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Saturday, July 07, 2007

The following report references Fall Dwindle Disease.

This name has been
changed to Colony Collapse Disorder

What’s in a name?

Symptom’s similar to those described for this disorder have been described
in the past, and the condition has received many different names. These
include autumn collapse, May disease, spring dwindle, disappearing disease,
and fall dwindle disease. The CCD working group felt none of these names
were appropriate for the current condition.

The reasons are as follows:

1) References to the season are inappropriate as there is increasing
evidence that the condition manifests itself throughout the year

2) Dwindle implies a gradual decline of colony population. While the
actual rate of adult bee loss in populations have not been recorded, it
is clear that otherwise strong colonies can quickly lose their entire
workforce in a matter of weeks.

3) Disappearing has been used to refer to a host of other conditions that
do not necessarily share the same symptoms as those presently being
described.

4) The term “disease” is commonly associated with a pathogenic agent.
While the definition of disease does have a broader meaning (i.e.
coronary disease), until (or if) such an agent is found the use of the
word disease would be misleading. Should a biological or other
agent(s) be found the name of this condition will likely be
reconsidered.

Symptoms of CCD

1) In collapsed colonies

a. The complete absence of adult bees in colonies, with no or little build up
of dead bees in the colonies or in front of those colonies.

b. The presence of capped brood in colonies.

c. The presence of food stores, both honey and bee bread

i. which is not immediately robbed by other bees

ii. when attacked by hive pests such as wax moth and small hive
beetle, the attack is noticeably delayed.

2) In cases where the colony appear to be actively collapsing

a. An insufficient workforce to maintain the brood that is present
b. The workforce seems to be made up of young adult bees
c. The queen is present
d. The cluster is reluctant to consume provided feed, such as sugar syrup and
protein supplement

