Tracheal Mite

 

Causal agent

Acarapis woodii – mite.  The mite is 143-174 mm long in the female and 125-136 mm long in the male.

 

Age group

Parasitises young bees up to 2 weeks old

 

Egg

Larvae

Pupae

Adult - worker

Drone

Queen

 

No

No

No

Yes

Yes

Yes

 

Clinical signs

 

 

None

 

May contribute to Colony Collapse Disorder

 

 

Bees may have disjointed wings and be unable to fly.  Seen crawling around the entrance

 

 

Bees die early

 

Honey production reduces

 

 

Tracheal mites inside a honey bees trachea x100

Greasy patty to control Tracheal mite infestation

 

Infectivity

 

 

Very infective.  Most colonies are infected

 

Transmission

 

 

Between bees.

The first egg hatches is a male and the subsequent mites are female.  The male mates with his sisters

 

Post-mortem Lesions

 

 

Mites live in the prothoracic tracheal system.  There may be 100’s of mites in a single bee.

 

Diagnosis

 

Dissection and examination of the prothoracic tracheal system especially those found crawling around the entrance.  Other Acarapis mites have different habitats.

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Description: DSC01286

Healthy uninfected tracheae

Stained tracheae indicating severe infection

 

Obtain fresh bees and place in 70% ethyl alcohol as soon as possible awaiting detection.

 

Diagnostic method:

 

Pin the bee on its back. 

Remove the bee’s head and first pair of legs by pushing them off with a scalpel or  razor blade in the downward and forward motion.

 

Description: bee postmortem trachea

 

Cut a disk of thin transverse section of the pot

 

Description: D:\2010\1009\pics 1009\Bee anatomy tracheal tubes2 exam.jpg Description: D:\2010\1009\pics 1009\Bee Anatomy throrax mid label.jpg

 

Place the disk on a microscope slide and add a few drops of lactic acid.  This makes the material more transparent and helps to separate the muscles.

 

With the aid of a dissecting microscope carefully separate muscles and examine trachea.

 

Remove suspect trachea and examine at x40-100.

Note the mites are extremely common and may be present without any clinical signs.

Treatment

 

Grease patties placed in the autumn through winter – they interfere with the ability of the mite to recognised the young bee

Grease patty – Vegetable shortening plus sugar (1:3 ratio).  Add 4.5g peppermint flavouring.  Place handful of patty place on waxed paper top and bottom and place between the two boxes.  Remove top layer of waxed paper.

Some Russian bees are claimed to be resistant

Reduce drifting and robbing

Re-queen annually to keep strong colonies

Reduce other stresses

Maintain excellent biosecurity

Menthol fumes are toxic to the mites.  Fume all equipment.  Note requires warmth to make the menthol crystals fume.

Formic acid can be used on the bottom boards.  This can be useful to control tracheal mite.  Administer 30 mls every week for 3 to 5 applications in the spring.   Then again in June.   Air temperature needs to be above 22C but below 30C

Other

The condition is associated with Acute and Chronic paralysis virus

Common differentials

There are two other Acarapis spp affecting Honey bees, A. externus,  A.doralis.

These are none pathogenic but look extremely similar.

Zoonosis

None

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