Think all bees are vegetarians? Strange reasons some eat meat

Inside: Although we think bees are vegetarians, they’re more like flexitarians. Occasionally, they eat meat for special reasons.

How to tell a bee from a wasp

How can you tell a bee from a wasp? Both groups sting, buzz, drink nectar, and induce fear into the hearts of man and beast. So what’s the difference?

Because they are close relatives, both groups behave in similar ways. And, depending on the species, they can be super hard to tell apart. In fact, if you need to be sure, a microscope comes in handy.

The short answer is diet

Beekeepers often explain that bees are vegetarians, and wasps are carnivores. Or, more to the point, bees are “vegetarian wasps.” This is a good short answer because it’s mostly true.

Wasps came first. They hunt for meat to feed their young. This meat is usually other insects, but it can also be the carrion of larger animals. And while they are out hunting, wasps frequently stop at flowers for some energizing nectar — not much different from taking a Coke break.

Food that doesn’t run or fight is a bonus

But during the long-ago past, a splinter group of wasps began collecting pollen for protein instead of meat. Because these early renegades were already stopping at flowers for nectar, they tried pollen as larval food, scooping it up and carrying it back to the nest — the ultimate try-it.

Pollen became a hit with both kids and adults. This new food was plentiful, healthful, and docile — never fighting back or squirming free.

As the millennia passed, the forerunners of today’s bees became accustomed to this dietary shift. And to make the collection process easier, these early bees developed structures to help them collect pollen: branched hairs that could capture and hold pollen during the flight home.

Eventually, bees gained more collection paraphernalia, including pollen baskets, grooming brushes to corral the pollen, and enzymes to preserve it. All good.

Over time, bees lost some of the fighting tools they no longer needed. They traded spines, jaws, and grasping claws for more effective body parts, and bees became strict vegetarians.

Or did they?

Nature breeds exceptions

Many bees are not strict vegetarians, not even honey bees. Bees are more like flexitarians: Although they eat mostly plant-based foods, they occasionally consume meat or eggs.

The biggest group of meat-eating bees are the kleptoparasites (cuckoo bees). These are the bees that don’t collect pollen themselves. Instead, they sneak into the nests of other bees and lay their eggs on the pollen balls the host bee collected for her own young.

However, to avoid competition between the different larvae, the cuckoo larvae often eat the eggs or larvae of the host bee. Eggs and bacon for breakfast, followed by pollen for dessert! This may seem unusual, except that fully 10 percent of bee species are cuckoo bees. 

Honey bee cannibals

We know honey bees may cannibalize their siblings in the egg or larval stage. For example, if a worker bee detects the egg of a laying worker, she may eat it. Similarly, if a worker detects a larva is diseased or deformed, she may eat that, too, especially if the larva is very young. (Although workers may choose to carry older larvae from the hive and drop them on the ground.)

Eating eggs and larvae is a way of conserving energy and food resources within the colony. Reabsorbing nutrients is a way of recycling, saving energy, and avoiding waste.

The scavengers: vulture bees

Down in South America, three species of stingless bees eat a pure meat diet. They even have specialized mandibles (jaws) to help them slice delectable portions from a rotting carcass. These are called vulture bees or carrion bees because they collect the meaty portions of dead birds, lizards, fish, and snakes.

Oddly, they swallow the meat and store it in their honey stomachs, where specialized microbes help digest it. At home in the nest, they regurgitate the partially digested chow and store it in waxen pots from which they feed their larvae.

Although these bees (all in the genus Trigona) collect rotting meat, they also collect nectar and make honey for a winter food supply. So in many ways, they are not so different from regular honey bees.

Flexibility for all living things

I think it’s cool that some bees eat meat, just like some wasps eat pollen. It demonstrates that nature has few hard and fast rules, and there is always room for flexibility.

Rusty
Honey Bee Suite