3.22 - Effects of CBPV, ABPV, BQCV, sacbrood and DWV Flashcards
Describe the impact of Chronic Bee Paralysis Virus 1 and what is is associated with (11)
- Assoc with Varroa
- More common in bees than type 2
- Abnormal trembling motion of adult bees’ wings
- Wings may be spread or dislocated (k-wing).
- Paralysis of adult bees’ bodies
- Adult bees are unable to fly so often found crawling in large numbers on the ground
- Bloated abdomens due to build up of fluid in honey sac
- This can lead to dysentery-like symptoms;
- Sick bees die in a few days
- Can lead to sudden collapse of colony.
- Heavily infected colonies may collapse, particularly seen at the height of the season
Describe the impact of Chronic Bee Paralysis Virus 2 (6)
- Assoc with varroa
- Bees hairless and appear shiny and black.
- They look greasy in bright light
- Can fly at first and then become trembly and lose ability to fly
- Other bees aggressive, nibbling them and preventing them returning to hive
- Die.
What are the causea of chromic Bee paralysis virus 6
- Not yet associated with Varroa
- May be endemic in many colonies with no symptoms until the colony is stressed
- Infect older bees more frequently and foragers are often found to have a higher virus burden
- Outbreaks at the peak of spring and summer.
- In laboratory experiments, direct contact with infected individuals causes spread of the virus, body hairs are rubbed away through repeated contact and, as a result, the virus is able to penetrate the cuticle and establish infection.
- The virus is also known to spread through faeces of infected bees
CBPV treatment - Official plus Robert Carpenter Turner’s advice 7
- Give bees plenty of space to avoid them rubbing up against each other. Add a super or extra brood box.
- Regular change of frames and comb so that the virus does not hang around to be picked up by house bees. Bailey comb change or routine turnover of frames every two or at most three years.
- Treat for Varroa if there is a high count.
- Prevent robbing
- Consider re-queening if problem persists.
CBPV 1 (K wing) v CBPV 2 (black)
Type 1:
• Trembling wings and body
• Not flying - crawling on ground and up plant stems
• Huddle on top bars - do not react to smoke
• Bloated abdomen (full honey sac)
• Dysentry
• Dislocated wing - K wing
• Deaths
Type 2
• Trembling, not flying
• Refused entry to hive
• Broad abdomen
• Black, shiny, hairless as nibbled by other bees (appear smaller)
• Deaths
ABPV
- Associated with varroa
- Weakening of the colony without signs of brood diseases and mites
- Increasing numbers of dead or dying bees on the inner cover or front of the hive.
- Dying bees may be trembling and display uncoordinated movement.
- Affected Bees are partly or completely hairless where the upper surface of the Thorax is especially dark
- Older Adult Bees have a greasy or oily appearance while recently emerged Bees may appear opaque as if pigmentation of the tissue had not been completed prior to emergence
- Rapid decline within a few days
Black Queen Cell Virus: What is is associated with, what are its symptoms and transmission vectors 5
- Associates: Nosema apis
- Q larvae infected through infected royal jelly
- Q cells become dark/black and Q pupae die
- Virus remains viable in larval remains, honey or pollen for up to 4 weeks.
- TX by drifting, robbing, contaminated water, equipment and comb
All about sacbrood virus in brood 8
- Found in capped cells - chewed like AFB
- Nurse bees get it from contaminated water, pollen/nectar or cleaning out larval remains
- Nurse bees infect larvae when they feed larvae with infected brood food.
- Prevents pupa shedding 5th larval skin - Fluids accumulating under skin give it a sac-like appearance
- Infected larva change from pearly white to pale yellow
- Death occurs just before pupation with larva streatched on on its back.
- Larva remains rigid, swells and larval head sticks up
- The scales formed as dead larvae dry out ar brittle but easy to remove
Sacbrood virus impact on adults
- Can shorten adult lives: start foraging earlier; stop feeding larvae; collect v little pollen
- Usually clears up on its own or requeen
- Virus viable for 4 weeks in larval remains, pollen or honey
Deformed Wing Virus. What is it associated with and what are its symptoms 5
- Assoc with Varroa and multiply in the mite
- Deformed wings, which are not always apparent.
- Stunted bodies.
- Bees can’t fly
- Doesn’t kill bee so is endemic.
Name the viruses associated with Varroa
- Varroa destructor virus 1.
- Deformed wing virus.
- Cloudy wing virus.
- Kakugo virus.
- Kashmir bee virus.
- Israeli acute paralysis virus.
- Slow bee paralysis virus.
- Acute bee paralysis virus.
- and some say: Chronic Bee paralysis virus 1
- plus 2
Name the viruses associated with Nosema
- Bee Virus Y
- BQCV
- Filamentous virus
Name the viruses associated with Amoeba
- Bee Virus X
06 ways to reduce impact of viruses 6
- Keep varroa pop low
- Test for nosema in autumn
- Use resistant queens
- Avoid moving bees - inhibits their natural controls
- Keep no more than 10 colonies per apiary
- Disinfect by scorching or acetic acid. Viruses cannot survive in dead colonies.
Bee Virus X: what is it associated with and what are its symptoms
- Assoc with Malpighamoeba millificiae
- Assoc with deaths of colonies in spring.
- Shortens bee’s life.
