From September 2001 through September 2002, house fly and stable fly pupae were collected weekly from three fly habitats at the University of Florida Research dairy in northcentral Florida and evaluated for parasitism. Varying parasitism percentages were observed throughout the study but they were not affected by temperature, precipitation or fly abundance. Of the 6,222 house fly pupae and 1,660 stable fly pupae that produced either a host fly or a parasitoid, 26.9% and 26.7% were parasitized, respectively. Ten parasitoid species were recovered, with the genus Spalangia accounting for 85.7% of the total; the most common parasitoids attacking house fly and stable fly pupae were Spalangia endius Walker (33.9% and 27.3%), S. cameroni Perkins (27.9% and 40.6%), and S. nigroaenea Curtis (21.0% and 24.8%), respectively. Other parasitoids included one specimen of S. erythromera Förster and four specimens of Phygadeuon fumator Gravenhörst (Ichneumonidae). The percentage parasitism of pupae collected from bunker silos was higher than that of pupae from calf pens and open pastures. Spalangia cameroni was consistently recovered through the entire year. Spalangia nigroaenea was predominant in July, August, and September. Spalangia endius was most active from October to May with a peak of relative abundance in January.

Os objetivos deste estudo foram comparar, dos pontos de vista biológico e econômico, o impacto de várias estratégias de controle e avaliar os seus efeitos sobre a Musca domestica L., resistente à ciromazina, e sobre parasitóides benéficos da pupas de mosca doméstica em aviários (240.000 frangos) na Argentina. As estratégias avaliadas foram: controle químico, controle químico + cultural, e químico + cultural + biológico (manejo integrado de pragas). Os produtos utilizados foram: ciromazina 1% e 50%, DDVP, azametifós com e sem z-9-tricoseno, calcário, e os parasitóides Spalangia endius Walker e Muscidifurax raptor Girault & Sanders. No caso de ausência de medidas de controle, a densidade populacional da mosca aumentou rapidamente e a média de parasitismo foi de 12%. Quando somente o controle químico foi utilizado, as populações de moscas foram reduzidas para 40 por grupo e a média de parasitismo foi de 2%. Quando a ciromazina tópica foi utilizada em conjunto com o controle cultural (calcário), a população de moscas foi reduzida mais rapidamente que nos tratamentos com moscas alimentadas com ciromazina 1%. Com o uso subseqüente de vespas parasitas, altos índices de parasitismo foram observados e a população de mosca doméstica foi reduzida aos níveis de tolerância em tempo menor que em todos os outros tratamentos. Dos pontos de vista biológico e econômico, o melhor tratamento para controle de mosca doméstica resistente à ciromazina foi o controle biológico + cultural + químico com aplicações localizadas de ciromazina tópica.

The objectives of this study were to compare, from both biological and economic viewpoints, the impact of various control strategies and evaluate their effect on cyromazine-resistant Musca domestica L., and beneficial house fly pupal parasitoids on caged-layer farms (240,000 hens) in Argentina. The strategies evaluated were: chemical, chemical + cultural, and chemical + cultural + biological (integrated management). The products used were: cyromazine 1% and 50%, DDVP, azamethiphos with and without z-9-tricosene, lime, and the parasitoids Spalangia endius Walker and Muscidifurax raptor Girault & Sanders. In the absence of control measures, fly density increased quickly and the average parasitism rate was 12%. When only chemical control was used, fly populations were reduced to ca. 40/grid and parasitism averaged 2%. When topical cyromazine was used in conjunction with cultural control (lime), fly populations were reduced more rapidly than those treated with cyromazine 1% feed-through. With the subsequent use of parasitic wasps, high parasitism levels were observed and house flies were reduced to tolerance levels in the shortest time. From an economic and biological point of view, the best treatment for house flies resistant to cyromazine was biological + cultural + chemical with localized applications of topical cyromazine.