Whiteflies

Whiteflies can be devastating in gardens and greenhouses. They are tiny flies that look like tiny white moths if you used a magnifying glass to view them.

Whiteflies-Pest Diagnostic Clinic (left), Whiteflies-Clemson University (right)

Description:
There are several different species including greenhouse whiteflies, silverleaf whiteflies and sweetpotato whiteflies. They occur worldwide and move onto other crops and plants when their food source runs low. They go from egg to larvae to adult very rapidly.

Whitefly Life Cycle-Dept. of Entomology NCSU (left), Whitfly Eggs-Oregan State University

Whitefly damage-College of Agricultural and Human Resources (left), Whitefly damage-Top Turf Insect Damage (right)

Diet and Damage
Host plants include strawberries, house plants, greenhouse plants, vegetables and some ornamentals. Whiteflies are sucking insects and excrete honeydew which can cause a secondary problem…..sooty mold. They cause plants to become weak and plants die from lack of photosynthesis once sooty mold sets in. They are very difficult to control and over the years have developed immunity from some inorganic pesticides.

Biological Controls

1. Plant Guardian^TM Houseplant Insecticidal Soap – use on the underside of leaves as this is where you’ll find them.
2. Pyola^® Insect Spray
   – a plant based organic pesticide that comes in a liquid or powder. The liquid type needs to be diluted with water and then sprayed directly on the affected plants. It also kills a wide range of insects, caterpillars and beetles.
3. Pot Stickers – you can buy these or make your own with bright yellow card coated with a sticky substance like tanglefoot.
4. Rubbing Alcohol – dilute alcohol in water and wipe the undersides of the leaves.
5. Beneficial Insects - ladybugs, lacewings, pirate bugs, spiders and tiny parasitic wasps.
6. Your Trusty Vaccuum Cleaner – they can be sucked off your houseplants with it.