A national survey of managed honey bee colony losses in the USA: Results from the Bee Informed Partnership for 2020–21 and 2021–22

Figures & data

Figure 1. Colony loss rates (%) of Apis mellifera honey bee colonies in the United States. Panes specify losses for (A) all operation types; (B) backyard beekeepers (1–50 colonies); (C) sideline beekeepers (51–500 colonies); and (D) commercial beekeepers (>500 colonies). The points represent the percentage of colonies lost, and the shaded bands and error bars represent the bootstrapped 95% confidence intervals (n-out-of-n, 1000 rep). Yellow, blue, and red represent summer, winter, and annual seasons, respectively. The survey year on the figure denotes the year the survey was conducted. For example, the 2022 survey year includes data for the summer of 2021 and the winter of 2021–22. Data for 2008–2020 are from previous surveys.

Table 1. Colony loss rates (%) of Apis mellifera honey bee colonies in the United States for 2020–21 and 2021–22.

(A) All U.S. beekeepers
Survey year	Season	Operation type	n	Colonies at risk	Loss (%)
2020–21	Summer	All	2962	192,124	31.1 [19.2–44.1]^a
	Winter	All	3420	224,497	33.5 [28.0–40.7]^b
	Annual	All	2794	193,701	50.8 [38.0–63.1]
2021–22	Summer	All	2916	357,277	23.8 [16.3–31.9]^a
	Winter	All	3397	326,727	24.2 [20.0–30.3]^a
	Annual	All	2712	333,776	39.0 [31.5–47.9]
(B) U.S. beekeepers by operation type
2020–21	Summer	Backyard	2849	26,014	27.1 [25.4–28.9]^a
		Sideline	79	13,206	19.7 [13.0–26.9]^b
		Commercial	34	152,904	32.7 [18.0–47.2]^c
	Winter	Backyard	3283	25,293	42.2 [40.6–43.7]^a
		Sideline	97	13,551	35.1 [28.0–41.8]^b
		Commercial	40	185,653	32.3 [25.3–39.8]^b
	Annual	Backyard	2688	26,278	56.3 [54.5–58.1]^a
		Sideline	73	12,420	46.8 [38.3–54.6]^b
		Commercial	33	155,003	50.2 [33.1–63.6]^b
2021–22	Summer	Backyard	2810	27,874	35.2 [28.0–43.6]^a
		Sideline	63	9779	29.3 [21.7–35.8]^a
		Commercial	43	319,624	22.7 [14.6–31.2]^b
	Winter	Backyard	3262	24,630	37.2 [35.8–38.8]^a
		Sideline	90	11,272	32.0 [25.3–39.4]^b
		Commercial	45	290,825	22.8 [18.2–29.1]^c
	Annual	Backyard	2616	28,009	58.5 [53.4–64.4]^a
		Sideline	60	9985	53.5 [44.1–61.8]^a
		Commercial	36	295,782	36.6 [28.3–47.0]^b

Loss estimates are presented for (A) all U.S. beekeepers; and (B) by operation type. Operation types are backyard beekeepers (1–50 colonies), sideline beekeepers (51–500 colonies), and commercial beekeepers (>500 colonies). n: number of valid respondents. Square brackets denote bootstrapped 95% confidence intervals. In (A), different letters show statistical significance between summer and winter within each year. In (B), different letters show statistical significance between operation types within each season for each year. For p-values of these comparisons, see Table S2.

Figure 2. Colony loss rates (%) of Apis mellifera honey bee colonies in U.S. states and territories in 2020–21 and 2021–22. Orange and green colors represent loss rates above and below 30%, respectively. The grey color indicates that results are redacted for those states that had fewer than 10 respondents during a season. The survey year on the figure denotes the year the survey was conducted. For example, the 2022 survey year includes data for the summer of 2021 and the winter of 2021–22. MSO: multi-state operation; NCU: non-continental U.S. (Guam, Hawaii, Puerto Rico, and the U.S. Virgin Islands). Multi-state operations were counted in each state that they reported owning colonies but were also reported as a separate subgroup.

Figure 3. Causes of Apis mellifera honey bee colony loss as reported by United States beekeepers in 2020–21 and 2021–22. The graph shows the proportion of beekeepers who identified each cause of loss as being in the top three causes of loss for their operation. Operation types are backyard beekeepers (1–50 colonies), sideline beekeepers (51–500 colonies), and commercial beekeepers (>500 colonies). Causes of loss are reported separately for the summer (yellow) and winter (blue) seasons. The points represent the numerical proportion of beekeepers reporting the cause of loss, and the error bars represent bootstrapped 95% confidence intervals (n-out-of-n, 1000 rep). ApiTreat: “Apicultural treatments”; Disaster: “Natural disaster”; EquipFailure: “Equipment failure (e.g., moisture, ventilation); Pollen: “Nutritional stress (pollen deprivation); QueenIssue: “Queen issues”; Scavengers: “Scavenger pests”; Weather: “Adverse weather”; ShedFailure: “Failure of environmental controls in sheds (wintering facilities)”; DK: “Don’t know.”