Apple-Aphid

Includes

Apple grain aphid (Rhopalosiphum fitchii)
Green apple aphid (Aphis pomi)
Rosy apple aphid (Dysaphis plantaginea)

Pest description and crop damage Rosy apple aphids are rose-purple. Their feeding causes severe leaf curling, along with honeydew and sooty mold. Fruits of certain varieties can be stunted and deformed by early-season feeding. The best time for control is before bloom. Once leaves are severely curled, aphids are extremely difficult to kill.

Green apple aphid and apple grain aphid are light green; apple grain aphid can be distinguished by a yellowish green stripe down the middle of the back. Apple grain aphids infest apple in the early part of the season; green apple aphid is present all summer. Damage is twisted leaves, honeydew, and sooty mold. The latter is a problem on green and yellow apple cultivars. Heavy populations can feed directly on the fruit, which may be marked or distorted.

Scouting and thresholds Begin observing growing shoots in late May as shoot leaves are expanding rapidly. About four to five infested leaves per shoot indicates a problem.

Management-biological control

Aphids have many natural enemies including ladybeetles, syrphid fly larvae, green lacewings, and parasitoid wasps. Avoid broad-spectrum insecticide applications which would disrupt these controls.

Management-cultural control

Aphid populations tend to be higher in plants that are fertilized liberally with nitrogen.

Home orchardists: Wash aphids from plants with a strong stream of water or by hand-wiping.

Management-chemical control: HOME USE

Stages 0-1: Egg control with dormant & delayed-dormant sprays

Apply sprays during dormant or delayed-dormant period (March to April). Do not use after pink appears in buds. Use enough water to cover the entire tree thoroughly including small limbs and shoots.

  • superior-type oil-Some formulations OMRI-listed for organic use.

Spring and summer

Once leaves have become severely curled, control is very difficult. Do not apply after blossoms open.

  • acetamiprid
  • azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
  • bifenthrin-Highly toxic to bees.
  • Beauveria bassiana-Some formulations are OMRI-listed.
  • carbaryl-Highly toxic to bees.
  • esfenvalerate-Highly toxic to bees.
  • gamma-cyhalothrin-Highly toxic to bees.
  • imidacloprid-Soil drenches may have residual activity in woody plants lasting for 12 or more months. If short-term management is the goal, consider other approaches. Highly toxic to bees.
  • insecticidal soap-Some formulations OMRI-listed for organic use.
  • kaolin-Applied as a spray to leaves, stems, and fruit, it acts as a repellant to some insect pests. Some formulations are OMRI-listed.
  • lambda-cyhalothrin-Highly toxic to bees.
  • malathion-Highly toxic to bees.
  • permethrin-Highly toxic to bees.
  • plant-derived essential oils-Some have shown efficacy against aphids. Some formulations are OMRI-listed for organic use.
  • pyrethrins (often as a mix with other ingredients)-Some formulations are OMRI-listed for organic use.
  • spinosad-Highly toxic to bees.Some formulations are OMRI-listed for organic use.
  • zeta-cypermethrin-Highly toxic to bees.

Management-chemical control: COMMERCIAL USE

Stages 0-1: Egg control with dormant & delayed-dormant sprays

  • chlorpyrifos (Lorsban 4E) at 1.5 to 4 pints/a + horticultural mineral oil at 6 to 8 gal/a in up to 400 gal of water. Cold or dry conditions may cause Lorsban 4E oil sprays to infuse into trees, resulting in bud damage or bud drop. Do not apply until winter rains or irrigation has replenished soil moisture such that bark and twigs are not desiccated. Do not use the EC formulation of Lorsban beyond the delayed-dormant period. Do not exceed more than 4 pints of product/a per season as a delayed-dormant application. Organophosphate insecticides are highly toxic to birds and fish. Avoid drift to open water and maintain buffers. [Group 1B]
  • diazinon (Diazinon 50W) at 4 lb/a + horticultural mineral oil at 6 to 8 gal/a in up to 400 gal of water. Dormant or delayed dormant use of diazinon is limited to one application. Delayed-dormant control with oil, plus an organophosphate, is most effective for scale control. Do not apply more than two applications or 12 lb of product /a per year. The minimum treatment interval is 14 days. Organophosphate insecticides are highly toxic to birds and fish. Avoid drift to open water and maintain buffers. PHI 21 days. [Group 1B]
  • horticultural mineral oil at 6 to 8 gal/a in up to 400 gal water. Some formulations are OMRI-listed for organic use.
  • lime sulfur (Ca polysulfide 29%) at 5 to 10 gal/a, or lime sulfur ultra (Ca polysulfide 27%) at 2 to 3 gal/a + horticultural mineral oil at 6 to 8 gal/a in up to 400 gal of water.
  • methidathion (Supracide 2E) at 8 pints/a in up to 400 gal of water + horticultural (light) mineral oil at 1.5 gal per 100 gal of water. Supracide is labeled to control San Jose scale, without adding oil; however, its use alone will not control European red mite eggs. Do not use Supracide beyond the delayed-dormant period. Do not exceed one application per acre per year. Organophosphate insecticides are highly toxic to birds and fish. Avoid drift to open water and maintain buffers. [Group 1B]
  • pyriproxyfen (Esteem 35 WP) at 4 to 5 oz/a + horticultural mineral oil at 6 to 8 gal/a in up to 400 gal of water. Apply by ground with airblast equipment in a minimum of 50 gal/a. Thorough coverage is critical for control. It is essential to use adequate water volume to ensure thorough coverage. Apply at delayed-dormant through pink. For delayed-dormant use a superior spray oil at the manufacturer's recommended rate of oil. Under heavy scale pressure, use the higher rate of Esteem 35 WP. Follow local recommendations regarding in-season use and rates of oil in your area.[Group 7]

