The purpose of this project was to evaluate diflubenzuron ovicidal effects on adult female alfalfa weevils " Hypera postica in the laboratory. There was little relationship of weevil mortality to dosage or length of exposure of the adult to the chemical. An indirect result of diflubenzuron was an increase in muscardine fungus (Beauveria Sp.). Other effects of the chemical on the adults were yellow deposits and tissue extending from the tip of the abdomen. The main effect of dilfubenzuron when fed to female alfalfa weevils was on the eggs. The effects were dosage related, especially on eggs viability. The viability was dropped from 99% in the control to 38.9% on the treated insects in ten days using the highest dosage. Another effect of diflubenzuron on alfalfa weevil eggs was on the shape of the eggs. The treated insects laid longer and lighter color eggs.