If your lawn appears thinner than usual or has a spongy feel when you step on it, a grub infestation is a likely culprit. If left unchecked, grubs can cause significant damage to grass and underlying soil. Taking preventative measures every season and treating your lawn for grubs in the earliest stages may help prevent severe infestations. 

What Are Grubs?

Grubs are beetle larvae found in outdoor soil sources. They feed on plants and roots and burrow deep underground during the fall and winter, eventually emerging as full-grown adult beetles. Grubs are often referred to as nuisance pests, as they can be highly destructive to lawns, gardens and plants. 

The life cycle of a grub lasts approximately a year. It consists of the following four stages:

• Egg: During the egg stage, adult beetles lay eggs in the soil. During this time, you may notice small holes in your lawn. This stage usually occurs in June and August, and the entire cycle takes approximately 2 weeks. 
• Larva: Once the eggs hatch, they enter the larvae stage. This is when they start feeding on roots and plants. As the larvae develop, their feeding habits grow stronger, and you may notice signs of damage, such as weakened grass or brown patches. 
• Pupa: After the immature grubs complete the larvae stage, they move into the pupae stage. During this time, the pupae remain in the soil and grow into adult beetles. 
• Adult: Adult beetles generally emerge from beneath the soil during the summer months. The adults then enter a mating period of approximately 3 weeks. After the mating period is complete, the adult beetles begin laying their eggs again. If uninterrupted, each beetle can lay up to 60 eggs in your lawn’s soil. 

Signs of a Grub Infestation

Lawn damage is the most telltale sign of a grub infestation. Here are some common lawn and soil problems caused by grubs:

• Visible grubs: During a grub infestation, you may spot grubs in the soil. The best way to check for grub activity is by digging up a small area of soil in your yard. Live larvae are creamy white in color and have a C-shaped appearance. If each square foot of soil contains more than five live grubs, this can indicate an infestation. 
• Brown or dead patches on your lawn: As grubs feed on grass and roots, their activity can kill your grass. You may notice brown patches, or your lawn may contain dead spots in unusual shapes or patterns. 
• Spongy areas: Does your grass feel squishy or have a sponge-like consistency when you step on it? When grubs feed on roots, it can damage the root system and cause the soil to lose density. 
• Thinning grass: Patches of very thin grass that pull up easily can indicate grub activity. When the grubs feed on roots, the grass can weaken to the point where it thins out or pulls right out of the soil with minimal effort. 

How to Treat for Grubs

Treating your lawn with insecticides containing ingredients such as carbaryl or trichlorfon (Dylox) may help to eliminate active grubs. When applying insecticide, make sure the product is specifically designed for grub control. 

The Best Time to Apply Grub Control

To prevent grubs from infesting your lawn, the best time to treat the area with insecticides is late spring or early summer. For active infestations, you should treat your lawn in early fall. While it’s not always possible, it’s generally better to apply grub control products as a preventative measure rather than after an infestation. Preventative treatments don’t automatically guarantee a grub-free season, but they do offer better grub control when applied early.  

How to Prevent a Grub Infestation

Applying preventative insecticide to your lawn is a simple solution to stopping or minimizing grub activity. Treating the area of concern in late spring or early summer is recommended, as this may help prevent the new larvae from feeding on the roots and soil. 

Mowing and fertilizing your lawn regularly may also help keep grubs at bay. Healthy, vital lawns tend to be more resistant to pest infestations. Aeration is another beneficial procedure that can promote root growth and improve the overall health of your soil. 

Let Lawn Doctor Help With Grub Control

Preventative treatments and regular lawn maintenance are helpful ways to prevent grub infestations. If you’re dealing with an active invasion and need grub control and assistance, or you’d like some tips on managing grub activity throughout the seasons, contact us at Lawn Doctor today.