title: Population divergence of aggregation pheromone responses in Ips subelongatus in northeastern China.
abstract: The Asian larch bark beetle, Ips subelongatus, is considered to be the major pest of larch within its natural range. We investigated the electrophysiological and behavioral characteristics as well as mitochondrial DNA cytochrome oxidase subunit I sequences of I. subelongatus from 13 geographic populations throughout northeastern China in order to explore population divergence of aggregation pheromone responses and the extent of potential genetic divergence. Electrophysiological analyses showed that antennae of I. subelongatus from all the six tested populations responded strongly to (S)-(-)-ipsenol (100% detection; 0.35-0.73 mV) in gas chromatography (GC)-electroantennographic detection (EAD) analyses, while its antipode, (R)-(+)-ipsenol was antennally inactive. I. subelongatus populations varied in their responses to (R)-(-)- and (S)-(+)-ipsdienol in GC-EAD analyses. Behavioral bioassays demonstrated that (S)-(-)-ipsenol alone was significantly attractive at all the tested sites, supporting its status as a key pheromone component of I. subelongatus, whereas (S)-(+)-ipsdienol was inactive alone. Adding (S)-(+)-ipsdienol to (S)-(-)-ipsenol did not have any effect on the trap catches from some populations in Inner Mongolia. However, (S)-(+)-ipsdienol showed a strong synergistic effect on (S)-(-)-ipsenol from several populations in Jilin and Liaoning Provinces, and a weak synergistic effect from some transition populations in Heilongjiang Province. Furthermore, 27 mitochondrial haplotypes were found among the 13 populations (intraspecific nucleotide divergence, 0.1%-1.1%). Analyses of molecular variance and haplotype networks indicated that different geographic populations have developed some genetic variation but did not form completely independent groups. From an applied point of view, a universal synthetic binary blend of racemic ipsenol and (S)-(+)-ipsdienol might have a potential for monitoring or even mass-trapping of I. subelongatus across northeastern China, even though some populations only use (S)-(-)-ipsenol alone as their active pheromone component.
authors.affiliation: Key Laboratory of Forest Protection of State Forestry Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China.|State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Da-Feng
authors.initials: DF
authors.lastname: Chen
authors.affiliation: Key Laboratory of Forest Protection of State Forestry Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China.
authors.forename: Ye-Jing
authors.initials: YJ
authors.lastname: Li
authors.affiliation: Sterling International, Inc, Spokane, Washington, USA.
authors.forename: Qing-He
authors.initials: QH
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Forest Protection of State Forestry Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China.
authors.forename: Su-Fang
authors.initials: SF
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Forest Protection of State Forestry Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China.
authors.forename: Hong-Bin
authors.initials: HB
authors.lastname: Wang
authors.affiliation: Key Laboratory of Forest Protection of State Forestry Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Li-Lin
authors.initials: LL
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Forest Protection of State Forestry Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China. kongxbo@hotmail.com.
authors.forename: Xiang-Bo
authors.initials: XB
authors.lastname: Kong
mesh_terms: D000080462:Acyclic Monoterpenes; D000438:Alcohols / Q000494:pharmacology*; D000818:Animals; D057506:Arthropod Antennae / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects; D002681:China; D004272:DNA, Mitochondrial / Q000235:genetics; D005260:Female; D008297:Male; D039821:Monoterpenes / Q000494:pharmacology*; D000442:Octanols / Q000494:pharmacology*; D010675:Pheromones / Q000235:genetics / Q000494:pharmacology*; D048889:Weevils / Q000187:drug effects / Q000235:genetics*
chemical_list: D000080462:Acyclic Monoterpenes; D000438:Alcohols; D004272:DNA, Mitochondrial; D039821:Monoterpenes; D000442:Octanols; D010675:Pheromones; C424142:ipsenol; C515391:ipsdienol
keywords: GC-EAD; Ips subelongatus; aggregation pheromone; field trapping; mtDNA-COI; population divergence