Overwinter Survey Summary of Methodology

Please contact apiary@ontario.ca for the report in PDF format.

Introduction

Since 2007, the Canadian Association of Professional Apiculturists (CAPA) has compiled and published statistics for Canadian honey bee colony losses. These statistics provide an ongoing picture of the general health of apiculture in Canada. CAPA's Statement on Honey Bee Wintering Losses in Canada (2014) is a summary of the reported winter losses from all provincial beekeepers surveys, including Ontario's. It can be found at www.capabees.com.

In 2014, to improve the consistency and comparability of winter loss statistics across the country, the CAPA National Survey Committee developed a core set of questions for inclusion in the provincial surveys on honey bee wintering losses. Beyond the core set of questions suggested by CAPA, each province has the option of asking additional questions in their own annual provincial survey that are specifically relevant to their regional conditions and issues.

Outlined below is the methodology for information collection and preliminary review of the data collected through the Annual Beekeeper Winter Loss Survey conducted by the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). This survey is designed to seek the thoughts, impressions and opinions of Ontario's beekeepers. Information provided by beekeepers has not been verified by OMAFRA or any other independent body. The information yielded by the survey provides an indicator of the state of bee health and beekeeping practices in the province and can be used to inform future investigations surrounding the factors potentially associated with honey bee overwinter mortality.

Survey Methodology (Ontario)

The Ontario Provincial Winter Loss Survey, conducted by the OMAFRA's Apiary Program, is sent annually to all registered "commercial" beekeepers. For the purpose of this survey, a commercial beekeeper was defined as a beekeeper operation with 50 or more colonies.

In Ontario, the survey has been consistent for many years in collecting the following primary information from beekeepers (survey attached in Appendix 1): county; number of colonies at the start of the winter; number of viable colonies in the spring (as of May 1); possible reasons for colony loss; various management practices (e.g. treatment for varroa mites, treatment for Nosema disease); replacement of queens; and source / origin of queens. As do other provinces, Ontario alternates between a long and a short version of the survey to maintain a reasonable response rate (the survey is administered during a busy period for beekeepers and long versions may discourage participation).

In 2014, several new questions were added to the survey including: percentage of colonies used for pollination services, types of crops pollinated, major impacts on apiary operation in 2013, abnormal loss of bees in-season in 2013, main crops surrounding bee yards, and whether beekeepers observed differences between bee yards in terms of losses.

The 2014 survey had a total of 30 questions (one-third of these were core questions aligned with the other provinces and two-thirds were tailored to Ontario's specific needs). By comparison, Ontario's 2013 beekeeper survey (short version) included a total of 14 questions.

Survey Distribution

Ontario's 2014 Beekeeper Winter Loss Survey was mailed out in early June. As is done each year, the survey was sent to all registered commercial beekeepers (247). Follow-up phone calls were made by the ministry as necessary to encourage commercial beekeepers to complete the survey. Beekeepers had the option of completing the survey orally on the phone at that time. Anonymity was maintained during the survey process; beekeeper identity was not recorded with their responses nor was it requested on the paper surveys.

In 2014, for the first time, the survey was also sent to a sample of registered non-commercial beekeepers (beekeepers with fewer than 50 colonies). These account for 90 per cent of the beekeepers in the province, but only 20 per cent of the colonies. This was initiated to help the Apiary Program better understand the state of health across the broader beekeeping industry. As there are more than 2,500 registered non-commercial beekeepers, selection from this group was conducted randomly, using a numbering system and randomization software. These beekeepers were stratified by region and by size of operation. Using this process, the survey was mailed to 399 non-commercial beekeepers.

Survey Responses and Analysis

TThe ministry received survey responses until mid-July from a total of 100 commercial beekeepers and 129 non-commercial beekeepers. The official winter loss statistic for Ontario for 2014 (as published in the CAPA report) is based solely on information from the 97 commercial beekeepers who provided data on their colony losses, to enable comparability with previous years. It should be noted that commercial beekeepers account for approximately 80 per cent of the colonies in the province, and 99 per cent of the colonies in the survey.

