Ambrosia beetle (Coleoptera: Curculionidae) responses to volatile emissions associated with ethanol-injected Magnolia virginiana.
Xylosandrus germanus (Blandford) and other species of ambrosia beetles are key pests of ornamental nursery trees. A variety of laboratory- and field-based experiments were conducted in pursuit of improved monitoring strategies and to develop a trap tree strategy for ambrosia beetles.  Traps baited with bolts prepared from Magnolia virginiana L. injected with ethanol caught five times more X. germanus than ethanol-baited traps. Basal stem injections of ethanol into M. virginiana induced more ambrosia beetle attacks than irrigating or baiting with ethanol, and no attacks  occurred on water-injected trees. A positive correlation was also detected between concentration of injected ethanol and cumulative attacks. Solid phase microextraction-gas chromatography-mass spectrometry characterized bark emissions from ethanol- and water-injected M. virginiana at 1, 2,  10, and 16 d after treatment. Ethanol emission from injected trees steadily declined from 1 to 16 d after treatment, but was not emitted from water-injected trees. A variety of monoterpenes were also emitted in trace amounts from the ethanol- and water-injected trees. Antennal responses of  X. germanus via gas chromatography-electroantennographic detection to volatiles from ethanol-injected M. virginiana occurred for ethanol, but not the various monoterpenes. X. germanus and other ambrosia beetles were also equally attracted to traps baited with ethanol alone compared with a  synthetic mixture of ethanol plus various monoterpenes formulated to mimic ethanol-injected M. virginiana. Injecting concentrated solutions of ethanol into trees may be useful for establishing odor-based trap trees, which could aid with monitoring programs and/or potentially deflect ambrosia  beetles away from valuable nursery stock.
USDA-Agricultural Research Service, Application Technology Research Unit, Horticultural Insects Research Laboratory, Wooster, OH 44691, USA. christopher.ranger@ars.usda.gov
Christopher M
CM
Ranger
Michael E
ME
Reding
Peter B
PB
Schultz
Jason B
JB
Oliver
D000818:Animals; D057506:Arthropod Antennae / Q000187:drug effects; D002849:Chromatography, Gas; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D007300:Insect Control / Q000295:instrumentation / Q000379:methods*; D031566:Magnolia / Q000737:chemistry / Q000378:metabolism*; D013058:Mass Spectrometry; D039821:Monoterpenes / Q000494:pharmacology*; D010675:Pheromones / Q000494:pharmacology*; D052617:Solid Phase Microextraction; D055549:Volatile Organic Compounds / Q000494:pharmacology; D048889:Weevils / Q000187:drug effects*
D039821:Monoterpenes; D010675:Pheromones; D055549:Volatile Organic Compounds; C010411:insect attractants; D000431:Ethanol