Toxicity of deltamethrin on Ditylenchus destructor and the effects on its locomotion and feeding behaviors

Effects of deltamethrin on the mortality, locomotion and feeding behaviors of Ditylenchus destructor were investigated by dipping method, sand column method and incubating fluorescent Cy3 method, using profenofos, carbofuran and abamectin as control. The results showed that deltamethrin had moderate nematicidal activity against D. destructor, with LC50 value of 459.8 mg/L, while the LC50 values of profenofos, carbofuran and abamectin to D. destructor were 159.9, 331.9 and 257.3 mg/L, respectively. Deltamethrin also showed better inhibitive activity on the locomotion of D. destructor, with IC50 value of 3.1 mg/L, which was higher than that of profenofos (8.3 mg/L) and carbofuran (16.1 mg/L), but lower than that of abamectin (0.8 mg/L). In the case of feeding, the minimal concentration of profenofos that stimulated more than 90% nematode intake of Cy3 was 0.6 mg/L, and that of carbofuran was 40 mg/L. The minimal concentration of profenofos that inhibited all of the nematode intake of Cy3 was 360 mg/L, and that of carbofuran was 300 mg/L. Deltamethrin and abamectin could not stimulate the feeding of D. destructor. After exposure to 10 mg/L profenofos for 2 h, abamectin and deltamethrin could inhibit all of nematodes intake of Cy3 at 20 and 200 mg/L, respectively. The results indicated that deltamethrin have the potential in the control of D. destructor.