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 (12)

By Greg Russell 22nd November 2018

By: on 22 November 2018
HELP PLEASE Hi we have guinea pigs that roam free in our yard but now have black beetle , can you please suggest a pet friendly way of getting rid of these , some have told me to use washing up soap and others have told me to use salt water spray Your advice would be much appreciated.

Paul Munns Instant Lawn Response
Hey Greg, Black beetles in themselves are not a big problem for lawn. Its their larvae that do the damage. There are some non chemical means to flush out the black beetles such as soapy water however this wont solve the problem because the larvae will still be there. I don't know of any non chemical ways to control black beetle larvae but having said that, despite the reputation they have for killing lawns, in our experience black beetle larvae are rarely the cause of dead spots in your lawn. Give us a call on 08 82980555 and we'll have a chat with you about your lawn. Regards, Stefan

Black beetle

By: on 7 November 2018
When can I spray a new buffalo lawn for black beetle.

Paul Munns Instant Lawn Response
Hey Jeff, Yes you can spray a new buffalo for black beetle with a product such as Yates Complete. As it is an insecticide, it wont have any effect on the lawn.

Beetles attracted to my whites

By: on 19 October 2018
Good morning I appear to have a beetle problem but they seem to be attracted to my washing, particularly my white washing. Are these the same black beetles that I've read about here?

Paul Munns Instant Lawn Response
Hi Beverly, I've not heard about beetles being attracted to white washing so I'm not sure if they are the same as the ones that live in the soil and thatch of your lawn. If you want to knock out the beetles, I can recommend a product called Yates Complete.

Black beetle in deep and hibiscus being eaten

By: on 8 April 2018
Hi..i have a small house on one acre. I had 16 black beetle larvae alone in one small trough. They r everywhere, even in hanging baskets. How they can climb up 2M is beyond me. Just emptied out 5 baskets and each one had around 8 hige white grubs. How can the Yates Complete possibly get deep enough to kill the beetles or larvae. My Hibiscus leaves r constantly eaten and the flowers r beautiful but the leaves r covered in tiny holes. How often do u need to spray? What is the best product to use pls as the previous one wasn't effective. Is it a minute grub?

Joe stirling perth 18 march 2018 bloody black beet

By: on 18 March 2018
been using richgro spary on lawn beetle with no luck for some time lots of beetle come up lawn is looking sad used complete same resoult ready to dig lawn out need some help

Paul Munns Instant Lawn Response
Hi Joe, If your lawn is look so bad that you are ready to dig it up, then I would be highly possible that the issues facing your lawn are more than just Black Beetle Larvae. To eliminate beetle problems, I would recommend spraying with a chemical product containing an active ingredient called Imidacloprid (such as Yates Complete or Brunnings lawn grub and beetle kill). If you have already done that in the last 3 months and your lawn is not improving then beetles are not your problem. The best way to solve a problem like yours is to dig out a core sample and take it into a lawn specialist near you. They should be able to help you get it back on track. If you don't get an understanding of the issue, then there is a fair chance the same issues will return on any new lawn that you plant.

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