CCD
Working group
Bee Alert, Inc
Jerry Bromenshenk,
Colin Henderson,
Robert Seccomb,
Larry Tarver,
Scott Debnam
Florida Department of
Agriculture
Jerry Hayes
The Pennsylvania State
University
Diana Cox-Foster,
Maryann Frazier,
David Geiser,
Nancy Ostiguy
Pennsylvania Department
of Agriculture
Dennis vanEngelsdorp
The USDA/ARS
Jeff Pettis
Fall Dwindle Disease: A preliminary report
December 15, 2006
“Fall-Dwindle Disease”:
Investigations into the causes
of sudden and alarming colony
losses experienced by
beekeepers in the fall of 2006.
Preliminary Report:
First Revision
Dennis vanEngelsdorp12,
Diana Cox Foster2,
Maryann Frazier2 ,
Nancy Ostiguy2,
Jerry Hayes3
December 15, 2006
Revised January 5th, 2006
During the months of October, November, and
December 2006, an alarming number of honey bee
colonies began to die along the East Coast of the United States. West Coast beekeepers are also
beginning to report unprecedented losses. This phenomenon, without a recognizable underlying
cause, has been tentatively been termed “Fall Dwindle Disease”, and threatens the pollination
industry and production of commercial honey in the United States. This has become a highly
significant yet poorly understood problem for beekeepers. States, like Pennsylvania, can ill
afford these heavy losses; the number of managed colonies is less than one half of what it was 25
years ago. Many beekeepers are openly wondering if the industry can survive. There are serious
concerns that losses are so great that there will not be enough bees to rebuild colony numbers in
order service pollination needs and to maintain economic viability in these beekeeping
operations.
This preliminary report consolidates our findings and current thoughts on the symptoms and
causes of “Fall Dwindle Disease”. While our investigations continue, the epidemic nature of this
disease demands that we share information as it becomes available. It is hoped that, despite its
incomplete nature, this report will help to formulate plans of action on how to best tackle this new
challenge to the industry. The apicultural industry has proven resilient in the face of past
challenges; it is our firm belief that it will do so again.
1 Pennsylvania Department of Agriculture
2 The Pennsylvania State University
3 Florida Department of Agriculture
Fall Dwindle Disease: A preliminary report
December 15, 2006
Survey of Beekeepers Reporting Large Losses Typical of “Fall Dwindle Disease”
A Case History Report
Seven beekeepers (as of 12/15/06) reporting heavy loses in their operations were
interviewed by phone. These interviews detailed management practices employed by the
beekeepers over the last year. Interviews lasted 45 minutes to 2.5 hours, and were often
followed up with a second phone call to clarify certain points. To encourage full
disclosure, all beekeepers interviewed were assured that the particulars of each interview
would be kept confidential, and the reports resulting from the survey would not disclose
their identity. Beekeepers interviewed represented operations based in four States
(Florida, Georgia, North Carolina, and Pennsylvania). The colonies managed by these
operators were located in these states and moved to and from an additional six States
(California, Delaware, Maryland, New York, Maine, North Dakota). The size of the
operations varied from 200 to over 3000 colonies. All beekeepers were experienced and
knowledgeable. At the time of the interview, beekeepers reported losses of 30 to 90 %.
One beekeeper, having 1200 colonies, expects 9 to survive the winter.
General description of condition:
Beekeepers report the sudden loss of a colony’s population of adult bees. In all cases
few, if any, adult bees were found in or near the dead colonies. Capped brood was often
found in these colonies. Dead out colonies often contained food reserves that had not
been robbed out, despite the presence of living colonies in an area. Most dead out
colonies showed no, or minimal, evidence of wax moth or small hive beetle damage. In
colonies that still have bees, small clusters were reported with evidence of a laying queen.
The surviving workers tended to look young in age.
Practices and conditions common to interviewed beekeepers.
1. All were migratory beekeepers. All had moved their colonies at least 2 times in
the 2006 season, with some colonies being moved as many as five times over the
2006 season.
• Implications:
i. Moving colonies is stressful on bees;
1. Possible reasons: confinement, temperature fluctuations,
and possible reduction (or cessation) of egg laying
ii. Moving colonies is thought to amplify adult bee disease agent
loads,
1. Possible reasons: increase rate of defecation in the colony,
forced mingling of young and older (possibly infected and
would otherwise be foraging) adult bees increase chance of
disease transmission
iii. A remote possibility is the bee colonies are more apt to be exposed
to new diseases or pathogens.
