How do I control Black Beetles in my lawn?

Author: Jon Lamb   Date Posted: 7 March 2018 

At last, a simple and much safer solution for controlling black lawn beetles.

During summer and early autumn, far too many Adelaide lawns are regularly bombarded with chlorpyrifos (an extremely toxic and environmentally damaging chemical) in an often futile attempt to control black lawn beetles and their witchetty grub-like larvae.

The alternative is to spray the lawn with a relatively new but very low toxic systemic chemical containing imidacloprid (Confidor, Bug Kill, Conquest and others). In this case, the aim is to kill the black beetle larvae in spring well before they begin damaging your lawn by feeding on their roots.

Black beetles overwinter in lawn grass before mating and laying eggs anytime during spring. During late spring and early summer, the overwintering generation of beetles dies.  Meanwhile, the grubs or larvae that started life early in spring begin to emerge as lawn foraging beetles. At this stage, it’s possible to have both adults and larvae feeding on your lawn and if the problem is ignored, dead lawn patches quickly appear.

Imidacloprid is new aged technology designed to kill soft bodied and sap sucking insects at a very low concentration.  When it is mixed and ready to spray, it has a very low toxicity to humans and animals. However, being systemic, it is absorbed by the roots of lawn grasses and while it kills all root eating lawn grubs, it has no effect on other beneficial insects in the soil. Imidacloprid remains active in the soil for up to three months.  This is a major breakthrough as an infestation of either lawn beetles or lawn grubs (or both) can occur over an extended period.

Quick guide to lawn beetle attack

A preventative spray with imidacloprid is warranted if

  • You experienced serious damage (bare patches, loose turf (easy to pull)) from either lawn beetles or lawn grubs last season.
  • You observed or observe large numbers of black beetles in your lawn this spring.
  • Large numbers of birds continue to land on your lawn and appear to be feeding (on lawn grubs).
  • You find very large numbers of witchetty grub-like larvae in garden beds adjacent to your lawn (five to six grubs per spadeful).

When to spray

  • The best time to spray your lawn for beetles and beetle larvae is October and March.

What to use

  • The best product on the market for home gardeners is Yates Complete. It contains 2 active ingredients - one being the imidacloprid I have already mentioned for the control of the larvae, and the other is called Cyfluthrin which will conrol the adult beetles.

Is it really lawn beetles?

Bare patches caused by lawn beetles and their larvae are easily confused with a range of management issues including

  • Compacted soil
  • Poor (uneven) watering
  • Annual weeds with a spreading canopy coming to the end of their growth cycle
  • Lawn diseases.

Experienced gardeners are quick to point out your best defence against black beetles is a well managed vigorous lawn. A healthy lawn can tolerate low populations of lawn beetles and their larvae

Comments (6)

Lawn bettles

By: on 27 February 2018
I have an infestation of lawn bettles. I have treated lawn twice with richgo lawn an bettle killer. Am i better changing products??? We can i get the above yates product?? Bunnings or is there a commercial product i can get applied. I am from perth and live on the coast

Paul Munns Instant Lawn Response
Hi Michael. You need to use a beetle killer with an active called Imidacloprid such as Yates Complete. You can't get it from Bunnings but most smaller Mitre 10 stores sell it. If you have no luck there, you can get it from our webstore

Timing for black beetle eradication

By: on 21 February 2018
It is now late summer and both front and back lawns have been almost decimated by black beetle despite sevetal applications of various products. What can I do at this time of year to eradicate them and give my lawns a chance to regenerate.

Paul Munns Instant Lawn Response

It is possible that your issues are not Beetles. With the limited amount of information I have about your circumstances, I suspect that there could be other issues at play.

As far as rulling beetles out as the cause of your problems, there are a couple of reasons that beetle killers won't work properly. 1) timing: It is important to time your applications. The best times are November and March.  If you miss these windows, the larvae can grow too big and become resistant to chemical controls. 2) The product you use. Most products target the adult beetle, not the larvae. Its the larvae eating the roots of your lawn rather than the adult so its important to apply a product that contains an active ingredient called imidacloprid such as Yates Complete or Brunnings Lawn Grub and beetle kill. If you've applied one of these chemicals at the right time, then your problem isn't beetles as these products are extremely effective and last in the soil for 3 months. 


Black beetle

By: on 11 February 2018
We are relandscaping, have just removed the front lawn , so we have just dirt. I was digging around a water pipe to relocate and found 8 black beetles in 1 metre, I assume the whole front is the same about 100 metres. Is there anything we can do now as we are putting new turf down in a couple of weeks

Paul Munns Instant Lawn Response

Hi Robert,

As a precautionary, you could treat the area with Yates Complete which will last in the soil for 3 months making sure you don't get any issues with these critters for the rest of the season.

Lawn beetle in Kikuyu

By: on 29 January 2018
I am experiencing this problem now. Is it too late to spray confidor?

Paul Munns Instant Lawn Response

No - Its a good time of year to spray confidor. Yates have a new product called Complete. Where Confidor only controls the larvae, Complete controls the larvae and the adult. 


By: on 14 January 2018
Do black beetles that live in the lawn also eat dung or they a different beetle.

Paul Munns Instant Lawn Response

Black beetles dont eat dung and are different to the dung beetle.

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