title: Disruption of host-seeking behaviour by the salmon louse, Lepeophtheirus salmonis, using botanically derived repellents.
abstract: The potential for developing botanically derived natural products as novel feed-through repellents for disrupting settlement of the salmon louse, Lepeophtheirus salmonis (Caligidae) upon farmed Atlantic salmon, Salmo salar, was investigated using an established laboratory vertical Y-tube behavioural bioassay for assessing copepodid behaviour. Responses to artificial sea water conditioned with the odour of salmon, or to the known salmon-derived kairomone component, α-isophorone, in admixture with selected botanical materials previously known to interfere with invertebrate arthropod host location were recorded. Materials included oils extracted from garlic, Allium sativum (Amaryllidaceae), rosemary, Rosmarinus officinalis (Lamiaceae), lavender, Lavandula angustifolia (Lamiaceae), and bog myrtle, Myrica gale (Myricaceae), and individual components (diallyl sulphide and diallyl disulphide from garlic; allyl, propyl, butyl, 4-pentenyl and 2-phenylethyl isothiocyanate from plants in the Brassica genus). Removal of attraction to salmon-conditioned water (SCW) or α-isophorone was observed when listed materials were presented at extremely low parts per trillion (ppt), that is picograms per litre or 10-12level. Significant masking of attraction to SCW was observed at a level of 10 ppt for diallyl disulphide and diallyl sulphide, and allyl isothiocyanate and butyl isothiocyanate. The potential of very low concentrations of masking compounds to disrupt Le. salmonis copepodid settlement on a host fish has been demonstrated in vitro.
authors: School of Biological Sciences, University of Aberdeen, Aberdeen, UK.
authors: B
authors: B
authors: O'Shea
authors: EWOS Innovation AS, Dirdal, Norway.
authors: S
authors: S
authors: Wadsworth
authors: EWOS Innovation AS, Dirdal, Norway.
authors: J
authors: J
authors: Pino Marambio
authors: Biological Chemistry and Crop Protection Department, Rothamsted Research, Harpenden, Herts., UK.
authors: M A
authors: MA
authors: Birkett
authors: Biological Chemistry and Crop Protection Department, Rothamsted Research, Harpenden, Herts., UK.
authors: J A
authors: JA
authors: Pickett
authors: School of Biological Sciences, University of Aberdeen, Aberdeen, UK.
authors: A J
authors: AJ
authors: Mordue Luntz
mesh_terms: D000818:Animals; D000977:Antiparasitic Agents / Q000494:pharmacology / Q000627:therapeutic use; D033342:Copepoda / Q000187:drug effects* / Q000502:physiology; D003512:Cyclohexanones / Q000494:pharmacology / Q000627:therapeutic use; D004478:Ectoparasitic Infestations / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*; D005393:Fish Diseases / Q000188:drug therapy* / Q000469:parasitology; D000072777:Host-Seeking Behavior / Q000187:drug effects*; D017879:Isothiocyanates / Q000494:pharmacology / Q000627:therapeutic use; D019684:Magnoliopsida / Q000737:chemistry; D010675:Pheromones / Q000494:pharmacology / Q000627:therapeutic use; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use*; D020317:Salmo salar
chemical_list: D000977:Antiparasitic Agents; D003512:Cyclohexanones; D017879:Isothiocyanates; D010675:Pheromones; D010936:Plant Extracts; C005940:isophorone
keywords: 
  Lepeophtheirus salmonis
  ; Y-tube bioassay; botanical extracts; isothiocyanates; repellency