Bees 3 diseases pests and poisoning Flashcards
(187 cards)
00 epidemic and endemic -
define these two words
- Epidemic: prevalent among commuity at a specific time where most individuals have no resistance to pathogen
- Endemic : it can be found all the time and depends on resistance of host which can be
- genetic
- induced
- behavioural
- environmental
0 define pathogen
An agent causing a disease
0 septicaemia - define
Multiplication of micro-organisms in blood
0 0 healthy brood - describe the appearance of healthy brood
- Single eggs laid in bottom of cell
- larva swimming in brood food
- C shaped, pearly white, clearly segmented
- Cappings domed, biscuity brown, dy and rough, no perforations
- Brood of different ages in concentric circles
- Even brood pattern with few empty cells
0 list 8 key bee pathogens
- Virus
- Bacteria
- Fungi
- Microsporidia - reproduce inside animal cells
- Protozoa - single celled animals
- Mites
- Flies
- Moths
0 1 virus
Give examples 5
How viruses are spread 5
How they work and reproduce 2
Treatment options 1
Impact reduction options 2
- Examples
- Sacbrood, CBPV, BQCV, Bee Virus X, Bee Virus Y, Acute Bee Paralysis Virus etc
- Spread
- by ingestion, inhalation, injection + vertical transmission: Q>E, Sperm>Q etc.
- Quickly dies outside its host so must pass on quickly to another host
- Helped if hosts live in confined space
- Can be endemic without causing noticeable disease/effect
- Mutate easily
- Reproduce
- Hijacks host cell’s ability to produce energy and build proteins so that cell is programmed to produce new virons while normal functions of cell shut down
- When cell dies it releases millions of viruses to infect other cells. Signs visible when sufficient cells are affected
- Treatment
- Any treatment to kill virus kills the cell
- Reduce impact
- Reduce impact of viruses by reducing varroa numbers
- Requeen with more resistant queens.
0 bacteria
Examples 2
What they are 1
How they work? 1
What kills them 1
- Examples include EFB and AFB
- Unicellular organisms that can produce very resistant spores
- Pathenogenic species invade animal tissues to produce infection.
- Most helpful, a few baddies. Can be killed with antibiotics.
0 fungi
Give 2 examples 2
Give and overview of how they work 1
What kills it 2
- Chalk brood, Stone Brood
- Long threads called hyphae grown through the body to form a mycleium like mushrooms/ahtletes foot
- Once established in larvae cannot be treated
- Spores killed with acetic acid;
0 4 Microsporidiam 5
two examples and overview 4
- Nosema apis and Nosema ceranae
- A single celled organism, which forms spores, and generally affect gut.
- Fires a hollow tube into targeted cell and microsporidian contents pass through tube into host cell where they multiply.
- Reproduce inside animal cells (obligate parasites)
0 5
protozoa
Give an example
- Malpighamoeba mellificae
0 Mites
Give 2 examples, and family
How key characteristic
What kills them
3
- acarine and varroa destructor
- Arachnids - 8 legs
- IPM and acids - formic, oxalic
0 6 Give an example of a fly and how to recognise it
- Braula coeca
- 6 legs
- wingless fly, not a pathogen
08 Moths
Give two examples of moths 2
Large WM: Galleria Mellonella
Lesser WM: Achroia grisella
01 AFB signs confusion
Name 3 other conditions that could be confused with AFB
and explain why they are different. 4
- Parasitic Mite Syndrome
- Larva slumped against the lower wall and dry to a scale.
- The scale and the larva can be removed easily.
- Sacbrood
- Larva remains rigid in its sack and the larval head sticks up.
- Removal is easy and the remains do not produce a ‘rope’ in a matchstick test.
- but
- Addled brood
- Typically with abdomen underdeveloped in rel to head and thorax
- Easily removed by bees
- AFB
- Matchstick test produces a 1-2cm rope
- Scales hard to remove
- Scales light up under a florescent lamp
03 EFB signs
Explain why the visual evidence of EFB infection is likely to vary throughout the inspection season. 6
- Impossible to spot EFB when there is little brood. The house bees remove the infected larvae quickly with their package of EFB spoors sealed inside, leaving just a pepperpot brood.
- In spring, more brood that adult bees, and the nurse bees may only just be able to keep up with demand for brood food.
- So only healthy larva to survive and pupate. The infected larvae die of starvation and become visible to the beekeeper.
- When there is plenty of food for both larvae and bacteria, larvae may survive, perpetuating the disease.
