By Lambert Strether of Corrente
Patient readers, this post will be shorter and more ill-proportioned than it should be, because I got caught by the effing time-change (which I hate and which should be abolished). I wish I could be taking a long tour of this fascinating corner of the biosphere, but here we are. So there will be two parts: The first, a collection of true facts about bees, strutured like a listicle, though hopefully with better content.
Bees immediately plummet to ground when lights turn off. I saw this go by on my Twitter timeline, and I thought “I’ll have to post on bees!” Here is the video:
Here's another video of bees falling out of the sky when the lights go out. I'm surprised it's an on/off choice for them – no graceful trying to glide to land or anything like that, they literally just stop flying and plummet. Surely that's more dangerous than keeping flying? pic.twitter.com/TotxihLywQ
— Hamish Symington (@HamishSymington) December 3, 2021
But why? It’s a mystery! From IFL Science:
So, why is this bizarre bee-haviour happening, and how could it possibly benefit the bees?
Quite frankly, scientists aren’t exactly sure. Several ideas have been put forward, but there is very little research in the area and only a few examples of it happening. A commenter on Reddit suggests it could be a “navigational locking mechanism”, which enables the hive swarm to immediately lock its position in case of sudden turns of weather. Once the weather has passed, they could then return to their hive without the risk of being blown to an unknown location by stormy conditions. This could also link to how bees use the Sun’s position to navigate back to the hive, so once the Sun dips below the horizon, they immediately stop moving.
Another theory suggests it is a prey response, with a shadow from a large predator above them resulting in the bees dropping out of the air and falling to the ground, where they would have less chance of being spotted.
Either way, the phenomenon is fascinating to look at, and a welcome comic relief for the PhD student. As [HamishSymington] states in an earlier tweet: ‘One of the funniest noises I know: the sound of a hundred bees falling out of the sky when I turn out the lights in the bee room.'”
Bees evolved social apoptosis to protect against mites. Anybody who knows a beekeeper knows about Varroa mites and hoe they destroy colonies. From Entomology Today:
The mite Varroa destructor has been a devastating parasite and disease vector to honey bees worldwide. After being introduced to the honey bee (Apis mellifera), it has resulted in enormous bee colony deaths over the past two decades.
However, the mite’s original host, the Asian bee Apis cerana, has been able to survive mite infestations and avoid the colony collapses seen in western honey bees.
One significant difference appeared to be a social response among A. cerana called “social apoptosis.” Bee colonies exhibiting this behavior involve delayed development and eventual “intentional” death by female (worker) bees. On the colony level, social apoptosis produces resistance to Varroa. Researchers have found some resistance among stocks of western honey bees recently. Could “social apoptotic” behavior be behind this resistance and develop in western honey bees, too?
Because Varroa mites and A. cerana honey bees share a longer evolutionary history, the bee species has developed a number of defenses against the mite. Mites only reproduce in drone (male) broods of A. cerana, which are usually outnumbered by workers (females). In A. mellifera, the mites reproduce in both broods. When Varroa invades A. cerana worker broods, the bees uncap infested cells and kill and discard the infested larvae. Social apoptosis expands on this behavior to produce social immunity against the mite, sacrificing individual young (pupae) to prevent infection.
Honey bees are not the only species of bee. OK, wasps, but the state of Oregon recently updated its bee atlas to include hundreds of new species, for a total of 650:
Me, A Naive, Bee-Ignorant Child: There are 2 kinds of bees: honey bees & bumblebees!🤓
Me Today: These glittering green orchid bees, which blend scents into signature perfumes, are but one of 20K+ species w/ secret lives we may never fully comprehend🥺pic.twitter.com/zkWKJINCYA
— Ferris Jabr (@ferrisjabr) March 4, 2022
The multitude of different species explains why–
Keeping bees in cities may not be a good idea. From Phys.org:
“The key message from our results is that urban green spaces can’t keep up with the existing density of hives,” Casanelles Abella says. The researchers’ findings confirm a similar trend observed in other European cities such as Paris, Berlin or London.
According to a scientific study from Great Britain, 7.5 beehives per km2 of green space is a suitable limit for a sustainable beehive density. In Switzerland, however, only rural areas comply with this value, whereas in cities the hive distribution is much more dense and frequently exceeds the limit. Even when the researchers simulated an increase in urban green space with a model calculation, there was no significant improvement. “Increasing green spaces by 75 percent is very unrealistic anyway, but it shows that in truth there are simply not enough resources,” Casanelles Abella says.
In addition, honeybees are not the only pollinating insects in cities. “When you overcharge a system beyond its carrying capacity, you automatically exhaust all its resources. In turn, this causes the other organisms that depend on the same resources to suffer,” Casanelles Abella says. Thus, the food shortage affects all insects that feed on the same flowering plants as the managed honeybees, including wild bees. Of the approximately 600 wild bee species in Switzerland, roughly 45 percent are considered endangered. Cities can harbor a surprisingly large diversity of wild bees species, 164 in the case of Zurich, a recent WSL study showed.
