Bees Swarming Your Linden? It's Likely Aphids or Scale, Not the Tree

Why Bees Are Attracted to Your Linden

Bees aren't visiting the linden (Tilia) flowers—they're harvesting honeydew, a sugar-rich excretion from aphids or soft scale insects feeding on the tree. Both pests suck phloem sap and secrete this sticky substance.

Diagnosing the Pest

• Aphids: Small, soft-bodied, often clustered on leaf undersides and new shoots. Mobile.
• Soft scales: Immobile, turtle-shell bumps on twigs/branches. Often overlooked.
• Both produce honeydew → sooty mold (black coating) → bee/wasp attraction.

Effective Treatment: Systemic Soil Drench

• Imidacloprid (Bayer Advanced Tree & Shrub Insect Control) applied to soil.
• Roots absorb → translocates to foliage/twigs → kills sucking insects as they feed.
• Takes 2-3 weeks to reach canopy on large trees.
• One application protects full season.
• Honeydew stops → bees leave → sooty mold weathers away.

Why Not Spray?

Large lindens are difficult to spray thoroughly. Systemic treatment avoids drift, protects beneficials better, and provides longer control.

Prevention

• Monitor annually—early detection = easier control.
• Maintain tree vigor: water during drought, mulch, avoid excess nitrogen.
• Healthy trees resist pest buildups naturally.