Abstract:
Objective This study was to investigate the effects of three pesticides (bisultap,tetrachlorantraniliprole,and oxyfluorfen) on the movement speed and protective enzymes activity of
Neoseiulus californicus,so as to provide a theoretical basis for appropriate use of pesticide,and to support the promotion and field application of
Neoseiulus californicus for biological control of pest mites in citrus orchards.
Method The toxicity of three pesticides (bisultap,tetrachlorantraniliprole,and oxyfluorfen) on
Neoseiulus californicus was detected using medicated film method,and their safety was also evaluated. The three pesticides at sublethal concentrations (LC
10,LC
30 and LC
50) were used to treat the feeding group and the starvation group of
Neoseiulus californicus for 24 hours,with a control group treated with clear water,to measure their movement speed. The three pesticides at LC
10 and LC
30 were used to treat
Neoseiulus californicus for 24 hours,with the control group treated with clear water,to determine enzyme activities of catalase (CAT),peroxidase (POD) and superoxide dismutase (SOD) using the spectrophotometric method.
Result The LC
50 values after 24-hour treatment of bisultap,tetrachlorantraniliprole and oxyfluorfen on
Neoseiulus californicus were 1.626,3.818 and 0.234 g/L,respectively. The maximum safety coefficients after 24-hour treatments of bisultap,tetrachlorantraniliprole and oxyfluorfen on
Neoseiulus californicus were 5.20,171.81 and 5.85,respectively,indicating that the safety order of the three pesticides for
Neoseiulus californicus was tetrachlorantraniliprole>oxyfluorfen>bisultap. After the 24-hour LC
50 bisultap treatment,the movement speed of
Neoseiulus californicus in the feeding group was significantly higher than that of the control group (
P<0.05,the same below). After the 24-hour treatment of oxyfluorfen of LC
50,the movement speed of
Neoseiulus californicus in the feeding group was significantly lower than that of the control group. After the 24-hour LC
30 tetrachlorantraniliprole treatment,the movement speed of
Neoseiulus californicus in the feeding group was significantly lower than that in the control group and the LC
50 treatment group. After the 24-hour LC
10 tetrachlorantraniliprole treatment,the movement speed of
Neoseiulus californicus in starvation group was significantly lower than that in the control group. No significant difference in total protein content was found in
Neoseiulus californicus after the 24-hour treatments of LC
10 and LC
30 of the three pesticides (
P>0.05,the same below). No significant difference in CAT activity of
Neoseiulus californicus was found between the control group and the 24-hour LC
10 and LC
30 bisultap treatment groups. Under the 24-hour LC
10 tetrachlorantraniliprole treatment,the CAT activity of of
Neoseiulus californicus was significantly lower than that in the control group and the 24-hour LC
30 tetrachlorantraniliprole treatment group. Under the 24-hour LC
10 and LC
30 treatments of bisultap and tetrachlorantraniliprole,the POD activity of
Neoseiulus californicus was significantly lower than that in the control group. Under the 24-hour LC
30 treatments of bisultap and tetrachlorantraniliprole,the SOD activity of
Neoseiulus californicus was significantly higher than that of the control group. Under the 24-hour LC
10 and LC
30 oxyfluorfen treatments,the activities of three protective enzymes of
Neoseiulus californicus was significantly lower than that of the control group.
Conclusion The three pesticides (bisultap,tetrachlorantraniliprole,and oxyfluorfen) influence the athletic ability of
Neoseiulus californicus. Tetrachlorantraniliprole inhibits the CAT of
Neoseiulus californicus; bisultap and tetrachlorantraniliprole inhibit POD but activate SOD of
Neoseiulus californicus. Oxyfluorfen significantly inhibits activities of the three protective enzymes of
Neoseiulus californicus. Therefore,tetrachlorantraniliprole,which is rather safe for
Neoseiulus californicus,is recommended to be applied for integrated management of cirtus orchards,so as to achieve the synergistic effect of biological control and chemical control.