- Author: Ryan Daugherty
I was dealing with a gopher problem in a lawn awhile back and I came across another turfgrass pest that you may or may not be familiar with; a chafer beetle.
These white grubs are the immature larval form of a chafer beetle.
Here in California we deal mainly with the masked chafer (Cyclocephala spp.). Mature grubs have white or cream colored, C-shaped bodies, six legs on their upper half, and a chestnut brown head. They can be confused with the somewhat smaller black turfgrass ataenius larvae (Ataenius spretulus). To identify the difference between the two, look at the tip of the abdomen (the opposite end from the head) for the arrangement of bristles and overall anatomy, we call this the raster pattern. A chafer's raster will have a transverse anal slit with an indistinct pattern of bristles all over. An ataenius will have two distinct pad-like structures on the tip of the anal slit.
The chafer grubs feed on turf roots in early spring then stop around May to pupate with adults emerging around June to mate. Adults actually have non-functional mouthparts and so do not cause feeding damage, in fact they die of starvation shortly after laying eggs. Adults are about 3/4 inches long with golden brown bodies and they emerge during the night with a strong attraction to light. If you see adults during the summer, eggs are likely being laid in your grass. Eggs hatch around August and the grubs do most of their damage in September and October before moving deeper into the soil to overwinter until the spring.
Damage looks like drought symptoms in turf: brown, blueish, or gray spots, brittle straw colored grass, thinning stands, and footprinting. These symptoms are from the extensive root feeding of the grubs as the grass loses much of its ability to take up water. You may also see vertebrate feeding from birds or skunks that can cause further damage digging for the grubs. Spots of affected turf may be small, only being a foot or two across but may combine with other spots to form large sections of damaged turf. A hallmark of grub damage is that damaged turf can be peeled back from the soil like a carpet, due to the turf having no roots.
Insect damage in home lawns is rarer than you might think, with abiotic problems like poor irrigation, mowing, or fertility practices being a more likely culprit for a struggling lawn. If there is an insect pest make sure you correctly identify the insect before intervening with any control measures. Also remember that the presence of a pest doesn't always necessitate control. A healthy lawn can withstand damage from a few grubs and a robust lawn is always the best defense against pest damage.
Damaged turf can be helped by irrigating more frequently to keep soil moist around the lawns now shallow roots. Lawn aeration can also kill segments of grub populations. Reserve any kind of chemical intervention until you see 6 or more grubs per square foot. Several insecticides are available on the market for chafers or white grub control just look at the label. UC IPM has a page dedicated to masked chafers, but keep in mind the pesticides recommended there are for professionals.
Always read and understand the label of any pesticide you intend to use. Be careful to refrain from applying insecticides (especially broad spectrum) if there are flowering plants in and around the lawn; this includes weeds like clover or dandelions as it can harm beneficial insects like pollinators that may come into contact with them.
- Author: Karey Windbiel-Rojas
After all the winter rains you may find yourself dealing with weeds and struggling to control them. The first step in successfully controlling weeds is knowing what weed you have. Well, you're in luck: the UC IPM website contains many useful resources to help you identify and manage weeds in the garden or landscape.
A great place to start is the Weed Gallery, which contains images and identification tips for more than 150 common weeds.
If you think you know the name of your weed, you can use the common or scientific name to view photos to confirm identification. Just use the “List of All Weeds” link from the main weed gallery page.
If you don't know what the weed is, the gallery will help you identify the plant using visual characteristics. First, narrow your search by choosing “identification” in the weed category—broadleaf, grass, sedge, or aquatic plant. That will show you a collection of photos in that category.
Select the photo of the plant form or leaf characteristic that resembles your weed (Figure 1) to see another sub-menu of weeds that exhibit more traits of your weed. Scrolling over a thumbnail image on this sub-menu will bring up several photos of the weed—as a seedling and mature plant, its flower, and seeds—to further help you identify it.
Once you think you've identified the weed, click on the linked weed name, which will take you to a photo gallery page. Here you will find details about the weed's habitat, growth characteristics, and life stages. For many weeds, there is a link to the Pest Notes that will give you information about its management, both chemical and nonchemical. Each page in the gallery also links to the Calflora website to show where the weed grows in California.
The gallery contains other features as well:
- Want to know more about plants and their parts? Illustrated tutorials distinguish among broadleaf, grass, and sedge plants and define plant parts used in characterizing certain plant species.