Fall Dwindle Disease: A preliminary report
December 15, 2006
2. All experienced a cumulative dead-out rate of at least 30% over the course of the
season. It is common that 10% of colonies die after transportation; some
beekeepers claim losses of 30% are not uncommon after pollination of crops such
as blueberries.
• Implications
i. Beekeepers are constantly “splitting” colonies to make up for
losses (see below)
ii. The equipment from the dead-out colonies is continually being
recycled back into the operation in creation of new splits. Existing
food reserves in the dead-outs and comb is provided to the new
colonies; potentially any disease agent or chemical contaminant
would be carried over to the new colony.
3. Upon finding a dead-out colony, all interviewed beekeepers placed the dead-out
equipment on strong neighboring colonies to facilitate comb care and splitting.
When the queen from the strong colony began to lay in the dead out equipment,
the dead-out equipment and brood were removed (split) from the surviving
colony. Some beekeepers then introduced a mated queen or queen cell into the
queenless unit while others allowed the unit to rear a new queen naturally.
• Implications
i. Continual reuse of dead out brood comb
1. Reuse is a known way to transfer disease agents and
possibly other chemical contaminants (e.g. Miticide
buildup in colonies)
2. Reuse can potentially amplify the presence of disease
agents on comb
ii. Large-scale spitting of colonies is stressful on bees and can
amplify disease agent populations
1. The age profile of the worker population is altered by
splitting
a. Older bees are forced to act as nurse bees; these
bees are not as efficient in brood provisioning and
may be more likely to be infested with diseases
affecting adult bees
4. All producers experienced some form of extraordinary “Stress” at least 2 months
prior to the first incidence of “die off” associated with “Fall dwindle disease”.
The nature of this stress was variable but included nutritional stress (apiary overcrowding,
pollination of crops with little nutritional value), dramatic pollen and
nectar dearth, or varroa mite pressure. Due to drought in some areas, the bees
may have had limited water resources or contaminated water supplies.
• Implications
i. Stress compromises the immune system of bees, making them
more susceptible to infection by opportunistic microbes.
Fall Dwindle Disease: A preliminary report
December 15, 2006
Practices and conditions not common to interviewed beekeepers.
1. Feeding: The practice of feeding was common to most of the interviewed
beekeepers. The reason for feeding varied. Some fed to help encourage build up,
while others fed to hold off starvation in the summer during particularly severe
drought.
a. Carbohydrates: some did not feed, some feed HFC, others sucrose. They
used frame feeders, top hive feeders, and barrel feeders. Some added
mineral salts to the feed, some added antibiotics, none used Fumaigillan.
b. Protein: most did not feed, some used pre-made protein supplement.
2. Chemical use:
a. Antibiotic use: While all used antibiotics, the type, frequency of
application, and method of application varied.
b. Miticide use: all but one beekeeper had applied a miticide treatment over
the course of 2006. The products used, method of application, varied.
3. Major income:
a. Some reported that their major purpose was the production of honey,
while others received most of their income from pollination contracts.
Some used both.
4. Source of Queens:
a. All purchased at least some queens throughout the year. One beekeeper
reared a majority of his own cells, but most bought either mated queens or
queen cells. Queens were bought from at least 5 different states (Florida,
California, Texas, Georgia, Hawaii) and 2 foreign countries (Canada and
Australia)
Continuing Activity:
1. Interviews of beekeepers will continue, especially in other regions.
a. As of 12/15/06, at least seven other beekeepers were known to have large
losses.
b. Beekeepers have been asked to “interview” fellow beekeepers based on
questions derived from initial interviews. (Appendix 1)
2. Beekeepers not experiencing problems will be interviewed to determine if there
are other factors that are not shared in common with those experiencing the
losses. This may help pin-point critical factors triggering the colony collapses.
a. Anecdotal second hand reporting suggests
i. that non-migratory operations are experiencing this phenomena
only in split colonies and not parent colonies
Fall Dwindle Disease: A preliminary report
December 15, 2006
ii. migratory beekeepers not experiencing this problem either do not
have high losses though out the year or have aggressive comb
management/replacement procedures in place
Suggested future action:
1. Monitoring colonies year round to look for evidence of stress and disease agent
build up. Little is known about the normal levels of some microbes/pathogens
associated with bees, such as fungi causing stonebrood, flagellates, or amoebae.
There is also a potential of other viruses infecting bees to be present, which have
not yet been fully characterized or have developed methods of detection. New
fungal pathogen strains with increased virulence are being reported in other
countries and may have been introduced to the U.S.
Examination of submitted samples
Sample collection
A beekeeper complaining of heavy losses to colonies approached Dr. Diana Cox-Foster
of Penn State University. In response, Diana accompanied by Dr. Nancy Ostiguy, visited
the beekeeper’s home yard and collected samples of 1) bee bread in dead-out colonies, 2)
honey from dead-out colonies, 3) frames of dead brood (no dead bees were found by the
beekeeper at the original location or within the dead-out colonies) and 4) four living
nucleus colonies which were transferred to Penn State and stored in a secure building
until live bees could be collected. Live worker bees and queens were placed in individual
vials and stored at –80OC. An additional ~50 bees were placed in alcohol. Samples of
bee bread and honey were also collected. The bees in alcohol were sent to Dennis
vanEngelsdorp (who is affiliated with both the Pennsylvania Department of Agriculture
(PDA) and Penn State University), and he analyzed the samples for Varroa mite
abundance, HBTM infection, amoeba disease, nosema disease, and digestive tract
abnormalities. Diana Cox-Foster participated in the examination of the samples, given
her expertise in bee immunity, physiology, and pathology. Fungal isolations and
characterizations were made by Dr. David Geiser at Penn State at the request of Diana
Cox-Foster. Dr. Geiser is an expert in fungal taxonomy and molecular chacterization,
particularly in the group of fungi causing stonebrood disease.
A second beekeeper located in GA, also complaining of high losses, contacted Jerry
Hayes, with the Florida Department of Agriculture. Samples of comb from near dead
colonies were sent to the PDA. Samples of bees from those same near dead colonies were
collected and shipped in rubbing alcohol. Honey and bee bread from the combs were
sent to Dr. Diana Cox-Foster for viral analysis. A sample of dead immature bees (imago
stage) pulled from beneath the capping were also sent. Samples were stored at room
temperature until they were transported to Penn State. These samples were also
Fall Dwindle Disease: A preliminary report
December 15, 2006
transferred to David Geiser, when recognizable fungal growth was observed on these
bees.
Maryanne Frazier received wax samples from the combs collected from the PA
beekeeper. Theses samples are undergoing pesticide residue analysis.
Examination of the bees, honey, and bee-bread
Varroa mite abundance was examined in those bees received in alcohol (Table 1). While
abundance levels were high, these numbers may be artificially inflated considering that
the bees tested were the last in collapsing colonies and apiaries.
None of the samples examined had evidence of HBTM (n= 25 per sample). However,
when preparing samples for HBTM analysis, morphological peculiarities were found
(Figure 1). Crystal-like formations were observed in the thorax where muscles are
located. Similar structures have been described in some viral infections; however, it is
not clear if these are the same type of structures.
A set of tweezers was used to grab the posterior end of the abdomen and pull the gastro
intestinal tract out of the bees abdomen. Along with the intestinal tract, the venom sac
and sting gland were often removed (Figure 2). The Malpighian tubules (the bee’s
“kidneys”) were examined for the presence of Amoeba disease. Only the occasional
amoeba cyst was found in tubules, but never at levels that would seem pathogenic (Figure
3). However, the tubules were found to be swollen and discolored in many bees, a
condition not normally observed. Pyloris scarring was evident between 0% to 45% of the
samples examined (Figure 4; Table 1). In research done in the early 1950’s, this
discoloration or scarring has been attributed to the infection of the bee by small singlecell
organisms known as flagellates. Both flagellates and amoeba have been claimed to
be non-pathogenic in bees; however, little or no information is readily available to
document these protozoa.
The contents of the rectums of PA and GA bees differed (Figure 5). In the PA bees,
cursory examination of the gut contents revealed many pollen grains of unknown origin.
The pollen grains seemed largely intact and many did not appear digested (which is
abnormal). All PA samples were found to have nosema spores in their rectal contents.
The sting gland of many examined bees were obviously scarred with distinct black
“marks” (Figure 6). This type of pin-point melanization or darkening is indicative of an
immune response to some sort of pathogen. Both yeast and bacteria have been identified
as causal agents for this condition (called H melanosis and B melanosis depending on
casual agent). Fyg (1969) reported this condition in queens. In addition to their sting
glands, evidence of melanosis was found in the ovaries of infected queens. These queens
were superseded by colonies. Subsequent research has documented damage to
hypopharyngeal glands of worker bees.
In several samples, there were distinct debris clumps in the tracheal network examined in
the abdomen of bees (Figure 7). In at least one case what appeared to be fungal
Fall Dwindle Disease: A preliminary report
December 15, 2006
mycelium were observed growing from a tracheal branch into a larger tracheal trunk. In
several live bees from PA, other potential fungal mycelium was observed in other tissues
such as the sting gland, the body wall, etc. Potentially these bees have a low –level
fungal infection. Of note, there was few or no dead brood in the colonies exhibiting overt
signs of any type of common brood disease. In particular, there was no indication of
Chalkbrood mummies.
The dead brood from GA were late-pupae or adults that were about to emerge. The
fungal growth on these bees was composed of at least two-different types of fungi. One
was chalkbrood and the other was the species of fungi causing stonebrood. These fungi
are being characterized as to exact species/strain by David Geiser.
Samples from PA and GA were examined for known viral, bacterial, and fungal
pathogens of honey bees using methods to detect the genetic material belonging to these
organisms. Given that few adult bees or brood were available from the "dead out"
colonies, the honey and bee bread were examined. The detection of viruses in the honey
and bee-bread in combs has previously been demonstrated to reflect the viral infections
present in the colony when infected bees were the ones making those food stores (Cox-
Foster and Ostiguy). In the PA colonies (19 to date) and GA colonies (5 to date), the
examination of the honey and bee-bread did not reveal significant infections in the deadout
colonies. The samples collected came from 15 dead-out colonies and the four living
nucleus colonies. In the honey and bee bread samples from the 19 PA samples, only one
had detectable deformed wing virus (DWV), four had sacbrood virus (SBV), and one had
a virus similar to Kashmir bee virus (KBV). The identity of the Kashmir bee virus needs
to be confirmed since the detected viral was abnormal. No acute bee-paralysis virus,
blackened queen cell virus (BQCV), or chronic bee paralysis virus were detected. In
addition, no chalkbrood spores, AFB, or EFB were detected in the honey/bee bread
samples from the PA operation. Likewise, the GA honey and bee bread samples had
little viral contamination, except for two samples with DWV and one with BQCV.
Additional analyses were done on five queens and five workers from the living colonies
that were declining from the PA operation. These samples revealed extensive viral and
fungal co-infection, with all bees being infected by DWV, nearly all infected by BQCV, a
significant number having KBV, some SBV, and almost all having chalkbrood infection.
One sample tested positive for AFB. Given the extent of infection in these bees and the
lack of corresponding detection in honey/bee bread in the same colonies, there is a
chance that the reserves remaining in the colonies are remainder reserves present in the
equipment used to make the new splits. These results suggest that it is best to gain data
from any living bees present in colonies undergoing the dwindle disease. The extent of
the infection levels in these bees is also unusual and not comparable to data reported by
others in the literature to date or by the extensive studies done by Cox-Foster and Ostiguy
on over 200 colonies. The characterization of pathogens needs to be performed more
fully before any conclusions can be reached on underlying diseases causing the fall
dwindle disease.
Fall Dwindle Disease: A preliminary report
December 15, 2006
Ongoing activities:
1. Additional observation and a more careful review of the literature regarding gut
contents will be initiated.
2. Attempts to positively identify any microbes infecting the bees have been initiated
and continue. These analyses include the detection and characterization of fungal
pathogens in the bees. Additional attempts will be made to determine if other
viruses are present in these bees. These detections of other microbes will not be
definitive in determining the culprit underlying the collapses, but will allow for
future research to determine if these microbes are the cause.
3. A researcher working on characterization of either new or emerging pathogens in
humans has agreed to help determine if other pathogens are present in the bees.
This researcher has developed a method that may allow any type of pathogen to
be identified and provide the means to further characterize these microbes and
