Whitefly Infestation on Shrubs and Plants

The tiny white flying insects that cloud when disturbed, causing leaf yellowing/browning and limb dieback, are whiteflies. They're not true flies but related to aphids and scales (order Hemiptera).

Damage

• Suck sap → wilting, stunting, leaf drop, death in severe cases.
• Excrete honeydew → sooty mold (black coating).
• Can transmit viruses.

Control Strategy

1. Systemic insecticide (imidacloprid, dinotefuran) as soil drench—best for season-long control. Apply early.
2. Foliar sprays for immediate knockdown:
   • Insecticidal soap (thorough underside coverage)
   • Neem oil
   • Pyrethrin
   • Repeat every 3–5 days for 2+ weeks.
3. Yellow sticky traps monitor adults.
4. Remove heavily infested leaves if feasible.

Persistence Is Key

Whiteflies have overlapping generations. Treat weekly for 3 weeks, then as needed. Check new growth regularly. Avoid broad-spectrum sprays that kill whitefly parasites (Encarsia, Eretmocerus).