Science News - April 9, 2011

discovery: a company in Idaho that raises bluebottle flies to sell.

Raising bees isn’t so hard on the nose but has its tough moments too. The alfalfa leafcutting bee, one of the most intensively managed among alternative pollinators, for example, refuses to stick out its tongue when its antennae are tickled with sweets. And that quirk may force a change in the way researchers study how farmers could make nesting sites more alluring.

Unlike honeybees, many alternative pollinators don’t nest in colonies, so farmers can’t haul an existing hive into a field and be done with nest location. Each solitary bee arrives in a field nest-less and chooses a home, possibly where the farmer wants the bee but quite possibly not. To keep alfalfa leafcutting bees and other helpers near a crop, a farmer needs to lure them to a prefab home, so the farmer has to know what the bees like.

A standard test for honeybee preferences relies on the bees’ reflexive response when a bit of sucrose is touched to their antennae. But when Cory Stanley of Utah State University in Logan and Theresa Pitts-Singer of the Department of Agriculture’s bee lab in Logan tried to design a similar test for alfalfa bees, the insects’ tongues wouldn’t budge.

A previously unrecognized feature of at least some solitary bees is this difference in the proboscis reflex, the researchers reported last year in the Journal of the Kansas Entomological Society. Now researchers are developing other tests that might reveal the types of odors that could attract bees to a farmer’s housing offerings.

Another challenge of domesticating pollinators also comes from their non-honeybee biology. Individual honeybees may not live long as adults, but new workers grow into tasks as older bees falter. With the right conditions, the pollination fleet can keep flying most of the year. For alfalfa leafcutting bees, blue orchard bees and other non-colony-dwelling species, however, six weeks or so of flight-worthy adult life means just six weeks or so of pollination,

A tale of two bees a blue orchard bee typically pollinates for only about six weeks, after developing and hunkering down in its nest. each honeybee doesn’t have a long pollination period either, but bees in a colony reach adulthood at different times, meaning new pollinators replace old ones and pollination can continue throughout the year. Farmers who hope to rely on blue orchard bees need to stir the bees from dormancy just as the crop is blooming — or miss a crucial window.

Life cycles of blue orchard bee (top) and honeybee (bottom)

JAN FEB MAR APR MAY JUN JUL AUG

Dormant adult Pollinating bee Egg hatches, larva grows into pupa

SEP OCT NOV DEC
Dormant adult
Egg,
larva,
pupa
Pollinating
bee
Cycle continues
throughout year
soUrce: r.r. James and t.l. pitts-singer, ed./Bee Pollination in agricultural ecosystems 2008

for the whole year. The farmer needs to get bees in the air when a crop is in bloom. The rest of the year, bees hunker in their nests.

During their short flying period, female blue orchard bees need to mate with males and then lay a series of eggs, packing enough pollen into a nest to sustain the youngsters until the next year. Eggs hatch, larvae grow into adults, and adults lower their metabolism for a long winter’s wait. Yet despite that slowdown, blue orchard bees lose substantial weight, Jordi Bosch of the Autonomous University of Barcelona and his colleagues reported in December in the Journal of Insect Physiology. Farmers have to make sure the time-pressured females can get enough pollen to adequately provision their nests. Too few flowers for the number of bees loose on the farm may leave youngsters underfed.

Back at Paramount, Wardell already knows his blue orchard bees like a purple wildflower called Phacelia, and he’ll provide a waving field of it in his rearing tent, and a twin rearing tent nearby. For nests, the red, yellow and blue boxes will hold bundles of strawlike tubes, open end out, as well as blocks with rows of bee-diameter tunnels. Wardell is even experimenting with marks on the faces of the nesting boxes to see if bees find their nests faster with a landmark.

To test whether raising blue orchard bees would even be worthwhile for Paramount, though, Wardell is going to test the bees outside the tents, in the actual almond groves. He’ll set the insects out to see whether pollination improves and how they get along with honeybees during the frenzy of pollen collecting in an ocean of almond flowers.

After envisioning a field abuzz, it’s time for an almond tourist to meet the blue orchard bees. Wardell leads the way into a roomy warehouse, where in the far corner stands what looks like a big, silvery food cooler behind the scenes in some restaurant. It is a big food cooler, he says.

As the heavy door eases open, Wardell
points out a container of what from a
distance look like miniature misshapen
peanuts. Actually they’re blue orchard
bees still robed in their protective win-
ter covering, a netting as delicate as a silk
stocking. Wardell peels the covering off
one little bee, who stirs groggily in pro-
test. “A male,” Wardell says. “Look at the
mustache.”
As well as the fuzzy vest, the little fel-
low has a tiny wisp of white fuzz on his
face. If his is the face of tomorrow, then
the future of pollination is pretty cute. s