# Grub Seen After Application



## Jeep4life (Jun 19, 2019)

I applied Scott's GrubEx on 4/14/21 (it's now 5/9) at the rate stated on the bag. However, today I went to place a plug in an area that's seen damage (I thought it was from fungus) and there was a young grub an inch or so in the soil. I assume this means I must have applied incorrectly some how (we did just receive over a month's worth of rain in 2 days last week). Are there any options since you can only apply once per season or should I retreat only the area with damage? Thanks!


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## ionicatoms (Mar 8, 2020)

Perfectly normal. The grubs you see now are from last year. GrubEx doesn't target these.

Did you apply a preventive product last year?

I like the bio advanced 24 hour grub killer product for a knock down.


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## Jeep4life (Jun 19, 2019)

ionicatoms said:


> Perfectly normal. The grubs you see now are from last year. GrubEx doesn't target these.
> 
> Did you apply a preventive product last year?
> 
> I like the bio advanced 24 hour grub killer product for a knock down.


Thanks for the info. We just moved into the house in Aug of last year and Dylox was applied 10/1 when I noticed multiple signs. Should I still apply the bio advanced product to be safe?


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## ionicatoms (Mar 8, 2020)

The active ingredient in the Bioadvanced product is the same as Dylox. You only need to treat if the number of grubs per square foot exceeds a threshold for action. I think the threshold is debatable, and is a question of your tolerance.

From:

http://extension.msstate.edu/publications/insect-control-commercial-turf

"White grubs are the larvae of several species of beetles, including May beetles, June beetles, and chafers. When fully grown, grubs are whitish or grayish in color, are about 1½ inch long, have a distinct brownish head, have three pairs of legs (which distinguishes them from the larvae or billbugs), and characteristically rest in a C-shaped position.

Most grubs spend about 10 months in the soil, but some require two to three years to develop into beetles. White grubs feed on grass roots and organic matter in the upper three inches of soil. Turf with severe white grub damage has dead patches that roll back like a loose carpet when pulled. Periods of drought with water-stressed grass accentuate this damage. Grub damage is often most noticeable in the spring, when severely grub-damaged areas fail to "green up," but damage also can occur in summer and fall. Grubs are easiest to control in mid-summer, when larvae are the smallest.

Well-watered and maintained turf can harbor lots of white grubs without showing signs of damage. In such cases, vertebrate predators, such as skunks, moles, or armadillos, may do more damage to the turf than the grubs themselves. Controlling the grubs may eliminate or reduce the damage caused by these predators.

When scouting for grubs in the spring or summer, cut several one- to two-foot square samples two to three inches deep, lift out or roll back the turf square, and examine for grubs. If you find an average of three to five grubs per square foot, you may need to treat.

Water grass before treatment if soil is dry (this causes grubs to move nearer the soil surface), and thoroughly water again after treatment (this leaches the insecticide into the soil where the grubs are feeding).

Insecticides labeled for use against white grubs should be applied at or before egg hatch. Imidacloprid, clothianidin, thiamethoxam, or Allectus (a combination of imidacloprid and bifenthrin) applied at that time can provide greater than 90 percent control of the annual grub species. However, only trichlorfon or carbaryl will control large grubs."


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