title: Activity of chlorantraniliprole and thiamethoxam seed treatments on life stages of the rice water weevil as affected by the distribution of insecticides in rice plants.
abstract: BACKGROUND
  The systemic insecticides chlorantraniliprole (CAP) and thiamethoxam (TMX), applied to rice as seed treatments, may affect multiple life stages of the rice water weevil, Lissorhoptrus oryzophilus. Effects of CAP and TMX on adult survival, egg-laying and first- and late-instar survivals were determined by infesting plants treated as seeds with different rates of insecticides. The biological activity was related to insecticidal concentrations in leaves, shoots and roots.
  
  
  RESULTS
  CAP did not affect adult survival but decreased egg numbers and reduced the survival of the first and late instars. The greatest reduction in weevil population occurred in late instars feeding on roots. In contrast, TMX reduced adult survival and egg and larval numbers. The high biological activity of CAP on root-feeding stages was consistent with the accumulation of CAP in roots, whereas in TMX-treated plants the high activity on adults correlated with high concentrations of TMX in leaves and stems.
  
  
  CONCLUSIONS
  The differential activity of insecticides on adults suggests poor inherent potency of CAP as an adulticide and/or its limited systemicity in foliage. The distribution of insecticide in specific plant parts can be attributed to the different physicochemical properties of CAP and TMX. The field implications of this research on management of L. oryzophilus are discussed.
authors: Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA, USA.
authors: Srinivas K
authors: SK
authors: Lanka
authors: Michael J
authors: MJ
authors: Stout
authors: Julien M
authors: JM
authors: Beuzelin
authors: James A
authors: JA
authors: Ottea
mesh_terms: D000818:Animals; D007306:Insecticides / Q000378:metabolism / Q000494:pharmacology; D008018:Life Cycle Stages / Q000187:drug effects*; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000378:metabolism / Q000494:pharmacology*; D012275:Oryza / Q000378:metabolism*; D010078:Oxazines / Q000378:metabolism / Q000494:pharmacology*; D010573:Pesticide Residues / Q000378:metabolism / Q000494:pharmacology; D012639:Seeds / Q000378:metabolism*; D000077922:Thiamethoxam; D013844:Thiazoles / Q000378:metabolism / Q000494:pharmacology*; D048889:Weevils / Q000187:drug effects* / Q000254:growth & development*; D062367:ortho-Aminobenzoates / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010078:Oxazines; D010573:Pesticide Residues; D013844:Thiazoles; D062367:ortho-Aminobenzoates; C517733:chlorantranilipole; D000077922:Thiamethoxam
keywords: LC/MS/MS; chlorantraniliprole; rice water weevil; seed treatment; systemic insecticides; thiamethoxam