determine if they underlie the collapse. This researcher is an international expert,
who is recognized as a leader in this area by many branches of the U.S.
government and by international health organizations. The cost of supplies for
this analysis is expensive (approx. $350 per sample); but this expense is justified
for a small number of samples, since this may be the only viable means to find in
a timely fashion undescribed or new disease agents that may be associated with
the collapse of bee colonies. Of particular note, the researcher having this
technology is willing to donate the time and expertise needed to perform these
analyses, which represents a significant contribution.
Chemical Analysis for Pesticide Contamination
Goals:
1) To analyze pollen, honey and bees for the presence of neonicotinoid pesticides (and
possibly certain fungicides)
2) To analyze beeswax (brood nest combs) for possible accumulation of Fluvalinate,
Coumaphos and/or Amitraz
The neonicotinioids, for example imidacloprid, are a rather new class of pesticides. There
have been new chemicals of this sort introduced over the past few years (clothianiden and
thiamethoxam). There is conflicting information about their effect on honey bees,
however the EPA identifies these chemicals as highly toxic to honey bees. "Clothianiden
is highly toxic to honey bees on an acute basis (LD50>0.0439 mg/bee). It has the
potential for toxic chronic exposure to honey bees, as well as other non-target pollinators
through the translocation of clothianidine residues in nectar and pollen. In honey bees,
the effects of this toxic chronic exposure may include lethal and/or sub-lethal effect in the
larvae and reproductive effects on the queen". [EPA Fact Sheet on Clothianiden]. Some
researchers have not found this effect but most were looking for mortality and not chronic
Fall Dwindle Disease: A preliminary report
December 15, 2006
or behavioral effect. In addition, a study in NC found that some of these neonictinoids in
combination with certain fungicides, synergized to increase the toxicity of the
neonicotinoid over 1,000 fold in lab studies. Both the neonicotinoids and the fungicides
(Terraguard and Procure) are used widely.
Recent research tested crops where seed was treated with imidacloprid. The chemical was
present, by systemic uptake, in corn, sunflowers and rape pollen in levels high enough to
pose a threat to honey bees. Additional research has fond that imidacloprid impairs the
memory and brain metabolism of bees, particularly the area of the brain that is used for
making new memories.
Implication: If bees are eating fresh or stored pollen contaminated with these chemicals at
low levels, they may not cause mortality but may impact the bee’s ability to learn or
make memories. If this is the case, young bees leaving the hive to make orientation
flights may not be able to learn the location of the hive and may not be returning causing
the colonies to dwindle and eventually die. It is also possible that this is not the sole
cause of the dwindling but one of several contributing factors.
Action: Dr. Chris Mullen is a chemist in the Penn State department of Entomology who
has worked on the toxic and behavioral effects of pollen feeding beetles, feeding on
neonicotinoids in pollen. He is willing to work on this problem and will attempt to
analyze pollen, honey, and bees from colonies involved in the die off, for the presence of
neonicotinoides. He is capable of detecting ppm but to detect ppb we would have to do a
more complex analysis (that would cost more) but this would still require the preliminary
work that Dr. Mullen will need to do for the ppm analysis.
Ed Bogas worked for many years as the technical specialist in the Penn State Pesticide
Research Lab and was responsible for most of pesticide residue work conducted by this
lab. He now works for Dr. Consuelo DeMoraes, who is not involved in pesticide residue
work but she has agreed to allow him to do this work, using her lab’s equipment but we
will need to cover the cost of the analysis. Ed will work on the analysis of wax and other
hive materials for the presence of chemicals typically used in colonies for the control of
varroa mites. We are hopeful that he will be able to detect pesticide residues at the ppb
level. Pesticides residues at these levels might not have lethal effects but could have
chronic or behavior effects
Fall Dwindle Disease: A preliminary report
December 15, 2006
Table 1: Findings in submitted samples
Sample Varroa
abundance
Sticky
board
Malpighian
tubule
damage
Sting
gland
damage
Pyloris
scarring
PA-20 8/80 na 6/11 2/11 n.a.
PA-21 8/45 na 10/21 9/20 9/20
PA-23 14/64 na 7/23 15/22 5/24
PA-24 7/37 na 8/14 11/14 1/14
GA-1 1/21 1 8/16 7/16 4/16
GA-2 1/408 0 19/20 0/20 0/20
GA-3 0/63 88 10/20 na na
Figure 1: When thoracic discs were cut from sample GA-2 the musculature of bees was notably soft and
