On bees

So, my recent post on short-haired bumblebees got me a-wonderin' about bees. There's honey bees, bumblebees, carder bees, cuckoo bees, carpenter bees, sweat bees, stingless bees... and they're just the ones that spring immediately to my mind. But what's the difference between the bees and why don't we eat bumblebee honey?


WHAT THE F*** IS HONEY ABOUT

Honeycomb, George Shuklin

Honey is a food source used by some social bees to feed their young. It's essentially nectar from flowers that foraging worker bees have sucked up into a special nectar stomach. When a foraging honeybee returns to the hive it regurgitates the nectar into the mouth of a hive bee. The hive bee then adds various enzymes and such that break down the complex sugars into more simple fructose and glucose. Once this is done, the honey is deposited into a wax honeycomb, the hive bees fan the comb to help water evaporate increasing the sugar concentration -- once the honey is a supersaturated solution that by rights shouldn't be liquid, the bees seal of the honey, which is then ready to use as a food source for the hive in winter. The primary food source of most bees is pollen, some bees other than honeybees do make honey, but only in small amounts and never to quite the same magical effect: bumblebee honey is often said to be quite watery, and no more than a 100 g (usually a lot less) will be in the colony at any one time.



HONEY IS THE ONLY FOOD THAT DOESN'T GO OFF
If anyone ever asks you in a pub quiz what the only food is that never goes off, answer "honey" -- it's the answer they want. However, this isn't really true. So, OK, honey is pretty sterile and almost no bacteria will grow in it. When it changes from liquid to solid in your cupboard, that's just a process of crystalisation and it's still perfectly edible. So yeah, maybe honey won't go off as long as it doesn't get wet. But what about salt, and sugar, and canned goods? They don't go off? I've got a bag of flour in my cupboard with a best before date of 2005, it's fine! How many times have you read a news story about a can of Spam found in an old bomb shelter that still tasted just as good as the day it was canned during the Blitz? I mean, I don't know what the strict definition of "foodstuff" is, but I'm about as likely to eat a bowl of sugar as I am a bowl of honey -- and I'm as likely to add salt to my porridge as I am honey (I'm no Goldilocks).


BEES' DISTANT COUSINS
Bees are part of the large group of insects, the hymenoptera, the etymology of which I once discussed here, which also include sawflies, wasps, and ants. With over 130 000 species, hymenoptera are one of the largest groups of insects; we know quite a lot about some hymenoptera because the trait of sociality, which is by no means universal to the group, but expressed by many of the best known members (some bees and wasps and all ants). Sociality in this sense is not just hanging out together, lots of animals do that, but rather hanging out in groups in which different individuals have different roles within the group (for example, but not limited to, workers, reproductive individuals, guards, and so on). This form of sociality, called eusociality by biologists, is very rare in the animal kingdom, naked mole rats provide another example.


BEEING
There are nine families (groups based on shared physical and genetic characteristics) of bees comprising 20 000 known species found on all continents except Antarctica. But we are perhaps most interested in bees because of just one species, the honey bee, Apis mellifera. Among the 20 000 bee species, honey bees and bumblebees are quite closely related, relatively.


BUMBLEBEES
Bumblebees, any of 250 species in the genus Bombus, belong to the same family as honeybees. They are essentially large, hairy, social bees. Unlike honeybees, bumblebees live in small colonies of at most a hundred or so individuals that typically die off after just one breeding season. A queen will start a colony in spring, or earlier, produce workers throughout the summer. Towards the end of the summer, the colony will start to produce breeding bees -- queens and drones. These bees fly off, look for mates from other colonies, and the mated queens then hibernate, emerging in spring to start a new colony.



WHEN IS A BEE A CUCKOO?

Cuckoo bee

NEVER! However, there are quite a few species of bees that have given up collecting pollen and nectar to feed their own young, and instead lay their eggs in the colonies of other bees, just like the European cuckoo does with other birds. Most cuckoo bees belong to the group Nomadinae, and these generally look a bit waspish, parasitise solitary bee species, and nip in to a nest, lay their egg, and leave. In the genus Bombus, cuckoo bees in the subgenus Psithyrus resemble closely the social bumblebees they parasitise; the cuckoo queens invade the bumblebee colony, kill the queen and take up residence, getting the workers of that colony to raise her own brood.



ETYMOLOGBEE
Just 153 years ago in the Origin of Species, Darwin wrote of humblebees rather than bumblebees, and for centuries before, although both terms were in use, humblebee was more prevalent. For no apparent reason, however, since the end of World War II the term humblebee has fallen into almost complete disuse. The "humble" had nothing to do with pie or low rank, but instead was related to the hum the bees make as they fly. The Latin name for the genus of bumblebees is Bombus, so one might think that the newly adopted preference for the "b" spelling arose that way somehow given the similarity between "humblebee" and "bumblebee". This is actually all much of a muchness: the Latin "bombus" has its origins in the Greek "bombos" meaning "hum".


STINGLESS, CARPENTER, MASON, SWEAT
No, I'm not counting cherry stones. There's basically crap loads of bees -- like honeybees, bumblebees, cuckoo bees, many of their names describe their habits. Sweat bees are attracted to human sweat, as such you'd think I'd be more familiar with them than I am. Most stingless bees are social relatives of honeybees that, you guessed it, can't sting because their stingers are greatly reduced; although several other groups of bees have lost their stings, and are also stingless bees but not known as such. Carpenter bees nest in holes in wood, bamboo, or structural timber. Mason bees make compartments of mud or clay in their nests. Orchid bees are bees from central and south America that gather fragrances from orchids. There are so many bees that some of them don't even have common names: the 25 species in the smallest family of bees, the Stenotritidae, are known only by their latin binomials.

Orchid bee

TWO BEES OR NOT TWO BEES
Although we often think of bees as social animals, the vast majority of species aren't. The same is true of wasps and sawflies their hymenopteran cousins. Rather than being common to all hymenoptera, sociality has evolved numerous occasions within the group. The reason bees, ants, and wasps are prone to sociality is probably to do with the haplodiploid method of sex determination, which means that males arise from unfertilised (haploid; one set of chromosomes) eggs, but females arise from fertilised (diploid; two sets) eggs -- this means that sisters are often more closely related to each other than to their mothers or fathers, which means that cooperation between sisters will lead to evolutionary success.



BEE GEEKERY
Actually, sometimes diploid bees will be males, but that's because they share identical copies of the genes that determine sex on both the relevant chromosomes (normally the copies of these genes on two different chromosomes in a pair would differ).  The likelihood of a queen producing a diploid drone increases if the male she mates with is a close relative. Diploid drones are less fertile than haploid drones, so actually detrimental to a colony -- workers typically sniff out diploid drones and kill the larvae before they develop too far, thus saving the hive the energy of raising them.


EPBEELOGUE
This, er, brief foray into the world of bees reflects some things I thought interesting about bees, some things I'd wondered about, and then some interesting things I found out while researching the things I had pondered. There's about a million and one things known about bees that I have not even scraped the surface of, and even more that people don't know about bees. But don't you worry, I am sure to return to the topic in future AOTWs. One might say "I'll bee back".