Grub concerns

Question: I live in Sioux Falls, SD, near Minnesota and have been at this address since 2019.  I have grubs in my yard.  I actually found them last fall after areas of concern and had my yard treated by the company green 4 ever.  This year, I hired loan oak yard care and they just applied an insect spray of some sort to my yard.  I pulled up 3 areas of grass tonight and found Grubs.  I took some pictures of them.   

Do you have any advice of what I can and should do?  I’m a neat freak when it comes to my yard so hoping to stop the bleeding and get this under control asap.  Attached are some pictures.

responder: An Ask Extension Expert Replied May 19, 2024, 11:20 PM EDT
response: Good Sunday evening and Thank you for your question. It has been assigned to me. I will try to help you. This is the time of the year (late May, early June) that white grubs appear close to the upper regions of soil. This is very natural and occurs in most lawns. Most likely they are either Japanese beetle grubs or May/June bugs. For me to answer your question, please provide the following background information: 1). In past years have you noticed any defoliation of your trees or shrubs? Related to this, in past seasons have you had any reason to suspect the presence of grubs.? 2). In the picture that you provided showing the grubs, what was the approximate area of the turf under which you found them?  The reason why I am asking this is to ascertain the severity of the problem. As a rough rule of thumb, unless 10 or less grubs are under a square foot of turf, there is not a grub problem. Many thanks for your anticipated response. Thanks for consulting our forum.

responder: The Question Asker Replied May 20, 2024, 9:37 AM EDT
response: Hi,Thanks you replying back to my email. To answer your questions, 1) I don't have any shrubs in my landscape and the only tree I have was a maple tree planted 3 summers ago that was a 10' tree. I don't see any damage to that tree.2) I  just pulled up 3 areas of some grass that I didn't like by hand and noticed 3-4 grubs under each glob of grass pulled up. my guess is that is a 3"x3" area of grass pulled up by hand. All of it was under some really stalky type grass.Last summer, I noticed my yard not looking right so I took some pictures that I attached to this email. These were all taken in September. Last September I pulled up some more areas of grass but the unevenness of the grass grown didn't seem right. Also, a lot of that grass looked like white king grass stems.  I noticed grubs under those spots last September so I had a granular pellet put down by a lawn care company.  The pictures of what the yard looked like last September are attached.  The unevenness kept spreading further and furthe into the yard as well.The previous summer (2022) I didn't notice anything besides the yard not getting enough water in this area. I then had my sprinklers adjusted and I overseeded by hand that fall. Any suggestion or help you can  provide would be great!THanksAaron VanDeBerg<personal data hidden>On Sun, May 19, 2024 at 10:20 PM Ask Extension <<personal data hidden>> wrote:

responder: An Ask Extension Expert Replied May 21, 2024, 12:04 AM EDT
response: Thanks for getting back to us. It certainly appears that white grubs are visiting your yard. These are Scarab larvae and often are just called “white grubs”. Usually the adults are May bugs, June bugs, and Japanese beetles. See: https://extension.umn.edu/corn-pest-management/white-grubs - larvae-1191610 https://hort.extension.wisc.edu/articles/mayjune-beetles/ There are two windows in which effective grub control can be done: early June as grubs move towards upper regions of the turf and late July/early August as newly born grubs are also near the surface. At these two times chemical interventions are possible. See the following for further information: https://extension.umn.edu/news/white-grub-control-lawns https://extension.umn.edu/yard-and-garden-insects/japanese-beetles https://extension.umn.edu/yard-and-garden-insects/japanese-beetles - when-to-manage%3A-start-early%21-1591110 https://ipm.missouri.edu/MEG/2018/1/organic_management_japanese_beetle/ https://www.thespruce.com/controlling-adult-japanese-beetles-1402495 Bottom line: Timing is the most important part of grub control. As I described, you have two windows for treatments. For maximum effectiveness, two grub treatments should be done in each window, separated by two weeks. Good luck. Please get back to us if you have further questions. Thanks for consulting us.

responder: The Question Asker Replied May 21, 2024, 9:28 AM EDT
response: Thanks for this. I want to make sure I’m understanding this correctly.  Put down an application on June 1 and 14,   And then again like July 27 and August 10?If this was your yard, what would your purchase to put down?  Is it something that I should order online or would I be a me to purchase at like a Lowes or Home Depot or Menards?Thanks again for all your help. Much appreciated. I owe you a gift card! ThanksAaronOn Mon, May 20, 2024 at 11:04 PM Ask Extension <<personal data hidden>> wrote:

responder: An Ask Extension Expert Replied May 21, 2024, 9:45 AM EDT
response: Thanks for getting back to us. The dates you mentioned sound good but recognize that dealing with white grubs can be a moving target. In early summer, as well as later in the summer, these grubs are in the higher levels of the soil under your grass. In this state and location, they are most susceptible to insecticide intervention. My suggestion of two treatments at both times is an attempt to deal with the continual movements of the grubs. Trying to get rid of them is rarely a “one shot deal”. As a volunteer Master Gardener of the University of Minnesota, I cannot recommend any specific commercial product. Having said that, in one of the links I previously sent to you, the following was stated: “The best timing is during the month or so before the adult beetles first emerge and start laying eggs (mid-June to mid-July in Minnesota). Chlorantraniliprole (such as Scott's Grub-Ex) is an effective, preventative insecticide that is also low risk for bees. Products containing imidacloprid or clothianidin are also effective if applied preventively, but they can pose a hazard to bees foraging on flowering weeds or nesting in treated lawns.” These products can be purchased at any gardening center or big-box store. There should be no need to online ordering. Good luck. Glad to be of assistance. Thanks for consulting us.

responder: The Question Asker Replied May 31, 2024, 12:11 PM EDT
response: I have another question. Is there anyway to kill tall fescue grass but not the KBG that I have growing?   It’s slowly spreading and over taking more and more of my yard.Thanks AaronOn Tue, May 21, 2024 at 8:45 AM Ask Extension <<personal data hidden>> wrote:

responder: An Ask Extension Expert Replied May 31, 2024, 12:39 PM EDT
response: Thank you for submitting your latest question regarding fescue.  Please submit this question by starting a new thread.  It is our policy that separate questions should be submitted individually.  This will insure that your specific question will be directed to the most appropriate Master Gardener. Thank you for your understanding in this regard