Problem Statement: Whiteflies (Hemiptera: Alevrodidae) are well-known for transmitting viruses harmful to crops. Viral outbreaks in the 1990s seriously affected the farming areas of Argentina, principally the cultivation of cotton and soya (in Santiago del Estero and Tucumán) and market gardens in Buenos Aires (tomato, eggplant, some ornamentals, associated weeds etc.).

Methods: Using published taxonomic information on the whiteflies that affect crops of economic importance, as well as their associated parasites (Hymenoptera), the species responsible for the infestations, as well as their natural enemies, could quickly and easily be identified. The whiteflies were initially identified with classical methods using the larvae and pupae. One of the species encountered was Bemisia tabaci, a complex biotype requiring molecular analysis. (The group B. tabaci is the principle transmitter of the geminvirus, a type of virus that causes serious damage to infected plants.)

Outcomes and Impacts: Some of the species of aleirodids encountered were new cases for host plants and included the registration of a new species from outside Argentina. This species, Siphonius phillyreae Haliday was seriously affecting forest plantations around the city of Mendoza. Access to information allowed ready management of the outbreaks via the registering of a natural enemy, Encarsia hispidia. Further access to information on natural enemies permitted the establishment of two other biocontrol species not registered before in Argentina, E. protransvena Viggiani and E. transvena Timberlake. As a result, the outbreaks were quickly and effectively brought under control.

Lessons: Knowing what species to treat and, in particular, of which biotype, is very useful for the determination of a strategy of preventative management. Likewise, being able quickly to establish which natural enemies are the most effective is fundamental to the implementation of effective biological control. However, having access to information, whilst required, is not sufficient in itself; the presence of trained taxonomists is also required in order to utilise this information.