Media frenzies and
vanishing bees?
From the Davis Enterprise, March 22, 2007
Musings in early
springÉ.
A couple of
stories from the popular press have caused comments and questions to come our
way.
ÒIÕd better get
these things planted early; IÕve heard itÕs going to be a really hot summer
this year.Ó
Tracking this
back, I found a January report from the University of East Anglia (UK) as the
early source of this rumor. Based on computer models incorporating global
temperature trends and the impact of El Ni–o, climatologists there stated they
believed there was a 60% chance that this yearÕs worldwide temperatures could match or exceed the records set in 1998 (previous record:
1934). Reporters then interviewed some researchers here who, at least as
quoted, mostly just confirmed the global temperature trends. This didnÕt stop
the breathless headlines. My favorite: California SteaminÕ: Forecasters
Predict Hellacious Summer, WorldÕs Hottest Year on Record! (DailyNews.com).
It is true that El
Ni–o has been correlated with higher summer temperatures in the west of North
America. But El Ni–o has fizzled. By February, the ocean temperature data
showed Òno anomalyÓ – that is, no warming – and in fact we appear
to be heading into La Ni–a (cooling) pattern of ocean temperatures. North
American summer temperatures during La Ni–a events have generally been near
average. So a major component of that January prediction no longer holds.
In fact, the
National Weather Service Climate Prediction Center (www.cpc.ncep.noaa.gov)
issued regional forecasts on March 15. Their outlook? An equal chance of
temperatures being above or below normal for most of North America. Exceptions:
Arizona, southern Texas, southern Florida, the Great Lakes, and New England are
likely to be warmer than the 30-year average.
What does this mean
for gardeners? It will, undoubtedly, be a hot summer here in the Sacramento
ValleyÉit usually is! Expect a couple of dozen days with high temperatures over
100 degrees, a couple of dozen in the 80Õs, and the rest likely in the 90Õs.
Expect the delta breeze to make it livable most of the time, and a couple of
real hot spells in July. That would be normal.
But you can
plant any time the soil is workable here. The key is the after-care you give the plants, especially
proper watering. The most important factors in plant success, regardless of the
time of year you plant them, are
- Choosing the right plant for the
situation and for this area.
- Digging a proper planting hole.
- Watering correctly and carefully
during the weeks after you plant.
ÒWhere are all
the bees? I hear thereÕs a new disease killing them all.Ó
There have been
several stories about bee problems in the last few weeks. Item: Honey
production fell 23% in the nationÕs top beekeeping state (guess which state
ranks #1 in honey production? Answer below!) and fell 34% in California, which
ranks #2. Dry weather in the
Midwest, and mid-summer heat waves there and here, were blamed.
Item: GrowersÕ
costs are up. European honeybees have been beset by Varroa and tracheal mites
since the 1980Õs. ÒWildÓ (feral) hives of European honeybees are mostly
gone. Increased management
expenses for beekeepers have been passed along to almond growers, with colonies
costing over $135 each this year (2004: $55).
The most recent
publicity is about Colony Collapse Disorder. Some beekeepers in some states are opening their bee boxes
and finding no adult bees. The capped brood are present, there is pollen and
honey, but the queen and all the adult bees are gone. Not dead, just decamped.
This is not entirely new: there have been reports going back over a hundred
years. But in late 2006 the loss rate reportedly reached unusually high
levels. Possible causes, including
stress, pathogens, parasites, nutrition, and heredity, are being explored by a
working group at Penn State.
We have had calls
for several years about lack of pollination on early summer crops such as
melons and squash. There are plenty of bees in the area in the spring, as local
almond and fruit growers import hundreds of hives that remain active here
through the spring bloom period. But many of those hives are trucked north by
early summer, and the loss of the ÒwildÓ honeybees has reduced the pollinators
for your vegetables.
So imported bees
will probably take care of your fruit trees. But if your zucchini doesnÕt seem
to be setting, you may need to pluck the male flowers and take them to tickle
the female flowers. TheyÕre easy to tell apart: the female flowers already have
undeveloped, but visible, fruit at the base of the flower. Planting flowers
that draw bees among your vegetables can be helpful. Try Borage, Cosmos, and
Sweet alyssum. All are easy from seed and tend to reseed themselves (to put it
mildly) for subsequent years.
You may be
fortunate enough to have an amateur beekeeper in your neighborhood, and they
donÕt have to be right next door. How far do bees fly? The flip answer is Òas
far as they have to.Ó In a classic
study published in 1933, it was shown that honeybees would fly as much as 7
miles! They also exhibit strong preferences for some flowers more than others.
We do have native bees of various types, though they tend to be less efficient
pollinators.
Speaking of bugs,
we get questions as lots of critters emerge in the springÉ..
ÒWhy are we
still getting aphids on our hackberries? HavenÕt natural predator populations
increased to take care of them?Ó
You will see lots
of ladybugs, lacewing larva, syrphid flies, and other aphid-eating beneficial
insects on your hackberry tree, feasting on the Asian woolly hackberry aphid
that arrived in 2002. But they canÕt reproduce anywhere near as fast as the
aphid. Biological control programs usually focus on introducing a predator that
is specific to the pest, which can be reared readily and which reproduces
rapidly. No naturally occurring beneficial insects in our area meet that job
description. So for now the most effective management is imidacloprid (Merit),
a systemic applied in the spring. Or you can just live with the incredibly
sticky mess all over everything. Even very heavy aphid populations donÕt seem
to stress the hackberries, though they definitely stress the homeowners.
ÒSo, can I
release ladybugs in my garden?Ó
Sure. On a cool,
overcast day ladybird beetles will stick around. On a hot sunny day they will
tend to fly away. In either case, release them in the evening and they will eat
a lot of aphids before they go. Put them at the base of infested plants, and
then cover those with seedling blankets (Òfloating row coverÓ) for a few days,
and they will eat even more aphids. If you have a diversity of plants in your
garden, including ornamental grasses and herbaceous perennials, they may settle
in.
Note: you could
not release enough ladybugs to control your hackberry aphids, at least not at a
reasonable cost.
ÒWhat about
praying mantids?Ó
TheyÕre fun,
theyÕre interesting to watch, but being general feeders they eat everything
– including other beneficial insects and each other. So of the hundreds
that tumble out of an egg case in the spring, only a few remain by seasonÕs
end. But if your garden has suitable habitat, they will lay eggs and show up in
future years as well.
DonÕt panic about
a sudden increase in pests. In most cases the problem will run its course, and
safe solutions are available. Learning to recognize the good guys is an important
first step!
The #1
honey-producing state is (drumroll, please) É North Dakota! Their official
state beverage is milk. So I guess North Dakota is the land of milk and
honey.
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