3.6-3.8 & 3.10 - Asian Hornet, Tropilaelaps and SHB

Question 1

SHB Facts
Latin Name

Answer 1

Aethina tumida

Question 2

SHB Facts
Lifecycle

Answer 2

Several generations per year (1-6) depending on environmental conditions
Adult bees can survive up to 9 days without food/water
Females can lay 1000-2000 eggs in lifetime
Larvae eat brood, pollen and honey and take 10-16 days to mature
Mature larvae crawl out of hive to pupate
Pupation usually occurs in soil within 20m of hive at depth of 10cm (in rare instances can crawl up to 200m!) and takes 3-4 weeks but can be between 8-84 days depending on temp
Temp above 17-25° required for completion of lifecycle
Pupation rates vary from 92%-98% in a range of soil types provided the soil is moist
Soil moisture is major limiting factor in beetle reproduction and thus population build up
Adults start to look for honey bee colonies as soon as they emerge and females generally mate and begin laying eggs about a week after emergence.
Adults can fly around 16km to infest new hives

Question 3

SHB Facts
Current

Answer 3

Indigenous to Africa
First found in USA in 1998 - now very widespread in all states
First found in Australia in 2002 - now well established and endemic in NSW, Queensland and Victoria. Detected in Western Aus
Detected in Canada in 2002 and confirmed in Quebec in 2008 (not well established)
Confirmed in Jamaica in 2005 and Mexico in 2007. Reported present in Egypt in 2000 but unsubstantiated
Intercepted and eradicated in Portugal in 2004
Confirmed in Cuba (2012)
Presence confirmed in the region o Calabria, Italy in 2014 and thought to have been eradicated in Sicily
Not currently present in UK (Notifiable pest status

Question 4

SHB Facts
Methods of spread

Answer 4

Spread by movement of package bees, honeybee colonies, swarms, honeycomb, beeswax, beekeeping equipment, soil and fruit.
Or movement of alternative hosts (bumblebees)

Question 5

SHB Facts
Damage caused to beekeeping

Answer 5

Indigenous African bees have natural defences to SHB that European honeybees don’t have.
Beetles multiply to huge numbers
Larvae tunnel through comb to eat brood
Either destroy infested colonies or cause them to abscond
They defecate in honey and thereby discolour it. The activity of the larvae causes the honey to ferment; it becomes frothy and develops a characteristic odour of decaying oranges. Damage and fermentation cause honey to run out of combs.
Can be up to 30 larvae per cell
Infested combs have a slimy appearance (no webbing as with wax moth)

Question 6

SHB Facts
Control methods

Answer 6

Cannot be eradicated once well established
Control by IPM (integrated pest management), pesticides in hive and surrounding soil
Also control with improved bee husbandry and changes to honey handling procedures in equipment storage and extraction rooms

Question 7

SHB Facts
Genetics

Answer 7

Belongs in order Coleoptera to a family of scavenger beetles known as the Nitidulidae
Many are pests of fruit and stored food and some have a close association with Hymenoptera (bees, wasps and ants)

Question 8

SHB Facts
Identification

Answer 8

Adult:
• Club shaped antennae
• Shortened wing case over the abdomen (elytra) covered in fine hairs
• Oval shape 5-7mm long by 3-4.5 mm wide. Dark brown to black.
Larvae
• Rows of spines along the back
• 3 pairs of legs near the head
(Eggs are white, 2⁄3 size of honey bee egg laid in massive numbers in crevices.)

Question 9

SHB Facts
Larval Development

Answer 9

After 2-6 days beetle eggs hatch and larvae start feeding
Prefer to eat bee eggs and brood but will also eat honey/pollen
Burrow through brood combs
Characteristic rows of spines on the back and 3 pairs of legs near head
Completed growth of 10-11mm after 10-14 days

Question 10

SHB Facts
Methods of detection

Answer 10

Using corrugated hive floor inserts:
Place plastic coated corrugated cardboard corrugated side down on bottom board towards rear of hive
Regularly examine debris under inserts for evidence of beetles or eggs
Immediately upon removal put the trap in clear plastic bag when examining it otherwise beetles will escape
Using beetle traps:
Better Beetle Blaster or Beetle Jail - disposable plastic trap inserted between frames, placed between two top bars of brood chamber. Half filled with vegetable oil and checked during each inspection

Question 11

SHB Facts

What actions should be taken by the beekeeper?

Answer 11

• Immediately report the presence to the NBU. Use Statutory Notifiable Pest form.
• Collect a sample. Place in a stiff container (match box).
• Kill the beetles by freezing for 24hrs. Place in Jiffy bag and post to NBU in York with a
completed sampling form from BeeBase.
• Impose a standstill order on the apiary. No movement of bees, equipment or hive products in or
out of the apiary.
• Standstill in force until cleared by the Bee Inspector.

Question 12

SHB Facts

What device can be used to detect the adult?

Answer 12

Corrugated card insert

Beetle trap

Question 13

SHB Facts

What could be the consequences to the beekeeper if it was discovered?

Answer 13

• Beetles multiply in large numbers. Thousands of beetles in a single hive, 30 larvae per cell.
• This generates heat and causes comb to collapse. Defecation in honeycomb causes honey to ferment and drip out of cells.
• Cells become slimy and smell of ‘rotten oranges’.
• Larvae tunnel through cells to eat brood and ruin stored honey.
• Depending on level of infection queens stop laying and colonies quickly collapse or abscond
• Beekeeper needs to adopt new IPM measures accepting pesticides in the hive and surrounding soil and changing handling practices.

