title: Genetic structure of Tribolium castaneum (Coleoptera: Tenebrionidae) populations in mills.
abstract: The red flour beetle, Tribolium castaneum (Herbst), is primarily found associated with human structures such as wheat and rice mills. Such structures are predicted to be spatially isolated resource patches with frequent population bottlenecks that should influence their genetic structure.  Genetic diversity and differentiation among nine populations of T. castaneum collected from wheat and rice mills (ranging from <1-5,700 km apart) were investigated using eight polymorphic loci (microsatellites and other insertion-deletion polymorphisms, each with 3-14  alleles). Seventy-two locus-by-population combinations were evaluated, of which 31 deviated significantly from Hardy-Weinberg equilibrium, all because of a deficiency of heterozygotes. AMOVA analysis indicated significant differences among populations, with 8.3% of the variation in  allele frequency resulting from comparisons among populations, and commodity type and geographic region not significant factors. Although there were significant differences in genetic differentiation among populations (F(ST) values = 0.018-0.149), genetic distance was  not significantly correlated with geographic distance. Correct assignment to the source population was successful for only 56% of individuals collected. Further analyses confirmed the occurrence of recent genetic bottlenecks in five out of nine populations. These results provide evidence that  populations of T. castaneum collected from mills show spatial genetic structure, but the poor ability to assign individuals to source populations and lack of isolation by distance suggest greater levels of gene flow than predicted originally.
authors.affiliation: Department of Entomology, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: Altair A
authors.initials: AA
authors.lastname: Semeao
authors.forename: James F
authors.initials: JF
authors.lastname: Campbell
authors.forename: Richard W
authors.initials: RW
authors.lastname: Beeman
authors.forename: Marcé D
authors.initials: MD
authors.lastname: Lorenzen
authors.forename: R Jeff
authors.initials: RJ
authors.lastname: Whitworth
authors.forename: Phillip E
authors.initials: PE
authors.lastname: Sloderbeck
mesh_terms: D025041:Animal Migration; D000818:Animals; D005433:Flour; D014644:Genetic Variation; D007300:Insect Control / Q000379:methods; D012275:Oryza; D016133:Polymerase Chain Reaction; D011157:Population Dynamics; D011647:Puerto Rico; D014231:Tribolium / Q000235:genetics*; D014908:Triticum; D014481:United States