Identification of a new blend of apple volatiles attractive to the apple maggot, Rhagoletis pomonella

Solid-phase microextraction (SPME) and gas chromatography coupled with elec troantennographic detection (GC-EAD) were used to identify a new blend of v olatiles from apples as the key attractants for the apple maggot BS' Rhagol etis pomonella (Walsh). The new five-component blend contains butyl butanoa te (10%), propyl hexanoate (4%). butyl hexanoate (37%), hexyl butanoate (44 %), and pentyl hexanoate (5%) compared with a previously reported seven-com ponent mix of hexyl acetate (35%), (E)-2-hexen-1-yl acetate (2%), butyl 2-m ethylbutanoate (8%), propyl hexanoate (12%), hexyl propanoate (5%). butyl h exanoate (28%), and hexyl butanoate (10%). Volatiles from five different va rieties of apple elicited reproducible and high EAD responses from R. pomon ella antennae to the same five chemicals. In flight-tunnel choice tests inv olving red sticky spheres with odor sources, the new five-component blend o f apple volatiles showed significantly more activity than the previous seve n-component blend or the single compound, butyl hexanoate. In a field trial captures with the new five-component blend were better than with butyl hex anoate, which is currently used with commercial apple maggot monitoring sph eres.