Problem Statement: Around 1980 the spiralling whitefly, Aleurodicus dispersus, native to Central America, was found spreading and causing heavy damage to many agricultural crops in Asia and the Pacific Region, Australia included. It seemed to attack any "green" broad-leaved crops and fruit trees such as guava and mango. However, in Thailand and some other countries it was initially thought to be Bemisia tabaci, B. argentifolia or an alien whitefly species, A. destructor, already present in the region for quite some time, and its potential economic importance was ignored.

Methods: Following good networking and communication, a Thai entomologist visited Hawaii to learn about similar infestations. The use of this knowledge and the relevant taxonomic keys led to the definite identification of this invasive alien pest as A dispersus. Further, a potential biological control agent existed that could be introduced from Hawaii to help lessen the infestation and provide an eventual long-term control. Researchers favoured the use of biological control as the best way to avoid an eradication programme involving the widespread use of non-specific pesticides and the resulting high biodiversity and environmental costs. It was only after the infestation peaked in the early 1980s that entomologists were able to introduce a coccinellid, Nephaspis oculatus (formerly N. amnicola) from Hawaii in 1984 to control it.

Outcomes and Impacts: The economic damage and loss have been felt in almost all the infested Asian and Pacific countries. In Thailand alone, the damage caused by this whitefly is estimated at several million US dollars over a decade spanning from the 1980s to 1990s. However, it is not known how much more economic damage the whitefly could have caused if a pesticide-based eradication campaign had been carried out. The introduction of the coccinellid to control this whitefly cost less than a few thousand US dollars and provided an effective long-term control. Today, A dispersus is only found sporadically, causing negligible damage.

Lessons: Access to taxonomic expertise, the use of earlier case studies and co-operation among entomologists from other areas with infestations and facing the same economic problems led to the discovery of a solution. Avoiding the destructive use of non-specific pesticides allowed application of the more sustainable biological control approach.