Host-plant interaction of Phyllotreta nemorum and Barbarea vulgaris
Janna Barel, Ilona Knaapen & Janneke Koster
Wageningen UR, Laboratory of Entomology, The Netherlands
The yellow striped flea beetle Phyllotreta nemorum is an oliphagous beetle, attacking only a number of cruciferous host plants, including Sinapis vulgaris, Raphanus raphanistrum, Lepidium draba, Brassica nigra and cultivated radish (Raphanus sativus). The flea beetle is usually susceptible to chemical defenses of the G-type of Barbarea vulgaris. However in Denmark some populations are found to spread their host range to B. vulgaris. Currently the entomology group is trying to unravel the genetics behind the resistance of P. nemorum. Ilona Knaapen will investigate whether the resistance in the different populations of P. nemorum is caused by genes at the same or at different loci. Additionally field studies have shown that a surprisingly low amount of flea beetles are resistant. Janneke Koster will examine the resistance frequency to investigate the changes over time over the whole flea beetle season and the parasitic rate and choice between resistant and non-resistant beetles. Furthermore Janna Barel will look if competition between resistant and non-resistant beetles can be the cause of the low frequency of resistant beetles on Sinapis plants. She is testing the overall completion on radish plants as well as potential differences in larval development duration.
