Abstract
ABSTRACT
Organic farming has been shown to offer advantages over conventional farming in protecting insect biodiversity, but our overall understanding of its relationship with wild bee population parameters, especially cuticular lipids, remains limited. In the current study, we installed bee hotels at different farming sites in southern Germany and hypothesized that the local farming system (organic vs. conventional), the extent of organic farming, and the extent of forest (percentage of each component in the analyzed landscape) influence the abundance of nests and individuals of small‐bodied solitary bees of the genus
Hylaeus
. Moreover, at the species level, we investigated the influence of the same agricultural landscape elements and forest cover on the number of nests, bee abundance, sex ratio, and body size of
H. communis
, the most common
Hylaeus
species at our study sites. We further investigated how this landscape variables influence the composition of cuticular lipids in females and males of this species. Our results were more conclusive at the species level. We found that organic farming positively influenced the abundance of
H. communis
, whereas abundance decreased with increasing forest cover. In contrast, the sex ratio was higher at conventional farming sites and increased with forest cover. Although females were larger than males, no effect of landscape variables on body size was detected. The chemical composition of cuticular lipids of
H. communis
was significantly influenced by the farming system. These findings raise concerns about potential mechanisms through which farming practices may influence the reproduction of cavity‐nesting wild bees in agricultural environments. In conclusion, our findings show a positive effect of organic farming on the abundance of
H. communis
, while also highlighting potential effects of farming practices on physiological traits and population‐level parameters of this small wild bee species.