Chalkbrood - Status Today and Hopes for Control' - Golden Rule Honey

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beef in california. ancl IitrcHCoCI( anc CIIRISTENSLN (19?2) found tlre
disease - in honey bee lan.ae fronr Nebr.aska anc \v)-oming. $ri, firsi
founcl the clisease in bees from Arizona iu rlay, lgzi lctillalt ana-
TAB_!R. 1.97-3). The cisease r)or\: appears to be ivides?reacl in b:es in
the Unitecl States.
De JONG and IiOR.SE (19?6) noted the clifficultl, that resear-chers
!1r'e 91t;:r'ienced in. inducing' chailtbrood infections iir bees fo5i;J;.:
.Since 1972. s'e have been corilucting experinrents on ffr" transrnission of
4. gPt"- Specificall)'. l'e have been attempting to infect brooC artificiattJ-.
Such infccticns s'ould gir-e infomratio.t on ttft transmission anC path;genesis
of the disease.anc rvoulc provide a leprocucible .bioassay.'They
rvould also allorv us to perform ControlleC expeliments .o1 methoCs df
treat:rrent such 'as the use of nrolc inhibitors (TABER et al.,lg7i).In this
Papgr. lrre report the $'ork that rve have conducted on full-size-colonies
in the apiary and on brood rnaintaineC in an ineubator.
Attempts to infect apiary ctllonies rvith A. apis
il{any at,ternpts rvere made to infeot brood in apiary colonies rvith
Ascosphaera . -
-apis uncer a r-ariety of conditions itrelting both the
pathogen and the host colonies. These included the use-of inocula
prepareC frorn altificial cultures of A. opis vs. suspensions frorn naturally
infected larvae, ap1:lication of the inocula in syrup sprays ana/or ii
pollen cakes, use of mummies rvith sporulatec vi. vegeiative g.o."tt, ot
the pathogen, -alteration of the ratio bf adult rvorkuibe"r to iroocl by
i'emoval of acult bees or frames of brood prior to application of thl
inoculurn. and application- of grounc mu,nmies in duifs or in pollen.
The rncst severe infections were produced in colonies thit had
been fed uncontaminated pollen to promote ,brood rearing and from
."-hi"lr-.q.f ing nun'rbers of adult bees ivere removed befor-e i suspension
of 3 black (sporulated) ,mum,mies in 90 ml of 5olo sucrose in rvatei When
this treatment rvas applied 3 times a day on the first, thirc. anc fifth
9oy._of the.experiment, it yieldec heavy infections lttioTo of the broo-1
by' the sixth day. Hrvever, even this ireatment ruas less effective in
other colonies that rvere treated et later periods. Thus ryariation in susceptibilit.v
may be an important factor in'expression of disease.
Attempts to infect brood in an incubator rvith A. apis
Beeause of the 'difficulty of inducing infections in apiary colonies.
rve cleviseC teehniques fol reirovat of broid fr.orn coilbs, iurflce sterilization
of brooc, maintenance ,of brood in an incubator, anc inoculation
of brooC n'ith A. apis. No differences in survival rvere noted in larvae
in the incubator f.ed 25oio sucrose solution. royal jelly, or nothing. Thus.
suspensions of A. apis for inocula were ,prepared by homogenizing i
black or spore-bearing rnummies (mated- stiain) oi s rvhite cha'iky
mtrnrmies (unmatec strain) in 5 .rnt of sterile distilled rvater. ThesL
susp-ensio;rs rvere qlatec to confinn viability and n'ere also sprayec or:
conrbs, in apiary colonies. Sorne murnmies rv-ere found in spral'ec cornbs
after 5 days. The dead A. apfs suspensions used for controls s'ere'obtaiped
by autoclaving the homogenate.
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