François Verheggen - Thématiques de recherche
Electrophysiological and Behavioral Activity of Secondary Metabolites in the Confused Flour Beetle, Tribolium confusum
Abstract - Several previous studies have addressed pheromone communication in various
flour beetles (Coleoptera: Tenebrionidae), including the confused flour beetle, Tribolium
confusum (du Val). Different stereoisomers of 4,8-dimethyldecanal (DMD) were reported as
the only components of an aggregation pheromone, but the behavioral activity of DMD is
low. In the present study, additional previously reported secondary metabolites (benzoquinones
and hydrocarbons) were tested for electrophysiological activity (EAG) with both
sexes of T. confusum. Two benzoquinones and three monoenic hydrocarbons elicited
significant EAG activity from both male and female antennae. There was an elevated male
EAG response (vs. the females) to two out of the three hydrocarbons and for both
quinones. The EAG-active compounds were subsequently investigated for behavioral
activity in a walking bioassay. Benzoquinones are considered toxic and have been
assigned a function as alarm substances in flour beetles, but we found that methyl-1, 4-
benzoquinone in intermediate concentrations was attractive to both male and female
beetles and could therefore act as an aggregation pheromone component. Males were also
attracted to ethyl-1,4-benzoquinone. The corresponding hydroquinones, presumed precursors
of the benzoquinones, did not elicit any electrophysiological response and were not tested
for behavioral activity. The unsaturated hydrocarbons (1-tetradecene, 1-pentadecene, and1-hexadecene) elicited significant EAG responses from both male and female antennae
and were also attractive in the behavioral assay. Our results show that several beetleproduced
compounds, in addition to 4,8-dimethyldecanal, may be part of a complex
pheromone system in flour beetles and play a role in mediating aggregation in T.
confusum.
Keywords - Tribolium confusum . Tenebrionidae . Electroantennography (EAG) . Behavior . Chemical communication . Benzoquinones . Hydrocarbons . Aggregation pheromone . Dimethyldecanal
Référence - Verheggen F., Ryne C., Olsson C., Arnaud L., Lognay G., Persson D., Haubruge E., Löfstedt C. (2007). Electrophysiological and behavioural study of some secondary metabolites in the confused flour beetle, Tribolium confusum. Journal of Chemical Ecology, 33 (3) : 525-539.