Comparison of the metabolic fate of carbaryl-naphthy1-1-¹⁴C in two beetle species(Coleoptera: Scolytidae)

Adult southern pine beetle, Dendroctonus frontalis Zimmermann, and spruce beetle, Dendroctonus rufipennis (Kirby), were treated topically with carbmyl-l-naphthyl-14C, after which metabolism of the labeled chemical was studied. Methylolcarbaryl was the major metabolite in both beetle species; its concentration reached .5.18% in internal extracts from southern pine beetle at 8 hand 1.21 and 3..58% in internal extracts from spruce beetle at 12 and 24 h. respectively. The southern pine beetle metabolized 14C-carbaryland excreted its metabolites more quickly than the spruce beetle. Other methanolic extractable metabolites were tentatively identified from both species as 4-hydroxy-l-naphthyl methylcarbamate, 5- hydroxy-1-naphthyl methylcarbamate, 1-naphthyl methylcarbamate. 1-naphthol. 1,4-naphthalt'nediol. and 1,5-naphthalenedioI. Several unidentified metabolites were also present.