Comparison of a commercial Varroa mite honeybee treatment with treatment-free Varroa management techniques

Comparison of a commercial Varroa mite honeybee treatment with treatment-free Varroa management techniques

Summary

To date, the trial “Comparison of a commercial Varroa mite honey bee treatment with treatment-free Varroa management techniques” is off to a pretty good start. All apiaries have been successfully established and a fourth apiary with an additional study group (TFQueen) was added to the project.

While it is too early in the trial to reach any final conclusions, it is clear that survival has been severely impacted in the TF group by the added challenge of having to successfully raise a new mated, fertile queen to replace the queen that was removed to break up the brood cycle.

It is also clear that honey production has been severely impacted in both the TF and the TFQ groups due to the interruption of the brood cycle by removing bees and brood.

Varroa mite loads in late August/early September were significantly lower in both the TF (treatment free) and the TFQ (treatment free queen) groups as compared to the C (control) and QS (Mite-Away treatment) groups.

Objectives/Performance Targets

The following performance targets outlined in the project description are summarized below based upon all available data to date. (See attached data file For specifics).

SARE Project Data  

Mite Monitoring – Varroa mite loads were monitored in late June/early July after the hives for all treatment groups were established in their apiaries and again in September. Average mite loads were as follows:

Late June/early July Mite Counts

Control (C) Group: Initial mite levels in late-June/early July ranged from a low of 4 mites per 300 bees to a high of 53 mites per 300 bees. The average number of mites per 300 bees was 20 for group C.

Mite Away Quick Strip (QS) Group: Initial mite levels in late-June/early July ranged from a low of 1 mite per 300 bees to a high of 19 mites per 300 bees. The average number of mite per 300 bees was 8.5 for group QS.

Treatment-Free (TF) Group: Initial mite levels in late-June/early July ranged from a low of 1 mite per 300 bees to a high of 10 mites per 300 bees. The average number of mite per 300 bees was 4.7 for group TF.

Treatment-Free with Queen (TFQ) Group: Initial mite levels in late-June/early July ranged from a low of 1 mite per 300 bees to a high of 11 mites per 300 bees. The average number of mite per 300 bees was 3.7 for group TFQ.

Late August/early September Mite Counts

Group C: Mite levels in September ranged from a low of 15 mites per 300 bees to a high of 50 mites per 300 bees. The average number of mite per 300 bees was 28.8 for group C.

Group QS: Mite levels in September ranged from a low of 11 mites per 300 bees to a high of 45 mites per 300 bees. The average number of mites per 300 bees was 24.7 for group QS.

Group TF: Mite levels in late August/early September ranged from a low of 1 mite per 300 bees to a high of 29 mites per 300 bees. The average number of mite per 300 bees was 8.2 for group TF.

Group TFQ: Mite levels in late August/early September ranged from a low of 2 mites per 300 bees to a high of 25 mites per 300 bees. The average number of mite per 300 bees was 10.6 for group TFQ.

Late September Mite Count

A final mite count was taken from group QS in mid-September following treatment with MAQS. Mite counts ranged from a low of 3 mites per 300 bees to a high of 52 mites per 300 bees. The average number of mites per 300 bees following treatment was 13 mites for group QS.

Survival – Colony survival during the initial year (prior to their first winter) was as follows:

Control (C) Group: Of the 15 colonies initially established in May, 14 colonies (93.3%) were alive and healthy heading into the winter of 2016-2017.

Mite Away Quick Strip (QS) group: Of the 15 colonies initially established in May, 13 colonies (86.6%) were alive and healthy heading into the winter of 2016-2017.

Treatment-Free (TF) group: Of the 15 colonies initially established in May, 9 colonies (60%) were alive and healthy heading into the winter of 2016-2017.

Treatment-Free with Queen (TFQ) group: Of the 15 colonies initially established in May, 15 colonies (100%) were alive and healthy heading into the winter of 2016-2017.

Productivity – Honey supers harvested from all hives were recorded. (see attached data table) In establishing the figures below, it is assumed that a full shallow super harvested typically contains 20 pounds of honey.

C Group – an average of 1.5 supers of honey was harvested from each hive in this group representing approximately 30 pounds per hive.

QS Group – An average of 1.18 supers of honey was harvested from each hive in this group representing 23.5 pounds per hive.

TF Group – No honey was harvested from any of the hives in the TF group in the first year.

TFQ Group – An average of .1 supers of honey was harvested from each hive in the TFQ group representing 2 pounds of honey per hive.

Accomplishments/Milestones

As planned, 45 nucleus colonies were purchased, divided into three groups of 15 colonies each, and established in two apiary locations. One location (Bassett Knoll) is the home of 15 hives that are acting as the Control (C) group. The other location (Elgin Springs) is about 3/4 miles from Bassett Knoll and is the location of the 15 Treatment-Free (TF) hives in which the Queen, brood and bees are removed each spring to break up the brood cycle, as well as the 15 hives that are to receive Mite Away Quick Strip (QS) treatment for mites.

An addition was made to the original design of this project by creating a fourth apiary composed of the bees and queens removed from the treatment-free (TF) yard. This fourth apiary location is about 15 miles from the other yards and makes up the Treatment-Free with Queen (TFQ) Group. These bees will be treated the same as the treatment-free apiary (TF) except, rather than removing bees, brood and the queen as is being done with the TF group at Elgin Springs, the queen will stay with the colony when bees and brood are removed to interrupt brood rearing.

Impacts and Contributions/Outcomes

While it is too early in the trial to reach any final conclusions, it is clear that following the first nine months of this trial: survival was severely impacted in the TF group with the added challenge of having to successfully raise a new mated, fertile queen to replace the queen that was removed to break up the brood cycle.

It is also clear that honey production was severely impacted in both the TF and the TFQ groups due to the interruption of the brood cycle by removing bees and brood.

Varroa mite loads in late August/early September were significantly lower in both the TF and the TFQ groups as compared to the C and QS groups.

Collaborators: