A bidirectional selection experiment to test the evolution of specialization and dispersal in the invasive wheat curl mite, Aceria tosichella

Funding: National Science Centre grant no. 2016/21/B/NZ8/00786

PI: Anna Skoracka

Co-investigators: Sara Magalhães, Lechosław Kuczyński, Mariusz Lewandowski, Jacek Radwan, Alicja Laska, Agnieszka Kiedrowicz, Kabita Bharati, Kamila Karpicka-Ignatowska, Anna Radwańska

Description: The aim of this proposal is to empirically test the hypothesis that there is an evolutionary interplay between host specialization and dispersal, using invasive eriophyoid wheat curl mite (WCM), Aceria tosichella, as a study system.

Specifically we will investigate:

  1. If WCM strains with different host ranges also differ in dispersal ability?
  2. How evolution in constant (one host species) or changing (several hosts species) environments shapes the host range of WCM and its dispersal ability?
  3. How selection for high and low dispersal affects the host range of WCM?
  4. How high or low dispersing phenotypes perform in constant or changing environments?

The study will be conducted on the most polyphagous and invasive lineage of the WCM species complex, MT-1, identified on the basis of mtDNA COI sequence during the course of our previous studies. The WCM MT-1 lineage will be first subjected to experimental evolution. For this purpose mites will be reared for many generation on single or on randomly rotated several hosts. As an effect, two genetically distinct lines will be obtained: specialists and generalists. Then, these two selected lines will be subjected to artificial selection in wind tunnels towards and against dispersal. Finally, all selected lines will be tested for the fitness consequences in combinations of the specialization/dispersal strategies in single vs. multi-host environments.

The project will produce the first experimental evidence based on joined experimental evolution and artificial selection to test whether selection for specialization affects dispersal ability. This will also be the first empirical attempt to resolve evolutionary questions regarding the dispersal of WCM and eriophyoid mites in general. The question whether WCM high dispersal ability influences local adaptation to different hosts and thus the likelihood of host shift and range expansion will be answered. In addition, the results will provide a great opportunity to influence the development of applied fields of research, by contributing to the knowledge on the dispersal of the most invasive WCM lineage. This will be of significance to managers who wish to develop control strategies for WCM in agricultural landscape.