Thursday, January 22, 2009

Bees do more than pollinate

The buzz of bees in flight causes some caterpillars to slow or cease feeding on plants.

German researchers Tautz and Rostas report in December’s Current Biology a 60 to 70 percent reduction in pepper leaves consumed by beet armyworm caterpillars in tented enclosures with honeybees than in tented enclosures without bees after two weeks.

Several caterpillars have evolved freeze-motion or drop-off-plant avoidance behaviors in response to predatory wasps. Sensory hairs on the caterpillars pick up vibrations from flying wasps and trigger the response. These behaviors are often combined with defensive coloration that blends caterpillars into the background color of the plant.

So bees can be beneficial to plants by slowing feeding even though honeybees are not predators of caterpillars. Note that pepper flowers (like those of tomatoes and eggplant) self-pollinate with wind movement, not from visits by bees or other insects.

This may be another reason to plant bee-attracting flowers in your Colorado edible garden in addition to wanting bees for pollinating squash, cucumbers, melons and pumpkins.

[Honeybee photo credit: David Cappaert, Michigan State University,]
[Beet armyworm photo credit: Frank Peairs, Colorado State University,]


  1. We planted borage in between my tomato plants last year. Not only were the flowers great at attracting lots of bees all season long but we didn't find one tomato worm. Coincidence? Perhaps - but we'll definitely be planting more this season - even if it's only for the bees.

    Denver, CO

  2. So this doesn't pertain to bees or caterpillars but I'm desperate. I've got either aphids or spider mites (I think it's the latter) attacking my new hops plants. Any suggestions on how to get rid of them? Any help would be appreciated.