Bee aware

Tip for farmers: caterpillars fear the sound of bee wings

Jurgen tautz has a passion for delving into the daily lives of bees. He has figured out much of the complex mechanism behind the waggle dance which honeybees use to beckon other bees to a food source. Now this scientist, from the University of Wurzburg in Germany has come up with a novel way of pest control involving bees. Tautz and his team observed that the flapping sound of bees' wings scares away caterpillars feeding on leaves. They put bell pepper plants in a tent with bees and caterpillars. The plants suffered 70 per cent less damage in tents with bees, compared to plants in tents with caterpillars alone.

When a caterpillar senses the presence of an insect, it drops down from the leaf's surface.

They have sensory hairs which help them detect air vibrations, including those made by an approaching insect. "These sensory hairs are not fine-tuned. Therefore, caterpillars cannot distinguish between hunting wasps and harmless bees," Tautz said. If the caterpillars are constantly stressed by buzzing bees, as on trees heavily laden with blossoms, they will feed a lot less. The study was published in the December 23 issue of Current Biology.

These results show that honeybees can be much more than pollinators. The group plans to plant flowering plants along with crops so that honeybees are constantly in the area. If this works, farmers with beehives in their fields will have better yields without the use of pesticides. Pesticides cause the colony collapse disorder in honeybees. According to the research this only means stripping the plants off one level of pest control.

Source

Down To Earth, January 2009