Basic results have been reported in CAPA's Statement on Honey Bee Wintering Losses in Canada (2014). A detailed analysis of the Ontario 2014 survey is currently underway. Results will be included in the annual Provincial Apiarist's report which will be posted on OMAFRA's website in the fall of 2014.

Results and Interpretation

Based on survey results, the overall winter loss reported for Ontario in 2013-14 is 58 per cent. In April and May 2014, 150 field inspections were conducted by OMAFRA bee inspectors to directly assess and document winter losses for a sample of both commercial and non-commercial beekeepers. Observed losses during these inspections were consistent with the loss rate and range calculated from the survey.

Commercial operations reported mortality rates ranging from 0 to 100 per cent, with 56 out of 97 commercial operators reporting mortality rates greater than 50 per cent. Information was collected from five regions in Ontario (Central, East, North, South and Southwest). There does not appear to be differences in bee mortality between different geographic locations.

Producers were asked to attribute the percentage of loss to specific factors. The percentages provided are producer estimates based on their observations. Losses were most commonly attributed to the following factors: weak queens, starvation, acute and chronic pesticide poisoning, weather related events, and unknown causes. Other less frequently reported attributions included: exhausted bees, ineffective Varroa control, lack of staff, poor ventilation, pests (mice) and lack of forage.

Respondents were asked to discuss any environmental or external factors that may have negatively affected their operation in 2013. Many producers cited pesticide poisoning as events they perceived had an impact on their operation. Estimates of the relative importance surveyed beekeepers placed of the impact of pesticides varied from small (less than 5 per cent) to the only external factor that affected the operation (100 per cent). Many producers suspected that chronic pesticide damage contributed to the winter loss in their operation, and these suspected pesticide incidents were investigated by the federal Pest Management Regulatory Agency (PMRA) to evaluate the role pesticides may have played in these bee losses. Other external events cited included: adverse weather events (cold temperatures, prolonged winter) and invasion by other pests (ants, wasps).

Disease management and colony health status are important considerations in the discussion of winter mortality. Variability in treatment application times and products, effectiveness of treatments and producer impressions of the response may also influence the interpretation of the data and therefore the estimates of disease contributions to winter mortality.

Varroa mite infestation is endemic in Ontario's honey bee population, and is usually thought to be the most significant factor influencing winter survival in Ontario. However, Varroa mite infestation was not considered to be a significant contributing factor to winter mortality rates in 2014 among the producers surveyed, with very few producers citing mite infestations as a potential cause of loss. Treatment for Varroa mite is practised widely within the industry, with most operations reporting treatment for Varroa mites in the spring, summer and fall of 2013.

Summary

The results of the survey provided information from beekeepers from across the province with respect to colony numbers, colony management, pollination services, disease treatment and management and mortality statistics. Events such as starvation, pesticide damage, cold weather and unknown factors have been noted by beekeepers as factors likely to have contributed to overwinter mortality. While this information suggests possible risks associated with compromised honey bee health, further investigation is needed to determine the true risks and impacts of these events on honey bee health and winter mortality.

The reason(s) for the prominent increase in the provincial winter mortality from previous years are not immediately discernable from the information provided from the surveys. Further analysis is being conducted and will be released in the fall of 2014. Weather factors have been consistently associated with winter mortality, and the unusually cold and prolonged winter in Ontario in 2013/2014 was expected to result in higher than normal winter losses.

The survey provides a baseline overview of the impressions of individual producers throughout the province. However, the results contained within the survey should not be extrapolated and considered as definitive evidence for reasons behind the reported winter losses.


