Parasitoid wasps control insect pests in agricultural crops, but often require additional resources from non-crop plants. Vineyard growers sometimes address this need by planting or sowing pre-selected herbs around the plots or between the vine rows. Here, we explored the simpler strategy of conserving spontaneously growing weeds within Mediterranean vineyards, and trimming them mechanically when they reach large size and interfere with farming activities. We compared this strategy with matched plots, in which resident weeds were sprayed regularly with herbicides, representing the conventional treatment.
As predicted, overall parasitoid abundance and the number of parasitoid species were higher in the weed conservation plots. However, the direction and magnitude of the effect differed between the dominant parasitoid species, and populations of some potential pests increased in the weed conservation treatment. Conservation of weeds that grow spontaneously in vineyards is a low-cost practice that offers multiple benefits, such as reduced soil erosion, stabilization of soil temperatures, and diminished exposure of farmers to agrochemicals.
Significance of the study
Our results show that communities of important biological control agents may gain from this practice as well. Nevertheless, weed conservation within vineyards can only be sustainable if its benefits outweigh the risks of attracting crop pests.
Reference: Möller, G.; Keasar, T.; Shapira, I.; Möller, D.; Ferrante, M.; Segoli, M. Effect of Weed Management on the Parasitoid Community in Mediterranean Vineyards. Biology 2021, 10, 7.
Link to article: https://doi.org/10.3390/biology10010007
This abstract is republished in its original form, with headings inserted, as permitted by the following Creative Commons licence: https://creativecommons.org/licenses/by-nc/2.0/