I want to expand this section on turfgrass insects. If you refer back to one of my earlier categories – “Lawns We Are Working On” – you will see where I answered Marc’s question about grubs (Wednesday, March 06, 2013, 6:15 PM). When you feel like it, please review that section. I won’t bore everyone with repeating that information on white grubs. Also, in response to that question, I started this section on turfgrass insects and I posted a drawing and a picture (above & below) of a lawn grub. Now, I’ll provide some more information regarding turfgrass insects.
Insects are all around us. They are some of the most plentiful creatures on this planet. They are 70 to 80 percent of all known animals. There are over a million species of insects on earth and the US has about 100,000 different species. But, the good news is; less than 3 percent are a nuisance to plants or people. As I said in my post referenced above, less than 100 species attack turfgrass.
A true turfgrass warrior should have at least a basic understanding of insects and how they form, their life cycles and how they damage our turfgrass. What are they and where are they? If you can’t operate the internet, you wouldn’t be reading this. So, in this blog post, I can give you the basic information and then you can search from here.
Insects go through a progression of changes in their life cycles called metamorphosis. There are two categories of metamorphosis – simple and complex. When an insect develops from an egg into a larva, or a worm-like organism, that is a complex (or complete) metamorphosis. Like the larva of a butterfly is called a caterpillar. Larvae eat a lot. This is the stage when the insects that attack turfgrass cause the most damage. Then the larva goes through pupation to become an adult. Most turfgrass insects go through complete metamorphosis.
The insects that have simple metamorphosis do not have a larval stage. They hatch into nymphs which are merely smaller versions of the mature adult.
Insects have three main body parts: the head, the thorax and the abdomen. And, the insects that damage turfgrass have two different types of mouths – chewing and piercing-sucking. They either chew up pieces of the plant tissue or they suck the juices from the plant tissue with an extended, hollow, beak-like extension or siphon.
Here I will list the common species of grubs and where they are usually located.
Japanese Beetles: most common east of the Mississippi River but can be found throughout the US.
Green June Beetles: primarily found in the east from NY to FL, but can be found as far west as TX & OK.
European Chafer: mostly found in the northeast, with some in MI & OH.
Southern and Northern Masked Chafer: the Southern masked chafer is found east of the Rockies but most likely in KY, IN, IL, MO & TX. The Northern Masked Chafer can be found from CT west to OH & MO.
May or June Beetles: mostly found in eastern CONUS. Less likely to be found on the west coast or southwest.
Black Turfgrass Ataenius: found usually on golf courses or other intensely managed turf. Can be found in the north Atlantic coast and the Midwest.
Oriental Beetles: Found in NY, CT, MA, NJ, RI, PA, NC & HI.
Asiatic Garden Beetle: can be found in most northeastern states and along the Atlantic coast from MA to SC.
Here are some more “soil inhabiting” insects:
To the left is a picture of an adult Billbug. These insects have bills or snouts. These can be found throughout the US. There are basically three species: the Hunting Billbug, the Phoenix Billbug and the Bluegrass Billbug. The larvae have no legs. Unlike turf damaged by grubs, billbug damaged turf cannot be rolled back like a carpet. Turf damaged by Billbugs will pull away easily because the chewed stems break away from the crown. If you have Billbugs, you will most likely see some fine, tan sawdust-like excrement that accumulates in the feeding area. Turf damaged by Billbugs will have firm soil whereas turf damaged by grubs will have loose soil. Below is what Billbug damage looks like.
These can be found in the southeast US, especially in FL, and along the south Atlantic and Gulf Coasts. There are two main species: the Southern Mole Cricket and the Tawny Mole Cricket. Mole Crickets have shovel-like front legs which actually cut the turfgrass roots. They also feed on the roots. They go through simple metamorphosis, so the nymph looks like the adult. Usually a soap solution is applied to see if Mole Crickets emerge. Insecticides can handle the Mole Cricket. To the right is a drawing of a Mole Cricket.
These can be found in the southern and southwestern states. They look like miniature pearls. They are actually a type of insect called: Scale. They have piercing-sucking mouth parts. Not much is known about their life cycle. They attack Bermudagrass, Zoysiagrass, Centipedegrass and St. Augustinegrass. They can go as deep as 10 inches so fighting them can be tough.
