Studies On The Prefernces To Plant-Derived Baits And Insecticide Screening For Controlling Solenopsis Invicta

The red imported fire ant,Solenopsis invicta Buren,originatedfrom South America.It is one of the most dangerous invasive species in the world.S. invicta had posed a serious threat to the local people, animals,agriculture, ecological environment, economy and public safety since it invadedin Guangxi in 2005.In order to develop more suitable poison bait to control the red imported fire antin Guangxi,preferences to plant source baits and chemical controlfor S. invicta were studied. The main results of this study were showed as following:1.Baits testingPreferences of S. invicta to six plant source baits were tested, including corn, corn cob, peanut, peanut bran, oats and soybeans.Results showed that corn was the most suitable to be used as the bait vector, but it need compound with other attractants to enhance its effectiveness. Data of further studies showed that compared with other attractants, corn flour compound withshrimp powder and butter can significantly enhance the selectivity of the bait for S. invictaamong the six compound (i.e.,corn flour+ earthworm powder, fish, liver, butter, brown sugar, shrimp powder, respectively). Corn flour+shrimp powder and corn flour+butter were 2:1 and 4:1 were the bestratio of the two-component baits, while corn flour+sugar+shrimp+butter was 5:2:2:1 was the optimal ratio of the multicomponent baits.2.Insecticides screeningEffects of 14 kinds of insecticides were examined to control the redimported fire antin laboratory. Results showed that Indoxacarb,Rotenone, Thiamethoxam, Chlorfenapyr, Dinotefuran,Acetamiprid,Clothianidin, Sulfluramid and Abamectin had toxic effect for the red imported fire ant.Among of the 9 insecticides,Indoxacarb and Rotenone had the strongest toxicity thanThiamethoxam, Chlorfenapyr and Sulfluramid.The capacity of toxicant transmitting for S. invicta was evaluated. Results indicated that S. invicta had the better toxicant transmitting for Chlorfenapyr at the concentration of 100-～200μ,g/g. However, this species had a poor toxicant transmittingeffect for Thiamethoxam.Among the 5 mixture ratios ofSulfluramid and Thiamethoxam, the ratio of 1:1 and 4:1 had significant synergistic effect. Among the 5 mixture ratios of Sulfluramid and Chlorfenapyr, the ratio of 4:1 and 8:1 had significant synergistic effect. The mixture of Abamectin and Indoxacarb has no evident synergistic effect to S. invicta.S. invicta had the better toxicant transmitting for the mixture of Chlorfenapyr and Sulfluramid at the concentration of 25～50μg/g. However, this species had a poor toxicant transmittingeffect for the mixture of Sulfluramid and Thiamethoxam. Results suggested that mixture of Sulfluramid+Chlorfenapyr could be used as bait formulation.