Appendix 1

Ontario's 2014 Provincial Winter Loss Survey

Spring Summer Management 2013
  1. What is the County where the majority of your colonies are managed? __________________
  2. How many bee yards do you manage? (Please enter a number) ___________
  3. How many productive colonies did you operate during the summer of 2013? (Do not include colonies or nucs produced for sale) (Please enter a number) ___________
    (The term "productive colony" is defined as one which could be used for honey production or pollination service.)
  4. In what percentage of your colonies operated in 2013 did you replace old queens with new queens? (Please enter a number between 0 and 100) ________
  5. In what percentage of colonies did you provide a new queen because of queen problems last year? (Do not include re-queening of old queens. Please enter a number between 0 and 100) ______
  6. What is the origin of the majority of your queens?
    Reared by colony itself ______ %
    Reared from one of your own selected queens ______ %
    Queen breeder in Ontario ______ %
    Queen breeder in other Canadian province ______ %
    Queen breeder in Hawaii ______ %
    Queen breeder in California ______ %
    Queen breeder in Chile ______ %
    Queen breeder in New Zealand ______ %
    Queen breeder in Australia ______ %
    Other (specify) ____________________ ______ %
  7. Percentage of your colonies used for pollination services in 2013. (Please enter a number between 0 and 100) ______%
  8. What types of crops did you pollinate in 2013?
    Please list type of crop, date of pollination and proportion of your colonies used for each crop:
    Crop 1 __________________, Date ____________, % colonies used __________
    Crop 2 __________________, Date ____________, % colonies used __________
    Crop 3 __________________, Date ____________, % colonies used __________
    Crop 4 __________________, Date ____________, % colonies used __________
    Crop 5 __________________, Date ____________, % colonies used __________
    Crop 6 __________________, Date ____________, % colonies used __________
    Crop 7 __________________, Date ____________, % colonies used __________
    Crop 8 __________________, Date ____________, % colonies used __________
    Crop 9 __________________, Date ____________, % colonies used __________
    Crop 10 _________________, Date ____________, % colonies used __________
  9. Were there any major environmental/external events that impacted your operation during 2013? (Please indicate the proportion of your colonies impacted for each category; eg. 0%, 5%, 23%, etc.)
    • Vandalism ___________%
    • Bear (or other mammal) damage _______%
    • Pesticide poisoning (if known indicate crop, active ingredient and type of application) __________%
    • Other (please specify) __________________%
  10. In Spring or Summer 2013 did you report (or experience) an event where there were an abnormally large number of dead bees at the entrance of honey bee colonies or an abrupt decline in colony population within colonies in your operation?
    Yes ____ No____
  11. If yes, in how many yards did you see this? __________
    Percentage of colonies impacted in your entire operation? ___________%
  12. What are the main crops surrounding the majority of your bee yards and what percentage of bee yards would they cover by crop?
    Crop 1 ________________, ______ % of bee yards
    Crop 2 ________________, ______ % of bee yards
    Crop 3 ________________, ______ % of bee yards
    Crop 4 ________________, ______ % of bee yards
    Crop 5 ________________, ______ % of bee yards
  13. Which method of treatment did you use for varroa management in spring 2013? (Pick all that apply )
    ____Apistan®
    ____CheckMite+™
    ____Apivar®
    ____Thymovar
    ____65% formic acid - 40 ml multiple application
    ____65% formic acid - 250 ml single application
    ____Mite Away Quick Strips®
    ____Oxalic acid
    ____Other (please specify) _____________________
  14. What was the date of application? Month ______________ Day_______
  15. Did you treat in summer 2013 for varroa?
    1. Mite Away Quick Strips®
      b. Other
      c. Did not treat
  16. If so, what was the approximate date? Month ________________ Day ______
2013 In-Season Losses
  1. Did you experience high mortality or a major decline in health of honey bee colonies in your operation? Yes ____ No _____
  2. If yes, what percentage of colonies (in your entire operation) was impacted? (Please enter a number between 0 and 100) __________%
    In how many yards was this noticed? (Please enter a number) __________
  3. How serious would you rate this loss in terms of loss of production in your operation? (Please enter a number between 0 and 100) _____%
Fall Management
  1. Which method of treatment did you use for varroa management in fall 2013? (Please pick one)
    ____Apistan®
    ____CheckMite+™
    ____Apivar®
    ____Thymovar
    ____65% formic acid - 40 ml multiple application
    ____65% formic acid - 250 ml single application
    ____Mite Away Quick Strips®
    ____Oxalic acid
    ____Other (please specify) _________________________
  2. In reference to the above question #20, what date did you treat?
    Month ____________ Day ______
  3. Did you treat for Nosema disease in the fall? Yes____ No ____
Winter Management
  1. What was the total number of viable full size colonies and viable nucleus colonies put into winter in your operation in October 2013?
    Full sized ________
    Nucleus _________
Winter Survival
  1. On May 1 (or your last day of winter loss assessment), 2014:
    How many colonies that survived the winter were considered commercially viable? (i.e. with 4 or more frames of bees)
    Please do not include any new nucleus colonies or increases made during the spring of 2014, colonies purchased, or colonies made commercially viable by uniting. (Note: a frame of bees is defined as having 75% or more of its surface covered, on both sides, with a single layer of bees.)
    Full sized colonies _________
    Nucleus colonies _________
  2. On May 1, 2014, what did you calculate as your overall rate (%) of wintering loss for full-sized colonies? Include dead colonies and those too small to be commercially productive.
    (Please enter a number between 0 and 100) _______%
  3. In the previous year (2013), what did you calculate as your overall rate (%) of wintering loss for full-sized colonies? Include dead colonies and those too small to be commercially productive. (Please enter a number between 0 and 100) _________%
  4. In the winter of 2013/2014, to what do you attribute the major cause of the death of colonies in your operation? (Please indicate a percentage (%) between 0 and 100 for each factor.)
    ______ Don't know
    ______ Starvation
    ______ Poor queens
    ______ Acute pesticide damage
    ______ Chronic pesticide damage
    ______ Ineffective varroa control
    ______ Nosema
    ______ Weather (specify)_____________________
    ______ Weak colonies in the fall
    ______ Other (please specify) __________________________________
  5. Were there major differences in winter mortality between bee yards?
    Yes ____ No _____
  6. If yes, please describe: _______________________________________________________
  7. Additional comments? ______________________________________________________

