In a new study, entomologists show that the lifespan for individual honey bees kept in a controlled, laboratory environment is 50% shorter than it was in the 1970s.
Bee colonies naturally age and die off, making colony turnover an accepted factor in the beekeeping business. However, U.S. beekeepers have reported high loss rates over the past decade, which has meant having to replace more colonies to keep operations viable. In an effort to understand why, researchers have focused on pesticide exposure, environmental stressors, parasites, diseases, and nutrition.
Nearman first noticed the decline in lifespan while conducting a study with entomology associate professor Dennis van Engelsdorp on standardized protocols for rearing adult bees in the laboratory. Replicating earlier studies, the researchers collected bee pupae from honey bee hives when the pupae were within 24 hours of emerging from the wax cells they are reared in. The collected bees finished growing in an incubator and were then kept as adults in special cages.
Although a laboratory environment is very different from a colony, historical records of lab-kept bees suggest a similar lifespan to colony bees, and scientists generally assume that isolated factors that reduce lifespan in one environment will also reduce it in another. Previous studies had also shown that in the real world, shorter honey bee lifespans corresponded to less foraging time and lower honey production. This is the first study to connect those factors to colony turnover rates.