Question 14

Tropilaelaps Facts
Lifecycle

Answer 14

(NBU)
The life cycle of Tropilaelaps is similar to that of Varroa although there are slight differences. Tropilaelaps has a higher reproductive rate than Varroa as it has a shorter life cycle - consequently, when both types of mite are present in the same colony Tropilaelaps populations build up far more rapidly (a factor of approximately 25:1).

Question 15

Tropilaelaps Facts
Reproduction

Answer 15

(NBU)
In order to reproduce adult mites enter cells containing larvae and start reproduction once the cell is sealed. As with Varroa, they prefer to populate drone cells.

Typically, three to four eggs are laid on mature bee larvae 48 hours after cell capping, about one day apart.
The eggs hatch after around twelve hours.
The larva goes through two nymphal stages (protonymph, deutonymph) before reaching the adult stage.
Once hatched, all stages of both female and male mites feed on the haemolymph (blood) of the developing bee.

Question 16

Tropilaelaps Facts
Development

Answer 16

(NBU)
Tropilaelaps development occurs in the following stages:

Development from egg laying to the adult stage takes approximately 6 days.
When the adult bee emerges, both adult male and female mites and the original invading mother mite exit the cell to search for new hosts.
With Varroa infestations, immature females and the male mites die in the cell.
Tropilaelaps cannot feed on adult bees because its mouthparts are unable to pierce the body wall membrane of the bees.
They depend on the developing brood for food, and move from the adult bees to feed on the larvae as quickly as possible after emergence.
The phoretic stage is much shorter than that of Varroa, and may only be between 1-2 days.
Gravid female mites (carrying eggs) will die within two days unless they deposit their eggs.
Tropilaelaps is therefore less well adapted for survival in hives where there are long broodless periods.

Question 17

Tropilaelaps Facts
Movement

Answer 17

Tropilaelaps mites are mobile and can readily move between bees and within the hive. However, to move between colonies they depend upon adult bees for transport through the natural processes of drifting, robbing, and swarming.

Mites can spread slowly over long distances in this way. They are also spread within apiaries through distribution of infested combs and bees through beekeeping management.

However, movement of infested colonies of Apis mellifera to new areas by the beekeeper is the principal and most rapid means of spread.

Question 18

Tropilaelaps Facts
Identification

Answer 18

Common characteristics of adult Tropilaelaps include an elongated body shape that is light-reddish brown in colour.
The females are about 1mm long x 0.5mm wide, but females of T.mercedesae are larger than those of T.clareae.
In both species, males are smaller than females and their bodies are less sclerotised. The mites move freely and rapidly on combs, and rely on brood for feeding; the mouthparts are not capable of piercing the membranes of adult bees. They have a life cycle similar to Varroa and it is thought that they are unable to survive for very long in broodless colonies.

Question 19

Tropilaelaps Facts
Monitoring

Answer 19

Below is a list of actions that you can take to monitor mite mortaility:

Maintain the colony on a mesh floor (commonly known as a Varroa floor) with a collecting drawer underneath.
Remove floor debris regularly during the summer.
If there is a lot of debris (e.g. after winter) mites will be very difficult to find. Mix the debris with methylated spirit in a large container. Most dead mites will float to the surface whereas wax and propolis particles will sink.
Pros

Capable of detecting very few mites
Can give a good idea of infestation level
Colony is not disturbed
Cons

Needs additional equipment
Monitoring takes several days
Encourages wax moths if debris accumulates

Question 20

Tropilaelaps Facts
Control

Answer 20

Kkeep the population at all times below the economic injury level (the point at which economic damage is equal in value to the cost of suppressive measures), where harm is likely. A combination of both veterinary medicines (acaricides or varroacides) and biotechnical methods can be used to control Tropilaelaps.
Acaricides are medicines that kill mites. These are applied either in the feed, directly on adult bees, as fumigants, contact strips or by evaporation. Many of the same acaricides used for Varroa are also likely to be effective against Tropilaelaps. Although currently there are no products specifically approved for the control of Tropilaelaps in the UK, in the event of the mite being discovered, contingency plans would be implemented and emergency approvals sought from the Defra Veterinary Medicines Directorate (VMD) to use varroacides against Tropilaelaps.

Biotechnical Methods use bee husbandry to reduce the mite population through physical means alone. Many of the effective methods involve trapping the mites in combs of brood, which are then removed and destroyed.

Tropilaelaps is considered relatively straightforward to control using husbandry methods that simulate broodless periods. The inability of Tropilaelaps to feed on adult bees, or to survive outside sealed brood for more than a few days, is a weakness in the mites’ life cycle, which can be exploited to control it. In areas where the mite is present, methods such as queen caging, the use of artificial swarms and comb trapping, to create breaks in the brood, should be effective to reduce numbers of mites.

Question 21

Asian Hornet Facts

Answer 21

Vespa velutina, sometimes known as the ‘Asian hornet’, is an invasive non-native species from Asia.
As a highly effective predator of insects, including honey bees and other beneficial species, it can cause significant losses to bee colonies, other native species and potentially ecosystems.
Active between April and November (peak August/ September). Mated queens over-winter singly or in groups, in various natural and man- made harbourages – underneath tree bark in cavities left by beetle larvae, in soil, on ceramic plant pots – potentially any small, well-insulated
refuge. In urban and rural areas it makes very large nests in tall trees (and in man-made structures such as garages, sheds, etc.), but avoids stands of conifers.