With the profit-eating lygus bug apparently developing resistance to a popular prebloom spray, it has become even more critical to find ways to check lygus damage without checkmating bees. At the University of Idaho's Parma Research and Extension Center, entomologists are evaluating new chemicals that would be friendlier to bees. They are also examining the lygus-reducing potential of biological control agents. In 1996 and 1997, they released tiny Braconid wasps they hope will successfully parasitize the pests. It's finding the right combinations of things to make it work.
Combinations are the scientific focus of ecologists.
While most studies of alfalfa seed production and bee mortality address individual factors, UI pollinator ecologist Karen Strickler is beginning to model the dynamic and complex system of interacting factors within alfalfa seed fields. According to Strickler, maximizing seed production while minimizing bee mortality will demand a precise understanding of the relationships among bloom times, bee numbers, bee release dates, temperature, humidity, soil moisture, carbohydrate reserves, and pests like lygus bugs and thrips. To manage alfalfa seed for bee survival, growers would put out fewer bees and keep their flowers blooming later into the season, says Strickler. But that would compromise seed yields, which benefit from early releases of generous numbers of bees. But the ecological secrets within alfalfa fields will take more than a diagnostic test to unlock.