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Dipterex and its homologues have been prepared by a single vessel reaction in good yields. The stability of O,O-dimethyl-2,2,2-trichloro-1-methoxyethyl phosphonate Ibtowards temperature and pH variation has been studied using P32-labelled compounds. Compared with the parent substance (Dipterex), Ibis much more stable.

In search for effective organophosphorus esters against the larva of the cotton leaf worm (Prodenia litura F), some α-hydroxy phosphonic acid dimethyl esters and related compounds have been synthesized. The effect of substitution on the antiesterase activity and toxicity towards Prodenia larvae has been investigated.

The metabolic fate of C14-methanol and 1-C14-ethanol in the adult larva of Prodenia litura has been investigated in vivo. Following the intersegmental injection of C14-methanol (1.2 mg/g. insect), about 70% of the radioactivity was recovered as C14O2in the expired air, after 20 hours. Also, about one fourth of the administered dose was recovered as unchanged methanol, during the first six hours. Only a minute trace of C14-formate was found in the excreta. It is suggested that a catalase-peroxide system is involved in the oxidation of methanol. Ethanol and its metabolites were eliminated at a slower rate than methanol. After 20 hours, C14O2- being the major C14-metabolite - accounted for 56% of the applied dose. In addition, there is at least one minor non-volatile C14-metabolite eliminated in the excreta of ethanol-treated larvae.