If you have documented the level of winter loss for each beeyard please fill out the following section. Please photocopy this page and provide the full number of yards if required.

Beeyard Number of Colonies Managed for Winter 2013/14 Number of Colonies Survived in Spring 2014 Notes, observations
1
     
2
     
3
     
4
     
5
     
6
     
7
     
8
     
9
     
10
     


Core Questions Used By all Provinces (provided by CAPA)

  • How many colonies were put into winter in fall 2013?
    Full sized colonies _________
    Nucleus colonies _________

  • How many colonies survived the 2013/2014 winter considered commercially viable? (i.e. with 3-4 or more frames of bees)
    Full sized colonies _________
    Nucleus colonies _________

  • Which method of treatment did you use for varroa control in spring 2013? (Choose all that apply)
    ______ Apistan®
    ______ CheckMite+™
    ______ Apivar®
    ______ Thymovar
    ______ 65% formic acid - 40 ml multiple application
    ______ 65% formic acid - 250 ml single application
    ______ Mite Away Quick Strips®
    ______ Oxalic acid
    ______ Other (please specify) _________________________

  • Which method of treatment did you use for varroa control in summer 2013? (Choose all that apply)
    ______ Apistan®
    ______ CheckMite+™
    ______ Apivar®
    ______ Thymovar
    ______ 65% formic acid - 40 ml multiple application
    ______ 65% formic acid - 250 ml single application
    ______ Mite Away Quick Strips®
    ______ Oxalic acid
    ______ Other (please specify) _________________________

  • Which method of treatment did you use for varroa control in fall 2013? (Choose all that apply)
    ______ Apistan®
    ______ CheckMite+™
    ______ Apivar®
    ______ Thymovar
    ______ 65% formic acid - 40 ml multiple application
    ______ 65% formic acid - 250 ml single application
    ______ Mite Away Quick Strips®
    ______ Oxalic acid
    ______ Other (please specify) _________________________