Stages 3-4: Prepink & tight cluster sprays

  • abamectin (Agri-flex Miticide/Insecticide 0.15 EC)-To avoid illegal residues, Agri-Flex Miticide/ Insecticide must be mixed with 0.25% or 1 gal/a light mineral oil. Apply dilute at 1.5 to 2.0 fl oz/ 100 gal water or use 5.5 to 8.5 oz/a. PHI 35 days. [Group 6]
  • acetamiprid (Assail 70WP) at 1.1 to 1.7 oz/a in up to 100 gal water per application. Do not make more than 4 applications per year or exceed 13.5 oz/a per growing season. PHI 7 days. [Group 4A]
  • chlorpyrifos (Lorsban 50W) at 3 lb/a in up to 100 gal water per application. Do not apply postbloom. [Group 1B]
  • diazinon (Diazinon 50W) at 4 lb/a in up to 100 gal water per application. Do not apply more than two applications per acre per year. The minimum treatment interval is 14 days. See label for use restrictions. [Group 1B]
  • flonicamid (Beleaf 50 SG) at 2 to 2.8 oz/a in up to 100 gal water per application. Use a minimum of 50 gal water when applied by ground.Do not apply more than 3 applications at 2.8 oz of product/a rate. Do not apply more than 8.4 oz/a per season. PHI 21 days. [Group 9C]
  • spirotetramat (Movento, Ultor) at 6 to 9 oz/a in up to 100 gal water per application. Do not exceed 25 fl oz/a per growing season. Do not apply after petal fall. PHI 7 days. [Group 23].
  • thiacloprid (Calypso 4F) at 2 to 4 oz/a in up to 100 gal of water per application. Do not exceed 16 oz/a per growing season. PHI 30 days. [Group 4A]

Spring and summer

  • abamectin (Agri-flex Miticide/Insecticide 0.15 EC)-To avoid illegal residues, Agri-Flex Miticide/ Insecticide must be mixed with 0.25% or 1 gal/a light mineral. Apply at 1.5 to 2.0 fl oz /100 gal water or use 5.5 to 8.5 oz/a. PHI 35 days. [Group 6]
  • acetamiprid (Assail 70WP) at 1.1 to 1.7 oz/a in up to 100 gal of water per application. Do not make more than 4 applications per year or exceed 13.5 oz/a per growing season. PHI 7 days. [Group 4A]
  • Chromobacterium subtsugae (Grandevo) at 2 to 3 lb/a. Under heavy pest populations, apply a knockdown insecticide prior to or in a tank mix, use the higher label rates, shorten the spray interval, and/or increase the spray volume to improve coverage.
  • clothianidin (Clutch 50WDG) at 2 to 3 oz/a in up to 100 gal of water per application. Do not apply more than 6.4 oz/a per growing season. PHI 7 days. [Group 4A]
  • diazinon (Diazinon 50W) at 4 lb/a in up to 100 gal of water per application. Do not apply more than 12 lb/a per growing season. Do not apply more than two applications per acre per year. The minimum treatment interval is 14 days. See label for use restrictions. PHI 21 days. [Group 1B]
  • flonicamid (Beleaf 50 SG Insecticide) at 2.0 to 2.8 oz/a. Use a minimum of 50 gal water when applied by ground. Do not apply more than 8.4 oz /a per season. Do not exceed three sprays per season. Allow a minimum of 7 days between applications. PHI 21 days. [Group 9]
  • imidacloprid (Provado 1.6F; Prey 1.6) at 8 oz/a in up to 100 gal of water per application. Do not use within 10 days prior to bloom or when bees are actively foraging. Allow 10 days between applications. Do not exceed 40 oz/a per season. PHI 7 days. [Group 4A]
  • pyridaben (Nexter Miticide/Insecticide) 5.2 to 10.67 oz/a in up to 100 gal of water per application. Only one application per season. PHI 25 days. [Group 21A]
  • pyriproxyfen (Esteem 35 WP IGR) at 3 to 5 oz/a per 100 gal water. Do not exceed two applications or 10 oz of Esteem 35 WP IGR per acre per season. PHI 45 days. [Group 7C]
  • spirotetramat (Movento, Ultor) at 6 to 9 oz/a in up to 100 gal water per application. Do not exceed 25 fl oz/a per growing season. Do not apply after petal fall. PHI 7 days. [Group 23]
  • thiacloprid (Calypso 4F) at 2 to 4 oz/a in up to 100 gal of water per application. Do not exceed 16 oz/a per season. PHI 30 days. [Group 4A]
  • thiamethoxam (Actara) at 4.5 to 5.5 oz/a in up to 100 gal of water per application. Do not exceed 16.5 oz/a per season. Actara is extremely toxic to bees. PHI 35 days. [Group 4A]
  • thiamethoxam/chlorantraniliprole (Voliam Flexi) at 6 to 7 oz/a in up to 100 gal of water per application. Do not apply exceed 16 oz/a per season and do not use an adjuvant within 60 days of harvest. Do not apply by air. Minimum interval between applications is 10 days. PHI 35 days. [Group 4A]