> So here's a question: I'm wondering why there is dysentery with N apis, but not N ceranae?
My understanding is that the association between Nosema apis and dysentery was correlative, not direct. In other words, colonies typically show signs of dysentery in the winter, due to hive confinement and these same bees generally had high levels of nosema. No causal connection, although perhaps the period of confinement leads to buildup of nosema in the bee. I still wince when I hear people say they don't have nosema because they don't see signs of dysentery, or the reverse (they see it, so they must have it).
* * *
"Dysentery" is a beekeeper's term for the voiding of visibly large quantities
of faeces by bees not in fl ight; such defaecation occurs when the
weight of the rectal contents exceeds about 40 per cent of the total body
weight. Excess water in food or prolonged confinement is a common
cause.
HONEY BEE PATHOLOGY
By L. BAILEY
* * *
Colony level symptoms of dysentery may be aggravated by
infections of N. apis (Bailey, 1981) but this agent is not the primary
cause of this condition (Bailey, 1967). Nevertheless, dysentery certainly
aids the fecal–oral route of parasite transmission.
Nosema ceranae in European honey bees (Apis mellifera)
Ingemar Fries
* * *
Although honey bee colonies with reduced longevity, decreased
population size, higher autumn/winter colony loss, and/
or reduced honey production are often reported to be associated
with the presence of N. ceranae, the disease signs such as dysentery
or crawling behavior or milky white coloration of gut, that are
usually associated with N. apis infection, has never been described
in N. ceranae-infected bees (Fries et al. 2006).
It is not clear why N. ceranae has different pathological
effects on the host A. mellifera compared with N. apis.
Morphological, Molecular, and Phylogenetic Characterization of Nosema ceranae,
a Microsporidian Parasite Isolated from the European Honey Bee, Apis mellifera
YANPING P. CHEN, et al
* * *
Dysentery, a condition rather than a disease, is caused by an excessive amount of water in a bee’s body. Afflicted bees cannot hold waste products in their bodies. Unable to wait until cleansing flights, these bees void their feces on the combs, at the hive entrance, on the exterior of the hive, and on the snow near the hive in late winter. Two leading causes of dysentery are prolonged confinement during winter and early spring and consumption of food with high water content. Nosema disease and damp hives may also contribute to the problem.
Beekeeping Basics MAAREC
* * *
the gross
symptoms of most adult bee
diseases are not unique. The
inability to fly, unhooked
wings, and dysentery, for
instance, are general symptoms
associated with many
disorders. Symptoms of a
contagious disease are
sometimes mimicked because
of unrelated factors.
Diagnosis of Honey Bee Diseases
United States Department of Agriculture
* * *
Nosema disease (nosemosis) is a disease of adult Apis mellifera caused by the parasitic
protozoan Nosema apis. Spores of N. apis are ingested by an adult bee and germinate in the
ventriculus within 10 minutes (Bailey, 1955a).
Spore levels of infected bees can range from 30 to 200 million spores per bee (Bailey and
Ball, 1991). Heavy infection can cause inflammation of the digestive tract, dysentery,
reduced nutrient uptake, increased physiological ageing and reduced longevity, reduced
ability to secrete larval food, and metabolic disorders in the queen (Fries, 1997).
IMPORT RISK ANALYSIS: HONEY BEE (Apis mellifera) GENETIC MATERIAL
Biosecurity Authority Ministry of Agriculture and Forestry
Wellington New Zealand
* * *
Chronic paralysis is an infectious and contagious disease of
adult honeybees caused by the chronic bee paralysis virus
Affected bees become flightless, often crawling on
the ground and on the stems of grass, sometimes in masses of
thousands of individuals. The bloated abdomen is caused by
distension of the honey sac with fluid, leading to the so-called
“dysentery” symptom. Sick individuals die within a few days of
the onset of symptoms (4, 5, 16). Many paralyzed bees from
each colony die throughout the year, often in thousands during
the summer (7).
Spread of Infectious Chronic Bee Paralysis Virus by Honeybee (Apis mellifera L.) Feces
M. Ribiere, et al
* * *
Hydroxymethyl furfural or HMF is a
naturally occurring compound in honey.
The levels are considerably lower in lighter
coloured honey than darker honey. HMF
has been demonstrated to be toxic to
honey bees and in one case a sample of
eight year old honey fed to bees gave them
dysentery similar to effects of poisonous
sugars. The HMF levels in extracted
honey rise over time, particularly when
exposed to heat. This is another good
reason for not feeding honey to bees
FAT BEES SKINNY BEES
By Doug Somerville
* * *
Colony symptoms are therefore often the first indication of nosema disease in an
apiary. In colonies with high levels of infection bees may walk on the floor of the hive and
on the ground next to the colony with distended abdomens and disjointed wings.
According to Moeller (1978) crawling bees are only characteristic of the disease during the
first few days of a heavy honeyflow.
Dysentery has for many years been
given as a sure symptom of infection, but Moeller (1978) found colonies with high levels of
infection without dysentery.
Because the effects of this disease are not obvious Kauffeld et al. (1972) suggested that
colony dwindling, queenlessness, supersedure and reduced honey yields should be
measured to estimate the true damage nosema infection had on a beekeeping operation.
THE OCCURRENCE OF Nosema apis (ZANDER), Acarapis woodi (RENNIE), AND THE CAPE PROBLEM BEE IN THE SUMMER RAINFALL REGION OF SOUTH AFRICA
DAWID JOHANNES SWART October 2003
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