Aphid

• Clusters of tiny soft-bodied insects on new growth, stems, or leaf undersides
• Curled, puckered, or distorted leaves — especially on growing tips
• Sticky honeydew residue on leaves and stems
• Black sooty mold growing on the honeydew
• Yellowing leaves on heavily infested plants
• Ants moving in columns up the stem (farming aphids for honeydew)

Aphids overwinter as eggs on woody plants and hatch in early spring. Populations can build rapidly through summer — a single female can produce dozens of live young per week without mating. Winged forms appear when colonies become crowded, spreading infestations to new plants. Natural predators (ladybugs, lacewings, parasitic wasps) typically arrive a few weeks after aphid populations peak.

1. 01Knock aphids off with a firm stream of water from a hose — repeat every few days while pressure is high
2. 02Encourage or introduce natural predators: avoid broad-spectrum insecticides that kill ladybugs and lacewings
3. 03Inspect new growth weekly so populations don't establish unnoticed
4. 04Apply insecticidal soap or neem oil to heavily infested areas, targeting leaf undersides — reapply after rain
5. 05Remove and bag heavily infested growing tips if the plant can tolerate the pruning
6. 06Control ant populations that protect aphid colonies from predators

If infestations keep returning despite regular knockdown treatments, or you're seeing new symptoms like mosaic patterns or ring spots on leaves — aphids can vector several plant viruses — a local extension office can help identify whether you're dealing with a virus and which aphid species is involved.

• Aphids in the Home Garden— University of Minnesota Extension
• Aphid Management in Vegetables— UC ANR Integrated Pest Management