Diseases and Pests of Honeybees

Transcription

1 Diseases and Pests of Honeybees Diseases of Brood Diseases of Adults Parasites Predators

2 Healthy Brood Important to Know What Healthy Brood Looks Like When Something is Abnormal it will be Obvious

3 Brood Development

4 Eggs

5 Healthy Larva - White, Plump

6 Healthy Eggs Healthy honey bee eggs normally are laid, one to a cell, by the queen. Each egg is attached to the cell bottom and looks like a tiny grain of rice. When first laid, the egg stands straight up, on its end. During the three-day development period, however, the egg begins to bend over. On the third day, the egg hatches into a tiny grub and the larval stage begins.

7 Healthy Larva - White, Plump

8 Larvae Healthy worker, queen and drone larvae (grubs) are pearly white in color with a glistening appearance. They are curled in a "C" shape on the bottom of the cell and continue to grow in size during the larval period, eventually filling their cell.

9 Sealed Brood

10 Healthy developing worker, queen and drone cells are capped after larvae are approximately 5.5, 6 and 6.5 days old, respectively.

11 Pupa The period just after the cell is capped is called the prepupal stage. During this stage, the larvae stretch out lengthwise in the cell and spin a cocoon. Larvae remain pearly-white, plump and glistening during the prepupal stage.

12 A healthy worker brood pattern is easy to recognize; brood cappings are medium brown in color, convex and without punctures. Healthy capped worker brood normally appears as a solid pattern with only a few uncapped cells; these may contain eggs, or uncapped larvae, nectar or pollen

13 New workers, queens and drones emerge approximately 12, 7.5 and 14.5 days, respectively, after their cells are capped. Individually, they must chew through the wax capping covering the beeswax cell in which they developed. They assume normal adult duties almost immediately.

14 Healthy Adults Wings Are Fully Formed & Iridescent Wings Are Kept Folded When Not Flying ( No K Wings) Adults are Hairy not Shiny

15 Summary Healthy : Eggs and larvae are pearly white and plump Capped brood is medium brown, convex with few missed cells -- more or less solid pattern / cappings are not perforated Adults have a overall healthy appearance with iridescent wings that are normally folded when not flying

16 Brood Diseases American Foulbrood European Foulbrood Sac Brood Chalk brood

17 American Foulbrood Paenicillus larvae

18 American Foulbrood Affects Honeybee Larvae AFB is a spore forming bacterium AFB is one of the most serious diseases of Honeybees

19 AFB brood can appear black and shiny The cappings are perforated and sunken

20 AFB Infected Larvae The young larvae are infected in the first two days of life. Larval death occurs after the cell is capped when the larvae is in the prepupal or early pupal stage

21 AFB Infected Larvae The young larvae turn coffee colored The larval remains continue to deteriorate and becomes quite odorous Hence the term Foulbrood

22 When a probe is inserted in an infected cell, the contents rope out Classic AFB Symptom

23 Scale The larva dies and is not removed from the cell The larval remains dry and become impossible to remove --this is Scale The larval tongue becomes prominent

24 Why is AFB such a Problem AFB is a spore forming Bacterium This means one infected cell produces billions of infected spores These spores await conditions that are ripe for sporulation. Spores can wait for a few weeks or 40 years Spores get in the infected colony s honey. As the infected colony weakens they are subject to robbing from other colonies Colonies feed infected honey to their brood

25 Spores get on the surfaces of supers and frames Years later infected equipment can cause disease in a reestablished colony

26 Treatment and Prevention - Prevention First

27 Hygenic Behavior Preventions Queen Breeders Have Bred Bees That are Very Good at Uncapping and Removing Dead Brood This may be enough to prevent an infection from getting a foot hold

28 Prevention Inspection and early detection may prevent the disease from spreading to other colonies

29 Prevention This is under the category prevention because it is ineffective as a treatment As a prevention measure it is useful

30 Prevention Terramycin kills the vegatative stage of the bacterium. This can prevent sporulation and arrest the progress of the disease

31 Prevention The problem is Terramycin does nothing to the spores The spores sporulate, start to grow (vegetative state ) The vegetative state takes up nutrients and Terramycin can act Colonies that show symptoms should not be treated with TM

32 Treatments Destruction of Bees and Fumigation of Equipment Burning of Equipment

33 Fumigation AFB spores are hard to kill ETO sterilant gas Fumigation spares good comb and equipment

34 Burning This is the preferred method for old, rotten equipment or where fumigation is not available

35 European Foulbrood Mellisoccus Pluton Caused by a non-spore forming bacterium Appearance similar to AFB

36 European Foulbrood Mellisoccus Pluton Appearance may be similar to AFB Sunken perforated cappings May be discolored Cells may not be capped at all

37 European Foulbrood EFB Kills the larvae at an earlier stage than AFB The larvae appear curled & twisted instead of stretched out

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40 Treatment TM is an effective treatment M. Pluton is not a spore former Infection is not as serious as AFB It will sometimes resolve itself

41 Chalk Brood Ascophaera apis Caused by a spore forming fungus Is not usually a serious disease

42 Chalk Brood Ascophaera apis Dead Larvae look whitish and dry They are easily removed from the cells Dead larvae are referred to as mummies

