Biological control of whitefly on greenhouse tomato in Colombia: Encarsia formosa or Amitus fuscipennis?

In Colombia, biological control of pests in greenhouse crops is only applied on a very limited scale in ornamentals and as yet non-existent in greenhouse vegetables. Greenhouse production of vegetables - mostly tomatoes- is a recent development, as a result of the high losses of field production due to pests and diseases. Pest spectra in those production systems vary greatly with altitude, being much broader in the intermediate climate zones (altitude 1800-2000) than in the cold climate zones such as the Bogota Plateau (altitude 2660 m). The most important pest in greenhouses situated on the Bogota Plateau is the greenhouse whitefly, Trialeurodes vaporariorum . In greenhouses where experimentally no pesticides are applied, aphid and leafminer pests are controlled beneath economic damage thresholds by naturally occurring parasitoids, with the exception of greenhouse whitefly. Therefore, with a biological control system for T vaporariorum , tomato production without insecticides should be possible. In this thesis I evaluate two natural enemies for the biological control of T vaporariorum : the introduced parasitoid Encarsia formosa and the native parasitoid Amitus fuscipenni s.