title: Host-plant dependent population genetics of the invading weevil Hypera postica.
abstract: Population genetics of invading pests can be informative for understanding their ecology. In this study, we investigated population genetics of the invasive alfalfa weevil Hypera postica in Fukuoka Prefecture, Japan. We analyzed mitochondrial tRNALeu-COII, nuclear EF-1α gene fragments, and Wolbachia infection in relation to three leguminous host plants: Vicia angustifolia, Vicia villosa, and a new host Astragalus sinicus cultivated as a honey source and green manure crop. A parsimony network generated from mitochondrial gene sequences uncovered two major haplotypic groups, Western and Egyptian. In contrast to reported Wolbachia infection of the Western strain in the United States, none of our analyzed individuals were infected. The absence of Wolbachia may contribute to the stable coexistence of mitochondrial strains through inter-strain reproductive compatibility. Hypera postica genetic variants for the mitochondrial and nuclear genes were associated neither with host plant species nor with two geographic regions (Hisayama and Kama) within Fukuoka. Mitochondrial haplogroups were incongruent with nuclear genetic variants. Genetic diversity at the nuclear locus was the highest for the populations feeding on V. angustifolia. The nuclear data for A. sinicus-feeding populations indicated past sudden population growth and extended Bayesian skyline plot analysis based on the mitochondrial and nuclear data showed that the growth of A. sinicus-feeding population took place within the past 1000 years. These results suggest a shorter history of A. sinicus as a host plant compared with V. angustifolia and a recent rapid growth of H. postica population using the new host A. sinicus.
authors.affiliation: Institute of Biological Control, Faculty of Agriculture,Kyushu University,Fukuoka 812-8581,Japan.
authors.forename: S-I
authors.initials: SI
authors.lastname: Iwase
authors.affiliation: Institute of Biological Control, Faculty of Agriculture,Kyushu University,Fukuoka 812-8581,Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakahira
authors.affiliation: Institute of Biological Control, Faculty of Agriculture,Kyushu University,Fukuoka 812-8581,Japan.
authors.forename: M
authors.initials: M
authors.lastname: Tuda
authors.affiliation: Institute of Biological Control, Faculty of Agriculture,Kyushu University,Fukuoka 812-8581,Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kagoshima
authors.affiliation: Institute of Biological Control, Faculty of Agriculture,Kyushu University,Fukuoka 812-8581,Japan.
authors.forename: M
authors.initials: M
authors.lastname: Takagi
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D007887:Fabaceae / Q000502:physiology*; D005247:Feeding Behavior; D020387:Food Chain; D014644:Genetic Variation; D019476:Insect Proteins / Q000235:genetics; D058865:Introduced Species; D007564:Japan; D008969:Molecular Sequence Data; D020648:Peptide Elongation Factor 1 / Q000235:genetics; D016133:Polymerase Chain Reaction; D011156:Population Density; D012356:RNA, Transfer, Leu / Q000235:genetics; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D048889:Weevils / Q000235:genetics / Q000382:microbiology / Q000502:physiology*; D020577:Wolbachia / Q000302:isolation & purification
chemical_list: D004272:DNA, Mitochondrial; D019476:Insect Proteins; D020648:Peptide Elongation Factor 1; D012356:RNA, Transfer, Leu; D003576:Electron Transport Complex IV
keywords: Chinese milk vetch; Hypera postica; extended Bayesian skyline plot; hairy vetch; narrow-leaved vetch; statistical parsimony network