Experimental evidence that honeybees depress wild insect densities in a flowering crop.

摘要: While addition of managed honeybees (Apis mellifera) improves pollination many entomophilous crops, it is unknown if simultaneously suppresses the densities wild insects through competition. To investigate this, we added 624 honeybee hives to 23 fields oilseed rape (Brassica napus L.) over 2 years and made sure that areas around 21 other were free from hives. We demonstrate depresses (bumblebees, solitary bees, hoverflies, marchflies, flies, flying flower-visiting insects) even in a massive flower resource such as rape. The effect was independent complexity surrounding landscape, but increased with size crop field, which suggests caused by spatial displacement insects. Our results have potential implications both for crops (if pollinators offsets benefits achieved adding honeybees) conservation negative fitness consequences).