Pest

Root aphids

Pemphigus, Rhopalosiphum and others

Aphids that live on the roots, often coated in white wax. Plants slow down, pale and wilt between waterings with no cause visible above ground.

Signs

• Small aphids coated in white wax on the roots; easy to mistake for root mealybugs.
• Knock the plant out of its pot to see them; nothing shows above ground.
• Stunting and yellowing; yellow sticky cards catch only the winged adults.

What favors it

Infested plants brought in from another grower, and host plants such as sedum, veronica, aster and coreopsis.

Prevention

• Knock new plants out of their pots and inspect the roots.
• Use new, clean media; do not reuse pots without cleaning.
• Yellow sticky cards catch winged adults only; check roots to confirm.

Crops it shows up on

Hemp & cannabis; Lettuce, spinach & herbs; Houseplants.

Often confused with

Sources

• Supplemental information for insect management guidelines (greenhouse)Cornell University
• Managing Aphids in the GreenhouseUConn Extension IPM

Why →