Title: Antennal response of the Asian citrus psyllid to citrus volatiles and their degradation product Authors
Submitted to: Florida Entomological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 18, 2013
Publication Date: N/A
Technical Abstract: Asian citrus psyllid antennae reacted strongly when stimulated with citral and ocimene stimulus tubes that had been aged for 3-5 days. When 20 µl of neat ocimene or citral were aged on filter paper strips in sealed Pasteur pipette stimulus tubes for 6 days on the laboratory bench, voltage changes were observed in both male and female antennae when a 1 ml air puff was applied through the pipette into the humidified airstream flowing past the antenna. This voltage change was not seen in newly prepared (0 day) stimulus tubes. Gas chromatography-mass spectrometry analyses of headspace volatiles of stimulus tubes loaded with 20 µl of citral or ocimene indicated that the compounds were present at 0 days but could no longer be found at 6 days. Using the solutions extracted from the aged filter papers, coupled gas chromatograph-electroantennogram analyses documented two peaks from both the ocimene and the citral tubes that were stimulatory to the psyllid antennae. Gas chromatography-mass spectrometry analysis determined that the indicated peaks were acetic and formic acid. Log dose testing of acetic and formic acids on male and female antennae indicated that acetic acid elicited greater responses from female antennae than from male antennae. There were no statistical differences noted between male and female antennae when the formic acid was tested. Whereas both primary host plant volatiles and induced host plant volatiles are well investigated, our observation of antennally detectable volatiles resulting from degradation products of constitutive plant volatiles provides a fresh view of the insect sensory world that is not yet understood.