Rare beetles

Besides the rare crested newt Luuk Croijmans and his colleagues recently found a brush-thighed seed-eater (Harpalus Froelichii) on two locations in our farm network.

We found this rare creeper on Eugène van den Eijnden's farm in Halsteren and on the Zenderense Es estate in Borne. Luuk Croijmans says: "This is a species that has been found somewhat more often in recent years, but only sporadically before 2022. This species is mainly found on sandy soils, which partly explains why we found them at Bijenhof and Zenderense Es. The species is normally found on sparse grasslands and heaths, which therefore makes it an interesting find to find in strip cropping. However, the find is not entirely coincidental, as the two sites are among the most diverse locations in the CropMix network."

In addition, Luuk sees a trend: "We notice that species of the genus Harpalus, the creepers, are consistently more common in strip cropping. The rarer species of this genus we find exclusively in strip cropping, and the somewhat more common species we find in larger numbers in strip cropping."

In all, Luuk and his colleagues found a total of eight species of this genus. "The two most common species we find both in strip cropping and monoculture, but more in strip cropping, such as the hairy creeper and red-legged creeper. Two species that we also find regularly we see only in strip cropping: the green creeper and sand creeper. The remaining four species we find sporadically and also exclusively in strip cultivation, namely the blue creeper, broad-headed creeper, sandpiper and Harpalus xanthopus.

Want to know more? Contact us at cropmix@wur.nl.