43 Chalk Brood Ascophaera apis Mummies are white and gray The color comes from the fruiting bodies of the fungus

44 Treatment Requeen colonies with a bad case Hygenic behavior helps to control the disease

45 Sac Brood Caused by a Virus Sacbrood virus SBR Larvae are dead with tails straight up

46 Sac Brood Larvae are easily removed intact in their larval skins sac Sac is full of virus particles Usually worse in the Spring No Treatment

47 Parasites Varroa Mites Varroa destructor Trachael Mites Acarapis woodi

48 Trachael Mites Acarapis woodi Caused by small microscopic internal mite Trachael mites infect the trachea of bees Trachea are the breathing tubes for bees

49 Microscopic view of trachea Tracheal Mite

50 They can be present in great numbers Mites pierce the tracheal wall and suck haemolyph ( bee blood)

51 Mites have a small beak-like mouth for piercing and sucking

52 Infestations like this can cause problems Bees become short lived and weak Flight muscles are affected

53 These bees are crawling but can t fly Some have K wings Fortunately pictures like this are not common anymore Bees are becoming much more tolerant and resistant to Trachael mites

54 Detection Microscopic examination of the trachea Thoracic Disks

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56 Treatment Menthol is the only approved treatment Some use menthol shop towels Some beekeepers don t treat anymore

57 Varroa Mites Varroa destructor Large external parasite Ecto-parasite Parasitizes brood and the Adult Reproduction takes place in the cell with the brood Mites suck blood from the larvae

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59 Different Ages of Varroa on Emerging Drone

60 Varroa on Larvae High levels can cause serious problems Deformed or dead workers Low colony population Colony death

61 Damaged or Dead Brood

62 Deformed Wings

63 Detection Ether Roll

64 Detection Ether Roll step 2

65 Mites Stick to the Jar

66 Sticky Board Slipped under Colony Mites fall from Brood and are trapped in sticky stuff Can be used for natural mite fall counts

67 Check the Drone Brood Mites show a preference for drone brood Use a tool, in this case an uncapping fork, to disturb the drone larvae to find varroa

68 Treatments Apistan Fluvalinate Check Mite Coumaphos

69 Treatment Summary Keep mite levels under control Varroa is one of the most serious pests of Honeybees Some Mites are Resistant to Apistan Current recommendation is to alternate between Apistan and CheckMite Treat when threshold levels are reached Follow label directions

70 Treatment Summary IPM approach Monitor levels Treat when thresholds are reached Screened bottoms may play a part in IPM approach

71 Treatment Summary The pest threat is dynamic Recommendations change as the pest changes Genetics and breeding are the future

72 Keep mite levels under control Varroa is one of the most serious pests of Honeybees Summary Varroa is an external parasite of Honeybees Varroa attacks both brood and the adult bees Varroa can kill a colony without intervention on the part of the beekeeper

73 Nosema Apis Caused by a protozoan Affects bees midgut Causes water retention Causes Dysentery

74 Detection Normal midgut is straw colored or translucent Infected one are white or milky

75 Treatment Not a major problem in eastern NC It does crop up from time to time Use Fumadil to treat according to Label Protects queens and Nucs

76 Small Hive Beetle Athena Tumida

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78 Small Hive Beetle Larvae

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80 Bad Infestations are Ugly Usually doesn t get this bad This pest needs monitoring carefully if found in your colony

81 Small Hive Beetle The larval stage eats just about anything Including: Bee larvae Pollen Honey Adult beetles are adept at avoiding irate workers Weak colonies are especially susceptible

82 The SHB slime is caused by yeast The slime encourages fermentation In bad cases the bees abscond and abandon the colony

83 Life Cycle The adult beetle enters the colony and finds food and shelter Females find mates and lay eggs One female can lay thousands of eggs in a month Populations can explode in a short time under ideal conditions

84 Life Cycle The larvae feed on pollen, honey and young bee larvae After completion of the larval stage they migrate out of the colony into the ground In the ground (soil) they molt several times and finish their development They emerge from the soil as Adults This can be as little as 3 weeks or longer if conditions are hostile

85 SHB can infect colonies with or without honeybees Honey houses and super storage areas can be infected It is at least a problematic nuisance and at worse a serious threat to to colony survival

86 Treatment Soil treatment around colonies can deter reproduction Checkmite is approved for SHB control Use as directed on the label

87 Summary Be Vigilant Control / CheckMite Keep Colonies Strong

88 Wax Moth (Galleria melonella) A pest that destroys Honeybee combs Larval stage eats the debris in comb and in doing so totally destroys it

89 Comb Damage

90 Cocoons Damage Frames

91 Control The best control is a strong colony

92 Other Controls Para Di-chorobenzene PDB cyrstals Not Naptha Freezer

93 Skunks Not a problem in Most of Eastern NC Scratch on hive and then eat the bees

94 Skunks Feces tell the tale Skunks chew the bees and the exoskeletons pass through in the feces

95 Black Bears Bears can cause a tremendous amount of damage Bears are found in much of Eastern NC Western NC has its share too

96 Control Avoid bear country may not be practical Electric Fence works as long as its hot!

97 Summary Brood Diseases American Foulbrood European foulbrood Sac Brood Chalbrood Varroa Mites Trachael Mites Small Hive Beetle Nosema Wax Moths Bears

98 Beekeeping can be fun in spite of the litany of pest, predators and diseases Contact your NC Dept of Agriculture State Apiary Inspector for Assistance