- The house bees still recognise infected larvae and remove them, leaving pepperpot brood pattern but no evidence of cause.
- As the bees clean out the dead and dying larvae, the clinical signs of the disease disappear and the levels of bacteria are reduced.
1 Field diagnosis - signs of AFB
detailed signs in brood and identification 12
- Any season.
- Open brood - NO signs tho HB may remove infected larva - leaving pepperpot
- Visible in sealed brood esp when bees shaken off comb
- Chewed cappings moist and dark, concave AFTER larva dies.
- Milky-coffee coloured brood slumped on lower wall with tongue stuck out across cell
- Larva disintegrates, melts down, becomes thick and sticky
- NO smell - any smell is due to secondary infections/putrefiction of larva
- Matchstick pushed through capping produces a 1-2cm rope - conclusive.
- Dries to hard black scale in a month, visible at bottom of cell
- Usually bees uncap cell and try to remove scale, seen when holding frame at 45˚ angle, and which floresce in UV light
- Pepper pot appearance -> suspicioius -> examine for scale
- Id by eye / match stick / Lateral Flow Device
1 field disgnosis AFB
Latin name 1
- Paenibacillus larvae
1 field diagnosis
Differences between when each EFB and AFB become evident 3
- Both of brood - no symptoms in adults
- EFB before capped
- AFB after capping
- Possible to have both on same comb.
1 Field diagnosis
Describe how lateral flow devices are used as diagnostic tools in the field for both EFB and AFB and state the limitations of these devices. 8
- Macerate suspect larva in a buffer solution for 20 seconds.
- Three drops into the LFD well, keeping the device horizontal.
- The sample flows across the solid substrate by capillary action over three minutes.
- It encounters lines of coloured reagent treated with a particular antibody.
- One line, negative; two lines, positive.
- The LFD: specific to one particular disease so separate tests for EFB and AFB.
- It may not show positive if a different strain of the disease has evolved.
- The LFD won’t show a positive result for a different disease, so if you are testing for AFB but EFB happens to be present instead, it will not show up.
1 field diagnosis of EFB
What are the signs of EFB 9
- Best time to spot it is in spring build up (may/June)
- Visible in larva - uncapped cells
- Large larvae (3-5 days from capping) lose segmentation, contort and ‘melt’; pearly white to yellow to light brown-green
- Confused with sacbrood
- Pull white gutted larva white apart - bacteria are white lumps/chains (shd be golden brown)
- Death by starvation
- Dead larva usually QUICKLY removed in one piece so hard to spot
- Decomposes rapidly to scale, is easily removed.
- Pepperpot - dead larva are either seen or there are just empty cells present
1 field disgnosis EFB
Latin name
Melissococcus plutonius
01 inspection techniques
How does a beekeeper inspect for disease? 7
- Know what looks normal
- Inspect for diseases regularly
- Remember disease may be present in very few larvae at first
- LF the unusual, poor brood pattern, gaps, abnormal larvae and dodgy cappings
- Monitor for varroa
- Remove cappings from cells which look doubtful
- Inspect microscopically colonies that fail to build up in spring
2 life cycle AFB 7
Yate and Davies 47
Se
- Life cycle 10-15 days (Yate 187)
-
Spores ingested in larval food
- Larve up to 24 hrs succumb with just 10 spores
- Larvae 3+ days need millions
- Germinate in gut producing vegetative cells (do not multiply)
- Upon sealing, vegetative cells penetrate gut wall into haemolymph, where they multiply (Yates 188)
- Sporulation (dormant form) enables bacteria to survive harsh conditions until ingested. Infective 35+ years and resistant to heat, dessication and disinfectant
- Death by septicaemia. Pupa melts, thickens and dries to a scale with proboscis protuding from scale to cell centre, a mass of bacerial spores
- As HB try to clean the cell for more eggs, they recycle toe spores around the colony. When they become nurse bees, they contaminate food with AFB
02 EFB life cycle
9
- The larva ingests the bacterial spores in broodfood from infected nurse bees
- Germinate in the gut and multiply between the peritrophic membrane and the larval food
- It starves to death in 4-5 days
- Secondary infections inc Paenibacillius alvei, Lactobacillus euridice, Brevibacillus laterosporus and Enterococcus faecalis - smell
- Or the larva is fed enough and survives to defecate into the bottom of the cell after the 5th moult
- The faeces will contain spores that the young house bees clean out, infecting their mandibles. Can survive 3 year in old comb.
