Grub identification and elimination - Ask Extension
I am trying to identify the grubs in the picture that have decimated my lawn last year and are still active adults. I would like to find a way they've...
Knowledgebase
Grub identification and elimination #930170
Asked April 30, 2026, 1:47 PM EDT
I am trying to identify the grubs in the picture that have decimated my lawn last year and are still active adults. I would like to find a way they've been not hurt the animals that are currently eating them. I cut him in half and took a few pictures of the rear end but unable to match with what your website has.
St. Clair County Michigan
Expert Response
It's not 100% clear from the photo, but these most resemble Asiatic Garden Beetles. See here for raster ID: https://ohioline.osu.edu/factsheet/hyg-2510
Regardless of the species ID, the only grub control product that is specific to one species is milky spore, which will only be effective against Japanese beetles.
Note that the grub life stage is not an adult but a larvae. None of the scarab beetles, which live as grubs, are active as adults this early in the season.
If you are looking for a biological based insecticide to kill grubs, I would suggest parasitic nematodes (Heterorhabditis bacteriophora) or entomopathogenic fungi. The best time to apply these is Aug - early September. They must be irrigated into the soil after application, and it is important to carefully follow the instructions on the label. Conventional products such as the active ingredients of trichlorfon or carbaryl can be applied in the next 2 weeks for grub control. These pose a higher risk to non-target organisms compared to the biological options mentioned above.
Regardless of the species ID, the only grub control product that is specific to one species is milky spore, which will only be effective against Japanese beetles.
Note that the grub life stage is not an adult but a larvae. None of the scarab beetles, which live as grubs, are active as adults this early in the season.
If you are looking for a biological based insecticide to kill grubs, I would suggest parasitic nematodes (Heterorhabditis bacteriophora) or entomopathogenic fungi. The best time to apply these is Aug - early September. They must be irrigated into the soil after application, and it is important to carefully follow the instructions on the label. Conventional products such as the active ingredients of trichlorfon or carbaryl can be applied in the next 2 weeks for grub control. These pose a higher risk to non-target organisms compared to the biological options mentioned above.
Thank you so much for your quick reply.
Do you think the grubs currently in my soil will be eating the grassroots before they turn into a beetle? I was considering using nematodes to get rid of the current infestation. What would be the best time to apply GrubEx to hopefully keep the new hatchlings at bay.
From: ask=<personal data hidden> on behalf of Ask Extension
Sent: Thursday, April 30, 2026 7:58:25 PM
To: Dale Bryeans
Subject: Re: Grub identification and elimination (#0200085)
Sent: Thursday, April 30, 2026 7:58:25 PM
To: Dale Bryeans
Subject: Re: Grub identification and elimination (#0200085)
At this time year, the grubs are large and can still feed for a brief period before pupating.
If the GrubEx you have has the active ingredient of chlorantraniliprole, it can be applied now. However, you'd have better results if waiting until mid July - Sep when the next season's grubs are laid in the soil and are small larvae.
This resource goes over timing for different products:
https://extension.entm.purdue.edu/publications/E-271/E-271.html
If the GrubEx you have has the active ingredient of chlorantraniliprole, it can be applied now. However, you'd have better results if waiting until mid July - Sep when the next season's grubs are laid in the soil and are small larvae.
This resource goes over timing for different products:
https://extension.entm.purdue.edu/publications/E-271/E-271.html
