Beekeeping Education

Honey Bee Disease Identification Chart

emmettroyalhoney
July 30, 2022

This chart aims to provide beekeepers with an easy-to-use reference out in the field when they come across suspected diseases in their hives. We will continue to improve this chart toward that goal. The quicker you, as a beekeeper, can spot and identify potential issues within your hive, the more successful you will be at keeping your honey bees alive and thriving.

Chart Layout

Diseases

Causative Organism

Brood Comb Appearance

Affected Brood/Bee Age

Dead Brood Position/Color

Diseases

Dead Brood Texture

Smell Of Brood

Brood/Bee Appearance

Field Identification

Bacterial Diseases

American foulbrood

Paenibacillus larvae

Capped brood with dark, sunken, greasy, and punctured cell cappings. Spotty brood pattern.

Older sealed brood, usually, prepupae or young pupae.

Dead Brood Position/Color

American foulbrood

Soft & gummy becoming sticking and ropey

Strong putrid "fish-like" odor

Dead brood forms a dark brown or black scale that adheres firmly to the cell wall. In addition, pupal tongue in scale may be evident.

Once stirred with a toothpick, decomposed pupae (typically under perforated cell) strings out about an inch.

European foulbrood

Melissococcus plutonius

Larvae stage, rarely capped. Spotty brood pattern.

Young unsealed larvae at the "C" stage of development.

Off-white/yellow to brown with chalky white midgut and silvery tracheae visible through body wall. Larvae lie in irregular positions.

European foulbrood

Watery and having small grains or particles.

Varies from none to sour in smell.

Dead larvae are distorted and twisted in cells or have a melted appearance. Scale is rubbery but easily removed from the cell. Not as hard or dark as AFB scale.

Visible tracheae and having a darkened appearance, and twisted/distorted in the cell.

Spiroplasmas

Spiroplasma apis, S.melliferum

No noticeable symptoms

Adult honey bee

No noticeable symptoms

Spiroplasmas

No noticeable symptoms

None.

Infected bees exhibit neurological problems

Shaking, disorientated adult honey bees. Heavy death loss. Bees may die away from colonies, so a low/declining population may be evident.

Fungal Diseases

Chalkbrood

Ascosphaera apis

Perforated cell cappings and mummies. Unsealed or sealed brood.

Usually older larvae.

Chalk white, sometimes black or grey dense mummies, positioned upright in cells.

Chalkbrood

Paste-like

None to slight (non-repellent) odor.

Hard, smooth mummies do not adhere to cells and are easily removed.

Mummies from white to dark in color at the hive entrance and bottom board, scattered throughout brood cells.

Stonebrood

Aspergillus

Mummies with hard yellow or greenish color, both sealed and unsealed.

From larvae and pupae to occasional adults.

Harder than chalkbrood, yellow to grey-green cadaver. Larvae and pupae die in regular positions.

Stonebrood

Hardened body - tough to crush.

None.

Initial whiteish-yellow collar-like ring near head of larvae. After death, body hardens. Fungus eventually forms a false skin, covering cadaver with powdery fungal spores.

Restless, crawling adult bees with swollen abdomens that harden at death. Yellowish or greenish hard mummies.

Nosema

Nosema apis, N. ceranae

Brood comb may be contaminated by the feces of honey bees.

Adult.

No symptoms.

Nosema

No symptoms.

None.

No symptoms.

Colonies display poor population growth and honey production. Queen supersedure increases in highly infected colonies. Dysentery in front of hive, crawling bees (N. apis only).

Viruses

Deformed Wing

Deformed Wing Virus

No symptoms.

May affect all life stages without clear symptoms. Noticeable on pupae and adults.

No symptoms.

Deformed Wing

No noticeable symptoms.

None.

Dead pupae. Small, discolored adults bees with shrunken, crumpled wings.

Bees with shrivelled wings.

Sacbrood

Sacbrood Virus

Sealed brood with perforated cell cappings.

Usually, sealed prepupae.

Greyish to yellow larvae becoming black with head darker, positioned upright in cells.

Sacbrood

Watery, granular, with a tough sac-like membrane. Removed easily from cells, intact.

None- to slightly sour odor.

The dried scale lies flat with the head curled to the center of the cell. Scales are rough, brittle, and do not adhere to the cell walls.

Watery, granular in a tough, sac-like membrane.

Black Queen Cell

Black Queen Cell Virus

No symptoms.

May affect all like stages without apparent symptoms. Noticeable in prepupae or pupae stage.

Initially yellow then darkening after death.

Black Queen Cell

Tough sac-like skin.

None.

Queen cell wall becomes dark brown to black after the death of pupae.

Dead queen pupae with black cell walls. Associated with Nosema spp. infections.

Bee Paralysis

Chronic Bee Paralysis Virus, Acute Be Paralysis Virus, Kashmir Bee Virus, Israeli Acute Paralysis Virus.

No symptoms.

Pupae and adults. It may affect all life stages without apparent symptoms.

No symptoms.

Bee Paralysis

No noticeable symptoms.

None.

Pupal and adult paralysis. Trembling, bloated, shiny adult bees with little hair, unable to fly or having disjointed wings.

Trembling, crawling, adult bees.

Parasitic Mites

Trachael Mite

Acarapis woodi

No symptoms.

Adult.

No symptoms.

Trachael Mite

No symptoms.

None.

No symptoms.

Crawling bees at the entrance, unable to fly, sometimes in large numbers.

Varroa Mite

Varroa destructor

No symptoms.

Adult, prepupa, and pupae

No symptoms.

Varroa Mite

No symptoms.

None.

No symptoms.

May see a red female mite adhering to an adult bee on or near the abdomen. Whiteish spots (mite feces) inside recently emerged honey bee cells. May see, with heavy infestation, increased symptoms of other viruses and diseases present.

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