Term
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Definition
- infectious and contagious
- causes brood to harden
- caused by fungus Ascosphaera apis (A. apis)
- different strains vary in virulence |
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Term
| On what factor does the severity depend? |
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Definition
On the number of diseased larvae
- usually only 10-15
- really bad cases have 100s |
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Term
| When and how was EFB introduced to Canada and the US? |
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Definition
- in the early 80s
- most likely came with imported queens
- now worldwide |
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Term
| When are spores of Ascosphaera apis formed? What happens? |
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Definition
| When mycelia and hyphae of opposite sexes overlap. They are held inside brownish spore cysts, which change brood colour from white to grey/black |
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Term
| How long are spores viable on combs? |
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Definition
| 15 years - contaminating honey, and surviving in cells |
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Term
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Definition
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Term
| Describe the development of CB. |
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Definition
1) 3-4 day-old larvae infected
2) Ascosphaera apis germinates in hind-gut
3) Mycelium (roots) develop, pierce tissues, wrap and mummify the larvae
4) Death |
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Term
| Name the chemical that controls the spread of Chalk brood. |
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Definition
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Term
| Describe the ideal conditions under which Chalk Brood will grow. |
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Definition
- low temperatures
- weak colonies
- moisture in hives
- poorly ventilated hives (low O2)
- abuse of antibiotics (upsets equilibrium |
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Term
| What are the symptoms of CB disease? |
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Definition
- both open and capped = mummified
- caps may be pierced
- mummified larvae (white pre reprod., black post reprod.)
- if bees are hygienic, mummies can be found outside hive entrance |
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Term
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Definition
- observing symptoms
- will rattle if shake comb
- microscopic observation of spore-cysts |
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Term
| How can we control chalk brood? |
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Definition
- no chemotherapeutic agent registered
- replace combs with healthy brood (if severe)
- raise hives from ground and tilt slightly frontwards - less humid, drains rain out
- use queens from hygienic stocks
- irradiate equipment |
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