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ARS Home » Southeast Area » Stoneville, Mississippi » Biological Control of Pests Research » Research » Publications at this Location » Publication #358891
Title: Electrophysiological responses of eighteen species of insects to fire ant alarm pheromone

Author
item Du, Yuzhe - Cathy
item Grodowitz, Michael
item Chen, Jian

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/6/2019
Publication Date: 11/14/2019
Citation: Du, Y., Grodowitz, M.J., Chen, J. 2019. Electrophysiological responses of eighteen species of insects to fire ant alarm pheromone. Insects. 10:1-15.

Interpretive Summary: Olfaction plays a dominant role in insect communication, which can be exploited in pest insect management. Alarm pheromone is a major class of insect pheromones that alerts nestmates for colony defense. Alarm pheromones of red imported fire ants, honeybees and aphids have been identified. Do other insects respond to these alarm pheromones? In this study, electroantennography (EAG) responses to these three insect alarm pheromones were investigated using a wide range of insect species. Beside imported fire ants, fire ant alarm pheromone elicited strong EAG response of all other tested insects, including four other ant species, honeybee, bagrada bug, lady beetle, housefly, small hive beetle, yellow fever mosquito, termite, bedbug, water hyacinth weevil, southern green stink bug and two aphid species. In contrast, honeybee alarm pheromone elicited EAG responses only in honeybee and fire ants, but not in all other species tested. Aphid alarm pheromone only elicited EAG response in aphids and two other insects. These results strongly suggest that fire ant alarm signal may be eavesdropped by a number of distantly related insect species. Alarm pheromones from predators, such as fire ant, may be a rich source of insect repellants. Since fire ant alarm pheromone may repel many insect species, engineering crops to have ability of emitting compounds like fire ant pheromone may enhance the resistance of the crop to diverse pest insects.

Technical Abstract: Olfaction plays a dominant role in insect communication. Alarm pheromone is a major class of releaser pheromones, which alerts other insects of the same species of impending danger. The major component of alarm pheromones of imported fire ants, honeybees and aphids have been identified as 2-ethyl-3,6-dimethylpyrazine (2E-3,6-DP), isopentyl acetate (IPA), and E-ß-farnesene (EßF), respectively. In this study, electroantennography (EAG) responses to EDP (a mixture of 2-ethyl-3, 6-dimethylpyrazine and 2-ethyl-3, 5-dimethylpyrazine), IPA and EßF were investigated in a wide range of distantly related insect species. Beside imported fire ants, the EDP elicited strong EAG response of all other tested insects, including five ant species, honeybee, bagrada bug, lady beetle, housefly, small hive beetle, yellow fever mosquito, termite, bedbug, water hyacinth weevil, southern green stink bug and two aphid species. In contrast, IPA elicited EAG response only in honeybee, imported fire ant, the Aphaenogaster ant and water hyacinth weevil. The EßF only elicited responses in aphids and two other insects. Because a large number of distantly related insect species responded to EDP, the olfactory receptors for EDP may be highly conserved across different insect orders and the fire ant alarm signal may be eavesdropped by widespread insect species.