Bee Science Symposium
"Current Developments in Bee Research"
 
ABSTRACTED PROCEEDINGS
 
March 12, 1993
Cornwallis Room, Agricultural Centre, Kentville, Nova Scotia,Canada
 
Sponsored by the Nova Scotia Beekeepers' Association and the
Nova Scotia Department of Agriculture and Marketing
with assistance from the Human Resource Development component of
the Canada/Nova Scotia Agri-Food Development Agreement
 
FORWARD
On March 12, 1993 a unique symposium on current scientific research
related to honeybees and their diseases and pests was held in the
Cornwallis Room at the AgriculturalCentre, Kentville, N.S.  The
speakers at this symposium are recognized worldauthorities from
the U.K., U.S., Alberta, Ontario and Nova Scotia.  The topics
coveredgenetic engineering, selective breeding, viral diseases and
their transmission,honeybees as vectors of biological control
agents, and pests of bumblebees.The following are abstracts of the
presentations except in one case a summarytranscript is included.
 
C  O  N  T  E  N  T  S
 
1.    Dr. Brenda V. Ball, Honey Bee Virus Infections Associated
with Varroa jacobsoni Infestation.
 
2.    Don Stoltz, Virologist, Development of Diagostic Tools for
Virus Infection in the Honeybee.
 
3.    John Phillips, Engineering a Gene for Insecticide Resistance
in the Honeybee.
 
4.    Thomas E. Rinderer, Breeding of Resistance to Varroa
jacobsoni.
 
5.    Dr. Don Nelson, Tracheal Mites Detection and Control Methods.
 
6.    John C. Sutton, Use of Bees to Deliver Biocontrol Agents for
Controlling Flower-Infecting Pathogens.
 
7.    Richard M. Fisher, Bumble Bees:  Parasites, Predators,
Disease.
 
8.    Summary List of Speakers, Addresses and Fax Numbers.
 
 
 
 
 
 
 
 
 
1.  Honey Bee Virus Infections Associated with Varroa jacobsoni
InfestationBrenda V. Ball, AFRC Institute of Arable Crops Research,
Rothamsted ExperimentalStation, Harpenden, Herts.   AL5 2JQ   Fax:
0582 760981.
ABSTRACT
The parasitic mite Varroa jacobsoni causes little apparent damage
in colonies of itsnatural host Apis cerana, the eastern hive bee.
The transfer of the mite to theEuropean honey bee, Apis mellifera
and its spread to every continent except Australasiahas been
accompanied by reports of devastating colony losses, although the
effects ofinfestation seem variable and are still poorly
understood.  Differences in thereproductive potential of mites on
different species and races of bees and hostbehavioral responses
may account for some of this variability.  However, recentresearch
has shown that the mite affects the type and prevalence of honey
bee virusinfections causing mortality.  This talk will consider the
role of V. jacobsoni as anactivator and vector of honey bee viruses
and examine some of the factors affectingdisease outbreaks in
infested colonies.
 
 
 
 
 
 
 
 
2.  Development of Diagostic Tools for Virus Infection in the
HoneybeeDon Stoltz, Department of Microbiology & Immunology,
Dalhousie University, Halifax,Nova scotia   B3H 4H7   Fax:
902-494-5125.
ABSTRACT
My laboratory has been developing approaches to diagnostics which
we think will proveuseful in the not-too-distant future.  For
example, in preliminary studies we havefound that virus infection
in a single bee pupa can be readily detected by Westernblotting.
Our primary focus thus far, however, has been directed towards an
assessmentof polymerase chain reaction (PCR)-based technology for
the detection of black queencell and Kashmir bee viruses.  Use of
PCR primers specific for conserved humanenterovirus sequences gave
rise to several products; one of these, a 450 base pairamplicon
from KBV has now been cloned and sequenced.  Computer analysis
indicate thatthis sequence comes from the viral RNA polymerase gene
and shares significant homologywith the same gene found in a
variety of known picornaviruses - including humanhepatitis A - and
with many plant virus genomes as well.  Future work will be
directedtowards the development of both universal picornavirus
primers and primers specificfor individual bee viruses.
 
