title: Effects of Fastac 50 EC on bumble bee Bombus terrestris L. respiration: DGE disappearance does not lead to increasing water loss.
abstract: Sublethal effects of pesticides in insects can be observed through physiological changes, which are commonly estimated by metabolic rate and respiratory patterns, more precisely by the patterns of discontinuous gas-exchange (DGE) cycles. The aim of the present research was to study the effect of some low concentrations of Fastac 50 EC on the cycles of CO(2) release and respiratory water loss rates (WLR) in bumble bee Bombus terrestris L. foragers. Bumble bees were dipped into 0.004% and 0.002% Fastac 50 EC solution. Flow-through respirometry was used to record the respiration and WLR 3h before and after the treatment. The respirometry was combined with infrared actography to enable simultaneous recording of abdominal movements. Our results show that Fastac 50 EC has an after-effect on bumble bee respiratory rhythms and muscle activity but does not affect WLR. Treatment with 0.004% Fastac 50 EC solution resulted in disappearance of the respiration cycles; also the lifespan of treated bumble bees was significantly shorter. Treatment with 0.002% Fastac 50 EC solution had no significant effect on respiration patterns or longevity. We found no evidence for the DGE cycles functioning as a water saving mechanism.
authors.affiliation: Department of Plant Protection, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu 51014, Estonia.
authors.forename: Riin
authors.initials: R
authors.lastname: Muljar
authors.forename: Reet
authors.initials: R
authors.lastname: Karise
authors.forename: Eneli
authors.initials: E
authors.lastname: Viik
authors.forename: Aare
authors.initials: A
authors.lastname: Kuusik
authors.forename: Ingrid
authors.initials: I
authors.lastname: Williams
authors.forename: Luule
authors.initials: L
authors.lastname: Metspalu
authors.forename: Külli
authors.initials: K
authors.lastname: Hiiesaar
authors.forename: Anne
authors.initials: A
authors.lastname: Must
authors.forename: Anne
authors.initials: A
authors.lastname: Luik
authors.forename: Marika
authors.initials: M
authors.lastname: Mänd
mesh_terms: D000818:Animals; D001516:Bees / Q000187:drug effects* / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D019069:Cell Respiration / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects; D007306:Insecticides / Q000494:pharmacology*; D008136:Longevity / Q000187:drug effects; D011722:Pyrethrins / Q000494:pharmacology*; D015657:Respiratory Transport / Q000187:drug effects*; D014867:Water / Q000502:physiology*
chemical_list: D007306:Insecticides; D011722:Pyrethrins; D014867:Water; D002245:Carbon Dioxide; C017160:cypermethrin