Fly monitoring in three dairy farms of the province of Bologna

The adult fly populations in three dairy farms of the province of Bologna were studied during 1996/97 through a systematic fly monitoring, with particular reference to Musca domestica, the more noxious fly species. The daily farms are: 1) the "Nuovo Caseificio Crespellanese" (Crespellano) with 800 pigs, 2) the "Caseificio Granarolo" (Monteveglio) with 120 dairy cows, 3) the "Caseificio Castellettese" (Castello di Serravalle) with 150 dairy cows and 700 pigs. Dipterans were captured from April 1996 to July 1997 both in the cheese dairies and in the stables by two methods: the first consists of adhesive tablets (20x30 cm), the second consists of some small bags containing insecticide (1% Methomyl) baits, hung inside the premises, with a small lying below tray for collect the dead flies. It is necessary to emphasize that the animal production facilities of these investigated dairy farms take part in a three-year program for fly biological control; this integrated pest management supported by the municipalities of Crespellano, Bazzano, Monteveglio and Castello di Serravalle - is based on the release of parasitoids of flies as Muscidifurax spp., on the use of mechanical, physical and chemical traps and on the use of insecticides, if it is need. The more important results of fly monitoring are the Following: A) In the cow and pig stables of the three dairy Farms Musca domestica is present all year long, but it is more frequent from July to November. B) In the cheese dairies "Nuovo Caseificio Crespellanese" and "Caseificio Castellettese" M. domestica is practically absent, except some specimens during summer and autumn; the dairy-man and the shop-assistant are rest satisfied. C) In the cheese dairy "Caseificio Granarolo" there was on the contrary a high and troublesome presence of M. domestica from May to November 1996 and it was necessary to spray repeatedly insecticides. This last negative situation is probably due to the absence of those sanitary precautions (door and window shutting, fly-net, UV light traps) useful to prevent the entry of the flies coming from the dairy cow stables, where they favourably develop.