbage aphid (Brevicoryne brassicae)
Green peach aphid (Myzus persicae)
Turnip aphid (Hyadaphis pseudobrassicae)

Pest description, crop damage and life history

See:

There may be as few as two generations (the green peach aphid) or as many as 16 generations each year (the cabbage aphid), depending on the species and climate.

Pest monitoring Check fields frequently after seedling emergence. If aphids become numerous, increase frequency of sampling. Aphids often are concentrated in hot spots or near the field margin. Note the presence of any hot spots, but avoid sampling only those areas. Also, be sure to look for evidence of biological control; i.e., the presence of predators, parasites (aphid mummies), and disease. Aphid flights are most common during periods of moderate temperatures (60° to 80°F). Monitor fields particularly closely during April and May.

Management-biological control

Many parasites and predators attack aphids. Early year aphids have many natural enemies that frequently bring them under control later in the year. Among the more common predators are lady beetles and their larvae, lacewing larvae, and syrphid fly larvae. Populations of green peach aphids are reduced in winter by a parasitic fungus, Entomophthora aphidis.

Monitor the proportion of aphid mummies relative to unparasitized aphids and the numbers of predators such as lady beetles. If the proportion of mummies is increasing, or predators appear to be gaining control, and aphid populations are not yet damaging, avoid sprays that will disrupt these natural enemies if the crop is not entering a susceptible stage. Most materials available for aphid control are highly disruptive of natural enemy populations.

Management-cultural control

Destroy infested crops immediately after harvest to prevent dispersal. Destroying weed hosts late in the year may help destroy overwintering populations. Roguing diseased plants early may help slow the spread of aphid-vectored diseases. Aphid populations tend to be higher in crops that are fertilized liberally with nitrogen.

Management-cultural control

Aphid populations tend to be higher in plants that are fertilized liberally with nitrogen. Home gardeners can use row covers or wash aphids from plants with a strong stream of water.

Management-chemical control: HOME USE

Apply to both tops and undersides of leaves.

  • azadirachtin (neem extract)-Some formulations are OMRI-listed for organic use.
  • cyfluthrin
  • imidacloprid
  • insecticidal soap-May require several applications. Do not use on rutabaga. Some formulations are OMRI-listed for organic use.
  • kaolin-Applied as a spray to foliage, it acts as a repellent to some insect pests. Some formulations are OMRI-listed for organic use.
  • malathion
  • plant essential oils (rosemary, etc.)-Some formulations are OMRI-listed for organic use.
  • 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

  • alpha-cypermethrin (Fastac EC) at 0.02 to 0.025 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 4 days. Do not exceed 0.075 lb ai/a per season.
  • acetamiprid (Assail 30SG) at 0.038 to 0.1 lb ai/a. PHI 3 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.375 lb ai/a or four treatments per season. Turnip greens only.
  • Beauveria bassiana (Mycotrol O) at 0.25 to 1 quart/a. PHI 0 days. REI 4 hr. OMRI-listed for organic use.
  • beta-cyfluthrin/imidacloprid (Leverage 360) at 0.07 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.1 lb ai/a beta-cyfluthrin or 0.2 lb ai/a imidacloprid per season. turnip greens only.
  • 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.
  • bifenthrin + zeta-cypermethrin (Hero) at 0.04 to 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 treatments.
  • 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 use.
  • cyantraniliprole (Exirel) at 0.088 to 0.133 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 + imidacloprid (Leverage 2.7) at 0.08 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.17 lb ai/a cyfluthrin or 0.24 lb ai/a imidacloprid per year. Turnip greens only.
  • deltamethrin (Delta Gold) at 0.012 to 0.028 lb ai/a. PHI 3 days. REI 12 hr. Retreatment interval 3 days. Do not exceed 0.14 lb ai/a per season.
  • dimethoate (Dimethoate 400) at 0.25 lb ai/a. PHI 14 days. REI 48 hr. Retreatment interval 3 days. Do not exceed 1.75 lb ai/a per year. Turnip only.
  • dinotefuran (Dinotefuran 20SG, Venom) at 0.088 to 0.131 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.262 lb ai/a per season. Turnip greens only.
  • flonicamid (Beleaf 50SG) at 0.062 to 0.089 lb ai/a. PHI 3 days. REI 12 hr. Do not exceed 0.267 lb ai/a per season. Limit 3 applications. Retreatment interval 7 days.
  • flupyradifurone (Sivanto 200SL) at 0.09 to 0.16 lb ai/a. PHI 1 day, turnip greens, 7 days roots. REI 4 hr. Retreatment interval 7 days for greens, 10 days for roots. Do not exceed 0.365 lb ai/a per season. Limit 3 treatments.
  • imidacloprid (Admire Pro) at 0.16 to 0.38 lb ai/a, or 0.011 to 0.027 lb ai/1,000 row ft soil or 0.044 lb ai/a foliar. PHI 7 days foliar, 21 days soil. REI 12 hr. Retreatment interval 5 days. Do not exceed 0.13 lb ai/a foliar or 0.38 lb ai/a soil per year.
  • imidacloprid (Provado, Prey) at 0.048 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval 5 days. Do not exceed 0.23 lb ai/a per season.
  • malathion (Fyfanon 8E) at 1 to 1.25 lb ai/a. PHI 1 day turnips, 7 days rutabagas. REI 12 hr. Retreatment interval 5 days for greens, 7 days for roots. Limit 3 treatments.
  • permethrin (Loveland Permethrin) at 0.05 to 0.015 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 3 days. Do not exceed 0.45 lb ai/a per season. Washington only. Turnip only.
  • pymetrozine (Fulfill) at 0.086 lb ai/a. REI 12 hr. PHI 7 days. Retreatment interval 7 days. Do not exceed 0.172 lb ai/a per season. A penetrating adjuvant improves performance. Turnip greens only.
  • thiamethoxam (Actara) at 0.023 to 0.047 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.125 lb ai/a per season.
  • thiamethoxam (Platinum) at 0.078 to 0.188 lb ai/a at plant. REI 12 hr. Do not exceed 0.188 lb ai/a per season. See label for recommended in-row application instructions.