Individual study: Effects of tillage and irrigation practices on wild bees on pumpkin farms in northern Virginia and Maryland, USA
Julier H.E. & Roulston T. H. (2009) Wild bee abundance and pollination service in cultivated pumpkins: farm management, nesting behaviour and landscape effects. Journal of Economic Entomology, 102, 563-573
Tillage (ploughing/cultivation) and irrigation may affect ground-nesting bee species, such as the common Eastern bumblebee Bombus impatiens and the squash bee Peponapis pruinosa (which collects pollen only from the family Cucurbitaceae, including pumpkins Cucurbita pepo). This study examined the effects of no-tillage and irrigation on wild bee abundance on pumpkin farms in northern Virginia and Maryland, eastern USA.
There was no significant difference in the number of squash bees or bumblebees between farms that tilled after the pumpkin crop and those that did not. However, the pumpkin crop flowers later than other cucurbits and the authors suggest a tillage effect on squash beesmay have been masked by bees dispersing early in the season to find forage elsewhere.
Note: If using or referring to this published study, please read and quote the original paper, this can be viewed at: http://esa.publisher.ingentaconnect.com/content/esa/jee/2009/00000102/00000002/art00015