Under culture conditions, Bacillus subtilis metabolized sumithion 
primarily to the amino compound. This was metabolized, at a lower rate 
than the parent compound, to desmethylaminosumithion. Desmethylsumithion, 
and dimethylphosphorothioic acid were also observed. Desmethylaminosumi- 
thion arose from aminosumithion. Dimethylphosphorothioate came from 
sumithion. No sumioxon was detected (1018). 
When P32-labeled sumithion was applied to rice plants at the pre- 
heading stage, the sumithion penetrated into the tissues and was rapidly 
degraded to desmethylsumithion, dimethyl phosphorothioic acid and phos- 
phorothionic acid. Sumioxon was present and minute amounts of such de- 
gradation products as dimethyl phosphorothioic acid, phosphorothionic 
acid and free p-nitrocresol were identified. The latter compound was 
also found in cocoa beans exposed to sumithion (1019, 1020). 
When German cockroaches were treated with sumithion, the desmethyl 
analog was found (1021, 1022). 
Decomposition of sumithion at 100 - 140°C produces a mixture con- 
taining mostly organophosphorus polymers. 0,S-dimethyl 0-3-methy1-4- 
nitrophenyl phosphorothioate was formed as an intermediate which decomposed 
further to 3-methy1~4-nitrophenol and polymers. Sumioxon was not observed 
C57 8)-. 
292 

