Diseases of Honey Bees

1. Diseases of Honey Bees Presented By The Ohio State Beekeeper’s Association

2. Diseases • Based upon date provided by the Ohio Department of Agriculture -- 2005

3. Brood Disease American foulbrood

4. Brood Disease Good healthy brood American foulbrood 2005 Apiary Statistics From ODA Colonies Inspected 21,389 Number with AFB 388 That doesn’t seem like many but this is a serious disease spread very easily and at some time or other beekeepers will experience it. American foulbrood

5. Brood Disease American foulbrood Young larva ingest the bacterial spores when fed by nurse bees.  The spores then germinate and begin to grow rapidly.  Death to the larva usually occurs as the pupae stage is reached.    Larva that die turn a coffee brown and begin to melt down into a gooey mass.   Housecleaning bees then try to remove the dead larva and in the process become contaminated with the bacterial spores that are now dormant.  The house bees then carry the spores to other bees, and the spores end up either in the honey stores or are fed again to new larva.  Thus the disease is spread within the colony rather rapidly.

6. Brood Disease American foulbrood Robbing is one of the ways that American foulbrood is spread.    Robbing bees will take back contaminated honey to their own hives which will result in larva being fed with spore laced honey.  The disease will spread to many colonies within several miles from the infected hive. You should always check for American foulbrood when examining your hives.  If you are able catch this disease early,  further spread can be prevented. 

7. Disease American foulbrood The way to test for this disease is to place a thin stick, twig, straw into a cell with this coffee brown gluey substance. Stir and draw the thin stick out. If the gluey substance sticks and ropes, it is most likely AFB. You can also take a sample of comb from this frame and have your bee inspector send it in for confirmation of AFB.

8. Disease American foulbrood Treatment: If diagnosed as AFB, the colony and bees can be treated in Ohio with Terramycin or Tylan. This must be used and consumed by the bees at least 4 weeks prior to a honey crop. These only mask the disease. The spores are not killed and can re-infect the hive The only sure way to get rid of it…

9. Disease American foulbrood Treatment: Burn ……… This is the only way to effectively destroy the disease. Other chemical treatments only mask the symptoms and it can return at a later time. However, this is a disease you must always realize is in your hives at some point in time– some bees have built up a resistance to AFB. If you burn and your neighbor doesn’t which is legal in Ohio if he treats with chemicals, have you gained anything by burning?

10. Brood Disease European foulbrood

11. Brood Disease Good healthy brood European foulbrood 2005 Apiary Statistics From ODA Colonies Inspected 21,389 Number with AFB 13 European foulbrood

12. Brood Disease European foulbrood Cause European foulbrood (EFB) is a brood disease of honeybees caused by the bacterium Melissococcus pluton.. Larvae are most susceptible to infection when they are less than 48 hours old, and usually die while still in the coiled state. Poor nutrition and severe stress, for example insecticide poisoning, often cause this disease to break out. The larvae first turn yellow then brown in color. The disease is usually noticed in early spring, and to a lesser extent in autumn.

13. Brood Disease European foulbrood Multiplication and spread The bacteria multiply vigorously in the gut of larval bees which have been given food contaminated with M. pluton.. As with American foulbrood, EFB can also be spread by: bees robbing infected hives transferring infected honey supers and combs to clean hives using contaminated beekeeping equipment feeding infected honey and pollen.

14. Brood Disease European foulbrood Treatment: Good beekeeping hygiene will keep this disease in control, however, if a hive should be found with EFB it is important to prevent any robbing of the hive and frames from this hive should not be transferred to any other hive.   Treatment with terramycin – A colony recovers rapidly.The effect of EFB is to reduce a colonies bee population and thus reduce a honey crop.  Also consider requeening if the bees are not cleaning up the disease.

15. Brood Disease Chalkbrood

16. Brood Disease Good healthy brood Chalkbrood 2005 Apiary Statistics From ODA Colonies Inspected 21,389 Number with Chalkbrood 596 Chalkbrood

17. Brood Disease Chalkbrood Identification: A fungal disease caused by Ascosphaera apis .  It is now found throughout the United States.  It is a disease of stress in the early spring to early summer.  Severe cases can be found in the comb later in the year.  Often the bees will try to remove the mummy larva -- it is called chalk brood because the mummies are chalk like in appearance and touch.  These mummies can often be seen at the entrance of the hive.  

