Abstract: The inhibition of the main components of a new kind of permethrin termiticide on carboxylesterase (CarEs) and Ca-ATPase in Reticulitermes chinensis Snyder was investigated. The results showed that at concentration of 1.66×10⁴ mol·L¹ octachlorodipropyl ether and OP-emulsifier in the compound could inhibit the specific activity of CarEs, while permethrin could inhibit the specific activity of Ca-ATPase strongly. The IC₅₀ values were 7.1148×10⁵ mol·L¹, 7.3373×10⁴ mol·L¹ and 5.11×10⁷ mol·L¹ respectively. The fact that Ca-ATPase function was more strongly affected than that of Na-K-ATPase, and that permethrin could strongly inhibit the activity of Ca-ATPase on the synaptosome of Reticulitermes chinensis, implies that Ca-ATPase is the primary neuronal target site of pyrethroids in Isoptera.

Key words: Reticulitermes chinensis, CarEs, Ca-ATPase, termiticide compound, inhibition of enzyme activity