Overview
- What are the different types of lawn pests?
- Chinch bugs
- White grubs
- Sod webworms
- Mole crickets
- Japanese beetle
- Cutworms
- Cultural control: DIY lawn care
- Summary
Lawn pests are a significant concern in commercial and private settings, particularly for golf course managers, landscapers, and homeowners, who require substantial investment in pest control services. In the US, pests such as chinch bugs, white grubs (beetle larvae), and mole crickets are notorious for their destructive impact on grasses. Effective lawn pest control is essential to prevent these pests from damaging turfgrass, used for lawns and golf courses.
This article covers the various types of lawn pests, their specific symptoms, and effective biological control methods to help you achieve successful and ecologically responsible lawn and golf course pest control.
What are the different types of lawn pests?
Many species of insects cause damage to lawns. Common pests include the larvae of different moth and beetle species. Yellowing or browning of grass is a common symptom of most of these pests. However, many cause specific symptoms that make them easier to identify. Let’s look at the most common lawn pests in more detail.
Chinch bugs
Several different species of this type of insect (Blissus sp.) can cause damage to turfgrass in the US, with the hairy chinch bug (Blissus leucopterus hirtus) being the most common. Adult chinch bugs lay eggs during warmer months and cause damage by feeding on plant fluids using a straw-like mouth part, and their saliva is toxic, causing plant cells to die.
Identification
Adult chinch bugs are about half a centimetre long with black and white coloured wings. Chinch bug damage causes lawns to turn yellow or brown and if you suspect you have a chinch bug problem, look for adults at the borders of these yellow lawn patches. They are more likely to be found closer to the soil and are particularly active during summer.
Control
Biological control methods against chinch bugs include microbial products like Grandevo CG and natural substances like neem oil. The fungal pathogen Beauveria bassiana is another important tool against chinch bugs. Dry lawns are at particular risk to chinch bug damage, so keeping lawns well watered can help prevent damage.
White grubs
White grubs are the larvae of different scarab beetle species, including chafers and June beetles. White grubs feed on the grass roots in the late and early summer months. This stresses the turfgrass by reducing its ability to absorb water from the soil and causes patches of grass to turn yellow or brown. Extensive root damage can cause layers of grass to peel upwards when pulled.
Identification
These pests are white and found in the typical “C” shape. Their length and the colour of their heads vary between different species. Some species of white grub can be easily spotted in the root zone of turfgrass. We recommend screening for white grubs using the method we’ve outlined in this article.
Control
Biological methods for dealing with white grubs include macrobials like entomopathogenic nematodes (tiny worms) and microbials like the fungal species Beauveria bassiana.
Sod webworms
Sod webworms (Crambus spp.) are the larval stage of different species of moths and can grow to a length of roughly 2 cm (0.8 inches). They vary in colour but often appear as grey, brown, or green. More than twenty species of sod webworms affect turfgrasses in the US. Sod webworms feed directly on grass leaves and shoots during the night and hide during the daytime. This can cause brown patches in lawns and individual blades of grass to appear jagged after closer inspection.
Identification
You can identify sod webworms by finding silk-lined tunnels that they hide in during the day or inspecting grass close to the soil for signs of damage. Their excrement appears as small pellets and are visible to the naked eye.
Control
Mowing grasses to a length of 7.5 to 10 cm (3 to 4 inches) and ensuring adequate watering can help to reduce the damage caused by the sod webworm. Sod webworms like to hide in thatch, a dense layer of dead and living plant material that accumulates between the grass and soil. Removing thatch can help to reduce sod webworm numbers. The bacteria Bacillus thuringiensis provides effective control of lawn pests like sod webworms. Entomopathogenic nematodes are also effective at reducing their numbers.
Mole crickets
Several species of mole crickets cause damage to lawn grasses in the US. They feed on roots, shoots, and leaves and tunnel through soil. They are known to cause plant damage at all stages of their life cycle except the early stages after hatching.
Identification
Adult mole crickets appear in different shades of brown and grow to between 3 and 5 cm (1.2 to 2 inches). Nymphs look like adults but are smaller and often a lighter shade of brown. Mole crickets cause grasses to turn yellow and disrupt soil structure and root systems. Signs of a mole cricket problem include tunnels, dead patches (no plant growth), and birds that feed on the crickets.
Control
Entomopathogenic nematodes, as well as natural substances like canola oil and pyrethrin (an organic compound found in flowering plants), are effective biological pest control solutions against mole crickets. It is possible to catch and kill these pests at night using a flashlight, though this approach is not practical for large infestations across wide areas.
Japanese beetle
Adult Japanese beetles typically do not damage turfgrass when fully mature. However, high numbers of adults in an area may indicate a problematic infestation of grubs in nearby turfgrass. Grubs feed on turfgrass roots, which prevents the grass from absorbing water and other nutrients. This, in turn, leads to yellow patches of grass that grow larger and eventually join up
Identification
The grubs of the Japanese beetle grow to 2 to 3 cm (0.8 to 1.2 inches) in length, are milky-white with a light-tan head and are found in the classical “C” shape. Adults are a distinctive metallic green colour and around 1 cm (0.4 inches) in length. This pest is visible to the naked eye and can be screened for using a method we outlined in this article.
Control
Biological yard pest control methods for these pests include nematodes, neem oil, and fungi. More methods for controlling Japanese beetle numbers can be found here.
Cutworms
Cutworms are the larval stage of several species of moth and can produce 1-4 generations per year, depending on the species and climate. While the adult moths are not harmful to turfgrass, the larvae can cause significant damage. They damage grass by feeding directly on leaves close to the soil, eventually feeding on all parts of the plant except the roots.
Identification
Their body colour differs depending on the species, though all species have a dark grey or brown head. Cutworm larvae grow up to around 4 cm (1.5 inches) long. Cutworm damage appears as yellow patches of grass. Grass can have a “skeletonised” appearance after cutworms have fed upon it. These pests feed at night, so you have a better chance of spotting them in the early morning or evening.
Control
Planting crops early in the season and removing weeds from the growing areas can help to reduce cutworm numbers. Removing dead plant tissue helps reduce egg-laying locations. B. thuringiensis is an effective biological solution for cutworm infestations.
Cultural control: DIY lawn care
You can integrate a DIY pest control program with the biological methods above to help combat lawn pests. These methods include:
- Deep and infrequent watering to promote root growth
- Removing debris and dead material (many typical lawn pests hide here)
- Regularly clean mowing equipment to prevent the spread of pests
- Feed grass with environmentally friendly nutrients to promote growth
These measures may save you from hiring an outdoor pest control lawn service.
Summary
Insect pests can severely impact turfgrass, posing significant challenges for the golf industry. Common pests such as chinch bugs, white grubs, sod webworms, mole crickets, Japanese beetles, and cutworms cause distinctive symptoms in addition to causing yellow and brown patches in lawns. These pests may allow weeds to thrive, requiring emergent herbicides and pre-emergent herbicides to deal with.
Biological lawn insect control methods such as microbial products, macrobials like nematodes, and natural substances like neem oil provide advantages over broad-spectrum insecticides, which harm beneficial insects and lead to pest resistance. Early pest identification and treatment are essential for maintaining healthy lawns and protecting the golf industry. Understanding each pest’s specific symptoms and characteristics will help you effectively protect and preserve grass and lawn health.
Visit the CABI BioProtection Portal for more information on integrated pest management methods against common lawn pests, including microbial and natural substance approaches. Need more pest control help? Visit our resource page for information about other common pests.
