How to identify and control black beetle damage in 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 (32)

Dog Safe?

By: on 16 April 2020
We have a lot of African Army Beetle and my husband has used numerous chemicals to get rid of them to little/no avail. I am starting to think our dog's scratching (he has sensitive skin) may be a result of these chemicals. Is Yates Complete safe to use around dogs? And if not, can you suggest something else that is safe for dogs please?

Paul Munns Instant Lawn Response
Hi Sally Thanks for your query Yes, Yates Complete is safe to use around dogs. Just allow a few hours drying time

Beetle larvae

By: on 15 February 2020
When it rains, i have large amounts of grub like creatures on my sidewalk and porch. The sidewalk is covered. I've been told they are ground beetle larvae. We are having a very warm and wet February. Will this work on them and prevent beetle infestation in the spring??

Paul Munns Instant Lawn Response
Hi Hope Thanks for your query You can use a product called Yates Complete, this will control beetle larvae and last in the soil for up to 3 months and shouldn’t need reapplying until Spring Regards......Andrew

Beetles and larvae in my lawn

By: on 13 January 2020
Hi, was wondering why my lawn had dead patches - and we called in the gardeners. They confirmed that parts of the lawn are infested by lawn beetles. When I was pulling out weeds I can see some larvae as well. Reading the thread above - would using the Yates complete work on these? Thanks and great website.

Paul Munns Instant Lawn Response
Hi Rich Thanks for your question. Yes, Yates complete is the product we recommend to control both the beetle and larvae in your lawn. This will last for 3 months per application. Cheers.....Andrew

Black Beetle

By: on 2 December 2019
What can I use now to kill black beetle. I have dead patches every where on my lawn

Paul Munns Instant Lawn Response
Hi Teresa We recommend using either Yates Complete or Brunnings Lawn Grub and Beetle Killer to control both the Beetle and Larvae. Thank you

black beetle in garden and lawn

By: on 21 September 2019
I believe that by using complete that should look after the lawn, but these beetles are also in my garden, what should I use here. Thanking you in anticipation, John

Paul Munns Instant Lawn Response
Hi John Thanks for your enquiry. Unfortunately this product doesn't mention the use of it in garden beds. So we can't recommend it. There may be other beetle killers out on the market that can. Good Luck.

Lawn Bettle Larvae

By: on 21 August 2019
Hi . I have a fairly large lawn about 1000 square and have heaps of larvae present some large, some small, I know October is the time to treat down south, but as we live in Renmark (Riverland SA) should I do it earlier as spring seems to come well before Oct ? Cheers Craig

Paul Munns Instant Lawn Response
Hi Craig, Yes - you should treat them now, again in October and then one more time in March. This should break the cycle and make sure there are no more eggs or larvae left in the soil. I would recommend 1 litre of Turf Cultre Tirem (has the right active ingredient called Imidacloprid) which is enough to spray all three applications. Regards, Stefan

Cockshafers or African black beetle larvae destroy

By: on 18 July 2019
In our fescue lawn we have terrible damage from lawn grubs, made even worse by birds ripping up the grass to get to them. I had sprayed with Confidor in May (I missed doing it earlier), hoping for a lasting effect, but the grubs are voracious. We live on a farm at Kuitpo and the pasture spraying contractor advised me to spray per directions when rain was imminent. I did that, and not sure how long it will take for the Confidor to work. I am left with large (10mx10m in some places) patches of messily turned-up turf. I don't want to re-do a 500m2 area of lawn. In the past the grass - where I could lift it like a carpet - responded to fertilizer in spring, and grew back nicely, but this time the grass is in lots of 'bits' from the birds. It almost makes me cry!

Paul Munns Instant Lawn Response
Hey Sarah, Confidor is the right thing to use for controlling black beetle larvae however at this time of year (when the grubs are at their largest), they are hard to knock off - even with confidor. The best times to do it are October and March so I'd repeat then if I were you. There is a more concentrated form of product (with the same active ingredient as Confidor) called Tirem which will be much cheaper for you to apply. 1 Litre covers about 4000m2 and costs $65.

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