Evaluation of neonicotinoid insecticides as an alternative for aldicarb for early-season cotton pest management in Louisiana

During 2012-2013, four field trials were conducted in Louisiana evaluating the efficacy of the neonicotinoid insecticides thiamethoxam (Cruiser) and imidaclorpid (Gaucho) applied as seed treatments and in-furrow applied as Centric or Platinum and Admire Pro, respectively, relative to an in-furrow application of aldicarb (Temik) and non-treated seed.  Thrips counts were collected by sampling 5 or 10 whole plants from each plot at the two and four true leaf growth stage in each test and count the number of thrips present.  Damage ratings (1-5) were also conducted and yields taken. In 2012, the thrips populations were composed of approximately 50:50 western flower:tobacco thrips and all of the treatments provided thrips control relative to the non-treated but seed treatments appeared to provide shorter residual control. Both neonicotinoid in-furrow treatments appeared to provide activity similar to aldicarb. In 2013, the thrips population was predominantly tobacco thrips and treatments consisting of thiamethoxam performed poorly while the in-furrow applications of imidacloprid appeared as effective as aldicarb. There is evidence that some tobacco thrips in the Mid-south may be resistant to thiamethoxam.