17 



The outlook for H. illuaens as a biological control agent in Mexico 

 is considered good (Vazquez-Gonzalez et al., 1962). These authors advo- 

 cate keeping poultry manure wet, especially in the dry season, and 

 destroying manure cones to augment H. illuaens populations. 



Chemical control . In the past, most of the chemicals used for fly 

 control in privies were shown to cause resurgence of house fly popula- 

 tions and damage soldier fly populations (Kilpatrick and Schoof, 1959). 

 Under normal circumstances, privies produced few house flies. This was 

 attributed to water content of the excretia and the presence of H. 

 -illuaens. When privies were sprayed with dieldrin, BHC , or chlordane, 

 house fly production greatly increased. DDT, malathion, and diazinon 

 had little or no effect on house fly production. 



Axtel 1 and Edwards (1970) field-tested various larvicides against 



larval populations of H. -illuaens in poultry manure. The best control 



TM 

 was achieved with a 0.5^ solution of Ravap ' . After eliminating the 



soldier fly populations, retreatments were necessary to control resur- 

 gent house fly populations. 

 House fly pathogens 



Bacillus thurengiensis has been fed to caged layers for fly control, 

 but when fed at levels providing the best control, decreases in feed 

 consumption, body weight, and egg production resulted (Burns et al., 

 1961). When sprayed on manure as a larvicide, B. thurengiensis was 

 effective against fly larvae and did not damage populations of preda- 

 ceous mites (Wicht, Jr. and Rodriguez, 1970). Records of otner types 

 of pathogens affecting house flies are abundant in the literature 

 (Brigqs and Milligan, 1977; Burges and Hussey, 1971; Kramer, 1964; Beard 

 and Walton, 1965) . 



