Local genetic population divergence in a saw-toothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera, Cucujidae)

Relationships of pest populations living in human-made habitats compared with those living in natural habitats are not clearly understood. A lower total genome size in silo pest populations than in natural ones and genome size variability between natural populations at the local scale demonstrated in the beetle Oryzaephilus surinamensis (L.), was extended by testing for in-depth genetic differentiation. The natural habitats were represented by a sample from the north-facing slope "ES", covered by a "European maquis-like forest", and from the "African savannah-like" south-facing slope "AS" at Evolution Canyon (EC) lower Nahal Oren, Mount Carmel, Israel. The two slopes are separated by 100m at the valley bottom. The human-made habitat was represented by a grain silo "Sil", characterized by only slightly fluctuating temperature and by a nearly constant low relative humidity, located 26km from EC. Our results indicate: a) Genetic separation between analyzed populations by means of Amplified Fragment Length Polymorphism; b) Presence of the highest genetic diversity at the "AS"; c) Presence of only two mutations separating "Sil" from "EC" at the mitochondrial cytochrome oxidase I gene (309bp), and d) presence of no genetic differences in mitochondrial 16S ribosomal RNA (220bp).