18. Brood Disease Chalkbrood Treatment: There is no chemical approved treatment for this disease.  The best management plan would be to: strengthen a weak hive with more brood and bees, replace the queen (literature indicates that it might be genetic characteristic) with a queen of known hygienic behavior.   To avoid spreading chalkbrood, you can avoid using pollen from a chalkbrood hive for supplemental feeding and avoid mixing  frames of comb from a chalkbrood hive with other hives you may have.

19. Insect pest in hives • 2005 Apiary Statistics • From ODA • Colonies Inspected 21,389 • Varroa Mite 6,720 colonies • Tracheal Mite 41 colonies • Small Hive Beetle 539 colonies • Wax moth n/a

20. Insect pest in hives Varroa Mites 2005 Apiary Statistics From ODA Colonies Inspected 21,389 Varroa Mite 6,720 colonies The greatest threat to all beekeepers in Ohio. It has been responsible for more beekeepers leaving the hobby than anything else. This is the honey bees # 1 enemy.

21. Insect pest in hives Varroa Mites Identification: This mite is known as varroa destructor.    Varroa mites can be found in the United States except Hawaii.  The mite is small but can be seen with the naked eye.  Mites are about the size of a pin head and are reddish/brown in color. 

22. Insect pest in hives Varroa Mites They can be detected by several methods.  One is with varroa screens and a sticky board.  Mites fall through the screen onto the sticky board where then can then be detected and counted to determine the infestation level.  The second method involves checking drone brood for mites. The third method  involves scooping up 100 or so bees and subjecting them to a sugar roll or ether roll test.  The sugar roll test does not kill the bees and is preferred.  The method is simple.  Scoop up the bees into a pint jar, add powdered sugar (a tablespoon will do) and shake and roll the jar.  Varroa mites will drop off the bees to the bottom  of the jar where they can be counted.

23. Insect pest in hives Varroa Mites They can be detected by several methods.  Most common is the sticky board test. A protective screen is placed over the sticky board and the sticky board is left in the hive for a period of 24 hours. The mites on the sticky board are then counted. A sticky board can be made easily by taking a sheet of wax paper and coating it with vegetable oil. Lay it on the bottom board and place screen over it. This will also detect chalk brood.

24. Insect pest in hives Varroa Mites They can be detected by several methods.  Second method involves checking drone brood for mites like shown in the picture. You can check individual capped drone cells -- use your hive tool or a cappings fork to remove pupa from the drone comb.

25. Insect pest in hives Varroa Mites They can be detected by several methods.  Third method involves scooping up 100 or so bees and subjecting them to a sugar roll or ether roll test.  The sugar roll test does not kill the bees and is preferred.  The method is simple.  Scoop up the bees into a pint jar, add powdered sugar (a tablespoon will do) and shake and roll the jar.  Varroa mites will drop off the bees to the bottom  of the jar where they can be counted.

26. Insect pest in hives Varroa Mites They can be detected by several methods.  Remember that more than 85% of the mites in a colony are in capped brood cells and not visually detectable. If a bee inspector see one mite, he or she will indicate on inspection report that all hives in your bee yard are infected.

27. Insect pest in hives Varroa Mites Treatment: I can not tell you exactly what will work. A number of products are available for the beekeeper. Some work at times and at other times have no apparent effect.

28. Insect pest in hives Varroa Mites Treatment: In general use: Apistan strips (10% fluvalinate) CheckMite+ (Coumaphos) Formic Acid Sucrocide Apiguard (Thymol) Powdered sugar Also no chemical means such as drone comb capture frames. Don’t ask me which is best!

29. Insect pest in hives Tracheal Mites 2005 Apiary Statistics From ODA Colonies Inspected 21,389 Tracheal Mite 41 colonies Still a problem. Introduced in the mid 1880’s. A real problem in the early 1990’s in Ohio.

30. Insect pest in hives Tracheal Mites Identification:  This mite is named Acarapis woodi .  It was first identified as the Isle of Wight Disease.  This mite has become well established in the United States except Hawaii.  These mites can be observed under a microscope.  They are found in the tracheae of adult honey bees. 

31. Insect pest in hives Tracheal Mites   Highly infested hives usually die in the fall or winter.  One may find few bees in a dead hive.  This is contrary to starvation when most of the bees will be on the face of the comb -- dead.   Early detection is important.  If the beekeeper notices a rapid decline in population, the situation is already out of hand.  Fortunately, breeding better queen bees with resistance to the tracheal mite has reduced the tracheal mite problem from what it was 10 years ago.