- Need to find out what weeds are in your lawns? The broadleaf and grass categories link to an identification key for common turf weeds.
- Didn't find your weed? See the weed identification tool under “More information” to search the UC Weed Research & Information Center (WRIC) technical weed key.
You can find the weed gallery page on the left-hand column of the main Home & Landscape page on the UC IPM web site or from the many weed-related pages. To access the weed gallery directly, visit https://ipm.ucanr.edu/PMG/weeds_intro.html.
Visit UC IPM's Weeds library page to find general weed management tips, individual weed-related Pest Notes, the weed gallery, key to weeds in turf, and other useful resources. https://ipm.ucanr.edu/PMG/menu.weeds.html
[Originally featured in the Spring 2024 edition of the Home & Garden Pest Newsletter]
“Kill your lawn!” has become a popular phrase and landscaping trend in recent years. Whether you are looking to completely remove your lawn or just renovate it, this article will give you useful information to help you decide how best to do away with your existing lawn and prepare for your new design.
There are many reasons someone might be looking to get rid of their lawn.
- Can be costly to maintain (water, landscapers, time, equipment, fertilizers, etc.)
- Aesthetics (desire a different look)
- Create habitat (plants for birds, pollinators, natural enemies, etc.)
- Replace groundcover (plant different grass type, install turfgrass alternative)
- Save water by using drought resistant or low-water needing plants
On the other hand, someone might decide to keep or install a new lawn for many reasons.
- Use by children and pets (soft outdoor area for moving around and playing)
- Can be low maintenance (compared to certain plant selections)
- Aesthetics (prefer the look of a lawn)
Whatever your reasoning for killing your existing lawn or removing sections of it, there are several methods you can use to do so, both chemical and non-chemical. You may also choose to use a combination of both.
Sheet mulching
A low-cost method for killing your lawn is to cover it with cardboard or several layers of newspaper. Closely mow the grass and place 1 to 3 layers of unwaxed cardboard or newspaper on top to prevent sunlight from allowing the grass to grow. Top with 1 to 2 inches of compost and 3 to 4 inches of mulch.
Soil solarization
This method works to “cook” the existing lawn by trapping heat from the sun under a clear plastic tarp. Intense sunlight and high temperatures are required for this method, so it is best done in the summer, in areas that receive full sun. Cloudy or foggy regions, or shady parts of the yard won't be as effectively killed. Dig out or closely mow the existing lawn. Wet the soil in the area that you intend to cover. Tightly cover with a clear plastic tarp. Leave the tarp on for 4 to 6 weeks, and maintain soil temperature below the tarp between 110º to 125°F. For more in-depth soil solarization instructions and information, see the UC IPM Pest Notes: Soil Solarization for Gardens & Landscapes.
Hand-digging or machine use
You can remove a lawn manually by digging it out, using a sod cutter, or using a rototiller machine. These methods are more physically demanding so they are better for smaller spaces. Moisten the soil prior to removal to make it easier to dig or cut out. To dig out your lawn, use a flat shovel and dig parallel to the soil to remove the top 1 to 2 inches of lawn. A sod cutter can be rented to similarly remove the top 1 to 2 inches by cutting the lawn into strips.
Herbicide application
One of the quickest and less labor-intensive ways to kill an existing lawn is to apply a nonselective, systemic herbicide like diquat or glyphosate that will kill most weeds and the turfgrass and their roots. It may take up to 7 days after the application for the grass to completely absorb the material and plant damage to start showing. Depending on temperature, it can take up to 2 weeks for the entire lawn to die.
Herbicides that work on contact like acetic acid (vinegar) and ammonium salt of fatty acid (herbicidal soap) are not as efficient as they do not kill weeds and grasses to the root. Multiple applications of the contact herbicide are likely needed as well as hand-removing the plant material.
For more detailed information on lawn removal see Lawn Removal Methods by the UCCE Master Gardeners of Sacramento County.
You've successfully killed your lawn, now what?
If you want to reestablish your lawn and reseed, you'll need to think about irrigation, amending the soil (if needed), and choosing a grass variety that is best suited for your area and goals. To learn more about lawn renovation and how to establish and care for a new lawn, see the UC Guide to Healthy Lawns. If you're considering installing artificial turf (fake grass), evaluate the risks involved by visiting https://gba.org/blog/artificial-turf-fields-health-and-environmental-concerns/.
