Potato Aphid (Macrosiphum euphorbiae)
Detailing the identifying qualities of the Potato Aphid, including physical features and territorial reach.
Updated: 7/31/2017; Authored By Staff Writer; Content ©www.InsectIdentification.org
Potato Aphids can infest a variety of vegetable plants including tomatoes, leaving a sad bush and ruined fruit in their wake.
Members of the Aphid family, Potato Aphids are voracious plant suckers. Their mouth parts pierce plant tissue and they suck the life out of leaves and stems when in large numbers. Aphids are rapid reproducers so many generations can infest the same plant, which makes controlling their numbers problematic. Spraying affected plants with insecticide can help for a while, but new eggs that survived the chemical application can hatch and restart a population in weeks if not days. Natural predators are drawn to affected plants, but large populations may survive without a large population of predators to reduce their numbers and maintain them.
Plants suffer from the presence of aphids in a few ways. Depletion of xylem and phloem (water and liquid plant food) weakens and starves it. Many leaves of the plant will dry out and die, making photosynthesis and the creation of glucose difficult. Once leaves shrivel up and die, fruit is exposed to more sunlight than usual which can scald it, making it visually less appealing if not damaged. Aphids also secrete a sweet liquid substance called 'honeydew' which attracts other insects like ants to the plant. The honeydew can grow mold/mildew on it creating black ashy spots on the plant. One large, healthy population of aphids can do all this damage despite their individual size. This is why the Potato Aphid is the bane of many a gardener.