 
 
 
 
 
 
 
3.  Engineering a Gene f
   or Insecticide Resistance in the
HoneybeeJohn Phillips, University of Guelph, Department of
Molecular Biology and Genetics,Guelph, Ontario, Canada  Fax:
519-837-2075.
ABSTRACT
We are applying current techniques of insect molecular biology to
the design andintroduction of useful genes in beneficial insects.
Such genes would include thoseencoding resistance to conventional
insecticides.  A potentially useful insecticideresistance gene, the
`opd' gene, has been identified and cloned from bacteria.  Thisgene
specifies a unique phosphotriesterase which efficiently cleaves and
detoxifiesa broad spectrum of organophosphorus insecticides.  We
have redesigned this gene tofunction in insects and have
transferred it into the genome of the model insect,Drosophila
melanogaster, where it functions to confer significant resistance
toorganophosphate toxicity.  This demonstrates the feasibility of
conferring usefultraits on strains of insects through the design
and introduction of carefully designedgenes.  We are now refining
the structure of the gene to target expression in specifictissues
and developmental stages in order to enhance the efficacy of
insecticideresistance.  In addition, we have begun to develop
techniques for transferring thisand/or other useful genes into the
honeybee genome to confer useful and novel traitson the beneficial
insect species.
 
 
 
 
 
 
 
 
4.  Breeding for Resistance to Varroa jacobsoniThomas E. Rindere
   r,
United States Department of Agriculture, Agricultural
ResearchServices, Honey-Bee Breeding Genetics & Physiology
research, Baton Rouge, Louisiana Fax: 504-389-0383.
ABSTRACT
A stock of honey bees was bred in Yugoslavia for resistance to the
parasitic mite,Varroa jacobsoni.  This stock was imported by the
USDA to the US and extensively testedin field trials in Florida.
These tests showed that the stock has some degree ofresistance to
Varroa jacobsoni, a strong resistance to a second parasitic
mite,Acarapis woodi, which is also a relatively new and
economically troubling pest of honeybees in the US, and excellent
general beekeeping characteristics.  Based on theseresults, the
Yugoslavian honey bee stock is scheduled to be released to industry
nextspring.  This release will be the first honey bee stock
released from the USDA toindustry in decades.  The general
potential for developing honey bee stocks resistantto parasitic
mites will be examined.
 
Editor's Note:An excellent article by Rinderer, et al, in the
March '93 issue of American BeeJournal, covers this subject in
detail.
 
 
 
 
 
 
 
 
5.  Tracheal Mites Detection and Control MethodsDr. Don Nelson,
Agriculture Canada, Research Station, Beaverlodge, Alberta   Fax:
403-354-8171
ABSTRACT
Tracheal mites are becoming a common pest of honey bee colonies in
most of Canada. Therefore, it is important to know when colonies
are infested and at what levels.  Atthe same time it is important
to know at what levels tracheal mites are detrimentalto colonies,
and how to control their buildup.The only method of detection at
present is the dissection (and microscopic examination)of the
thorax of individual bees.  This method is time consuming and
costly.   TheBeaverlodge Research Station has developed a
monoclonal antibody specific to thetracheal mite and is currently
using and evaluating an ELISA (Enzyme-LinkedImmunosorbent Assay)
method for detection of tracheal mites in bulk bee samples.
Withfurther evaluation this method may become a preferred
alternative to individual beeanalysis.Several approaches to
reducing or minimizing the effect of tracheal mites are
beingstudied; a) chemical control, b) management practices and c)
selecting stock forresistance.  The emphasis in the short term has
certainly been to have one or moreregistered chemical controls
available.  Chemicals currently approved for use in Canadafor the
control of tracheal mites are menthol and formic acid (by spring
of 1993). For the short and mid-term, several management practices
along with chemical controlsseem promising and for the long term
selecting bees more resistant to the tracheal miteholds great
promise.  Ultimately, all three methods will be used in
variouscombinations to provide the best results.
 
 
 
 
 
 
 
 
6.  Use of Bees to Deliver Bioc
   ontrol Agents for Controlling
Flower-Infecting PathogensJohn C. Sutton, Department of
Environmental Biology, University of Guelph, Guelph,Ontario, Canada
 N1G 2W1   Fax: 519-837-0442
 
