(Bull, 1965). Similar results were obtained with lemon, bean, and 
alfalfa plants (Metcalf et al., 1957). 
The action of air and sunlight on surface residues is rapid and 
appears to promote oxidation. In addition to activation producing 
oxidative metabolites, there is hydrolysis to diethyl phosphoric acids 
and alcohols (Hartley, 1952a, b: Fukuto et al., 1955, 1956; Heath et al., 
1955). 
Kinetic studies have shown that temperature, by its general effect 
on chemical kinetics and by governing the rate of physiological activities 
of the plant, plays a large but somewhat predictable role in the metabo- 
lism of systemic insecticides in plants. Figures showed that for every 
rise of 10°C, the rate of disappearance of di-syston sulfoxide increased 
by about 1.86 times. Similar effects are presumed for the reactions 
giving rise to the other identified metabolites (Metcalf et al., 1959). 
S 
it i ll 
(CyH50) 9-P-S-CH9-CHy-CHy-CH3 ————~———=_ (C H50) 5 -P-S~CHy -CHy -S-CH, -CH 
Di-Syston Di-Syston Sulfoxide 
S 0 0 0 
tt " it n 
RCGHE Og B=8 “CH CHa SeCH = CH, (CH50) 9 -P-S-CH, -CHg -S-CHo ~CH3 
0 
S 0 0 
tl il 
(C,H.0) .-P-SH (C2 H50) 2 ~P-S -CHp ~CHy ~S-CHp -CH3 
0 
i q i 
(C,H50).-P-OH (C5H50) 9-P-OH HS - CHa ~CH9 -S CH) -CH3 
0 
0 0) 
Y 
" 
(C,H,0) ,-P-OH _—$—$— = CH 0-P-(0H) 9 
H3 PO, 
Inorganic Phosphate 
103 