European Crane Fly
Most likely found in the Pacific Northwest. They are tough; that’s why they are called “leather jackets”. The adult looks like a large mosquito. They do not harm people or property. They feed on turf roots and crowns. There are some preventative insecticides out there.
Below Are Thatch Inhabiting Insects:
These are the larvae of “lawn moths”, sometimes called “millers”. They can be found in most regions of the US and they like to feed on Kentucky Bluegrass, Perrenial Ryegrass, Fine Fescue, Bentgrass, Bermudagrass and Zoysiagrass. They differ from other moths because they fold their wings around their body, making them look real thin. That also makes them hard to see. They also have a snout-like projection from the head. They hide during the day. But, if disturbed, they will fly a few feet. They feed on the leaves just above the crown. The first sign of damage is yellow patches of turf. Large numbers of these moths flying just above your turf in the early evening is a bad sign. But, they can be easily controlled.
Cutworms are larvae of night flying moths too, but they are easily 2 to 3 times larger than the Sod Webworm. They feed on the turf at night and lay curled up in the turf during the day. They cut the turf and pull it into a burrow in the soil before eating it. You can detect them by seeing turf leaves that are unevenly chewed or severed. You may even spot their green excrement pellets. These can be easily controlled as well.
Armyworms are like caterpillars that attack turfgrass. They are found throughout the US – east of the Rockies. There are two species: The Armyworm and the Fall Armyworm. The larvae feed at night. They feed on the lower surfaces of the leaves. They can be very damaging. A horde of Armyworms can devour all the grass in an area and move on quickly. But, they can be controlled.
There are the Hairy Chinchbug and the Southern Chinchbug in the US. The hairy species is in the northern states and the southern one likes warm season turfs, especially St. Augustinegrass. They have piercing-sucking mouth parts. They suck out the juices and, in doing so; inject a toxic fluid into the plant tissue. Detection and control are fairly easy for Chinchbugs.
Leaf & Stem Inhabiting Insects
Mites are arachnids, not really insects. They have eight legs and two body parts. There are: The Bermudagrass Mite, Winter Grain Mite and Clover Mite. Bermudagrass Mites are very tiny and only feed on bermudagrass. Winter Grain Mites are only active in the winter. Clover Mites are so small they look like little, reddish specks and will leave a reddish stain when crushed.
The larvae of these flies (aka maggots) feed on most cool season grasses. Their tunneling also destroys stem tissue. You can detect them because they are attracted to white. Throw down a plain white piece of paper and they’ll hop right on it.
These are aphids. They attack about 60 species of turfgrass. They have piercing-sucking mouth parts. Like Chinchbugs, they suck out fluids and inject a toxin. The damage usually begins with turf in the shade. There can be as many as 4,000 in a square foot.
Both the adults and nymphs pierce and suck the leaves and stems. They can be detected as you walk through the lawn. They will “hop” or jump as you disturb them. Control is difficult because they can infest, cause damage and move away from the area so quickly.
These other pests may not feed on or damage turfgrass. But, they may build mounds or make holes. Or, they may be a nuisance to people or pets. These are:
Red Imported Fire Ant – Can make very large mounds and sting people.
Cicadas – They can be loud and there can be lots of them. Good thing they only come around every 13 or 17 years.
Sowbugs & Pillbugs – These sometimes feed on turfgrass or other succulent plants.
Millipedes & Centipedes – Centipedes in the south can sting you.
Slugs and Snails – These are mollusks. They may feed on other flowers and shrubs.
Fleas – These can get on your pets and then on you. There are insecticides to treat your yard if this becomes a problem.
Ticks – May cause anemia and transmit disease (like Lyme Disease). A female tick can lay as many as 6,000 eggs.
Spittlebugs – These suck plant juices. They hide in a froth-like substance they create. They rarely cause damage.
Chiggers – Immature larvae of certain mites. Spray-on or lotion repellants usually work on Chiggers.
Earwigs – They feed on other plants but do not damage turf or bother people.
A few final words about insect control….
It is not economically feasible or practical to absolutely eliminate all your insects. It just can’t be done. The goal should be to contain the problem enough to where there is little or no damage to your turf and little or no nuisance to yourself when working in or enjoying your yard. There are so many factors affecting the insect population in your AO (Area of Operation); climate and predators are just a couple factors. It is hard to control all the variables.
I will discuss pesticides later in a separate post.
