The number of pests has increased since the ban on seed treatment with neonicotinoids British scientists encouraged oilseed rapeseed producers to send samples of adult rapeseed flea beetles found in the crop at harvest time. Researchers want to assess the levels of both pest resistance to pesticides and biocontrol tools. In turn, scientists will provide farmers with information on their own area and analysis of the situation compared to the pest population at the national level. An important component of the initiative is to check whether the newly discovered wasp can parasitize bugs, becoming an effective means of biocontrol.
After the ban on neonicotinoid treatment of oilseed rapeseed in the UK in 2013, many farmers face serious crop losses, especially in the east and south-east of the country, where the number of rapeseed fleas is increasing. Pyrethroid aerosols are currently the only control option, but resistance to them is widespread in the UK. Patricia Ortega-Ramos, who conducts research at Rothamsted Research, says that without accurate information about the resistance of pests in each specific area, it is difficult for scientists to create an objective picture.
“Farmers risk economic losses, increased resistance to pests and harmful effects on non-target organisms. But we have a new hope of control. A natural parasitoid has recently been discovered in the adult stage of a flea, and studies of its life cycle have shown that the larvae of this wasp develop inside the adult beetle and kill the flea when it appears. However, the potential of biocontrol and the distribution of these parasitoids in the environment is still unknown. We seek to understand the mechanisms for the development of pyrethroid resistance in the UK rape flea populations and the importance of parasitoids in biological control. ”
In order to provide an objective sample, scientists ask farmers to send them a total of at least 250 bugs in order to assess both the resistance to pyrethroid and the level of parasitism of the wasps.