WVBA 2025-26 loss survey report

WVBA members were encouraged to complete a web-based survey document in a continuing effort to define overwintering losses/successes of backyard beekeepers in Oregon. This was the 17th year of such survey activity. I received 442 reports from Oregon beekeepers keeping anywhere from 1 to 49 colonies; Willamette Valley members sent in 41 surveys, twenty-four more than last year, double the average return for past 6 years = 20%. Maximum colony number was 22 colonies.

Overwintering losses of WVBA respondents = 22%, three percentage points lower compared to last year WVBA results, and two percentage points below average statewide losses of 24%. A total of 284 hives were included in survey. Percent losses, determined by hive types were 12% for Langstroth 8-frame (9 of 77 fall colonies lost, 16 individuals) and 29% for Langstroth 10-frames hives (178 total colonies in fall, 27 individuals); 2 of 21 nucs were lost (maintained by 5 individuals). One of two Top Bar hives survived but the single Warré hive did not. There were 5 long hives and all but one survived (managed by 3 individuals).

Graph 3 below illustrates the loss history of last 12 years. Dotted line in red shows trend. Obviously, the loss levels are going in right direction with losses in the last 7 years below 30%. Average loss for past ten years of WVBA members is 34.4%.

The survey also asked for hive loss by hive origination. Members could FAST Track and not provide information on survival by origination – 33 respondents (65%) elected to not respond – this is the record of the 18 respondents. Fourteen members reported 13% loss of previously overwintered colonies (statewide loss level was 19%). There were 2 packages (2 individuals), and both survived. Five of 10 nucs (5 individuals) were lost – 50% loss (statewide 55% of nucs did not survive.  The 6 individuals with swarms lost 4 colonies for 27% loss and the 8 individuals who overwintered splits also lost 4 – 18% loss. Three individuals overwintered one feral each and all 3 survived. Figure 4.

Twenty-one individuals (51%) had no loss (110 colonies). Six (14.5%) had total loss (14 colonies). Six individuals lost one colony, 6 lost 2 colonies and 2 individuals each lost 3, 5, 6 and 8 colonies. Eight was the greatest loss. Five WVBA individuals lost 5 to 25 colonies (19% loss), six individuals lost 33% to 50% of their colonies (43.5% loss) and 3 individuals lost 67%-86% of their fall colonies for a 77% loss.  Figure 5.

The eight WVBA members with one colony lost 2 colonies (25% loss), the 19 individuals with 1-3 colonies lost 14 of 34 fall colonies =41% loss. The 7 individuals with 4 to 6 fall colonies lost 11 colonies = 29% loss, the 4 individuals with 7 or 8 colonies lost 6 of 29 colonies = 21% loss and the 11 individuals with 11-22 colonies had the lowest percentage loss = 17%. Statewide the 70 individuals with 10+ colonies lost 20%. Statewide, as colony numbers increase, the loss level decreases, which was true for WVBA as well.

Statewide, and for WVBA respondents as years of experience increase, the loss level does not decrease. The seventeen WVBA individuals with 1-3 years’ experience had 16% loss level, the seven individuals with 4 to 6 years’ experience had 36% loss level, the seven individuals with 7-9 years’ experience had 17,5% loss and the 10 individuals with 11 to 37 years’ experience had 23.5% loss level.

Comparison WVBA with Statewide

We asked survey takers who had winter losses for the “reason” for their losses. Twenty-one had no loss and 3said they didn’t know. Thirty reasons were supplied by the 17 offering a reason (1.7/individual). Varroa with 8 and queen and weak in the fall had 7 selections each. The selections are shown below.

Acceptable loss: Survey respondents were asked reason for loss. Recall that 21 individuals, 41% of WVBA respondents had no loss. Ten individuals indicated 0, 1 indicated 5% was acceptable, and 13 said 10% was acceptable, the medium response. Eight individuals said 50% loss was acceptable.

Why do colonies die?

There is no easy way to verify reason(s) for colony loss. Colonies in the same apiary may die for several reasons. Examination of dead colonies is at best confusing and, although some options may be ruled out, we are often left with two or more possible reasons for losses. A dead colony necropsy can be of use. Opinions vary as to what might be an acceptable loss level. We are dealing with living animals which are constantly exposed to many different challenges, both in the natural environment and the beekeeper’s apiary. Interestingly, acceptable level was greater than actual average loss for ten Willamette individuals.

Major factors in colony loss are thought to be varroa mites and their enhancement of viruses especially DWV (deformed wing virus), VDV (Varroa destructor Virus (also termed DWV B) and Israeli and chronic paralysis virus. Varroa was the major selection of WVBA members, followed by starvation. 

Declining nutritional adequacy/forage and diseases, especially at certain apiary sites, are additional factors resulting in poor bee health. Yellow jacket predation is a constant danger to weaker fall colonies. Management, especially learning proper bee care in the first years of beekeeping, remains a factor in losses. What effects our changing environment such as global warming, contrails, electromagnetic forces, including human disruption of them, human alteration to the bee’s natural environment and other factors play in colony losses are not at all clear.

              There is no simple answer to explain the levels of current losses nor is it possible to demonstrate that they are necessarily excessive for all the issues our honey bees face in the environment. It was encouraging to see from survey responses that losses this past year of 22% were still at a low level. More attention to colony strength and possibility of mitigating winter starvation will help reduce some of the losses. Effectively controlling varroa mites will help reduce losses.

Colony Managements

Respondents to the 2025-26 survey could Fast Track and not need to respond to the management questions. There were questions on seasonal managements of feeding/ winterizing/ sanitation + questions on screen board use + questions on monitoring + questions on varroa non-chemical and chemical control + questions on queen rearing.

Anywhere from 10 to 15 WVBA respondents elected to skip answering and with the one to several whose reason was none (6 for example selected none for the non-chemical options offered i.e. they reported doing zero non-chemical mite controls) numbers begin to become small - meaning the data is not very robust. I therefore recommend that you examine the larger data base of the statewide respondents and compare your results with those numbers. I will be re-posting this report with updates from options selected by WVBA members at a later date on the website: https://www.pnwhoneybeesurvey.com