One hundred and eight compounds and mixtures were evaluated as fumigants for eggs and larvae of the oriental fruit fly ( Dacus dorsalis Hendel). These compounds and mixtures plus those previously evaluated against this insect bring the total to 350. In addition, 62 of the above compounds and mixtures were evaluated as fumigants for eggs and larvae of the Mediterranean fruit fly ( Ceratitis capitala (Wiedemann)). Materials toxic to one species were generally toxic to the other. Most of the halogenated esters, ethers, and alcohols had LD-95’s higher than 20 mg./liter for both eggs and larvae. Of the total of 333 chemical compounds (mixtures not included) evaluated thus far, 12% of 114 non-halogenated compounds and 12% of 219 containing halogens had LD-95’s of less than 20 mg./liter for both stages. The compounds most toxic to eggs and larvae of fruit flies were the iodides and the isothiocyanates, all of which were injurious to treated papayas.