Topically applied solutions of carbaryl in acetone were absorbed 
fairly rapidly by milkweed bug nymphs. Only unchanged carbaryl and a very 
polar unidentified metabolite were identified. With the German cockroach, 
(Blatella germanica L.) absorption was slow and excretion rapid. 1-Naphthol 
was evident in the excreta at 24 hours and in tissues at 72 hours. Six 
other unidentified metabolites were demonstrated. Two were identified only 
as conjugates of l-naphthol; one contained sulfur, probably as sulfate, and 
one contained a carbohydrate tentatively identified as glucose (399, 841). 
In the housefly, three metabolites were demonstrated. Changes undergone by 
l-naphthol showed that it formed the same series of more polar products, 
indicating hydrolysis of the ester bond as the first step in the metabolism 
of carbaryl (399). In the presence of fly homogenates, hydroxylation of 
carbaryl occurred at the 4- or 5- position and the N-hydroxymethyl analog | 
was also formed (1427, 1779). | 
Stable flies (Stomoxys calcitrans L.) and rice weevils (Sitophilus | 
oryza L.) converted carbaryl to 1l-naphthol and four unidentified metabolites 
(224). Metabolites produced by Pseudomonas melophthora were not identified (145) \ 

Adult boll weevils (Anthonomus grandis Boheman) were treated topically 
with labeled carbaryl. Subsequently, l-naphthol, 1l-naphthy-N-hydroxymethyl- 
carbamate, 5,6-dihydroxy-5,6-dihydro-1l-naphthyl-N-methylcarbamate, and an | 
unidentified compound were detected. 1] ~Naphthol increased markedly | 
coincident with the rapid disappearance of l-naphthy1l-N-hydroxymethylearbamate 
(25). Following injection of carbaryl into bollworm adults (Heliothus zea ! 
Boddie), 1,5,6-trihydroxy-5,6-dihydronaphthalene was observed in addition 
to those compounds found in the boll weevils. Metabolism of carbaryl by 
5th-instar bollworm larvae was qualitatively similar to that of boll weevils 
but quantitative differences were observed (25). 
The low toxicity of carbaryl to larvae of the cotton leaf worm 
(Prodenia litura F.) was attributed to the presence of enzyme systems capable 
of degrading this material: carbamate esterase, amine oxidase and catalase 
(631). Detoxication of labeled carbaryl in adult larva of the cotton leaf 
worm was primarily via non-hydrolytic paths involving hydroxylation. The ' 
hydrolytic path (about 14%) gave rise to l-naphthol and N-methylcarbamic acid. 
The latter gave methylamine by decarboxylation, which then underwent oxidative 
demethylation to formate and CO» (1538). 

1-Naphthol and phthalic acid have been identified by gas chromatography 
and thin-layer chromatography after ultraviolet exposure of carbaryl. 
Several other compounds were observed but not identified (3, 315, 1105, 391). 
74 


