U.S. honeybees simply weathered an unusually unhealthy winter.
About 38 p.c of beekeepers’ colonies died between October 1, 2018, and April 1, 2019, the Bee Knowledgeable Partnership estimates. Whereas it wasn’t the worst latest 12 months total for honeybee losses — that was 2012–2013 — preliminary outcomes launched June 19 present it’s the worst winter die-off recorded over the College of Maryland–primarily based nonprofit’s 13 years of surveying bee populations.
Beekeepers ought to be capable to rebuild these numbers this 12 months, however such ongoing winter losses elevate deep worries about the way forward for crop pollination. On common over the 13 years, about 29 p.c of colonies have died every winter. The 2018–2019 numbers got here from practically 4,700 beekeepers, representing about 12 p.c of the estimated 2.69 million U.S. hives.
Some floods and fires this 12 months destroyed colonies, however “the take-home fear for me is Varroa [mites],” says the Partnership’s Dennis vanEngelsdorp, a bee-health entomologist on the College of Maryland in Faculty Park. The invasive mite species Varroa destructor clamps its tiny pimple-shaped physique onto bees simply as they’re turning into adults (SN: 2/16/19, p. 32). Mites sap bee energy and unfold illness, but treatments towards the pests appear to be shedding their energy. “Ideally within the long-term, we’d have a bee that was resistant,” vanEngelsdorp says.
Whereas winter bee colony die-offs are worrisome, beekeepers can cut up surviving bee colonies and add new queens. Changing winter-killed colonies this fashion, nonetheless, takes labor, money and time.
Solely 5 p.c or so of U.S. beekeepers work on the business scale that provides 90 p.c of bees pollinating the nation’s crops, vanEngelsdorp says. If the relentless drain of changing winter losses drives them out of enterprise, “it’s very onerous to exchange that group of beekeepers.”