kw: opinion, bees, disorders
If you haven't heard of Bee Colony Collapse Disorder (CCD), it's time you did. This article in Wikipedia, a comprehensive treatment with 79 references, provides a grounding. There was also a recent presentation on PBS's Nature program on CCD.
Briefly, although the numbers of active hives of Western (i.e. mainly European) honeybees has been slowly falling for thirty years, the past 14-16 months has seen the sudden loss of 25% or more. Theories abound, and the salient fact is, there is no explanation yet. However, two things stand out:
Firstly, the honeybee is an intensively managed critter, with beekeepers trucking hives, hundreds to thousands at a time, to locations where farmers and growers pay for the pollination services. In the wild, bees of all kinds space their colonies, and two colonies of the same species are seldom found within the same acre. Whatever the cause of CCD, it is exacerbated by this intensive management and crowding.
Secondly, adult bees literally work themselves to death in a matter of a few months. They are a highly-tuned organism, and only a small hindrance to their efficiency will cause them to die much too soon, leading to problems maintaining hive population.
Why is this important to us? All non-grain botanic agriculture depends on honeybees. The "green revolution" had two parts, only one of which is generally known. One was the use of chemical fertilizers and pesticides to produce huge increases in grain crop yields. The other was the conscription of an entire species, the European honeybee, to produce significant increases in the yields of non-grain crops: all fruits and vegetables are pollinated by insects, mainly bees.
Every apple, pear, peach, orange, grape, and melon, every bean, pea, broccoli head, and brussels sprout you eat was produced by a plant that is pollinated by bees.
Growers that "hire" bees for pollination report that, where exceptional losses of hives have occurred, their crop yields have dropped by about half. In some of these areas, 90% or more of the honeybees have vanished.
Now here is an interesting question: Are other insects able to take up some or all of the slack? Most likely, yes.
Total yields will probably drop a little, but the bigger effect will be greater variation year-to-year. If we can keep honeybees from going extinct, one major method must be a change in how hives are managed, with litte or no trucking of bees from state to state, and more maintenance of local hives, kept at a distance from one another. Bees don't do well with the kind of crowding that is now common.
I have an apple tree. Its yield varies a lot from year to year, mainly because of varying weather. This year was the best year ever. It started out like other years, but a long, cool Spring and delayed Summer allowed young fruit to "set". In most years, an early "hit" of drought will cause the tree to shed most of the young fruit. HOwever, in late April, every year, the tree looks about the same, filled with marble-sized apples. So pollination doesn't seem to be the main factor in final yield.
I usually watch the tree a few times during flowering season, and I had noticed, almost subliminally, that in recent years I saw few honeybees, but larger numbers of other, wild bees. After seeing the Nature program a couple weeks ago, and reading up on the subject (including the Wiki noted above), I took a look at my fall flowers.
We have some Mums in bloom right now. Bees love them. I watched one plant, with hundreds of yellow blooms, for a half hour last Sunday afternoon. I didn't see a single honeybee. I did see two larger bee species, and more than twenty species of smaller bees, down to the tiny (6mm) greenish ones. I also saw four species of flies, plus two beetle species that eat the anthers, but spread pollen anyway when they go to another bloom.
In my small corner of the state, at least, there is no shortage of pollinators, just a shortage of honeybees, the bees one can hire out for money. I expect, over time, if honeybee numbers drop drastically and stay down, that honey will become a pricey commodity, but I don't expect insect-pollinated crop yields to drop as much as people are direly predicting.