Honey bees (Apis mellifera) were found in recent studies to
efficiently vector inoculumof microbial biocontrol agents to
flowers of strawberry (Peng et al. 1992), raspberry(J.C. Sutton
1991, unpublished observations), apple and pear (Thompson et al.
1992). These observations were made a century after Waite (1891)
reported for the first timethat honey bees vectored a pathogen,
Erwinia amylovora, to flowers of pear trees.  Foreffective
biocontrol of flower-infecting pathogens, it is likely that
intensivevectoring of biocontrol agents is required.  To achieve
adequate vectoring of agentsto flowers of crop plants, inoculum of
the organisms must be suitably formulated toallow effective
acquisition, transport, and deposition by bees.Bees successfully
vectored spores of various biocontrol agents (eg. Gliocladium
roseum,Epicoccum purpurascens, and Alternaria alternata) when
formulated as powders with talc,pulverized corn meal, wheat flour,
soya flour or corn starch (Peng et al. 1992, Israeland Boland
1992).  The bacterial antagonists Pseudomonas fluorescens and
Erwiniaherbicola were vectored to apple and pear flowers when
absorbed to pollen of apple orcattail (Thomson et al. 1992).  The
bees were contaminated with the formulations inspecial inoculum
dispensers or pollen inserts inside hives.  Bees acquired
inoculumon their legs and bodies and especially on the setae.In a
biocontrol study of fruit rot of strawberry caused by Botrytis
cinerea, bees eachacquired 88,000 - 1,800,000 (mean 570,000) cfu
G. roseum in a talc formulation (5 x108 cfu/g) and maintained an
inoculum density of 1,600 - 27,000 cfu of the antagoniston each
flower (Peng et al. 1992).  By comparison inoculum density in plots
sprayedweekly with spore suspensions (107 conidia/mL) of G. roseum
ranged from 300 to 15,000cfu/flower.  Propagule density was more
stable and often higher on flowers of the bee-vectored treatment
than in spray-treated flowers, but the treatments were about
equallyeffective in suppressing incidence of the pathogen on
stamens and petals, and incontrolling fruit rot.Efficiency of
inoculum deposition on flowers by bees probably depends on
subtletiesin physical contact between the bee and the flower as
well as the load and distributionof inoculum on the bee.  Size and
morphology of the flowers and of the bees, and theactivity and
posturing of bees while on the flowers undoubtedly affect the
amount ofinoculum deposited and where it is deposited on the
flower.  In studies at theUniversity of Guelph, bees delivered
about 10 to 18 times more conidia of G. roseumper flower to
strawberry than to raspberry.  The formulation and concentration
ofinoculum used was the same in all studies.  While strawberry
flowers are much largerthan raspberry flowers, and foraging
frequencies by bees on the two types of lower mayhave differed, the
bees also behaved differently on strawberry than on raspberry
(J.C.Sutton, unpublished observations).  In strawberry, bees tended
to move actively overthe face of the flower, often in a rotational
pattern, and their legs and bodiesfrequently contacted the stamens
and other flower parts.  In raspberry however, thebees moved only
slightly and tended to cling to the elongate stamens by means of
distalportions of their legs, and achieved only minor body contact
with the flower.  Whiledensity of vectored inoculum on raspberry
was low, the antagonist nonethelesseffectively suppressed Botrytis
fruit rot.Many variables influence the frequency of visits by bees
to flowers and may thusinfluence vectoring of biocontrol agents and
the effectiveness of biocontrol.  Cooltemperature, wind and rain
generally discourage foraging by bees (Free 1968 a,b),however in
our studies in strawberry, bees vectored high densities of G.
roseum to theflowers under a wide range of weather conditions (Peng
et al. 1992).  Foraging in testplots or in commercial crops can be
affected by the proximity and attractiveness tobees of other kinds
of flowers in the area that compete as sources of nectar and
pollen(Levin 1978).  For example, biocontrol of B. cinerea in
strawberry by means of bee-vectored G. roseum soon became
ineffective when the bees preferentially visited freshlyblooming
rapeseed in nearby field plots (Peng et al. 1992).  Chemical
attractants canbe used in some instances to maintain foraging in
the target crop.The mobility and foraging patterns of bees present
special problems in field studies. Screens generally are needed to
separate treatments with bees from those without bees,but may
modify microclimate and exclude important pollinators.  Bees
confined in screencages may forage and vector differently from
freely-ranging bees.  Screening of alltreatments equalizes
microclimatic modification but is impractical when plots or
hostplants are large, and can be costly.  Vectoring of biocontrol
agents will requirespecial studies in commercial crops to determine
the numbers, size and distributionof bee colonies needed for
effective vectoring of microbial antagonists and forbiocontrol.
In bee-vectoring studies in Utah, the antagonist Pseudomonas
fluorescenswas detected on only 556% of apple flowers at 61 m from
a hive, and on only 72% of pearflowers at 7 m from a hive, with an
average population of 102 cfu per flower (Thomsonet al. 1992) - A
stain of E. herbicola was detected on 92 - 96% of apple flowers ina
2.6 ha orchard (10-5700 cfu per flower).  To encourage bees to
establish foragingpatterns in a crop as opposed to other plants in
the area, it is important to introducebee colonies shortly after
the crop begins to flower.Various bees potentially could be used
to vector microbial antagonists to many kindsof plant for
biocontrol of various flower-infecting pathogens.  Several kinds
ofdomesticated bees, including bumble bees (Bombus spp.) and leaf
cutting bees (Megachilespp., Osmia spp.) as well as honey bees, may
have potential as vectors.  Wild speciesof halictid bees and
andrenid bees also possibly could be used, and contaminated
withbiocontrol agents at bait stations.  Various berry crops,
orchard fruits, crucifercrops, beans, clovers, and cucurbits
possibly could be protected by bee-vectoredantagonists.
Imaginative research could lead to effective, efficient,
andenvironmentally safe biocontrol of many crop diseases by means
of bee-vectoredantagonists.
 
