Biological control:: An important component in integrated management of Musca domestica (Diptera: Muscidae) in caged-layer poultry houses in Buenos Aires, Argentina

An Integrated Management program to control Musca domestica L. was developed by evaluating cultural + chemical control, cultural + biological control + granular bait (IMP 1), and cultural + chemical + biological control + granular bait (IMP 2) in poultry houses in Argentina. Adult fly density was estimated by a modified Scudder-grid method. Percentage of house fly parasitism was estimated by direct and indirect methods. Spalangia endius Walker and Muscidifurax raptor Girault & Sanders were released at a rate of 10 parasitoids/hen/week. Complete absence of control practices allowed a sustained growth of the fly population. When larvicides and adulticides were used, the number of adult flies decreased but parasitism was adversely affected. When insecticide use was decreased, the number of flies increased. Cultural + biological control + granular bait (IMP 1) produced a reduction of adults from 14 to 3 flies/grid. Where cultural + chemical + biological control + granular bait (LMP 2) was employed, the adult number was reduced from 40 flies/grid to 1 fly/grid. IMP 2 was efficient for reducing the number of larval development sites in the manure. Percentage parasitism exceeded 90% in both IMP 1 and IMP 2 treatments. IMP 1 and IMP 2 treatments both allowed for maximum control of house flies with minimal use of pesticides. With IMP 2, the potential effectiveness of the biological control agents was maximized by reducing adult fly populations with pesticide sprays, then terminating spray applications before parasitoids were released. Thus, IMP 2 would be most suitable for farms which have large adult house fly populations at the initiation of the treatment. The only pesticide used in LMP 1 was a granular bait. Thus, IMP 1 would be most efficient in situations with low initial adult house fly populations and small amounts of manure tee ensure the success of the cultural strategy. (C) 1998 Academic Press.