We are please to re share this very interesting blog by the team at GreenCast Advisory, which looks at the latest leatherjacket population counts.
Over the Christmas holiday we began to see some LeatherJacket damage. In my last Blog I wrote about the journey the offending grubs have been on since birth.
If you’re seeing damage or you feel there is a chance of LeatherJackets in your sward then having a good understanding of the population will help you make good decisions about what agronomic decisions to make, particularly for fertiliser programmes and aeration.
Population counts are pretty easy, get yourself a board or tarp and leave it on your surfaces overnight. The important thing is that it keeps the moisture in, keeps the light out and doesn’t blow away. I had some made up by Covers & all and are well worth investing in.

Lift it in the morning and then count what you find. Bare in mind that the LeatherJackets will be small so this it’s a time consuming job and during these early stages of the LeatherJackets life it’s a job that requires some commitment. You’ll need to get on you hands and knees and look closely.

This is a trial we have in place where we’re evaluating optimum timings for Acelepryn and I know it’s a painstaking task because I speak from experience!
This is not worth doing until the temperatures lift, I think around 5 – 6 C overnight is about the stage it’s a worthwhile exercise.
What to expect?
In the above trial we saw:
- Good quality turf – under 12 LeatherJackets M2
- OK turf quality – 13 – 24 LeatherJackets M2
- Poor turf quality – over 25 LeatherJackets M2
Of course this a one off trial but as move further into a world with fewer controls this kind of monitoring will become increasingly important.
Since you got this far I guess you’ll be interested in the Acelepryn trial – it’s early days but its showing some really positive results that we’ll learn alot from.

You can see the difference between untreated and treated here showing obvious control – the challenge is stopping the LeatherJackets from the left hand plot walking into the plot on the right.
Watch this space.
leatherjacket population counts by Glenn and team
For another couple of interesting blogs by Glenn check out the link below, one is of real interest of why aeration maybe encouraging leatherjackets –https://greencastadvisory.net/