Raspberry crown borer, Pennisetia marginata (Harris) (Lepidoptera:
Sesiidae), is a native North American species and pest of many cane fruits. Using
coupled gas chromatographic–electroantennographic detection analyses (GC-EAD) we
identified candidate sex pheromone components in pheromone gland extracts and
effluvia from calling females. Analysis of gland extracts on a Zebron-5 column
revealed four components (A, B, C, and D) that elicited strong responses from male
antennae. The two most EAD-active components A and B were hypothesised to be
(3E,13Z)-octadecadienal
[(3E,13Z)-18:Ald] and
(3E,13Z)-octadecadienol
[(3E,13Z)-18:OH], respectively. Their retention
times on other GC columns matched those of authentic standards, thus supporting
structural assignments. Synthetic (3E,13Z)-18:Ald,
and its GC rearrangement product
(2E,13Z)-octadecadienal
[(2E,13Z)-18:Ald; component C], also induced
antennal responses in GC-EAD analyses of female effluvia. Compounds D in pheromone
gland extract, and E and F in female effluvia, elicited EAD responses but could not
be identified. In field trapping experiments,
(3E,13Z)-18:Ald was the only component that
attracted male P. marginata when tested alone.
Attractiveness of (3E,13Z)-18:Ald was reduced when
combined in binary or ternary blends with any of the other identified components,
suggesting one or all may act as pheromone antagonists. In Aldergrove, British
Columbia, Canada, peak diel attraction of male P.
marginata to (3E,13Z)-18:Ald
occurred between 16:00 and 18:00 hours Pacific Daylight Time, at temperatures of
21–23°C, on 30 August 2010, 3 September 2010, and 13 September 2010. We conclude that
(3E,13Z)-18:Ald is the major pheromone component
of P. marginata.