What Is a White Grub?

White grubs can be one of the most damaging insects to your turf and unfortunately, the better the grass, the more likely the grubs are to attack. Grubs are the larval stage of several large beetles – June Bugs, May Beetles, Masked Chafer Beetles, and Japanese Beetles.  The grubs feed on the roots of your lawn and can kill large sections in a very short amount of time. 

What Is the Life-Cycle of the White Grub?

When adult beetles emerge in late May or June, they will be most noticeable around street lamps, porch lights, patio screens, and pool skimmers.  At this point, beetles will mate and lay eggs in the most beautiful lawn they can find. Eggs will hatch weeks later, and young grubs begin feeding voraciously, on grass roots.  

While some grubs reproduce on a three-year cycle, the annual white grubs that breed on a one-year cycle do the most damage here in the Mid-West. While most of these beetles mate and hatch only once each season, the Japanese Beetle live longer and continue to reproduce with multiple staggered hatching’s creating an almost continual wave of grubs from August thru October. Grubs continue to grow and consume more massive amounts of roots.

The Best Protection Against Grubs

The best protection against white grubs begins with a two step grub control program. Step 1 Long Lasting grub control is the first line of prevention against white grubs. The systemic action of Long Lasting grub control is absorbed by the grass plant. When baby grubs hatch in the fall, they feed on the roots and die. Step 2 Quick Kill grub control is a very fast acting curative control to kill late hatching grubs on contact.

Step 1 Long Lasting Grub Control 

Apply Step 1 Long Lasting grub control in mid-June to early-July before the lawn goes into heat stress. Long Lasting grub control gives greater flexibility in application timing and will stay active in the turf for about ninety days.

Step 2 Quick Kill Grub Control

Apply Step 2 Quick Kill grub control in the middle of September as Long Lasting control begins to fade. Quick Kill contains a fast acting compound and is the only effective contact control for white grubs.  Continuing waves of late hatching grubs are contained with this timely application.

Uncle’s Tip: For best results apply one inch of water immediately after application of Quick Kill.

Grub Control Calendar

How To Spot Grub Damage

 Identification of grub damage can be tricky as it occurs when lawns can be stressed by summer drought or lawn disease. The best way to check for grub damage is to grab a handful of the affected turf and gently tug.  The grass will peel back like a carpet, exposing the grubs that have eaten the roots. Grubs are often discovered after the turf has been disturbed by foraging skunks and raccoons.

When Will Grub Damage Occur?

Grub damage can occur from August through October. Grub damage is the most severe when the turf is dry or under stress from lack of proper fertilization.Visible grub damage may not appear until September or October.

What To Do If You See Grub Damage

A curative application of Quick Kill grub control can be applied any time as need late August through October when signs of turf damage appear. Quick Kill grub control kills on contact and when applied, will stop grubs in 72 hours.

How to Repair Grub Damage

An application of Loveland Renovator and an aggressive watering regime can help reduce the amount of damage that occurs. A thorough, fall lawn renovation will be necessary to complete the repair process.

Finding Grubs in Spring Gardens

Most folks first spot grubs while planting their spring flowers and gardens in late April or May, just before the time the grubs will pupate and change into the adult beetle.  These mature grubs don’t cause excessive damage to roots and require no immediate treatment. However, your best control for spring grubs is an application of Quick Kill grub control.

Using Milky Spore?

There are more reasons NOT to use this product than to use it on your home lawn. Milky spore has been around for decades and was the first biological disease to control Japanese beetle grubs. Milky spore comes in a powder and consists of bacteria.

The first reason not to use milky spore is that it was manufactured to control ONLY Japanese beetle grubs. But, unfortunately, many more turf-damaging grubs such as the European and masked chafers, the May beetle, and the June bug. So even if milky spore could work, you would only be controlling one grub out of multiple species, which is not very good odds.

Secondly, you must have sufficient numbers of Japanese beetle grubs in your lawn to promote the bacterial population enough to expand and spread out in the soil. Therefore, if you do not have a large Japanese beetle grub population, one where you would likely see damage – why bother?

Thirdly, the spore count must build-up for 2 to 3 years to be very effective. Therefore, you should not use an insecticide against the grubs needed to complete the bacterium cycle during this time.

To summarize, even under ideal conditions, using milky spore disease to control grubs, even Japanese beetle grubs, is a severe waste of money and time

See Related: How to Kill the Japanese Beetle


* indicates required
Click Here to Ask Uncle