If you'd like to replace your lawn with mulch or rocks, see our Mulch resource page to learn about this option. Prior to applying wood or rock mulch to an area, you may want to place landscape fabric or sheet mulch (cardboard or paper) over the soil to prevent weeds and grasses from growing.
If you wish to replace your lawn with an alternative, like clover or thyme, see the Lawn & Lawn Alternatives resource from the UC Marin County Master Gardeners. For more information about replacing your lawn with flowering plants to attract pollinators and beneficial insects, or reduce water use, visit:
- UC Master Gardeners
- UC Davis Arboretum's Planting Plans
- California Native Plant Society's Native Plant Lists and Planners
- UC IPM Insectary Plants
- CA. Department of Water Resources Water Efficient Landscaping
Keep in mind that none of these methods will absolutely prevent weeds and grasses from invading your lawn or landscaped areas in the future. Keeping weeds out and preventing undesirable grassy areas from regrowing, requires diligence and a combination of control methods. To learn more about weed management in landscaped areas, see the UC IPM Pest Notes: Weed Management in Landscapes. For weed management in lawns, see the UC IPM Pest Notes: Weed Management in Lawns.
/h2>- Author: Lauren Fordyce
Lately you may have seen some large, leggy insects bumbling around on your home, bouncing off walls and ceilings. What are these?
While many people call them “mosquito eaters” or “mosquito hawks,” they are actually crane flies. And unfortunately, they do not eat mosquitoes. Many reports claim that they bite or sting, and this is also false. The adults are harmless and many species don't even have mouthparts to feed at all! However, their larvae can be pests of lawns and turfgrass.
Larvae are to 1-1/2 inches long, brown, and wormlike with very tough skin. They may resemble white grubs, but crane fly larvae do not have legs. The majority of lawn damage from crane flies is seen along the Pacific Northwest coast. In California, damage has been found mostly in Humboldt and Del Norte counties, rarely in warmer, dryer inland areas of the state. Although, wet springs and waterlogged soils are usually associated with a higher populations of crane flies.
You can prevent crane flies in your lawn by properly irrigating and fertilizing. Adjust irrigation systems during rainy periods to avoid overwatering. Remove excess thatch and aerate you lawn to improve drainage. Reduce shady areas by pruning back tree branches to allow more light to reach the grass during the early morning and late afternoon.
Find out more about crane flies by reading the UC IPM Pest Notes: Lawn Insects.
Learn how to control mosquitoes around your home by visiting the UC IPM Pest Notes: Mosquitoes.
- Author: Lauren Fordyce
You may be noticing white grubs in your compost piles, lawns, or garden beds. These white, c-shaped critters can be 1/4 inch long or 2 inches long, depending on the species. White grubs are the larvae of some scarab beetles, and though many of them can cause damage to our landscapes, not all of them do.
There are three species that feed on the roots of grasses, making them a potential pest to lawns when in high numbers. These species may also be found in landscape or garden beds that are near grassy areas or were recently converted from grassy areas. Compare the size of white grubs you may find, as some species are much larger or smaller than others and can help you determine which is present.
- The larvae of masked chafer beetles are 1 inch long with dark heads and six legs. Adult beetles are golden brown and can be seen flying around in the evening hours.
- Billbug larvae are 3/8 inch long, also with dark heads andwhitebodies, but these grubs lack legs. Adults are brown weevils.
- Black turfgrass ataeniusls larvae are 1/4 inch long– much smaller than masked chafer grubs. Adult beetles are black and shiny.
One of the largest species of white grubs you might find in California are of the green fruit beetles, also known as figeater beetles or June beetles. The grubs of these beetles can be up to 2 inches long and are commonly found in compost piles, or near ripe and rotting fruits– which they feed on. These grubs, however, won't usually damage your landscape or garden plants. The adults are very large, metallic green beetles that are often mistaken for the invasive Japanese beetle, which is much smaller and, for the most part, is not found in California.
In most cases, the presence of white grubs does not require treatment and populations of 6 or less per square foot can be tolerated. If you notice them in your garden beds, they can be hand-picked and killed. Some may choose to feed them to their backyard chickens or leave them out for the birds. When infestations of grass-feeding white grubs occur, the lawn may feel soft and spongy, sometimes able to be rolled back like carpet. You may also notice animals like raccoons and moles digging in your yard, looking to snack on some white grubs.
To learn more about identifying and managing white grubs, see Pest Notes: Lawn Insects.