Honey Bee Medicine for the Veterinary Practitioner

Terry Ryan Kane, Cynthia M. Faux, Terry Ryan Kane, Cynthia M. Faux

• Publisher: Wiley-Blackwell
• Year: 2021
• Print ISBN: 9781119583370
• eBook ISBN: 9781119583424
• Edition: 1
• Topic: Medicine
• Subtopic: Veterinary Medicine

An essential guide to the health care of honey bees

Honey Bee Medicine for the Veterinary Practitioner offers an authoritative guide to honey bee health and hive management. Designed for veterinarians and other professionals, the book presents information useful for answering commonly asked questions and for facilitating hive examinations.

The book covers a wide range of topics including basic husbandry, equipment and safety, anatomy, genetics, the diagnosis and management of disease. It also includes up to date information on Varroa and other bee pests, introduces honey bee pharmacology and toxicology, and addresses native bee ecology. This new resource:

• Offers a guide to veterinary care of honey bees
• Provides information on basic husbandry, examination techniques, nutrition, and more
• Discusses how to successfully handle questions and 'hive calls'
• Includes helpful photographs, line drawings, tables, and graphs

Written for veterinary practitioners, veterinary students, veterinary technicians, scientists, and apiarists, Honey Bee Medicine for the Veterinary Practitioner is a comprehensive and practical book on honey bee health.

Section III
Honey Bee Diseases, Disorders, and Special Topics

18
Parasite Transmission Between Hives and Spillover to Non‐Apis Pollinators

Scott McArt

Department of Entomology, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, USA

Introduction

Unsustainable honey bee colony losses have been documented over the past several years in the US, Europe, and other parts of the world. While many factors are contributing to losses, a key challenge is parasites (vanEngelsdorp et al. 2009; Evans and Spivak 2010; Pettis et al. 2015). The varroa mite (Varroa destructor), Deformed Wing Virus (DWV), European Foulbrood (Melissococcus plutonius), American Foulbrood (Paenibacillus larvae), and chalkbrood (Ascosphaera apis) are major threats to honey bees and beekeepers, to name just a few.

When a colony of honey bees gets sick, can bees from the infected colony transmit parasites to other colonies within an apiary? What about transmission to nearby apiaries? Are all apiaries at risk, or is there a maximum distance at which transmission can occur? What about risk to wildlife? Can parasite spillover occur between managed colonies of Apis mellifera to wild, non‐Apis bees or other insects? Such spillover between domestic animals and wildlife occurs in other systems, with classic examples such as the transmission of brucellosis (caused by Brucella bacteria) between cattle and wild elk (Kauffman et al. 2016; Rayl et al. 2019), and rinderpest (caused by Rinderpest morbillivirus) transmission, which devastated domestic cattle, wildebeest, and other ungulate wildlife in Africa (Kock et al. 1999). Does similar cross‐species risk of transmission occur for parasites of honey bees and wild pollinators?

The past several years have seen a dramatic increase in research addressing how parasites of honey bees are transmitted. This is an important development, since knowledge of transmission is critical for any attempts to predict, and ultimately control, the spread of disease. While important parasites such as varroa or American Foulbrood may seem like impossible problems for beekeepers to surmount, remember that world‐wide eradication of rinderpest occurred in 2011 (OIE 2011). Notably, the eradication of rinderpest occurred because of participatory epidemiological methods that allowed veterinarians to interact closely with cattle herders and more effectively implement control measures (Mariner et al. 2012). Indeed, a major goal of this book is to provide information that will hopefully facilitate similar interactions between veterinarians and beekeepers.

Parasite Transmission Within an Apiary

Before they were domesticated, honey bee colonies occurred naturally at a relatively low density in the landscape. Today, feral colonies of honey bees are still found at this low density, primarily in tree cavities. For example, colonies inhabiting trees in forests around the city of Nizhny Novgorod, Russia were found to be present at a density of 1–2 colonies per km² (Galton 1971). Similarly, Tom Seeley has conducted numerous surveys of feral honey bee colonies in trees surrounding Ithaca, NY, USA, finding they exist at a density of about 1 colony per km² (Seeley 2007; Seeley et al. 2015).

In contrast, modern beekeeping practices often encourage colonies to be placed 1 m apart or less (Crane 1990). Commercial beekeepers typically stack multiple colonies side‐by‐side on a single pallet so they can be moved efficiently from location to location (e.g. orchards for crop pollination, followed by fields for honey production). This crowding of multiple colonies at a given location greatly improves the ease of beekeeping, of course. In fact, there are common beekeeping terms used to describe a location with multiple colonies: an apiary or a bee yard. However, crowding of colonies in an apiary comes with some costs.

There are two main reasons why crowding colonies in an apiary can increase risk of disease transmission. First, foraging bees from neighboring colonies can have difficulty distinguishing between their own colony and a neighboring colony, resulting in “drifting” between hives (Free 1958). While intuitively this may seem like a rare occurrence for anyone who's watched highly intelligent honey bee foragers leaving and entering a hive, it is not. In fact, when colonies of the same color are placed next to each other and face the same direction, it is common for 40% of the forager bees to be from a neighboring colony (Jay 1965, 1966a,b). Drifting by foragers can be greatly reduced by increasing the spacing between colonies, painting them different colors, and having them face different directions (Jay 1965, 1966b). However, some drifting between colonies that share a typical apiary will occur regardless of spacing between colonies.

Second, colonies within an apiary are at increased risk of having their honey stolen by foragers from other colonies when food is scarce (Free 1954; Downs and Ratnieks 2000). This phenomenon is called “robbing” and it is most common for weak hives to be robbed by foragers from strong hives (Figure 18.1). Because a leading reason why colonies become weak is due to disease, colonies that have high parasite levels are often at increased risk of being robbed (Sakofski et al. 1990; Greatti et al. 1992; Frey et al. 2011; Peck and Seeley 2019).

Both drifting and robbing increase contact rates between bees from different colonies in an apiary, which has the potential to increase parasite transmission. Indeed, one rec...

Table of contents

• Cover
• Table of Contents
• Title Page
• Copyright Page
• Dedication Page
• List of Contributors
• Acknowledgments
• Honey Bee Medicine: A One Health Challenge
• Section I: Biology and Medical Foundations
• Section II: Beekeeping Principles for Veterinarians
• Section III: Honey Bee Diseases, Disorders, and Special Topics
• Honey Bee Medicine
• Notes on Editors and Contributors
• Index
• End User License Agreement