Osmia cornifrons invasion risk is increased by commercially produced populations of Osmia lignaria deployed in the Sacramento Valley, California
摘要
Osmia cornifrons, a mason bee indigenous to Northern Asia, has been used as a non-native alternative pollinator for early spring orchard crops in the eastern United States of America (USA) since the 1980s. Since their introduction, O. cornifrons has become established in the mid-Atlantic region of the USA, Toronto, Canada and the Pacific northwest of the USA. Recently, we identified O. cornifrons co-nesting across an almond orchard in the Sacramento Valley, California, USA after the deployment of a commercially reared F0 population of O. lignaria. Based on genetic data, we determined that the origin of the intercepted O. cornifrons were co-nesting with a commercially produced O. lignaria population from Washington. From the O. cornifrons population in the almond orchard, we identified two mitochondrial haplotypes that are identical to haplotypes found in Washington, Ohio, Virginia, and South Korea. Haplotypes H001 and H002 were recovered from the F1 generation that were produced in the almond orchards at the end of the pollination season by the F0 generation from Washington. Furthermore, the F1 generation was recovered from nests that were constructed < 1 to 3 km away from the orchard were the F0 generations were deployed. Contrary to earlier Osmia studies, our results demonstrate that O. cornifrons females can disperse farther than 1 km from their natal site in search of suitable nesting sites, exceeding the known dispersal distance of a closely related Osmia species. Our results suggest that commercially produced O. lignaria is a pathway that may facilitate the spread of non-native O. cornifrons in the western USA unintentionally.