Tavistock Branch Devon Beekeepers Association 3rd March Glyn Davies, Editor, Devon BKA Magazine Beekeeping President, BBKA

Transcription

1 Tavistock Branch Devon Beekeepers Association 3rd March 2015 Glyn Davies, Editor, Devon BKA Magazine Beekeeping President, BBKA

2 It is greatly surprising to me that with the great interest by beekeepers in Nosema, how few actually make the effort to monitor the levels of this parasite in their colonies! Even more surprising is that, despite the considerable expense, many blindly treat their colonies without having any idea as to whether their bees are actually infected! Randy Oliver, ScientificBeekeeping.com

3 Apicultural Dysentery Is it Nosema?

4 Let s recognise the problem : A disease of Adult bees particularly in Temperate climatic zones It is a MICROSPORIDIAN ; not a bacterium, not a virus and not exactly a fungus Tends to be significant after long confinement of bees Explains the traditional term Spring Dwindling Infects the mid-gut of the bee Dysentery not always obvious and if present may have other causes Associated with Black Queen Cell Virus; & others Can be treated with antibiotic Fumidil B or other proprietry organic medicants

5 A schematic illustration: Actual size is 4-6µm so the internal structure is not normally visible. For diagnosis beekeepers use x400 magnification with a compound microscope

6 Where does it occur? In the mid gut (ventriculus)of a worker bee Thorax Petiole Crop Ventriculus Small intestine Malpighian tubules Rectum Rectal Plates Photo from Graham Royle Apis Through the Looking Glass BBNO

7 Life cycle of Nosema apis Ventriculus, (mid-gut) Cavity or Lumen Striated Border Cells of the mid-gut wall Springer Life Sciences

8 Photo: John Carr, PhD; MRCVS

9 Guide photos at X400 magnification High infection

10 The recent impact of Nosema ceranae Raquel Martín-Hernández, et al. Appl Environ Microbiol October;73(20):

11 to raise the profile of Nosema amongst members to have a series of practical events to strengthen the social relationships in the association to highlight the importance of monitoring all colonies for nosema infection to improve understanding of the disease to develop skills needed for the diagnosis

12 Database development: Preparation of the members Survey Form Data entry Nigel Lawrance Website Gold Medal Apimondia 2009

13 Newton Abbot Beekeepers (DBKA) DBKA Registered Charity Number Reference: Beekeeper apiary Nosema Survey Form 2012 Name Address Telephone Post code Apiary Name 6 Fig. Grid Ref SS SX

14 Information requested 2012 Apiary Name 6 Fig. Grid Ref SS SX Hive Ref Hive medications in 2011-now Nosema last year? New Combs? Queen origin

15 Devon Nosema Survey The purpose of the survey is to discover the extent of Nosema in Devon as accurately as possible. We will have a team of microscopists who will examine your bees for signs of Nosema. Please include a stampedaddressed-envelope with sample to enable us to post your results back to you. GUIDANCE NOTES Apiary Name - If your hives are located at your home just complete this field as home. Please continue on a separate sheet for additional apiaries. 6 Fig. Grid Ref (if known The Bee inspector can tell you or go to the web site of the Bedfordshire Natural History Society) -The 6 figure grid reference will enable us to map the results broadly to location to determine if there is a higher incidence of the condition in one or other part of the county. Please ensure you enter the correct 2 letter prefix by deleting the incorrect one on the form. Hive Ref - Use your own numbering/identification reference. This is important so that you can know which results belong to which hives. Hive medications in 2011-now - What treatments were applied to this hive in 2011-now? For example - Oxalic acid, Apiguard, Apistan, Formic Acid, Fumidil B, state name of any other, or none? (Up to 3 if there were more, list the most recent 3). Nosema last year? If this colony was tested for Nosema last year, by DBKA or otherwise, please state result nil, light, medium, heavy. New Combs? How many new combs were given to this colony last year? eg All; more than half; less than half Queen origin Where is the origin of the current queen? For example Local, Greece, Hawii, Unknown. (Up to. 2 nd generation)

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17 This is the form we want to use in Newton Abbot in 2014 It has been simplified to include the more relevant information. Data collected locally and compared after several years should be an important record to guide management of bee colonies in the area.