  • Did you treat for Nosema in Spring 2013? Yes ________ No _______
  • Did you treat for Nosema in Fall 2013? Yes __________ No _______
  • In the winter of 2013/2014, please rank the top three suspected major cause of the death of colonies in your operation?
    ______ Don't know
    ______ Starvation
    ______ Poor queens
    ______ Acute pesticide damage
    ______ Chronic pesticide damage
    ______ Ineffective varroa control
    ______ Nosema
    ______ Cold winter
    ______ Cold spring
    ______ Weak colonies in the fall
    ______ Other (please specify) __________________________________

Ontario Provincial Winter Loss Survey 2013

Spring/Summer Management

  1. What is the County where the majority of your colonies are managed? ____________
  2. What percentage of colonies did you have to provide a new queen because of queen problems last year? (Do not include re-queening of old queens). Please enter a number between 0 and 100 __________ %.
  3. What is the origin of the majority of your queens?
    ______ Reared by the colony itself
    ______ Reared from one of your own selected queens
    ______ Canada (Ontario)
    ______ Canada (different province)
    ______ U.S.A (Hawaii)
    ______ U.S.A. (California)
    ______ Chile
    ______ New Zealand
    ______ Australia
    ______ Other (please specify)
  4. What percentage of your colonies were used for pollination in 2012?

    Please answer between 0 and 100 _______ %.

  5. Which method(s) of treatment did you use for varroa management in spring 2012?
    ______ Apistan®
    ______ CheckMite+™
    ______ Apivar®
    ______ Thymovar
    ______ 65% formic acid - 40 ml multiple application
    ______ 65% formic acid - 250 ml single application
    ______ Mite Away Quick Strips®
    ______ Oxalic acid
    ______ Other (please specify)
  6. Did you treat in summer for varroa?
    1. Mite Away Quick Strips®
    2. Other
  7. If so, what was the approximate date of treatment?

Fall Management

  1. Which method(s) of treatment did you use for varroa management in fall 2012?
    ______ Apistan®
    ______ CheckMite+™
    ______ Apivar®
    ______ Thymovar
    ______ 65% formic acid - 40 ml multiple application
    ______ 65% formic acid - 250 ml single application
    ______ Mite Away Quick Strips®
    ______ Oxalic acid
    ______ Other (please specify)
  2. In reference to the above question #11, what was the approximate date of treatment?
    Month______ Day______
  3. Did you treat for Nosema disease in the fall? Yes____ No ____

Winter Management

  1. What was the total number of viable full size colonies and nucleus put into winter in your operation in October 2012?

Full sized ____________
Nucleus _____________

Winter Survival

  1. On May 1, 2013:

How many colonies that survived the winter were considered commercially viable (i.e. with 4 or more frames of bees)?

Full sized colonies _________
Nucleus colonies___________

  1. In the winter of 2012/2013, what do you attribute the major cause of the death of colonies in your operation? Please indicate a percentage (%) for each factor.
    1. Don't know ______
    2. Starvation ______
    3. Poor queens ______
    4. Acute pesticide damage ______
    5. Chronic pesticide damage ______
    6. Ineffective varroa control ______
    7. Nosema ______
    8. Weather ______
    9. Weak colonies in the fall ______
    10. Other (please specify) ______
  2. Additional comments? ________________________________________

2013 Survey Question not included in 2014 Provincial Winter Loss Survey
  • What percentage of colonies did you have to provide a new queen because of queen problems last year? (Do not include re-queening of old queens). Please enter a number between 0 and 100 __________ %.
2014 Survey Question by CAPA not included in Ontario's 2014 Provincial Winter Loss Survey
  • Did you treat for Nosema in spring 2013? Yes________ No ________

For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca
Author: Paul Kozak, Provincial Apiarist/OMAFRA
Creation Date: 27 October 2014
Last Reviewed: 23 October 2015