Growth and Development of the Cheese Skipper Under Sterile, Unsterile, and Sterile-Inoculated Conditions1

Abstract

Experiments were designed to compare growth and development of Piophila casei (L.) under sterile, unsterile, and sterile-inoculated conditions. A millipore-filter modification of an egg-sterilization technique was used. In unsterile treatments, eggs were washed only in tap water. For the sterile-inoculated condition, eggs were sterilized and inoculated with 0.5 ml of a 5-h culture of Proteus mutgaris (VPI strain no. 3). Chicken embryos served as growth medium. Use of the millipore-filter technique eliminated the transfer of eggs from one chemical to another, and allowed continual checks of egg survival. The results indicate that the normal flora accompanying eggs has no beneficial influence on the growth and development of P. casei, and that limiting the number of bacteria present may be advantageous to the insect. P. vulgaris has very little influence on growth and development of the cheese skipper.