An alternative chicken-based diet for mass-rearing screwworm flies

Screwworm flies are mass-reared and released along the Panama-Colombia border to prevent reinfestation of Central and North America. The cost of the production facility, labor, and diet materials makes mass-rearing the most expensive component of the program. The mass-rearing diet has a large impact on the quality and quantity of insects produced, both of which are necessary for the successful implementation of the sterile insect technique. The diet currently used to rear screwworm flies in Panama contains dried bovine red blood cells, dried bovine plasma, egg powder, milk replacement powder, cellulose (thickening agent), formaldehyde (antimicrobial), and water. Here, we tested an alternative diet containing 2 chicken by-products, which cost less and are locally available, to replace the egg powder and milk replacement powder currently used in the diet. We used 2 screwworm colony strains in our test, the current production strain (Jamaica) and an early female-lethal strain. The chicken diet performed similarly to the production diet with the Jamaica strain, while further optimization will likely be needed for transgenic strain. Finally, nutritional analysis conducted on 7 diet ingredients will assist with diet optimization and the identification of alternative diet ingredients.