by Dewey M. Caron, Communications and Content Specialist for the Oregon Master Beekeeper Program
Bee the change
We are aware that bees need flowers. Sometimes the discussion focuses on what bee-what flower. Studies are certainly mixed on how introduced species or populations (think Africanized honey bees for example) might be affecting the native population (in this example of Africanized bees it is a later introduced population affecting an earlier introduction). A plant native to North America (California say) might be invasive if introduced into the Carolinas. One common estimate is the percentage of native vegetation that remains in the United States is less than 25%. In the UK what is described as a “sparse native vegetation” of 1625 native species compares to 1798 introduced species.
These estimates indicate that significant portions of the original ecosystems here and there have been altered or displaced. The culprits as to why are many – urban development, agriculture, and other human activities are chief among them. Climate change seems to be the latest of environmental perturbations currently being documented as causing shifts in native flora (and fauna too of course). While it matters little to generalist pollinators like the honey bee, native pollinators may not be able to benefit as directly from introduced species.
As we come upon the New Year, for those who might be into making New Year resolutions a good one would be to plant/promote more flowers in your personal spere of influence. A pollinator, maybe many of them, will thank you.
Vespa Hornets as bee pests
Hornets (genus Vespa) are conspicuous large-bodied predators that form large annual colonies. (NOTE: what we might call a hornet in OR are yellow jackets of the genus Vespula). Several aspects of true hornet biology facilitate their successful invasion of new habitats; hugely important is overwintering females initiate nest construction after a diapause period. While in their diapause period fertilized queens might readily be transported over long distances hidden in most anything shipped from their homeland in Asia around the world.
Additional aspects of their biology facilitate successful invasion of new habitats. A plasticity of life history traits—such as colony size, colony longevity, polyandry, and polygyny— favors their initial survival and establishment in new habitats. Their nests are constructed from widely available wood and plant fibers. Most species have cosmopolitan food preferences: adults consume sugary substances such as floral nectar and plant sap and capture diverse arthropod prey to feed their larvae. Additionally, most have high reproductive rates.
At least 6 Vespa species have invaded continents outside Asia, their natural range. A new invasion of the Southern Asian hornet Vespa soror has just been reported in Spain. Closer to home V. mandarinia, the Northern Giant hornet (Aka murder hornet, Asian Giant hornet) is a significant predator due to its large size, exceptionally strong mandibles, and group hunting techniques. It is well known for attacking honey bee colonies. An earlier North American invader Vespa crabro is common in the east and was found in British Colombia in 2022: they will feed on honey bees but not invade colonies directly.
WA State Department of Agriculture reported the first known invasion of V mandarinia was in Whatcom Co (Blaine area) in 2019. Nests were found and eliminated in 2020 and 2021. After an extensive search and destroy Canadian and US officials concluded the invader was eradicated. This past summer another specimen was reportedly found in Burley, near Port Orchard. The WA Dept of Ag said it does not have the specimen, a dried adult found in a window so it can’t be determined at this time if what was reported is actually a new hornet find. It seems likely it is not a new find.
Sanchez, Omar, et al. 2024. Early Alarm on the First Occurrence of the Southern Giant Hornet Vespa soror du Buysson, 1905 (Vespidae) in Europe. Ecol. Evol. Nov9:14(11) DOI: 10.1002/ece3.70502
Otis, Gard W., Benjamin A. Taylor & Heather R. Mattila. 2023. Invasion potential of hornets (Hymenoptera: Vespidae: Vespa spp.). Front Insect Sci May 9:3: doi: 10.3389/finsc.2023.1145158
Report on bee losses REVISED
In 2023-24, Auburn University, with financial support of the Apiary Inspectors of America, Project Apis m, and the two national beekeeping associations, conducted a national survey of 1,652 commercial beekeepers. The beekeepers that were surveyed collectively managed 337,134 fall colonies, 55.7% of which they lost. Different from previous years, backyard beekeepers during the same period experienced a lower annual loss rate than commercial beekeepers. Their losses were 45.1%. The overall loss level was an estimated 55.1% of managed bee colonies in 2023-24.
The survey was conducted during May, for the April 2023 to April 2024 time period. Comparing this result with a 13-year average of the Bee Informed Project (BIP), commercial loss level was 16.8 percentage points higher than the 13-year BIP average of 38.9%; for backyard beekeepers loss was 4.1 percentage points lower than the 13-year BIP average of 49.2%. The survey asks how many survived; it does not answer the question as to why they died – surveys estimate Varroa mites lead a lengthy listing of reasons for colony losses.
The survey breaks down losses by seasons and also shows losses by beekeepers in individual states. Thirty-six OR beekeepers said of 10,729 colonies (less than 2% exclusive to state i.e. not moved to another state) their annual loss rate was 45.7%. Forty-six Oregon beekeepers with 11,671 fall colonies (less than 5% identified as OR colonies only) had a 41.7% winter loss rate.
The PNW survey I conduct from mid-March to end of April is only of overwintering losses (not annual losses). In the PNW survey of Oregon commercial beekeepers, 7 OR survey respondents (14,088 fall colonies) lost 23.5% of overwintering colonies. For the 172 backyard beekeepers of Oregon, loss level was 20%, the lowest level in 15 years.
Why the difference? The Auburn loss numbers clearly are of large-scale beekeepers when colony percent exclusive to state is considered. Their overwinter survey loss rate was nearly 3/ths higher (18.2 percentage points) compared to the PNW loss level. The surveys are not of the same populations of beekeepers. The PNW survey included nearly 3000 more commercial colonies (but the same number of individuals) and 78 more backyarders. Both were consistent in reporting larger-scale beekeepers percentage-wise lost more colonies than did backyarders with 50 or fewer colonies. Whatever the loss rate, I hope your numbers were on the lower side of these reports.
See https://apiaryinspectors.org/US-beekeeping-survey for Apiary Inspectors loss survey results and https://pnwhoneybeesurvey.com/ for the PNW overwinter loss results.