Honeybee Help Goes Beyond Pollination

Honeybees also serve another important role in the lives of plants: bodyguard

• Hannah Schardt
• Feb 01, 2009

EVERYONE KNOWS that bees are many plants’ best friends, serving as reproductive assistants by spreading pollen between plants. But a new study finds that honeybees also serve another important role in the lives of plants: bodyguard. Leaf-munching caterpillars have fine sensory hairs on their legs that they use to detect the presence of winged predators such as wasps.

But the hairs cannot distinguish between wasps and honeybees, German researchers have discovered. That means that when caterpillars sense an “unidentified flying object”—even a harmless honeybee—they will flee the plants, leaving them unharmed. The study found that bell pepper plants without fruit suffered almost 70 percent less damage to their leaves when they were isolated in a tent with both bees and caterpillars than when they were kept in tents with caterpillars alone. (Plants with fruit tended to suffer less leaf damage altogether, since caterpillars prefer to feed on the fruits.)

The discovery could lead to innovative planting techniques that would lessen the need for pesticides, according to the researchers. Planting caterpillar-prone crops are combined with attractive flowers in such a way that bees are constantly abuzz in the vicinity could lead to higher crop yields, they say.