Submitted to: Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/4/2005
Publication Date: 11/11/2005
Citation: Miller, N., Estoup, A., Toepfer, S., Bourguet, D., Lapchin, L., Derridj, S., Kim, K.S., Reynaud, P., Furlan, L., Guillemaud, T. 2005. Multiple transatlantic introductions of the western corn rootworm. Science. 310:992. Interpretive Summary: First detected in Europe in 1992, the western corn rootworm (Diabrotica virgifera virgifera), the most destructive pest of maize in the USA, is now present in several European countries. DNA comparisons and computer simulations show that in addition to spreading from the original introduction site in the former Yugoslavia, this species has been invading Europe by repeated new introductions from the USA. These results suggest that a unified plan for fighting this pest across Europe might not be the best strategy. Because outbreak populations may be coming from different locations in the USA, they could differ substantially in their response to pest management strategies such as insecticide treatments and crop rotation. These results will be useful to regulatory agencies and authorities because they highlight the role of transoceanic transport of harmful pest species and suggest that more attention should be paid to controlling pest species on intercontinental flights.
Technical Abstract: First detected in Europe in 1992, the western corn rootworm (Diabrotica virgifera virgifera), the most destructive pest of maize in the USA, is now present in several European countries. To discriminate between introduction scenarios, genetic variation of European and American western corn rootworm populations was analyzed at eight microsatellite loci, using an Approximate Bayesian Computation (ABC) framework relying on computer simulations. For each European outbreak, our ABC method allowed quantitative comparison of different introduction scenarios that differ by putative source populations: the USA or one of the other European populations. Our results indicate that three out of the five analyzed western European outbreaks did not originate from the Central Europe spreading area, but from the USA. Moreover, these introductions were independent from each other and from the initial European introduction in Central Europe.