Silverleaf Whitefly

  • Symptoms

  • Trigger

  • Biological Control

  • Chemical Control

  • Preventive Measures

Silverleaf Whitefly

Bemisia tabaci

Insect


In a Nutshell

  • Silver-whiteflies sit on the underside of the leaves and scatter upon shaking the plant.
  • Chlorotic spots appear on the leaf blades.
  • These spots later coalesce and the leaf eventually turns yellow, apart from the area around the veins.
  • The leaves may later curl or take a cupping shape.

Hosts

Additional

Bean

Cotton

Cucumber

Eggplant

Lettuce

Melon

Mung bean

Potato

Soybean

Tomato

Symptoms

The larvae and the adults consume the plant’s sap and cause chlorotic spots to appear on the leaf blade. These spots are later disfigured by honeydew and the sooty moulds that grow there. In heavy infections, the spots may coalesce and engulf the whole leaf, which eventually turns yellow, apart from the area around the veins. The leaves may later become deformed, curl or take a cupping shape. Silverleaf whiteflies transmit viruses such as tomato yellow leaf curl virus or cassava brown streak virus.

Trigger

Silverleaf whiteflies measure about 0.8 mm and have the body and both pairs of wings covered with a white to yellowish powdery, waxy secretion. They are often found on the underside of the leaves, where females lay their eggs. Tiny, yellow to white larval scales later appear there and are visible to the naked eye. In severe infestations, numerous small and white adult whiteflies will emerge in a cloud when the plant is shaken. Between plantings, adults survive on alternative hosts plants.

Biological Control

Employ natural insecticides based on sugar-apple oil (Annona squamosa) for effective population control. Also introduce or stimulate natural antagonists such as the parasitoid wasp Eretmocerus eremicus, predatory mites or nematodes. Pathogenic fungi have also been used to control/eradicate the pest. A new group of environmentally-friendly insecticides with surfactant-like properties kill the pest by overcoming the protective waxes on larvae and adults.

Chemical Control

Always consider an integrated approach with preventive measures together with biological treatments if available. Silverleaf whiteflies quickly develops resistance to all pesticides, so a rotation of different products is recommendable. If no alternative treatment is available, apply combinations of pesticides based on bifenthrin, buprofezin, fenoxycarb, deltamethrin, azadirachtin, pymetrozine or spiromesifen to control the insect.

Preventive Measures

Perform intercropping practices with non-hosts.,Check plants regularly for whiteflies, especially the young shots.,Remove leaves with eggs or larvae on them.