Fenoxycarb

Fenoxycarb is a non-neurotoxic carbamate insecticide that acts as an insect growth regulator via juvenile hormone-like activity.¹ It inhibits terminal development of first instar and newly transformed second instar nymphs of Florida red scale (C. aonidum) when used at a concentration of 0.0125% AI.² Fenoxycarb (5 and 10 mg AI/colony) reduces the colony size index of laboratory colonies of red imported fire ants (S. invicta) by 93.6 to 95.9% at 8 weeks post-treatment.³ It is toxic to D. magna (LC₅₀ = 0.5 mg a.s./L) and fish including O. mykiss, L. macrochirus, C. carpio, I. punctatus, and C. variegatus (LC₅₀s = 0.66-1.5 mg a.s./L), but is not toxic to rats (LD₅₀ = >10,000 mg/kg).⁴ Fenoxycarb is also an antagonist of α4β40-, α4β2-, α3β4-, and α3β2-containing rat nicotinic acetylcholine receptors (nAChRs; IC₅₀s = 3, 2.4, 1.8, and 7.6 μM, respectively) but not rat brain acetylcholinesterase (AChE; IC₅₀ = >1,000 μM).⁵

1.Grenier, S., and Grenier, A.M.Fenoxycarb, a fairly new insect growth regulator: A review of its effects on insectsAnn. Appl. Biol.122(2)369-403(1993) 2.Peleg, B.A.Effect of a new insect growth regulator, RO 13-5223, on hymenopterous parasites of scale insectsPhytoparasitica10(1)27-31(1983) 3.Banks, W.A., Williams, D.F., and Lofgren, C.S.Effectiveness of fenoxycarb for control of red imported fire ants (Hymenoptera: Formicidae)J. Econ. Entomol.81(1)83-87(1988) 4.Authority, E.F.S.Conclusion on the peer review of the pesticide risk assessment of the active substance fenoxycarbEFSA J.8(12)1779(2010) 5.Smulders, C.J., Bueters, T.J., Van Kleef, R.G., et al.Selective effects of carbamate pesticides on rat neuronal nicotinic acetylcholine receptors and rat brain acetylcholinesteraseToxicol. Appl. Pharmacol.193(2)139-146(2003)