Would the offending pest please step, crawl or fly forward?
If only it was that easy but it isn’t so identification will have to be done and there are many insects and worms and other creepy crawlies just waiting for us to discover. All vegetation is attacked by some sort of pest at one time or the other and knowing when the problem is a particular species and if it is seasonal infestation comes in handy.
If the problem is expected then pesticides can be applied in a timely manner and prevent infestation from occurring and help save a lawn in advance. Some infestations occur so slowly that you may not notice the damage until the lawn is gone. In this case preventative pesticide programs are an investment.
The first thing to remember is that not all insects are bad and many of them are beneficial not only to the plant but to us.
Bees for instance pollinate and make honey and the population is getting smaller through such misuse of pesticides and other factors.
Secondly watering, fertilization, mowing, shading, drainage or soil conditions that need amending may be the culprits and these need to addressed first. If none of those are the problem and there are no fungal diseases then it will be insect damage. There are many well researched and developed pesticides on the market but you must make sure you are getting the correct one and must read the directions for application. These are chemicals and not to be used without caution. One pesticide will not kill all insects and each species have a distinct poison that has to be used and a certain method of application depending upon where the damage is being done; on top of the ground or under the ground in the root system.
Some of the pests live under the ground and so you will have to cut an area and peel it back to identify these.
Grubs, bill bugs, ground pearls, nematode infestation, mole crickets tunnels.
Grubs and billbugs will be found here. Use a square foot measurement and count the offenders. Rule of thumb if there are more than 5 grubs or more than 1billbug use pesticide.
Some of the pests live in the thatch and debris area.
Some of the pests feed entirely in the grass blades and are easier to spot and probably to kill with a contact spray.
Many of the pests seen are the same insect only in a different form. For instance many moths which don’t do damage lay eggs and then the young which are worms or caterpillars do all the damage before turning into moths. These moths can be seen well at night flying over the grass. Some of these are the armyworm moth which is buff and gray in color; the fiery skipper which is grayish buff with darker markings and cutworm moth which is grayish brown with dark brown markings and longer, feather-like antennae.
Crane flies also lay eggs, which become larvae called leatherjackets. They are voracious eaters work their usually from the outside to the interior of the lawn. The brownish gray larvae can be controlled with chlorpyrifos or diazinon.
Mites are very small and instead of eating the blades of grass they literally suck the life from the plant. Infestation makes the grass become brown and dry and not from lack of moisture. On close observation you will see white moldy colonies of the mites. Control by removing build up thatch and if it is really bad apply diazinon.
Greenbug damage starts in the shady areas and spreads to the sunny open area. These are deadly to the grass blades and can completely kill a lawn if not halted. First they suck the sap out of the leaves then inject a poison thereby killing the plant. (control) At the onset of damage apply an Orthene containing product.
Ground Pearls are shaped like pearls and are attached to the roots of the plants. They are small organisms and kill the grass by sucking the juices out of the roots. The grass turns brown and dies. Well-fertilized, watered and mown lawns are least attacked. They prefer the sandier soils and drier conditions. Bermuda and centipede are the grasses directly infested.