discolored (A) when compared to healthy thoracic cuts (B). This discoloration suggests that the bees were
dead upon collection. When questioned the beekeeper confirmed that the bees were alive at the time of
collection. Further, the tracheal system of these bees did not show signs of desiccation usually associated
with the collection of dead bees. Thoracic discs from this sample, after being placed in KOH for 24 hours,
reveled peculiar white nodules (C). When wet mounts were examined they appeared to have crystalline
arrays (D) which may be indicative of Cloudy wing virus (CWV) (Bailey et al. 1980) . Alternatively these
may also be the same “sharp-edged crystalloids” observed in degrading bee muscle tissue by Willie
(1967)(as reported by (Bailey 1981)). Another possibility is that these are small tyrosine nodules, which
have been reported in the Gasters of bees (Erickson et al. 1997) and more recently observed by FDA (E –
Photo courtesy of Jerry Hayes and David Barnes).
Figure 2: Digestive tract of healthy bee.
Figure 3: The Malpighian tubules were examined for the
presence of Amoeba disease. Only the occasional
amoeba cyst was found in tubules, but never at levels
that would seem pathogenic (A). When compared to
apparently healthy tubules (B), many samples had
Malpighian tubules that were obviously discolored (C).
Examination of these tubules revealed heavy debris load
(D). GA-2 and GA-3 had significantly reduced
Malpighian tubules, a condition reported to have an
association with nosema disease (E).
Figure 4: Pyloris scarring was evident
in some samples (A). Wet mounts of
the scar area showed extensive
melanization (B) that may be the
result of Morison’s cell inclusion.
This immune response has been
previously reported in association
with chronic bee paralysis,
accumulation of flagellates, or
possibly some other microbe. The net
like distribution of this scarring
suggests an immune response to a
fungal infection (C).
Figure 5: The rectal contents of GA bees
(A) were distinctly different then the
contents of PA bees (B). The rectal wall
of GA bees were notably transparent
revealing contents that looked like small
stone packets (C). While (Fyg 1964)
describes similar stone like contents in
poorly laying queens, the stones
observed in the GA bees were not
attached to the epithelium layer as Fyg
(1964) describes. When these packets
were ground and mounted, some
unidentified floating objects (UFO’s)
were observed. A cubic particle (D) that
resembles the cubic bodies of
polyhedrios viruses (this viruses attacks
wax-moths) excepting that the cube
observed was ~10x too big for a virus
particle. There were fragments of pollen
grains husks in all samples examined. All
PA samples were found to have nosema
spores in their rectal contents (E) while
none of the GA samples did. In two
samples epithelial cells were apparently
packed with spores. Amoebae cysts (F)
and what appeared to be flagellates (G)
were also observed.
Figure 6: The venom sac and sting gland of bees were examined. In many examined bees (Table1) there
were obvious black scaring. In some cases the marks were small specks (A), while in other cases damage
was easily visible to the naked eye (B). The sting gland in some bees appeared “swollen” (C). What
appeared to be immune defense cells accumulated in thick layers around the sting gland (D). In some cases
there appeared evidence of fungal mycelium growing from the sting gland (E, my). Examination of the venom
sac also revealed evidence of fungal growth (F).
Figure 7: Distinct debris was observed in the tracheal network associated with the gastrointestinal tract. In
some cases what appeared to be fungal mycelium was observed growing from a tracheal branch into a
larger tracheal trunk.
Fall Dwindle Disease: A preliminary report
December 15, 2006
Appendix 1
Honey Bee Management Questionnaire
The following questionnaire is intended to help us identify common and not in common
practices in beekeeping operations. Beekeepers are encouraged to interview other
beekeepers, even if those beekeepers are not experiencing losses. Differences between
those with loses and those without could highlight some of the underlying causes of this
disease. The identity of those who are interviewed will remain confidential.
If the interviewed beekeeper does not know the answer to a question please indicate that
by writing "I don't know" next to the question. If the interviewed beekeeper does not
want to answer a question please write "refuse to answer" next to the question.
To ensure unbiased reporting the person interviewing should not comment on the answers
given by the interviewed beekeepers. A summary report will be made available to all
those who perform interviews, who can in turn pass them on to those they interviewed.
A typical interview will last between 1 and 2 hours. Some of the questions may seem
redundant, this is on purpose, as it acts as an internal check, perhaps jogging beekeepers
memories.