32. Insect pest in hives Small Hive Beetles 2005 Apiary Statistics From ODA Colonies Inspected 21,389 Small Hive Beetles 539 colonies

33. Insect pest in hives Small Hive Beetles Identification:  The SHB is found primarily in the Southern states of the United States is now found in many other states especially states that import bees for pollination.  It is called: Aethina tumida .  The small beetle is black and can be found moving rapidly inside the hive when exposed to sun light. The Larvae may be mistaken for wax moth larva but they do not spin cocoons as the wax moth larva and leave a slime trail within the hive.  They can make a complete mess of a hive which can result in the loss of comb in the frames and loss of honey crop.  This beetle seems to prefer weak hives especially queen less hives to do its damage.

34. Insect pest in hives Small Hive Beetles Treatment:  Several treatments are available to the beekeeper for SHB.  First, a ground drench - SHB larva crawl from the entrance of a hive and pupate in the ground around the hive stand.  The product is called: GardStar®.  Always read label directions for the use of the product.  Second, CheckMite+ - TM a strip which controls both SHB and Varroa mites. Third , various trap designs. This is the trap designed by Mike Hood.

35. Insect pest in hives Wax Moths 2005 Apiary Statistics From ODA Colonies Inspected 21,389 Not reported in data collected by ODA.

36. Insect pest in hives Wax Moths Identification:      There are two general types found in the United States: Galleria mellonella L. the Greater Wax Moth and Achroia grisella F. the Lesser Wax Moth. Both do considerable damage to bee hives that are in weak condition and to stored comb in supers.   It is the Wax worms are a serious problem in warm weather and dark conditions.  They can do a lot of damage in a very short period of time.

37. Insect pest in hives Wax Moths Treatment:  Wax moths attack weak hives.  Strong hives will kept them under control.   Wax moths do not like light.  Exposing equipment to light, closing up equipment tightly and fumigating with "Para-moth" (Para-Dichlorobenzene crystals) a product available from most bee suppliers, and using biological control such as Bacillus thuringiensis. See Ann Harman’s article in February 2007 Bee Culture Magazine. A good investment in beekeeping is to subscribe to the bee magazines.

38. Other Minor Diseases Nosema A protozoan disease caused by Nosema apis.   Although most beekeepers do not consider this a major disease, I am going to list it as such.  It is very damaging to colonies of bees that over winter in the north.  It  kills more hives of bees than it is given credit for.  You can not see this disease because it is caused by spores which germinate in the midgut of the honey bee. Symptoms include: shortened life span, fecal deposits on the inside of the hive and often on the outside of the hive.  One way to check for nosema is to pull the digestive tract out of a honey bee.  Healthy digestive tracts are tan in color.  If it is white, the bee is usually infected with nosema.   Treatment :  The antibiotic Fumagillin sold as Fumidil-B mixed with sugar syrup and fed to the bees in the fall and spring.  Literature suggest 1 gal. of syrup per hive.  0.5 grams are mixed with 6 gallons of syrup to feed 6 hives.   This is an adult bee disease.

39. Other Minor Diseases Sacbrood Identification:  It is a viral infection of the larva and is named after the sac-like appearance of dead larvae.  The skin of the larva is tough and rubbery and if pulled from the cell with a pair of tweezers, will look like a thin sac covering the dead larva.    It is not a common bee disease. Treatment :   There is no treatment for viral diseases.  Just use good sanitary beekeeping practices while working with bees and if you find a colony with this disease, do not mix other hive frames etc. with this colony.   Replacing the queen with a queen from less susceptible stock may help.  

40. Other Minor Diseases Paralysis Identification:  It is a viral infection of the adult bee.  Often the beekeeper will notice that the bees are hairless or very glossy as in old age.  One might notice a number of bees crawling on the ground around the hive entrance, or trembling on the landing board unable to fly.   I should point out that the trembling could be a symptom of pesticide poisoning as well.   In some cases the bees just disappear or dwindle away.Treatment:  No treatment for a viral disease.  Requeening with good stock may help.

41. General Treatments • The following chart is from the 2007 Dadant Catalog. If you don’t have a copy of this catalog, you should request one from Dadant.

42. General Treatments • From Dadant catalog 2007