If you really want to “save the bees,” it could be that the best thing for you to do is have your own garden, which both Jerri-Lynn and I can recommend. (Perhaps the simplest thing to do is buy a couple of pounds of pollinator seed — tuned to your Zone, of course — and broadcast it.)
“Bees explosively EJACULATE to death during heatwaves, with a phallus the size of their abdomen bursting from their lifeless bodies, study finds.” Best Daily Mail headline ever — it really tells the whole story. Except drones, not bees as such:
‘When drones die from shock, they spontaneously ejaculate,’ said Dr Alison McAfee, a postdoctoral fellow at the University of British Columbia (UBC). ‘They have this elaborate endophallus that comes out and is about the size of their own abdomen. It’s pretty extreme.’
Usually, the inside of a honey bee colony is a stable environment that maintains a temperature of around 95°F (35°C).
[The Drones] should have been able to cope with warm weather, but the heatwave pushed them to the brink, leading to a ‘drone apocalypse’.
But there’s a silver lining!
One of the positive outcomes of the massive heatwave of 2021 is that it drew Dr McAfee’s attention to drones in the first place.
She now believes drones may be even better indicators of environmental changes than queen bees.
‘Drones have the advantage that they are very sensitive and easy to see. If drones are dying, it’s much easier to study them than to take a queen from a colony to perform tests. It’s also more conducive to citizen science efforts,’ she said.
As readers know, I stan for citizen science.`
And as these drones could be said to be performing an “ecosystem service,” however temporarily, to that topic I will now turn, for the second part of this post. I’ll first give an extended usage example, then the definition, and then point to problems with the concept.
From “Save the Bees,” in the American Bee Journal:
The number of bee colonies is actually growing in the U.S., fueled by the demand for colonies to pollinate almonds. That may change as water availability will lead to major changes in almond cultivation. Each tree needs water — a lot of water. It is estimated each almond takes 1.1 gallons of water; to grow a pound of almonds takes 1,900 gallons. Although almond water use has been singled out, other tree crops such as walnuts, hazelnuts, pistachios, and cashews all use roughly the same amount of water. Animal culture is similar. It is estimated that it takes 1700 gal/lb. of water to raise beef cattle.
While high seasonal honey bee losses are being replaced, of greater concern is an apparent loss of diversity in native (sometimes termed wild) populations of non-managed bees and other pollinators. We are justifiably concerned expanding the term ‘bees’ to include native or wild bees. Studies of native bee species, their overall abundance and distribution in general, and has in some instances documented bee populations that are not as healthy or robust as they once were.
One of the challenges in documenting loss of bee diversity is a lack of records of earlier abundance. The media have picked up on declines in insect abundance and coined the term “insect apocalypse” (https://www.nytimes.com/2018/11/27/magazine/insect-apocalypse.html). Some readers may recall that after CCD was identified, “bee apocalypse” was used for the plight of the honey bee. The declines appear genuine even if we can’t document them precisely.
Could our food supply be in danger? A recent survey identified a mere 66 species of insects that are or could be used in planned pollination. Eighty-seven of the 107 leading crops are dependent upon insect pollination. Included are seven species of bumble bees, mainly used for greenhouse production, although commercially-propagated bumble bees may be useful in some field-grown crops like blueberries. Eight species of wild bees are used in orchard and alfalfa production.
Note the usage of “ecosystem services.” Here’s a short definition of the concept from the Brittanica:
[O]utputs, conditions, or processes of natural systems that or enhance social welfare. Ecosystem services can benefit people in many ways, either directly or as inputs into the production of other goods and services. For example, the pollination of crops provided by bees and other organisms contributes to food production and is thus considered an ecosystem service.
(How enhancing “social welfare” is distinct from benefiting humans is left as an exercise for the reader.) The difficulty here is that we live under a systen where the dominant definition of “benefiting humans” is determined by profit (“because markets“). Hence the American Bee Journal’s paradigm case of California almonds. It follows, then, under actually existing conditions, that which does not generate a profit is not an “ecosystem service” (not least because only the most intreprepid and dedicated scientist is likely to study that sort of natural entity, let alone get project funding. If we think of the ecosystem in its totality as a house — I know, terrible, category error-perpetrating metaphor — then its as if we could remove everything but load-bearing components and still consider ourselves as having a home.) Notice how “ecosystem services” thus defined prevents us from even asking the question of whether the California almond monoculture is a good thing (granted, for some definition of good, but identifying the most serviceable as the most profitable is only one definition. If the California water table were a person, like Lake Erie, it probably would not agree with it.)
All I’ve done in this post is suggest a heuristic: When you see the phrase “ecosystem service,” look for who profits from the service, and look also at what parts of the ecoystem are being erased. I wish I had another model to present — one where the scientists and economists perceived themselves as part of the ecosystem, instead of somehow standing outside it.
 Farber, Costanza, and Wilson give a more elaborate definition here, grounded in neoclassical economics.