Please answer the following questions on separate pieces of paper. Write the question
number beside the answer. Send the results of the survey to:
Dennis vanEngelsdorp
PA Department of Agriculture
2301 North Cameron Street
Harrisburg PA, 17110
Or email them to: Dennis.vanengelsdorp@gmail.com
Fall Dwindle Disease: A preliminary report
December 15, 2006
A. Questions for the interviewer:
Record:
1. Your name (the interviewers).
2. Record your phone number, address, and email address (the interviewer’s).
3. Record the date and time of the start of the interview
4. Assign a number to the beekeeper (note to interviewer: the people processing
these answers will never know who the interviewed beekeepers are, but we may
have follow up questions. In that case we will call you (the interviewer) and
refer to the assigned number to allow follow up questions.
B. Questions for the beekeeper being interviewed:
1. How many living colonies did you have at the beginning of January 2006 and in
which state were they located at that time?
2. How many living colonies did you have at the end of December 2006 and in what
state were they located?
3. At the beginning of the year, was it your intention to increase colony numbers,
keep the same number of colonies, or decrease the number of colonies you
managed?
4. Did you move colonies from one location to another over the course of the year?
If so, for each month of the year, how many colonies did you move and where and
why did you move them?
5. Did you find queenless colonies in your operation at any time in the year? If so,
in what months did you find them? How many did you find? What did you do
about the problem? What rate of queenlessness do you consider "normal"?
Fall Dwindle Disease: A preliminary report
December 15, 2006
6. Did you find dead out colonies in your operation at any time in the year? If so,
in what months did you find them? How many did you find each month? And
what did you do with the equipment? What rate of dead-outs would you consider
normal?
7. Did you make splits over the course of the year? If so, in what months did you
make these splits? How did you make them? Where did you get the queens to
make them? Where did you get the equipment to make them?
8. Did you monitor for Varroa mites over the course of the year? If so in which
months? How did you monitor levels? What levels would you have thought
problematic? What levels did you get? Did you ever get levels higher than you
think acceptable?
9. Did you treat for Varroa mites over the course of the year? If so when? With
what? Was the treatment effective? How did you know?
10. Did you apply antibiotics to colonies over the course of the year? If so, what?
How did you apply it? When did you apply it? Why did you apply it?
11. Did you see any brood diseases or pests in your colonies over the course of the
year (Small hive beetle, sac brood, European foulbrood, American foulbrood,
chalk brood , deformed wing virus, parasitic mite syndrome, wax moth)? When
did you see it? How severe were these infections? Would you have considered
the rates of infection you found normal?
12. Did you provide supplemental feed (sugar or protein) at any time over the past
year? If so in what months did you feed? Why did you feed? What did you feed?
How did you apply the feed? Did you add anything to the feed?
13. Did you collect a honey crop over the course of 2006? If so in what months?
Did you consider the crop average, below average, or above average?
14. Did your colonies experience a dearth at anytime over the last year? If so how
bad was the dearth? When was it? How long did it last?
Fall Dwindle Disease: A preliminary report
December 15, 2006
15. Did you rent colonies for pollination at anytime of the year? If so when? And
for what crops?
16. Did you rear queens over the course of the year? If so, when did you rear them?
How many did you use yourself? How many did you give away or sell?
17. Did you buy queens or queen cells over the course of the year? If so when did
you buy them? How many did you buy (Please indicate if they were queen cells
or caged queens)? How did you introduce them? What was their rate of
acceptance? Did you consider their rate of acceptance normal?
18. Did you experience the phenomena tentatively referred to as Fall Dwindle
Disease? If so when did it start? How many colonies have died in your
operation as a result of this condition? Is the rate of death equal across all your
apiaries? If not, can you think of any difference between the colonies in apiaries
with high rates of loss and those that do not? What do you think is the cause of
this condition? Are your bees still dying? If not when did they stop dying? To
what do you attribute the stop in the death rate?

Ask if the beekeeper would be interested in interviewing a couple of other beekeepers.

The more responses we get the more information we have.

Thank you.

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