Impact of Supplemental Feed Type on Winter Survival of Honey Bee Colonies

Project Overview

FS11-252
Project Type: Farmer/Rancher
Funds awarded in 2011: $9,957.00
Projected End Date: 12/31/2012
Region: Southern
State: North Carolina
Principal Investigator:
Barry Harris, Jr.
Silver Spoon Apiaries, Inc

Annual Reports

Commodities

  • Agronomic: corn
  • Animals: bees

Practices

  • Animal Production: feed/forage, feed additives, feed formulation, feed rations, livestock breeding, preventive practices, winter forage
  • Pest Management: prevention
  • Production Systems: holistic management

    Summary:

    Bees fed High Fructose Corn Syrup (HFCS) in preparation for winter did not have higher winter mortality or higher incidence of Nosema ceranae. There was no difference in winter outcomes or incidence of Nosema ceranae based on the composition of winter feed stores. However, a predicate experiment conducted by myself and Dr. Tarpy showed that the buildup of package bees could be significantly accelerated by making HFCS Type 55 the primary sugar source rather than feeding only liquid sucrose. There are significant advantages to feeding bees a 40/60 blend of liquid sucrose/HFCS Type 55 rather than only liquid sucrose or only HFCS Type 55 including avoidance of feed fermentation, avoidance of feed crystallization, and faster colony buildup over a broad spectrum of environmental conditions. Obtaining blended feed in appropriate amounts is a particular problem for emerging commercial beekeepers in the 300 to 600 colony size range as they typically lack the resources to obtain and store the feed. Obtaining good winter outcomes is most likely the result of the cummulative effect of multiple colony management best practices such as keeping diseases and pests under control, maintaining young queens in the colonies, timely provision of adequate supplemental carbohydrates, proteins, and amino acids, optimizing hive configuration, and consistently employing good hive manipulation practices.

    Introduction

    Beekeepers are experiencing increasing winter losses of colonies due to the increased presence and variety of honey bee diseases and pests. Consequently, commercial beekeepers are looking for methods to help reduce winter losses and to more efficiently replace winter losses so that replacement colonies are at production strength in time for pollination work and honey production. This is of particular concern in the Southern, USA where there is a very short time between the availability of package bees and queens and the pollination and production seasons. The principal method of colony replacement for most commercial beekeepers is package bees. Rapid buildup of replacement colonies requires substantial supplemental feeding of liquid bee feed. Some within the beekeeping community have asserted that High Fructose Corn Syrup (HFCS) is a major factor in losses of honey bee colonies. However, HFCS, either by itself or as a primary component of a blended feed is the only viable feed for commercial beekeepers. At the end of the day, it is the commercial beekeepers that get the crops pollinated and produce virtually all of the U.S honey. It is therefore of fundamental importance as to how different types of liquid bee feed effect winter survival and the buildup of package bees. In this SARE funded experiment we studied the effect of liquid bee feed type on winter survival, generally, and the incidence of Nosema ceranae, specifically, Immediately prior to this experiment we conducted a large scale experiment on the effect of liquid bee feed on spring package bee buildup. The results of the SARE experiment are reported herein. Where appropriate, we have included references to the predicate experiment to provide context for the SARE funded experiment. We are in the process of finishing a manuscript covering both experiments which will be submitted to “The Science of Bee Culture” for peer review and publication.

    Project objectives:

    We designed this SARE experiment prior to designing our predicate bee feed experiment on the effect of liquid bee feed on the buildup of package bees. Initially, we had three objectives in the SARE experiment:

    1. Determine if the feeding of HFCS led to higher winter losses or incidence of Nosema ceranae.
      If the answer to the first question was yes determine if this negative effect could be countered by the inclusion of a moderate amount of liquid sucrose in the feed.
      If the inclusion of liquid sucrose was beneficial determine if it is practical for emerging commercial beekeepers to employ this strategy.

    Although our predicate experiment was designed after the SARE funded experiment it was performed first. Our perspective on our initial SARE experiment objectives was changed by our experience in the predicate experiment, itself, and by interaction with people in the bee feed industry sweeteners industry during the course of the experiment. Given the appropriate ambient temperature and length of day, bees are stimulated to raise brood, draw comb, and forage when they receive binomial carbohyrdates such as the sucrose in nectar or liquid sucrose. The bees must invert these complex disaccharide sugars into monomial or monosaccharide sugars such as fructose and dextrose. While the bees are stimulated by this process it is not energy efficient as they consume much of the feed in the inversion process itself. Our predicate experiment results led us to believe that bees have a stimulation threshold for binomial sugars and that once sufficient binomial sugars are available maximum colony buildup can be obtained by providing monomial sugars that the bees can use immediately without inversion such as the fructose and dextrose contained in HFCS. The energy saved by avoiding the inversion process can be utilized by the colony to raise brood, draw comb, and otherwise expand the colony and its nest. We also learned from interaction with the bee feed and sweeteners industries that liquid sucrose is extraordinarily prone to fermentation and cannot be stored for significant lengths of time. This is because, even at the maximum possible liquid sucrose solids content of 67.5%, the solids content is not high to establish a pH that is inhospitable to microbial growth. The threshold for this pH is 71% solids. HFCS Type 55 has a solids content of 77% and is therefore not in danger of fermentation. However, 41% of its solids are in the form of dextrose. Liquid feeds with dextrose contents greater than 25% are likely to crystallize at temperatures below 60 degrees Fahrenheit so crystallization is a risk with HFCS. By the time we actually began the SARE experiment we had come to the conclusion that a 40/60 blend of liquid sucrose/HFCS Type 55 would be optimal from the standpoint of storage and would increase the likelihood of rapid colony buildup over a broad spectrum of environmental conditions when compared to liquid sucrose or HFCS Type 55 alone. This caused us to see our SARE experiment objectives as even more potentially relevant than first thought.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.