Use of the electroretinogram to measure the quality of vision of the fruit fly.

The electroretinogram (ERG) technique was used to measure the visual sensitivity of Caribbean Fruit flies Anastrepha suspensa (Loew), reared at 3 laboratories on 5 artificial diets. These ERGs were compared with those of flies reared from field-infested fruit. Flies reared on artificial diets differed greatly in visual sensitivity, and those reared on fruit were at least 10 times more sensitive than certain strains. Since ERGs can be obtained 3-4 days before the Caribbean fruit fly is sexually mature, the use of visually substandard flies in behavioral studies or field releases could be avoided. The results have stimulated further studies of the effects of nutrition and handling procedures on the vision and behavior of the Caribbean fruit fly in the laboratory and the field. A simple, easy to operate, and inexpensive ERG system is being developed that can be used at any rearing facility to monitor the quality of visual receptors of the insects being produced.