18 The laboratory in full flow. Slides in preparation. Microscopists waiting. White coats are important for cleanliness and atmosphere.

19 Chris Utting and Nigel Lawrance checking in a member s samples. One card for each sample.

20 Four printed on to A4 Card. Stapled to the sample at Reception; Clipped to prepared microscope slide. Returned to Reception when complete.

21 Slide preparation Essential conditions are to have a consistent system, obtain good slides and to avoid cross-contamination. Also important to avoid mess! NABKA Nosema Survey 2012 Instructions for preparing slides Please take every care to avoid contamination from previous samples 1. Check Sample Survey number & record on new clean slide; polish area for specimen & cover slip. 2. Empty bees into sample dish. ` 3. Count 30 bees in 6 x 5 piles on a sheet of paper. (In case you lose count!) 4. Place 30 whole bees into mortar do not remove any legs/wings etc. Place remaining bees into waste box. 5. Add 30ml clean water (1 ml per bee if fewer than 30) to bees and mince thoroughly with pestle for 1 minute. 6. Add one drop of liquid to centre of slide using round end end of cleaned swizzle stick SEE BELOW* Usually best if Swizzle stick is allowed one drop to drain off into mortar. Practise first time. Cover slip must not float but adhere to the slide. 7. Using left hand, pick cover slip by edges; lower one edge to liquid. 8. Use needle in right hand, to support cover slip, then withdraw needle to lower the cover slip. without trapping air bubbles. 9. Rotate completed slide to check adhesion of cover slip. 10. Clip slide to record card & pass both to microscopists 11. Empty contents of mortar into liquid waste box. 12. Wash & dry mortar & pestle; needle and swizzle stick. (Important to avoid cross contamination.)

22 Tools to prepare slide Cover slips Marked slide Swizzle stick Mounted needle Also see Technicians Item list Slowly lower cover slip onto specimen without introducing air bubbles See 7-9 above * Use the rounded end of the swizzle stick. Shake off the first large drop and then just touch the centre of the slide. This will consistently give an appropriately sized pool of liquid.

23 Low infection Medium infection Guide photos at X400 magnification High infection

24 Some data: Branch Total (not stated) East Devon Exeter Holsworthy Newton Abbot North Devon Okehampton Plymouth Tavistock Tiverton Torbay Totnes and Kingsbridge Total

25 Infection Rate nil light medium heavy Number infected Percent infected All samples % *All combs changed 2010 *More than half changed *Half comb changed *Less than half changed *No combs changed 2010 Nil Nosema in 2010 Light Nosema in 2010 Medium Nosema 2010 Nosema not recorded % % % % % % % % % 2011 Analysis

26 Table 3 Numbers of results by year Result Total Nil Light Medium Heavy (not recorded) Total Medium, 12% Heavy, 3% Table 4 Percentage of results by year Result Nil 72% 60% 62% Light 17% 19% 21% Medium 8% 15% 15% Heavy 1% 5% 2% (not recorded) 2% 0% 0% Light, 18% Nil, 66%

27 45% % testing positive for Nosema by year 25% % severity of infections by year 40% 20% 35% 30% 15% 10% Light Medium Heavy 25% 5% 20% %

28 80% 70% 60% 50% 40% 30% Heavy Light Medium Nil 20% 10% 0% No comb changes Less than half Half More than half All Results as a percentage of each comb-change category

29 Treatment advice High infection A complete comb change is essential when weather conditions are right Bailey or Shook swarm. Scorch Hive parts. Medium infection Remove as many older combs as you can and a feed additive such as Vita Gold has been useful for some people. Remove any stained hive components and scorch. Low infection Be aware. Remove a routine number of old combs and consider requeening and feed additive. Examine Apiary layout to avoid overcrowding of hives. Nil infection (Around 70% of samples) Do not be complacent and make sure that all your colonies are monitored very year not just the ones that look sick!

30 Beekeeping can be fun too!

31 My sincere thanks for support with the project and this presentation to National Bee Unit Devon Beekeepers Association Devon Branch Secretaries officers and members Nigel Lawrence for his IT expertise Dr Bryony Williams, Exeter University Biology Department Devon Bees which unwillingly sacrificed their lives for analysis Glyn Davies, Editor, Devon BKA Magazine Beekeeping President, BBKA