One thing is for sure. For many of these pests, you will not be able to make any sort of diagnosis from your deck or patio. You’ll have to get on your hands and knees, and maybe even have at least a 20 power lens to see what’s going on. Your neighbors may think you are a freak. But you will have a better lawn.
Thanks for your request.
There’s not much to say about a RASTER. It is just part of, like the tail end of, a white grub or chafer/beetle larvae. These pests are a real problem in the northern Midwest. Now, that being said, the raster (or the “raster pattern”) is the most common way to identify which species of white grub a turfgrass troop may have in his or her AO. The shape of the anal slit can also be used in identification. Determining the correct species provides a better way to develop a management strategy. Ohio State and Michigan State University have great fact sheets for identifying grubs.
There are some methods to remove white grubs. I talked some about grub control before, but here are some other ideas:
1. Keep your lawn healthy. Do the management practices I’ve talked about throughout this blog.
2. Aerate. Grubs prefer compacted soil.
3. Keep a lookout. Turf will turn brown and wilt. The turf could be rolled back like a carpet or rug because the grubs sever the roots. Look for skunks or moles feeding on grubs.
4. Water deeply.
5. Think about using milky spore. (But that only works on Japanese beetle grubs; those are the most common though.)
6. Consider using parasitic nematodes. That’s a stretch though…
7. Use “the spikes of death” lawn aerator attachments to your shoes. They are terrible for aerating but you might get the picture.
8. Try a mixture of diatomaceous earth mixed with soap powder at a rate of 6 to 9 kg per 100 m2. Alternately, use a tablespoonful of pyrethrum dissolved in 4 L of water. Spread either one of these mixtures across the infected area of the lawn.
9. Use a fertilizer high in potassium in the fall.
10. Then, there’s always chemical control……
Spittlebugs are a different story. They are moth like black bugs with the orange stripes. They are much like aphids. For protection, spittlebug nymphs release a mass that looks like spittle, hence the bugs' name. It serves to protect the nymphs. The insects can do serious damage to grass, especially the centipede variety. They fly about while you are mowing or walking through the lawn.
Spittlebugs feed on plants by inserting needle like beaks into the stem and suck out juices. Unchecked, this can cause grass to become bleached or yellow, then eventually wither and die. The symptoms are similar to the damage caused by chinch bugs in St. Augustine, but spittlebug adults are much more mobile than chinch bugs, so the damage tends to be spread out, rather than concentrated.
Spittlebugs overwinter as eggs in plant stems, under leaf sheaths or in plant debris. Nymphs hatch in the spring and begin feeding. The nymphs feed for about a month before becoming adults. Adults live about three weeks and lay eggs the last two weeks. The eggs take about two weeks to hatch. Two generations hatch each year.
Adult spittlebugs are about a quarter-inch long and black to dark brown. They have two bright red or orange stripes across their wings. Nymphs resemble small wingless adults. They're white to yellow-orange with red eyes and a brown head.
Early on, a damaged lawn will have yellow spots of dead or dying grass. Spots might overlap to form large areas of dead turf in heavy infestations.
The nymphs are easily detected. Just look on the grass stems near the soil surface for the distinctive spittle masses. In severe infestations, you can actually hear a squishing sound as you walk across the grass.
Adult spittlebugs also can damage ornamental plants, particularly in late summer and fall, when populations are at their highest levels. The ornamental plants they prefer include hollies, asters and morning glory. If spittlebugs feed on woody plants, the new growth will be twisted and deformed and the leaves will have irregular brown blotches.
Infestations can be controlled with turf insecticides that contain pyrethroids, such as bifenthrin (Ortho Max Bug-G-Gon), cyfluthrin (Bayer Advanced Multi-Insect Killer), cyfluthrin+imidacloprid (Bayer Complete Insect Killer), or lamba-cyhalothrin (Spectracide Once and Done Insect Killer).
Use plenty of water to apply the insecticides since you need to move it through the thatch layer of the grass and into the soil. When using a liquid insecticide, you can achieve the best volume of water with a hose-end sprayer. Spittlebug infestations are worse in a rainy summer or if a lawn has been over-watered.
The nymphs need high humidity to survive. Turf with excessive thatch is much more likely to provide them the conditions they need. This occurs when centipede is mowed higher than it should be. Reducing the mowing height will cut down on the spittlebugs' numbers.
Hope this scratches your itch!