title: Evaluation of neonicotinoid, organophosphate and avermectin trunk injections for the management of avocado thrips in California avocado groves.
abstract: BACKGROUND
  Trunk injections of systemic insecticides were evaluated for the management of avocado thrips. Insecticide residues were quantified in leaves to determine when after treatment, and for how long, toxic concentrations of the insecticides were present. Residues in fruit were quantified to determine whether trunk injection of insecticides might present a greater risk than traditional application methods for contaminating fruit.
  
  
  RESULTS
  Residues of imidacloprid and dinotefuran were at least tenfold higher in leaves when trees were treated via trunk injection compared with soil application. Dinotefuran uptake was more rapid than imidacloprid, and no residues were detected within fruit. Acephate was also mobilized very rapidly and gave good control of thrips in bioassays; however, residues of acephate and its insecticidal metabolite methamidophos were detected in the fruit for up to 4 weeks after injection. Avermectin uptake was very slow, and it was ineffective against avocado thrips.
  
  
  CONCLUSIONS
  Trunk injections of acephate and dinotefuran permitted rapid uptake into avocados, and they are strong candidates as control methods for avocado thrips. However, residues of organophosphates in fruit could necessitate increased preharvest intervals. Residues of neonicotinoids were below detection limits in fruit, suggesting that neonicotinoids may be the more suitable control option of the two chemical classes.
authors.affiliation: Department of Entomology, University of California, Riverside, CA 92521, USA. frank.byrne@ucr.edu
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Byrne
authors.forename: Anthony A
authors.initials: AA
authors.lastname: Urena
authors.forename: Lindsay J
authors.initials: LJ
authors.lastname: Robinson
authors.forename: Robert I
authors.initials: RI
authors.lastname: Krieger
authors.forename: Joe
authors.initials: J
authors.lastname: Doccola
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Morse
mesh_terms: D000818:Animals; D006146:Guanidines / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D007300:Insect Control / Q000379:methods*; D007306:Insecticides / Q000494:pharmacology*; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000494:pharmacology; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000494:pharmacology; D010755:Organophosphates / Q000494:pharmacology*; D027421:Persea / Q000469:parasitology*; D010935:Plant Diseases / Q000469:parasitology* / Q000517:prevention & control; D018547:Plant Stems / Q000469:parasitology; D061149:Thysanoptera / Q000187:drug effects*
chemical_list: D006146:Guanidines; D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010755:Organophosphates; C465368:dinotefuran; C082359:imidacloprid; D007559:Ivermectin; C019264:avermectin