Extension > Garden > Diagnose a problem > What insect is this? > Garden Pests > Beetles, bugs, ants, and other insects without obvious wings - Under 1/4 inch long > Potato aphid

Potato aphid

Macrosiphum euphorbiae

Whitney Cranshaw, CSU, Bugwood.org

Whitney Cranshaw, CSU, Bugwood.org

Size: Up to 1/8 inch long.

Description: Pear-shaped, light green or sometimes pink colored. They have long antennae and two cornicles ("tail pipes") on the rear of their abdomen (Identification of aphid species can be challenging; different species can be similarly colored).

Where/When: Feeds on a wide variety of herbaceous plants, most commonly on potato, tomato, and sometimes on rose earlier in the growing season. Additional hosts include eggplant, pepper, pumpkin, rhubarb, asparagus, celery, lettuce, sweet potato, iris, gladiolus, and several weeds. Aphids are active from June (possibly May) through October, with decline in populations during the hottest months of the summer.

Significance: Low to moderate numbers cause little or no damage. Heavy infestations can cause distortion of young leaves, stunt new growth, and possibly kill plants. Buds and blossoms are usually fed upon. Honeydew (aphid waste product) attracts ants and sooty mold (black fungus) may grow on it.

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