Florida tomato farmers have a new option to protect their produce from the silverleaf whitefly: the papaya plant.
How Can a Papaya Protect a Tomato?
The papaya serves and protects tomato vines because of a species of wasp that seeks out the papaya plant. This wasp preys on the silverleaf whitefly, as well as on the papaya whitefly.
The Disease-Ridden Silverleaf Whitefly
The silverleaf whitefly eats tomato leaves, and may infect the plant with the tomato yellow leaf curl virus. Agricultural control of silverleaf whitefly commonly requires insecticide to prevent damage to the tomato crop.
Let the Younger Generation Fight the War
It is actually the wasp larvae that kill either species of whitefly. The mother wasp lays an egg inside an immature whitefly. Upon hatching, the larva eats its host from the inside.
Banking on Papaya
The role of the papaya plant is to act as a ‘reserve bank’ of papaya whiteflies. This attracts the wasps, bringing them close enough to the tomato vines to detect their alternative prey.
Since the papaya whitefly does not eat tomatoes, there is no risk that the farmer would face a double attack upon the tomatoes.
A Single-State Solution
This approach seems to work well in Florida, particularly in greenhouses. It is not expected to completely eliminate insecticide use, but certainly reduces the need for them, while increasing the effectiveness of other pest control measures.
Since other states prohibit the import of papaya whiteflies, this solution might be limited to the Sunshine State.
Robert H. Wells, PhysOrg, "Papaya plants reduce the need for pesticides on tomatoes in Florida, new study finds", published June 30, 2011, referenced Nov. 18, 2011.