Lab-raised bees have half the lifespan they did in the ’70s

Lab-raised bees have half the lifespan they did in the ’70s

Without honeybees next week’s Thanksgiving dinner would be boring. Because of their hard work, foods like pumpkin pie, green beans casserole, and creamy mashed potatoes are possible because power pollinators are essential for growing the crops which eventually make it to the table. The FDA estimates that bee pollination accounts for about $15 billion in added crop value and says honey bees are, “like flying dollar bills buzzing over US crops.”

Bees have been in trouble since a long time. In 2006, beekeepers from Pennsylvania began to notice that their hives were dying off over winter. “Those were colonies that had, a couple weeks earlier, looked healthy, full of strong bees,” Nathalie Steinhauer, science coordinator of the Bee Informed Partnership, a national nonprofit that monitors honeybee populations, told PopSci earlier this year.

[Related: Do we still need to save the bees? ]

The problem has only gotten worse. Between April 2020 and April 2021, beekeepers across the United States lost 45.5 percent of their managed honey bee colonies, according to an annual nationwide survey conducted by Bee Informed Partnership.

In addition to this staggering colony loss, a study published yesterday in the journal Scientific Reports finds that the lifespan of individual honey bees that were kept in a controlled, laboratory environment is 50 percent shorter than it was in the 1970s. The lifespan decreased from 34.3 days to 17.7 days.

The team modeled the effect of these shorter lifespans on bees and it aligned with the increased colony loss and reduced honey production trends that have been seen in the last few decades.

According to the authors, this is a first study to show a decline in honeybee lifespan that could be independent of environmental stressors such as pesticides. This suggests that genes might be playing a role in what’s going on in the beekeeping industry.

“We are removing bees from their colony life just before the time they emerge as adults. So whatever is reducing them lifespan is happening before that time,” Anthony Nearman, a Ph.D. candidate in the University of Maryland’s Department of Entomology, stated in an . statement. “This introduces us to the idea of a genetic part. This hypothesis points to a possible solution if it is true. If we can identify some genetic factors, we might be able to breed longer-lived honeybees .”

The team researchers collected bee pupae, or the stage of bee growth between a larvae and an adult, from honey bee hives when the pupae were within 24 hours of emerging from the wax cells they grow in. After being collected, the bees were placed in incubators to finish their growth and were then kept in laboratory cages until they reached adulthood.

[Related: The first honeybee vaccine could protect the entire hive, starting with the queen. ]

Nearson supplemented the caged bees’ sugar water diet with plain water to better reflect conditions in nature and noticed that the caged bees had a median life span that was half of those in similar experiments in the 1970s.

“When I plotted the lifespans over time, I realized, wow, there’s actually this huge time effect going on,” Nearman said. “Standardized protocols for rearing honey bees in the lab weren’t really formalized until the 2000s, so you would think that lifespans would be longer or unchanged, because we’re getting better at this, right? We saw a doubling in mortality

Bee life is different in a laboratory setting than in a colony. However, records of lab-kept honey bees show a similar lifespan as colony bees. Previous studies have also shown that shorter honey bee lifespans correlate with lower honey production and less foraging time in real-world observation. According to the authors, this is the first study to link those factors to colony turnover.

The team modeled the effect of a 50 percent decrease in lifespan on a traditional beekeeping operation, where lost colonies and replaced every year. In this setting, the loss rate was about 33 percent, which is similar to winter losses of 30 percent and 40 percent that beekeepers have reported over the past 14 years.

In the study, they found that bees kept in a laboratory were exposed to pesticides or viruses during their larval stages. However, the bees did not show any symptoms. Also, a genetic component to longevity has been shown in fruit flies, which could help explain what is going on in bees.

The team will compare these trends with honeybees from other countries. Any differences in bee longevity can be used to determine if there are any viruses, pesticides, or bee genetics that could be responsible.

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