In laboratory studies with the codling moth, Cydia pomonella (L.), TH 6043 and TH 6044, new benzoylphenylurea chitin-synthesis inhibitors, were more effective than TH 6045 and diflubenzuron in reducing hatch of eggs from treated adults. With TH 6043 and TH 6044, egg hatch was reduced only when the female of each mating pair was treated. Topical application of diflubenzuron to adults moderately reduced egg hatch while TH 6045 had no effect. Diflubenzuron also reduced oviposition by females. None of these compounds adversely affected mortality, longevity, or mating propensity of adults.