 An egg mass containing 00 eggs was glued to a plastic label , and 00 egg masses each were placed in the sprayed and unsprayed control plots . During exposure , the number of hatched and missing eggs was observed daily . Egg predators were sampled in the fields before and after insecticide application . After the egg masses were retrieved from the fields , mortality factors of the unhatched eggs were assessed in the laboratory . The mean number of hatched and missing eggs was not significantly different between the sprayed and control plots in field A In field B , however , the numbers were significantly different . 