Sep 3 2014
Irina Ovcarenko, a scientist at Finland's MTT Agrifood Research, has as part of her thesis, conducted research on the ecology and genetic diversity of the greenhouse whitefly. Her study provides new insight about their survival in Finland and would also help in planning pest management.
The greenhouse whitefly (Trialeurodes vaporariorum) is an invasive pest that has been in Finland from 1920, though it is not a part of the country’s original fauna.
Greenhouses have enabled their survival, as they have found them to be suitable as overwintering habitats. These greenhouses have also increased the chances of greenhouse whiteflies invading the wild in the boreal region.
Globally, the greenhouse whitefly has a low genetic diversity. However, the whiteflies in Greece have a higher genetic diversity than that of the greenhouse whiteflies in Finland. The study found that whiteflies treated with insecticides were able to recover and maintain their genetic diversity in local populations.
The whitefly lives on many plant species but may specifically feed on greenhouse crops. Finnish greenhouses mostly grow cucumber and tomato, and the study found that the fly may have evolved specialized races for targeting these crops. Cultivating the same crop constantly increases the possibilities of adaptation of the whiteflies. This would lead to increased crop damage and abundance of pests. These flies utilize outdoor wild plants as summer habitats and return to greenhouses in August.
Some of the whitefly populations in Finland have developed resistance to pymetrozine insecticide. Ovcarenko suggests that pest management should begin by maintaining the area free of pests and keep checking the area for any signs of the pest. Biological pest control was found to provide better benefits than using chemicals.
The scientist recommends rotation of crops, complete destroying of the pests and simultaneous, cooperative monitoring of pests to reduce the chances of the greenhouse whitefly pest dispersing to other greenhouse agroecosystems. This study has been a key motivation for farmers to share information and control whiteflies in strawberry and potato fields.