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Spotted Aphid Reference Page

Common and scientific names

Spotted alfalfa aphid (Therioaphis maculata)

Pest description and crop damage

Small yellow to brown aphid with red bumps on its back. It secretes much honeydew and affects plant vigor. From July on, it can appear in damaging numbers.

Management—chemical control

1. Capture at 0.06 lb ai/a. PHI 3 days. Use prebloom at this rate. 24c label.

2. Capture at 0.032 lb ai/a. PHI zero days. 24c label.

3. endosulfan 3 E at 0.5 to 1 lb ai/a. PHI zero days. WA, ID, NV, OR 24c label. This aphid is very difficult to control. Spray by ground with at least 25 gal water/a. Damage is most severe on seedling stands. In established stands, treat when spotted aphids average 20 to 30 per stem or 50 per sweep and the population is increasing. Do not exceed the high rate during bloom.

4. Warrior at 0.015 to 0.03 lb ai/a. PHI 3 days for low rate, 5 days for high rate. 24c Prebloom and postbloom only.

5. Warrior at 0.015 to 0.02 lb ai/a. Bloom. Suppression only. Do not spray when bees are present. Advisable to move bee shelters for 2 to 3 days following application.

6. Lorsban 4 E at 1 lb ai/a. PHI 7 days. Use prebloom only.

7. permethrin at 0.05 to 0.2 lb ai/a. PHI 3 days. If used during bloom, remove bees from field for 3 days.

Source: 2002 PNW Insect Management Handbook

Integrated Pest Management Information:

UC Pest Management Guidelines-Spotted Aphid

Spotted Aphid Images

Updated June 7, 2002-jn