Browsing by Subject "suojeleva biologinen torjunta"

Conservation biological control is a strategy of biological control that aims to support natural enemies of pests. One of the potential ways to support natural enemies is to enhance diversity in agricultural landscapes. By establishing non-cultivated areas near crop fields natural enemies can be provided with many resources including food, shelter and overwintering sites. The availability of these resources potentially enhances the abundance and diversity of natural enemies and their efficiency to reduce pest populations. The goal of this study was to compare the effects of two different fallow strip types – meadow strip and grassland strip – on the abundance and species composition of predatory arthropods. To examine the differences between the strip types, data were collected from the strips and adjoining cereal fields. An experiment was conducted on two barley fields in Helsinki in summer 2014. Two fallow strips were established in the middle of each field. The strips were composed of four 3 m * 60 m-sized plots. Every other plot was sown with meadow seed mixture and every other with grassland mixture. Data on predatory arthropods were collected during June-July using pitfall traps. There were more predatory arthropods on the fallow strips than on the barley fields. However, there were no differences in the abundance of predatory arthropods between the fallow strip types. Moreover, the abundance of predatory arthropods on adjoining cereal field did not differ between the strip types. The species composition of predatory arthropods differed statistically significantly between barley fields and the fallow strips, and almost significantly between the strip types. The results indicate that the fallow strips succeeded to provide favorable habitats for predatory arthropods, which may be due to food or shelter that they provide. The lack of clear differences on the abundance and species composition of predatory arthropods between the strip types can be explained by the fact that the vegetation of the strips was not yet fully established in the first year. Other reasons include the substantial differences between the two study fields. However, it seems that fallow strips have potential to provide biodiversity benefits, which have previously been observed in environmental fallow fields, and to enhance ecosystem services such as biological control.