caterpillar on a plant stem

Do bees eat caterpillars?

No, bees do not eat caterpillars. Wasps and hornets regularly predate on caterpillars and can often be mistaken for bees.

Bees species excluding the Vulture bee feed on a predominantly pollen and nectar diet. This can lead to close encounters with many other insects present in the stems, leaves and flowers of plants.

As a general rule, most bees will prioritise gathering resources for their colony and simply ignore other insects they encounter. There are some rare cases when bees will interact with other insects but this does not extend to caterpillars.

You can learn more about some of the insects bees do interact with inside our short read on how bees eat Aphids honeydew for sustenance.

Despite this apparent lack of interest in caterpillars, bees actually have more of an effect than you might think.

Testing how bees and caterpillars interact

With bees and caterpillars spending so much time foraging in the same area it posed the question, do these two very different insects have any effect on each other.

Two researchers from the University of Wuerzburg, Jürgen Tautz and Michael Rostás began researching the links between bees, caterpillars and plants.

The two researchers used the University’s botanical garden as the site for their research. They used two large 2m squared cubic tents to house either 10 soybean plants or 10 bell pepper plants.

They added 10 third-instar caterpillars of the beet armyworm (Spodoptera exigua) to each plant. One tent was left to succumb to the caterpillar’s voracious appetite with no external influence. This tent and its occupants would act as the control for the test to measure against the results achieved inside tent two.

The second, much more interesting tent was exactly the same except for two key differences, the tent was connected via some tubing to a beehive containing a colony of western honeybees and two feeders containing 2.5 molar sugar solutions were mounted at half-plant height above ground in the two corners of the tent.

Why bees affect caterpillars and plant damage

The results returned by this very simple experiment highlighted some fascinating correlations between bees and caterpillars. Tent two, which contained the colony of honeybees looked completely different to tent one.

The pants contained inside tent two had experienced approximately a third of the damage of those inside tent one. The clear conclusion here is honeybees stop caterpillars from eating so much, but why?

The researchers conclude that this actually stems from a case of mistaken identity.

Wasps and hornets pose a serious threat to caterpillars, they use caterpillars’ bodies as incubators for their young or simply as a food source, the stuff of horror movies!

The tissue that makes up a caterpillar’s body is packed full of proteins perfect for wasps and hornets to feed on.

How do caterpillars identify bees as a threat?

Some species of caterpillar including those of thebeet armyworm (Spodoptera exigua) are equipped with tiny sensory hairs that cover the length of their body.

These hairs can sense vibrations created in the air just like when bees, wasps or hornets flap their wings. This sensory cue will lead to caterpillars dropping off the plant in an effort to avoid being eaten or injected with larvae.

Undisturbed, caterpillars will eat virtually constantly so the regular flights undertaken by the bees led to a significant drop in consumption of plant matter within the tent.

After assessing the plants thoroughly the researchers identified that the plants with a honeybee presence had 69.3% and 60.6% less foliage damage than the control test, staggering results.

In conclusion

So in answer to the question do bees eat caterpillars it’s a resounding no, but they do have an extreme effect on how much caterpillars eat when they’re around.

Check out our next short read on do bees eat butterflies for more interesting facts and knowledge about bees.