3.31 - Wax Moth Flashcards
Greater Wax Moth Facts
Huge melons
Galleria Mellonella
Bacillus
Prevented by B401 (certan - biological treatment which kills them in all stages)
Lesser Wax Moth Facts
griselly
Achroia grisella
Prevented by B401 (certan - biological treatment which kills them in all stages)
Methods of controlling wax moth
- Keep strong colonies
- Avoid cracked kit
- Remove moth larvae on comb
- Keep apiary tidy - don’t leave comb lying around as wax moth likes feeding on larval skins and pupal cases
- Don’t leave OMF monitoring tray in except when montioring
- Scorch boxes, esp corners, and stack comb over QE with newspaper between them to restrict movement between boxes.
- Fumigate with 80% acetic acid (150ml on a pad per box - vaseline on metals, seal boxes with tape, 7 days and then air)
- Spray with solution of Bacillus thuringiensis (trade name Certan), and leave to air dry before storing frames- kills WM larvae for one year - this does not harm bees so can be used in season.
- Heat combs to 46˚C for 1 hour
- Freeze combs to -0˚C for 5 hours
Life cycle of the greater wax moth
35 degrees - optimal temp - one month
Galleria mellonella
- Female moths leave the hive soon after hatching. Males produce a pheromone and an ultrasonic sound to attract females.
- After mating, females enter a hive or box of unoccupied comb and lay a large number of creamy white eggs depositing them in batches in cracks and crevices in boxes and combs to avoid then being eaten by the bees.
- After a few days they hatch into larvae that are dull white in colour with a reddish brown head.
- Larva can digest wax but prefer old larval and pupa skins of the bees and pollen.
- The rate of development depends on the temperature but once fully grown they change into pupae each enclosed in a silken cocoon.
- As they prepare to pupate they excavate hollows in the woodwork and may even make holes in frames where they spin their cocoons. At this stage they are also very gregarious lining up in rows very close to each other so causing much damage to frames and hives.
- After about a week the new generation of moths emerge and the cycle starts again.
- At optimum temperature of 35℃ the whole cycle can be completed in four weeks.
- At less than optimum temperatures the cycle can take up to six months being able to overwinter in both the larval and pupa stages.
How would wax moth in a colony be identified during an inspection?
- Might see an adult in the hive. Grey moth with reddish brown anterior wings bearing mottled spots and pale cream-whitish hind wings. 15mm long. Best caught and destroyed.
- Larvae up 12-20 mm long. Well developed mandibles. Four pairs of abdominal ‘pro’ legs. May be tunnelling through the combs leaving a silken tunnel containing their faeces and bits of wax - very messy.
- If left, the whole comb can disintegrate into a mass of silken webs and frass which is completely unusable.
- The larvae burrowing through the cappings causes bald brood.
- The pupae huddled together are easily spotted and can be removed.
Lifecycle of Lesser Wax Moth
- Female moths leave the hive soon after hatching. Males produce a pheromone and an ultrasonic sound to attract females.
- After mating, females enter a hive or box of unoccupied comb and lay a large number of creamy white eggs depositing them in batches in cracks and crevices in boxes and combs to avoid then being eaten by the bees.
- After a few days they hatch into larvae that are dull white in colour with a reddish brown head.
- Larva can digest wax but prefer old larval and pupa skins of the bees and pollen.
- The rate of development depends on the temperature but once fully grown they change into pupae each enclosed in a silken cocoon. In optimum temps this is 2-3 weeks
- After about a week the new generation of moths emerge and the cycle starts again.
- At optimum temperature of 35℃ the whole cycle can be completed in less than four weeks (less than GWM).
- At less than optimum temperatures the cycle can take up to six months being able to overwinter in both the larval and pupa stages.
Wax Moth - Greater and Lesser and comparison
The Greater Wax Moth (Galleria mellonella) is more destructive and prevalent than the Lesser Wax Moth (Achroia grisella). It drills holes in woodwork when preparing to pupate. Grisella usually pupates on the comb
Larvae of two species difficult to tell apart but when disturbed, Melonella tends to run and Achroia Grisella stands till feigning death
Larval stages differ slightly in time - Grisella 2-3 weeks, Melonella 4 weeks (rates of development vary dependent on temp.
Lifecycle: Grisella takes less time than Melonella - Mellonella takes 4 weeks
Both in pupal stage for about a week
Methods of treating for wax moth
FUMIGATION
- Fumigation with 80% acetic acid is effective against Nosema and wax moth.
- The acid needs to be treated with care as it can burn skin, ruin clothing and cause damage if inhaled. Wear gloves, overalls, eye protection and a breathing mask.
- Start with a solid floor, not concrete or metal as these will be attacked by the acid vapours. Place the first brood box/super with the comb to be sterilised on top. Place a square (12x12cm) of plastic sheeting on top of and in the centre of the frames with an absorbent pad on top. Soak with about 140ml Acetic Acid.
- Additional boxes and pads as required.
- Cover the top with a crown board and roof.
- There should be no gaps so best seal all gaps and joins with packing tape or similar. Better still seal with plastic sheeting or large plastic bags. The aim is for minimum escape of the fumes.
- Fumigate for at least a week and then ventilate for a further week before use.
- The frames should first be scraped clean and the boxes torched especially in the corners where AFB might lurk.
CERTAN (B40)
- Spray both sides of each frame with Certan (a suspension of Bacillus thuringensis)
- This provides protection from for a year. Does not taint wax or honey.
- Effective agains wax moth larvae.
FREEZING
• A hard frost outside will kill all stages of moth or 48 hours in the deep freeze.
Wax moth Identification
Greater Wax moth (Galleria melonella)
- 25-35mm wing tip to wing tip
- mottled buff and brown forewings with paler hind wings
- concave shape of outer edge of forewings
- Larvaetends to run when disturbed
Lesser Wax moth (achrioa grisella)
- 15-20mm wing tip to wing tip
- Overlapping wings at rest
- Silvery grey colour, pale almost white head
- Larvae feins death when disturbed
