Random Mating Between Two Widely Divergent Mitochondrial Lineages of Cryptolestes ferrugineus (Coleoptera: Laemophloeidae): A Test of Species Limits in a Phosphine-Resistant Stored Product Pest

• Published in: Journal of economic entomology Vol. 109; no. 5; pp. 2221 - 2228
• Main Authors: Toon, A, Daglish, G. J, Ridley, A. W, Emery, R. N, Holloway, J. C, Walter, G. H
• Format: Journal Article
• Language: English
• Published: England Entomological Society of America 01.10.2016; Oxford University Press
• Subjects: Animals; Climate change; Coleoptera - drug effects; Coleoptera - genetics; Coleoptera - physiology; Cryptic species; Electron Transport Complex IV - genetics; Entomology; Gene flow; Genetic Variation; Genetics; grain beetle; Insect control; Insect Proteins - genetics; Insecticide Resistance; Insecticides - pharmacology; Insects; microsatellite; Microsatellite Repeats; Mitochondrial Proteins - genetics; Pest control; Pests; phosphine resistance; Phosphines - pharmacology; Phylogeny; Pleistocene; Population genetics; Population structure; Resistance to control; Sequence Analysis, DNA; Sexual Behavior, Animal; species delimitation; STORED-PRODUCT; microsatellite; species delimitation; grain beetle; phosphine resistance
• ISSN: 0022-0493; 1938-291X
• DOI: 10.1093/jee/tow178

Effective pest management relies on accurate delimitation of species and, beyond this, on accurate species identification. Mitochondrial COI sequences are useful for providing initial indications in delimiting species but, despite acknowledged limitations in the method, many studies involving COI sequences and species problems remain unresolved. Here we illustrate how such impasses can be resolved with microsatellite and nuclear sequence data, to assess more directly the amount of gene flow between divergent lineages. We use a population genetics approach to test for random mating between two 8 ± 2% divergent COI lineages of the rusty grain beetle, Cryptolestes ferrugineus (Stephens). This species has become strongly resistant to phosphine, a fumigant used worldwide for disinfesting grain. The possibility of cryptic species would have significant consequences for resistance management, especially if resistance was confined to one mitochondrial lineage. We find no evidence of restricted gene flow or nonrandom mating across the two COI lineages of these beetles, rather we hypothesize that historic population structure associated with early Pleistocene climate changes likely contributed to divergent lineages within this species.