Whiteflies

• Whiteflies, like their relatives the aphids, are tiny, soft-bodied, sap-sucking insects that rise in clouds from the undersides of leaves on affected plants. They are most numerous as the weather warms in spring and early summer. Whiteflies are sensitive to few garden pesticides.
  
  

Management

• Given enough space, sunlight and water, healthy day lilies seldom attract whiteflies. When they do attract pests, however, the problem may be a lack of beneficial insects like dragonflies, lacewings or big-eyed bugs. Something as simple as daily sharp sprays of water may be enough to discourage whiteflies on day lilies planted in proximity to susceptible plants.
  
  

Control

• Control of the pesticide-resistant little whitefly can be difficult. To compound matters, day lilies are extremely sensitive to pesticides containing isotox or kelthane and products containing them should never be used. Low-toxic sprays like insecticidal soap, neem oil or other horticultural oils require several applications; they are the best bet for a chemical solution to whiteflies.