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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Pest Management and Biocontrol Research » Research » Publications at this Location » Publication #203040
Title: Behavioral response of Lygus hesperus to conspecifics and headspace volatiles of alfalfa in a y-tube olfactometer

Author
item Blackmer, Jacquelyn
item RODRIGUEZ-SAONA, C - UNIV OF TORONTO, CANADA
item Byers, John
item SHOPE, K - FORMER USDA-ARS WCRL AZ
item SMITH, J - FORMER USDA-ARS WCRL AZ

Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/7/2004
Publication Date: 8/1/2004
Citation: Blackmer, J.L., Rodriguez-Saona, C., Byers, J.A., Shope, K.L., Smith, J.P. 2004. Behavioral response of Lygus hesperus to conspecifics and headspace volatiles of alfalfa in a y-tube olfactometer. Journal of Chemical Ecology Vol 30(8): 1547-1564.

Interpretive Summary: The western tarnished plant bug, Lygus hesperus Knight, feeds and develops on a variety of weeds in the spring, with later generations moving to alfalfa and cotton where severe damage to reproductive structures can occur. A synthetic attractant for monitoring or mass-trapping L. hesperus, or the identification of potential attractants for natural enemies, would be useful tools for integrated pest management programs. Studies investigated the response of naïve and experienced fifth-instar and adult L. hesperus to odors associated with conspecifics and alfalfa, Medicago sativa L. Fifth-instar L. hesperus responded to all plant/insect combinations,whereas female L. hesperus only responded preferentially to vegetative and flowering alfalfawhere conspecifics had fed for 24–72 hr, and to vegetative alfalfa where conspecifics were added approximately 30 min before the test began. Males were not attracted to headspace volatiles from any of the alfalfa treatments. Analysis of headspace volatiles showed that (E)-2-hexanal, (Z)-3-hexen-1-ol, '-pinene, (Z)-3-hexenyl acetate, (E)-2-hexenyl acetate, limonene, (Z)-ocimene, (E)-'-ocimene, linalool, (3E)-4,8-dimethyl-1,3,7-nonatriene, and (E, E)-'-farnesene are emitted from both vegetative and flowering alfalfa. Indole and (3E, 7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene were only detected in flowering alfalfa. Damage to alfalfa by L. hesperus increased emissions of (Z)-ocimene, (E)-'-ocimene, (E)-'-caryophyllene, and (E, E)-'-farnesene, while '-pinene, myrcene, methyl salicylate, and (3E, 7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene were only detected from damaged plants. Thus, individual or mixtures of these alfalfa volatiles may be useful.

Technical Abstract: The western tarnished plant bug, Lygus hesperus Knight, feeds and develops on a variety of weeds in the spring, with later generations moving to alfalfa and cotton where severe damage to reproductive structures can occur. A synthetic attractant for monitoring or mass-trapping L. hesperus, or the identification of potential attractants for natural enemies, would be useful tools for integrated pest management programs. Studies investigated the response of naïve and experienced fifth-instar and adult L. hesperus to odors associated with conspecifics and alfalfa, Medicago sativa L. Fifth-instar L. hesperus responded to all plant/insect combinations,whereas female L. hesperus only responded preferentially to vegetative and flowering alfalfawhere conspecifics had fed for 24–72 hr, and to vegetative alfalfa where conspecifics were added approximately 30 min before the test began. Males were not attracted to headspace volatiles from any of the alfalfa treatments. Analysis of headspace volatiles showed that (E)-2-hexanal, (Z)-3-hexen-1-ol, '-pinene, (Z)-3-hexenyl acetate, (E)-2-hexenyl acetate, limonene, (Z)-ocimene, (E)-'-ocimene, linalool, (3E)-4,8-dimethyl-1,3,7-nonatriene, and (E, E)-'-farnesene are emitted from both vegetative and flowering alfalfa. Indole and (3E, 7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene were only detected in flowering alfalfa. Damage to alfalfa by L. hesperus increased emissions of (Z)-ocimene, (E)-'-ocimene, (E)-'-caryophyllene, and (E, E)-'-farnesene, while '-pinene, myrcene, methyl salicylate, and (3E, 7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene were only detected from damaged plants. Thus, individual or mixtures of these alfalfa volatiles may be useful.