POLLINATORS POLLINATION AND FOOD PRODUCTION

THE ASSESSMENT REPORT ON POLLINATORS, POLLINATION AND FOOD PRODUCTION
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6. RESPONSES TO RISKS AND OPPORTUNITIES ASSOCIATED
WITH POLLINATORS AND POLLINATION
• reducing robbing and absconding in honey bees and
social stingless bees (e.g., through use of unique colony
markings, entry orientation, height above ground, etc.)
• migration / movement: at least one managed species
(Apis cerana) has natural seasonal migrations in parts
of its range (Koetz 2013), and other managed species,
especially but not exclusively A. mellifera, are moved
extensive distances especially in the USA (Daberkow et
al. 2009). At a smaller scale, populations of Megachile
rotundata are moved between alfalfa fields. Once a
field has been pollinated, populations can be moved in
large trailers to a newly blooming field (Osgood 1974).
We continue to know very little about ways to manage
migration and movement that minimize stress to bees
• Africanized honey bees: a specific topic related to these
practices is the development of strategies for managing
Africanized honey bees, especially in the tropical and
subtropical Americas, in order to increase human safety
concerns related to management as well as colony
productivity (Winston 1992)
• stocking density of managed bees in crop fields and
forage areas. Maintaining appropriate stocking densities
can potentially increase crop yields and reduce costs
to farmers and/or pollinator managers (e.g., Eaton
and Nams 2012), and preventing overstocking could
potentially reduce competitive interactions with wild
pollinators (e.g., Thomson 2004), the risk of pathogen
spillover from managed to wild pollinators (Otterstater
and Thomson 2008), and speculatively the risk of
pathogen transmission in managed pollinators
6.4.4.1.1.2 Manage pathogen and parasite threats
This is a very large category, with intensive work for
both honey bees and bumble bees, along with a
growing body of work on other managed pollinators
(see Chapter 2 for an overview of disease threats).
We focus on five major categories of responses
related to disease: detection/diagnosis (6.4.4.1.1.2.1);
prevention (6.4.4.1.1.2.2); treatment (6.4.4.1.1.2.3);
supporting social immunity mechanisms in eusocial taxa
(6.4.4.1.1.2.4); and management of pathogen and parasite
evolution (6.4.4.1.1.2.5).
6.4.4.1.1.2.1 Detect / diagnose disease problems
Rapid, precise detection and diagnosis of parasite and
pathogen threats are critical for understanding, treating,
and controlling these threats in managed bees. For many
parasites and pathogens with macroscopic visual cues,
detection is well established based on apiary inspection,
including macroscopic mites (Sammataro et al., 2000) and
some fungal pathogens such as chalkbrood (Aronstein and
Murray, 2010). For other pathogens, either microscopic
analysis is needed, such as in tracheal mites (Sammataro
et al., 2000; Otterstater and Whitten, 2004), or molecular
methods are needed, such as in the microsporidian fungal
parasite Nosema (Fries, 2010) and many viruses (de
Miranda et al., 2010). There is considerable opportunity and
a research gap for improving detection and diagnosis of
managed bee pathogen and parasite threats. In particular,
improvements could be made in terms of speed, reliability,
and accessibility of diagnostic tests, as well as reduction of
costs. Rapid developments in molecular genetic technology
offer considerable promise on this front.
Another opportunity is to integrate detection of disease
in a legal framework with registration and inspection of
managed bees, as exists in some countries, including the
UK (The Bee Diseases and Pests Control [England] Order
2006, SI 2006/342). Such a framework has the potential
to contribute to prevention of widespread pathogen and
parasite outbreaks.
6.4.4.1.1.2.2 Prevent infections
This is a broad category, which includes: 1) management of
pollinator movement; 2) general management practices; and
3) rearing facility practices. As mentioned in the previous
section, detection of parasite / pathogen threats in a legal
inspection framework has considerable prevention potential.
We discuss country- and continental-scale preventative
measures (i.e., preventing introductions of parasites and
pathogens) in the “legal responses” section 6.4.4.2.
Managing pollinator movement is a key method of
disease prevention. Spatial scale is a critically important
consideration. At very large, within-continent scales, many
pollinators are moved considerable distances for crop
pollination, especially (but not limited to) honey bees in the
US (Pettis et al., 2014), and alfalfa leafcutter bees from
Canada to the US (Bosch and Kemp, 2005; Pitts-Singer
and Cane, 2011). These operations have potential to spread
diseases long distances, but limiting their movement could
reduce the provision of pollination to agriculture, and also
reduce beekeeper profitability.
At a smaller spatial scale, we can consider movement of
Apis mellifera colonies among multiple apiaries managed
by the same beekeeper at a landscape or regional scale,
as well as movement of brood or honey frames between
colonies. Movement of bees or frames again has the
potential to transmit disease, but stopping such practices
altogether is unlikely to be practical for most beekeepers.
General management of pollinators can also contribute
strongly to disease prevention. For example, chalkbrood
is a fungal disease that is highly prevalent in managed
populations of the alfalfa leafcutting bee, Megachile