Literature cited
FREE, J.B., 1968.  The pollination of strawberries by honey bees.
J. Hortic. Sci. 43:107-111.
 
FREE, J.B., 1968.  The foraging behaviour of honey bees (Apis
mellifera) and bumblebees(Bombus spp.) on blackcurrant (Rubus
nigrum), raspberry (Rubus idaeus) and strawberry(Fragaria x
ananassa) flowers.  J. Appl. Ecol. 5: 157-168.
 
ISRAEL, M., & BOLAND, G.J., 1992.  Influence of formulation on
efficacy of honey beesto transmit biological control for management
of Sclerotinia sclerotiorum.  Can. J.Plant Pathol. (Abstr.) (In
press).
 
LEVIN, D.A., 1978.  Pollination behaviour and the breeding
structure of plantpopulations.  Pages 133 - 150 in A.J. Richards,
ed., The pollination of Flowers byInsects.  Academic Press, London.
213 pp.
 
PENG. G., SUTTON, J.C. & KEVAN, P.G., 1992.  Effectiveness of honey
bees for applyingthe biocontrol agent Gliocladium roseum to
strawberry flowers to suppress Botrytiscinerea.  Can. J. Plant
Pathol. 14: 117-129.
 
THOMSON, S.V., hansen, D.R., FLINT, K.M. & VANDENBERG, J.D., 1992.
The disseminationof bacteria antagonistic to Erwinia amylovora by
honey bees.  Plant Dis. 76: 1052-1056.
 
WAITE, M.B., 1891.  Results from recent investigations in pear
blight.  Am. Assoc. Adv.Sci. Proc. 40:315.
 
 
 
 
 
 
 
 
7.  Bumble Bees:  Parasites, Predator
   s, DiseaseRichard M. Fisher,
Department of Biology, Acadia University, Wolfville, Nova
Scotia,Canada   Fax: 902-542-3466
ABSTRACT
During the 1980's, advances in bumble bee domestication technology
permitted the cost-effective use of these bees for greenhouse
tomato pollination.  At present, threespecies are used for this
purpose (Europe and New Zealand: B. terrestris; eastern
NorthAmerica: B. impatiens (Cr.); western North America; B.
occidentalls (Grne).  Threeprimary concerns have been associated
with the intensive laboratory culture of thesespecies:  1)
depopulation of bees in areas where queens are captured; 2) the
impactof species introductions into new area; 3) the possible
spread of disease,either amongBombus populations, or
interspecifically between bumblebees and other bees, notablyApis
mellifera.  Data are presented which demonstrate the genus
specificity of a numberof bumble bee pests and pathogens, including
mites, the microsporidian Nosema bombi,and a number of social
parasites.  The possible propagation of diseases among
culturedBombus species can be eliminated (or at least minimized)
through proper managementpractices.
 
 
 
 
 
 
 
 
8.  SPEAKERS
Brenda V. BallAFRC Institue of Arable Crops ResearchRothamsted
Experimental StationHarpenden, Herts    AL5 2JQFax: 0582 760981
 
Don StoltzDepartment of Microbiology & ImmunologyDalhousie
UniversityHalifax, Nova ScotiaB3H 4H7Fax: (902) 494-5125
 
John PhillipsUniversity of GuelphDepartment of Molecular Biology
& GeneticsGuelph, OntarioN1G 2W1Fax: (519) 837-2075
 
Thomas E. RindererUnited States Department of
AgricultureAgricultural Research Services, Mid South AreaHoney-Bee
Breeding, Genetics & Physiology Research1157 Ben Hur RoadBaton
Rouge, Louisiana   70820Fax:  (504) 389-0383
 
Don NelsonAgriculture CanadaResearch StationBeaverlodge, AlbertaT0H
0C0Fax:  (403) 354-8171
 
John C. SuttonDepartment of Environmental BiologyUniversity of
GuelphGuelph, OntarioN1G 2W1Fax:  (519) 837-0442
 
Richard M. FisherDepartment of BiologyAcadia UniversityWolfville,
Nova scotiaB0P 1X0Fax:  (902) 542-3466