Ophyra aenescens: a potential bio-control alternative for house fly control in poultry houses

Ophyra aenescens (Wiedemann), replaced the house fly, Musca domestica Linnaeus, as the predominant species of synanthropic fly present in the pits of two environmental poultry houses where cyromazine (Larvadexill) premix was incorporated in the feed (or house fly control After cyromazine was removed. O. aenescens remained the predominant muscoid fly breeding in the poultry manure. Because oC the predatory habits of the larvae, 0. aenescens may be useful 8S 8 biological control agent 8S part of Integrated Pest Management for house fly control on poultry farms. Seguy (1923), and Anderson and Poorbaugh (1964) both reported that Ophyra leucosloma larvae are predaceous on other muscoid larvae. The closely related Ophyra aenescens (Wiedemann) is a predaceous species as well (Nolan, unpublished data), L8n'se have been observed feeding on Musca domestica, Phormia regina and Sarcophaga sp. larvae in lab colonies. In the United States many workers have reported Ophyra aenescens (Wiedemann) in and around animal confinement areas. In Texas, Robertson and Sanders (1979) found 0. aenesecens in swine confinement areas while Hill and Williams (1980) reported 0. aenescens in newly constructed environmental type' poultry houses. In Florida, Hogsette (1979) reported 0. aen-escens among the dipterous fauna of poultry houses. In most cases, O. aenescens was associated with poultry and other confinement type animal housing. Despite alleged knowledge of the predaceous habit of this fly, no one has developed a procedure to use O. aenescens as a biocontrol agent for house fly suppression in poultry houses. During the summer of 1982 cyromazine (N-cyclopropropyl, 1, 3, 5-triazine, 2, 4, 6-triamine), was under evaluation as a feed-through larvicide for house fly control at a large high·rise environmental type (closed pit) poultry farm. As this study progressed it became apparent that Ophyra aenescens (Wiedemann) was becoming the predominant fly at this poultry farm. This muscoid fly has not been previously reported in any South Carolina poultry houses. The 1.5 ppm dosage of cyromazine appeared to have no effect on O. aenescens larvae. Apparently, the suppression of the house fly with cyromazine allowed 0. aenescens to become the predominant species.