title: Monitoring the effects of thiamethoxam applied as a seed treatment to winter oilseed rape on the development of bumblebee (Bombus terrestris) colonies.
abstract: BACKGROUND
  The development of bumblebee (Bombus terrestris audax) colonies that had foraged for 5 weeks on flowering winter oilseed rape grown from seed treated with thiamethoxam (as Cruiser OSR) was assessed (two control, one treated field). Colony development was evaluated by monitoring the colony mass, forager activity was assessed, both at the hive and within the crop, and the contribution of oilseed rape to the pollen stored within the colony was analysed.
  
  
  RESULTS
  Pollen collected from the treated crop contained residues of 1.0 µg thiamethoxam kg(-1) and 3.0 µg CGA322704 (metabolite likely equivalent to clothiandin) kg(-1) , and nectar contained residues of 1.8 µg thiamethoxam kg(-1) and no metabolite. No residues of thiamethoxam or CGA322704 were detected in samples from the control fields. Up to 93% of bumblebee collected pollen sampled from within the colonies originated from oilseed rape, and B. terrestris were observed actively foraging on all the fields. Colonies on all three fields showed similar rates of mass gain during the exposure phase and comparable production of gynes and drones.
  
  
  CONCLUSIONS
  B. terrestris colonies placed adjacent to a field of flowering oilseed rape grown from thiamethoxam-treated seed developed at a comparable rate with colonies placed adjacent to oilseed rape grown from untreated seed. © 2015 Society of Chemical Industry.
authors.affiliation: Syngenta, Jealott's Hill International Research Station, Bracknell, Berks, UK.
authors.forename: Helen
authors.initials: H
authors.lastname: Thompson
authors.affiliation: Syngenta, Jealott's Hill International Research Station, Bracknell, Berks, UK.
authors.forename: Mike
authors.initials: M
authors.lastname: Coulson
authors.affiliation: Syngenta, Jealott's Hill International Research Station, Bracknell, Berks, UK.
authors.forename: Natalie
authors.initials: N
authors.lastname: Ruddle
authors.affiliation: Fera, Sand Hutton, York, UK.
authors.forename: Selwyn
authors.initials: S
authors.lastname: Wilkins
authors.affiliation: Fera, Sand Hutton, York, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Harrington
authors.affiliation: Fera, Sand Hutton, York, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Harkin
mesh_terms: D000818:Animals; D001516:Bees / Q000187:drug effects* / Q000254:growth & development; D029688:Brassica napus; D004739:England; D005247:Feeding Behavior / Q000187:drug effects; D007306:Insecticides / Q000633:toxicity*; D007814:Larva / Q000187:drug effects; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000633:toxicity*; D010063:Ovum / Q000187:drug effects; D010078:Oxazines / Q000633:toxicity*; D012621:Seasons; D012639:Seeds; D000077922:Thiamethoxam; D013844:Thiazoles / Q000633:toxicity*
chemical_list: D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010078:Oxazines; D013844:Thiazoles; D000077922:Thiamethoxam
keywords: bumblebees; field monitoring; oilseed rape; thiamethoxam