If you build it, they will come. Native bees that is.
And when native bees do come, they may be a hundred times more efficient as pollinators than are honeybees, said Jeff Brady, research assistant with the Texas Agricultural Experiment Station.
Brady, working with Forrest Mitchell, Experiment Station entomologist in Stephenville, is building trap nests, a way to encourage native bees to do the agriculturally vital role honeybees have been relied upon for so long: pollinating crops.
Honeybee populations, either because of fierce competition from Africanized honeybees or from species of mites they have no resistance to, are on the decline.
Native bees offer an alternative because they are resistant to both the varroa and tracheal mites. And because they do not live in hives, native bees are not at risk of being overcome by Africanized bees.
Native bees, also called solitary bees, do not live in collective hives as do honeybees. They build nests in tiny holes or tunnels that they find, typically in trees and shrubs. Unlike honeybees, which have workers with specialized tasks, with only a part of the hive collecting pollen, each native bee is "on her own," and each is a potential pollinator, Brady says.
And while honeybees hover around flowers taking pollen when and if they can, many native bees may have evolved so their actions on the flower actually trigger pollination.
"You can actually find a native bee that's been (evolutionarily) tailored to a specific crop," Brady says.
For these reasons and others, for a specific crop at least, native bees, such as the alfalfa leafcutter bee, may be much more efficient pollinators than honeybees, Brady says. "Two hundred alfalfa leafcutters can to do the same amount of pollination that a 20,000 honeybee hive
Honeybees have other advantages however, most notably their honey production. Because humans have cultured them for centuries, Brady says, they offered some advantages to the agricultural producer who wished to ensure there were enough local pollinators for his crop. He or she could simply establish hives near the crop.
The first stage of Brady's research is to take a bee census, finding what bees are attracted to what
crops and what size holes they prefer.
Brady has been building dozens of different size"trap nests," blocks of wood with holes or collections of tubes designed to "capture and hold" the bees as eggs, larvae and/or pupae. He distributes the trap nests near crops in the spring, and when collected later in the year, they can give him a snapshot of what bees and how many frequent certain crops.
Brady can also get an idea of what size holes or tubes certain species prefer, he says.
Knowing the right nest for the right native bee species will eventually allow him to help build populations where they are needed.