Analysis of a successful classical biological control project: the alfalfa blotch leafminer (Diptera: Agromyzidae) in the northeastern United States.
A project for the biological control of the lucerne pest Agromyza frontella by parasites in the USA was analysed to identify research principles for future projects. Key events that influenced research were identification of the pest, establishment of a specific project without other research objectives, development of recovery techniques, determination that an empty ecological niche existed in the invaded region and parasite release precedures. Of 14 species introduced the braconid Dacnusa dryas, the eulophid Chrysocharis punctifacies and the pteromalid Miscogaster hortensis were established. The effective braconid and eulophid species were r-stategists with some K-oriented characteristics, were multivoltine, utilized alternative hosts, occupied a previously vacant niche in the invaded area, were intrinsically superior competitors and long lived, had high searching capacities and were from many localities in Europe. The benefit from their presence in 1983 was $13 million and research costs were approximately $1 million. Research approaches, parasite selection, life-table studies and role of alternative hosts are considered.