Where the trachea was ripped, GLD should be present. But they found the opposite. Infected tracheae had less GLD than healthy ones. Something didn't add up, so Fisher and Cox-Foster decided to approach the problem from a different angle. It appeared that tracheal mites might also do so.
Mites peak in the winter and spring months.
This February afternoon is prime time for studying the honeybee-tracheal mite interaction. Fisher gathers a sample of bees from the apiary and totes them back to the lab in wire cages. She doesn't know which ones are infected, but some 30 percent of the colony has tracheal mites. Then she waits, periodically monitoring the bees until their deaths, about 42 hours later. If the immune systems of the mite-infested bees are compromised, sick bees should have more difficulty fighting off harmless bacteria.