The European earwig, Forficula auricularia is an invasive insect found in many temperate regions of the world and is regarded as an urban and agricultural pest of numerous crops. Several studies have shown that F. auricularia aggregate in large numbers with the use of an aggregation pheromone. However, the identity of compounds which constitute the pheromone remains elusive. Our aim was to isolate and identify the aggregation pheromone used by F. auricularia using both solvent washes of individuals and thermal desorption of substrates exposed to earwigs. Solvent washes of male, female and juvenile earwigs isolated 51 different branched and unbranched alkanes, alkenes and alkadienes. Substrates exposed to aggregating field populations in situ were demonstrated to be attractive to earwigs after less than 24 h of exposure. Analysis of these substrates using thermal desorption and solvent washes showed that hydrocarbons were the only detectable compounds laid down by earwigs on these surfaces. Significant behavioural responses were observed to synthetic blends of the unsaturated hydrocarbons containing (Z)-7-tricosene, (Z)-9-tricosene, (Z)-7-pentacosene and (Z)-9-pentacosene at ≥25 insect equivalents in field-based bioassays. However, behavioural responses to these blends proved inconsistent particularly later in the field season, possibly due to a missing component within the pheromone blend or plasticity in the pheromones production and response.

Item Type:	Refereed Article
Keywords:	Forficula auricularia, earwig, aggregation, pheromone, cuticular hydrocarbons, entomology, chemical ecology
Research Division:	Agricultural and Veterinary Sciences
Research Group:	Horticultural Production
Research Field:	Horticultural Crop Protection (Pests, Diseases and Weeds)
Objective Division:	Environment
Objective Group:	Control of Pests, Diseases and Exotic Species
Objective Field:	Control of Animal Pests, Diseases and Exotic Species in Farmland, Arable Cropland and Permanent Cropland Environments
UTAS Author:	Quarrell, SR (Dr Stephen Quarrell)
UTAS Author:	Davies, NW (Associate Professor Noel Davies)
UTAS Author:	Walker, PW (Dr Paul Walker)
UTAS Author:	Corkrey, R (Dr Ross Corkrey)
UTAS Author:	Smith, JA (Associate Professor Jason Smith)
UTAS Author:	Allen, GR (Associate Professor Geoff Allen)
ID Code:	110583
Year Published:	2016
Web of Science® Times Cited:	3
Deposited By:	Tasmanian Institute of Agriculture
Deposited On:	2016-08-03
Last Modified:	2017-11-06
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