Safety comparison of eleven acaricides to Harmonia axyridis

In order to compare the safety of acaricide on Harmonia axyridis,we selected nine commonly used acaricides and two kinds of new acaricides( Spirotetramat and Milbemycins),and chose high,medium and low concentrations within its field recommended concentration range,used the pray method to deal directly with larvae,pupae and adult. The main results were as follows: 1) Through investigated the mortality of 24 h and 48 h,The toxic effect of the 11 acaricides for the 3rdstage larvae in descending order was: 25% Azacyclotin WP 20% Amitraz EC 1. 8% Abamectin EC 20% Fenpropathrin EC 73% Propargite EC 15% Pyridaben EC 5% Hexythiazox EC 1% Milbemycins ME 2%Emamectin benzoate EC 24% Spirodiclofen SC = 22. 4% Spirotetramat SC,and the mortality rate of24% spirodiclofen SC and 22. 4% spirotetramat SC were 0. 2) The eight acaricides had no significantly affect to adult eclosion except 1. 8% abamectin EC,20% fenpropathrin EC and 2% emamectin benzoate EC. But all acaricides had residual toxicity for new emergence adults,the descending order was: 1. 8%Abamectin EC 2% Emamectin benzoate EC 20% Amitraz EC 20% Fenpropathrin EC 24%Spirodiclofen SC 25% Azacyclotin WP 15% Pyridaben EC 5% Hexythiazox EC 73% Propargite EC 22. 4 Spirotetramat SC 1% Milbemycins ME,and the mortality rates of the last six acaricides were less than 13. 8%. 3) The adult mortality rates of 20% amitraz EC,24% spirodiclofen SC,25%azacyclotin WP,15% pyridaben EC,5% hexythiazox EC and 73% propargite EC were 0%,The toxic effect of the other five acaricides in descending order was: 1. 8% Abamectin EC 20% Fenpropathrin EC 2% Emamectin benzoate EC 22. 4% Spirotetramat SC 1% Milbemycins ME. In order to protect Harmonia axyridis,we should select the acaricide according to the occurrence period of H. axyridis in the field.