Integrated Varroa Management 4, Guide Tables

The names of the various organisations keep changing, so I have decided only to update when necessary. I will try to keep the buttons up to date. R.P.

National Bee Unit
South West Region

Integrated Varroa Management 4, Guide Tables.

The table below has been drawn up using data from the graphs in the CSL handout 'Treatment Thresholds'. It gives a simplified plan of what to do when you have estimated daily mite mortality. It can be adapted to suit your own needs.

The best method of deciding what action to take is calculating the mite population in the colony and using the treatment threshold graph.

Seasonal Action.

Timing Average Natural Mite Mortality per Day

Jan. to March. Less than 2
No Action Between 2 and 7
Plan Control for Coming Season Over 7
Consider Control

April to June. Less than 1
No Action Between 1 and 7
Light Control Over 7
Severe Risk

July & August. Less than 2
No Action Between 2 and 8
Light Control Over 8
Severe Risk

September to December Less than 6
No Action Between 6 and 8
Light Control Over 8
Severe Risk

Timing	Average Natural Mite Mortality per Day
Jan. to March.	Less than 2 No Action	Between 2 and 7 Plan Control for Coming Season	Over 7 Consider Control
April to June.	Less than 1 No Action	Between 1 and 7 Light Control	Over 7 Severe Risk
July & August.	Less than 2 No Action	Between 2 and 8 Light Control	Over 8 Severe Risk
September to December	Less than 6 No Action	Between 6 and 8 Light Control	Over 8 Severe Risk

If you are assessing mite populations using the 'Quick Guide' in the 'Measurement of Varroa Mite Populations' handout, i.e. making a quick assessment by forking out drone pupae, then handy tables can be made up like the one below. It must be pointed out that this is a rough guide only and is dependant upon drone brood being present. It may be helpful if routine drone brood removal is practised as the pupae can be easily examined for infestation.

These tables are drawn up based on an assumption that the brood nest contains 20,000 occupied brood cells, of which 5% are drone.

Drone Brood Tables.

Table 1. Number of Infested Drone Pupae

Up to June. Less than 1 in 60
No Action Between 1 in 60 & 1 in 25
Plan Control for Coming Season Over 1 in 25
Consider Control

June & July. Less than 1 in 30
No Action Between 1 in 30 & 1 in 15
Light Control Over 1 in 15
Severe Risk

August. Less than 1 in 20
No Action Between 1 in 20 & 1 in 10
Light Control Over 1 in 10
Severe Risk

Table 1.	Number of Infested Drone Pupae
Up to June.	Less than 1 in 60 No Action	Between 1 in 60 & 1 in 25 Plan Control for Coming Season	Over 1 in 25 Consider Control
June & July.	Less than 1 in 30 No Action	Between 1 in 30 & 1 in 15 Light Control	Over 1 in 15 Severe Risk
August.	Less than 1 in 20 No Action	Between 1 in 20 & 1 in 10 Light Control	Over 1 in 10 Severe Risk

Table 2. Proportion of infested drone pupae

Up to June. Less than 2 %
No Action Between 2% and 4%
Plan Control for Coming Season Over 4%
Consider Control

June & July. Less than 3%
No Action Between 3% and 7%
Light Control Over 7%
Severe Risk

August. Less than 5%
No Action Between 5% and 10%
Light Control Over 10 %
Severe Risk

Table 2.	Proportion of infested drone pupae
Up to June.	Less than 2 % No Action	Between 2% and 4% Plan Control for Coming Season	Over 4% Consider Control
June & July.	Less than 3% No Action	Between 3% and 7% Light Control	Over 7% Severe Risk
August.	Less than 5% No Action	Between 5% and 10% Light Control	Over 10 % Severe Risk

These two tables are a rough guide only.

As the least rough guide, 15% of drone brood infested indicates a colony that may collapse.

The tables are based on a 'worst case scenario'.