Evaluation of mid-summer splits on varroa
mite reduction and colony productivity
Citizen Science Field Study 2015
Summary of previous project (2012-2014)
Beekeeping is continuing to gain popularity across the country, but since
2006 beekeepers have suffered a 20 - 33% annual bee colony loss. Colony decline
is not linked to one factor, but evidence shows that the varroa mite, Varroa
destructor, is one of the primary causes behind the decline.
The apiary community has explored a variety of pest management
practices to reduce varroa mite infestations including drone brood removal and
miticides, but few practices have yielded long term success as stand-alone
treatments. We conducted a study to test the efficacy that splitting a colony into
two (parent colony and daughter colony) will have on varroa mite reductions and
the long term survival of a colony. Our results showed that the timing of a split
during the season, early summer through fall, is critical to long term reductions in
varroa mites and increased colony survival. Early summer splitting allows
sufficient time for the mites to rebound and reduces the productivity in the
parent and daughter colonies during important nectar flows.
Because there are stronger relationships between bees, brood and varroa
mites during mid-late summer, we predict that mid-summer splits will have a
greater impact on the reduction of varroa mites and increase winter survival of
the colonies. Mid-summer splits will also allow colonies to reap the benefits of
early summer nectar flows, and increase the number of colonies going into
winter leading to the maintenance of sustainable colony numbers within an
apiary.
Objectives
1. The project aims to test the effects of mid-summer splits on varroa mite
populations and the population dynamics (bee population, brood area) and
productivity (pollen, nectar and honey quantities) of the hive.
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2. A second goal of the project is to conduct a citizen science field study
within the beekeeping community. We hope to promote the establishment of
citizen science among hobbyist and small scale beekeepers, particularly in the
mid-Atlantic.
3. A long term goal is to better understand the temporal relationship
between varroa mites and honey bees.
Overview
Data will be collected in multiple states throughout the mid-Atlantic from
small scale and hobbyist beekeepers. The project will begin this May 2015 and
last through October 2015. Colonies will be split into two groups: a control group
and a treatment group. Each beekeeper must have a minimum of one colony in
each group. If you only have one colony and would like to participate please
contact me. Control colonies are maintained through swarm preventative tactics
and treatment colonies will be split in late June. As June approaches, I will give a
specific date to split colonies and a colony split protocol to all participants.
Throughout the field season (May–October), a total of 6 monthly colony
assessments will be performed. Monthly assessments are an evaluation of the
strength and productivity of the colony and estimates of varroa mites. Colony
assessments include estimates of adult bee population, brood area, brood health,
varroa mite numbers (3-day mite monitoring sticky sheet), pollen, carbohydrates
(nectar and honey), queen cups tallied and the presence of all diseases or viruses.
Nectar and honey are combined into one group, carbohydrates. Colony
assessments are somewhat time-consuming; each colony assessment will take
about 30 minutes to an hour, depending on the size of the colony and the time of
the season. It will also require the regular checking of a colony to prevent
swarming, possibly 1-2 times per week during the current nectar flow. Monthly
colony assessments will begin mid-late May; however, swarm prevention and
varroa mite counts should begin as soon as possible. All chemicals are prohibited
during this field study.
The most important part of this project, based upon previous data, is the
timing of the split and monthly varroa mite counts. It is important to prevent all
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colonies from swarming until they are ready to split. The swarming season is
generally late May through early July and colonies have already beginning their
swarming preparations. A few colonies that I have recently assessed had up to 22
uncharged queen cups, so strong efforts will be required to prevent colonies from
swarming until it is time to split in late June. When a colony is preparing to
swarm the most common sign would include the presence of queen cups. Below
are common swarm preventative tactics. Swarming is related to space
availability; here are several techniques that can keep the incidence of swarming
low: 1). removing queen cups, charged and uncharged 2). providing ample room
for queen egg laying and expansion of the brood nest 3). providing ample room
for pollen, nectar and honey storage. During swarming season, the prevention of
swarming will require you to regularly check your colonies 1-2 times per week.
We are in the midst of an intense nectar flow so the first step will be to check
your colonies for swarm prevention.
I greatly appreciate all the time and energy that will be put forth by you
and your bees. All the data collected will be beneficial in developing more
sustainable management practices for beekeepers. We hope that it will reduce
the amount of time and costs beekeepers must spend on varroa mite control
treatments while overall increasing colony health and survivorship long term.
Thank you!
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