both the number of bees and species diversity declined with increased distance from
a forest edge. The bee taxa included those that nested in particular wilderness
habitats. The data indicates that nearby natural and seminatural habitats such as
forest edges may serve as “reservoirs” of pollinators and would directly benefit
agriculture by providing shelter and mating sites appropriate for specific bee
species [67].
To further the implication that uncultivated plants play a critical role in both bee
health and crop success, several other past studies have shown that pollination
services increase in crops near forest patches or other seminatural areas rather than
in uniform crops surrounded by yet other crops [68].
It thus stands to reason that as pollinator activity increases with the presence of
diverse wild habitat near croplands, loss of such habitat will reduce pollination
potential at the same time. Moreover, if managed honey bees are imported to
mitigate wild pollinator loss, the increased operating costs will be passed on to
consumers as well.
4.2.6 Parasites
A number of pests and parasites target honey bee colonies and pose significant risks
to individual bees as well as overall colony health due to the bees’ close proximity to
each other in the hive. Not all pests are associated with CCD, though their presence
could precipitate additional issues such as infection that may lead to CCD
symptoms.
Honey bee pests and parasites include Varroa and tracheal mites, Nosema fungal
microsporidian infestation, small hive beetle, and wax moths; risks vary by region
and climate.
The Varroa destructor mite is the most dangerous to honey bees and is associated
with CCD; it is a parasitic mite about 1–2 mm long. It was first identified in the
1960s in Japan and the former USSR. It made its way across the world and was
introduced (identified) in many European countries in the decades following,
reaching the United States in 1987, with the latest identification in Hawaii in
2007 [69].
Parasitic mite infection begins when the female mite enters a honey bee brood
cell. As soon as the cell is capped (sealed with food), the Varroa mite lays eggs on
the bee larva, which typically hatch into several females and one male; they hatch at
about the same time as the young bee develops, and the mites thus leave the cell with
the host bee. Infestation occurs when the young developed bee emerges from the
capped cell, allowing the Varroa mites to spread to other bees and larvae. The mite
preferentially infests drone cells. The adults suck the “blood” (hemolymph) of adult
honey bees, leaving wounds and weakening the adult bees such that their immune
systems become compromised. These weakened, mite-infested bees become prone
to a variety of viral, bacterial, and fungal infections [70].
The primary lethality of Varroa mite infestation occurs during the overwintering
period, particularly in longer winters where honey bees are under environmental
1 Understanding, Conservation, and Protection of Precious Natural Resources: Bees
25
a forest edge. The bee taxa included those that nested in particular wilderness
habitats. The data indicates that nearby natural and seminatural habitats such as
forest edges may serve as “reservoirs” of pollinators and would directly benefit
agriculture by providing shelter and mating sites appropriate for specific bee
species [67].
To further the implication that uncultivated plants play a critical role in both bee
health and crop success, several other past studies have shown that pollination
services increase in crops near forest patches or other seminatural areas rather than
in uniform crops surrounded by yet other crops [68].
It thus stands to reason that as pollinator activity increases with the presence of
diverse wild habitat near croplands, loss of such habitat will reduce pollination
potential at the same time. Moreover, if managed honey bees are imported to
mitigate wild pollinator loss, the increased operating costs will be passed on to
consumers as well.
4.2.6 Parasites
A number of pests and parasites target honey bee colonies and pose significant risks
to individual bees as well as overall colony health due to the bees’ close proximity to
each other in the hive. Not all pests are associated with CCD, though their presence
could precipitate additional issues such as infection that may lead to CCD
symptoms.
Honey bee pests and parasites include Varroa and tracheal mites, Nosema fungal
microsporidian infestation, small hive beetle, and wax moths; risks vary by region
and climate.
The Varroa destructor mite is the most dangerous to honey bees and is associated
with CCD; it is a parasitic mite about 1–2 mm long. It was first identified in the
1960s in Japan and the former USSR. It made its way across the world and was
introduced (identified) in many European countries in the decades following,
reaching the United States in 1987, with the latest identification in Hawaii in
2007 [69].
Parasitic mite infection begins when the female mite enters a honey bee brood
cell. As soon as the cell is capped (sealed with food), the Varroa mite lays eggs on
the bee larva, which typically hatch into several females and one male; they hatch at
about the same time as the young bee develops, and the mites thus leave the cell with
the host bee. Infestation occurs when the young developed bee emerges from the
capped cell, allowing the Varroa mites to spread to other bees and larvae. The mite
preferentially infests drone cells. The adults suck the “blood” (hemolymph) of adult
honey bees, leaving wounds and weakening the adult bees such that their immune
systems become compromised. These weakened, mite-infested bees become prone
to a variety of viral, bacterial, and fungal infections [70].
The primary lethality of Varroa mite infestation occurs during the overwintering
period, particularly in longer winters where honey bees are under environmental
1 Understanding, Conservation, and Protection of Precious Natural Resources: Bees
25