Summary: Above ground a lawn can look beautiful but down below the can be a war going on in which lawn grubs and other enemies are fighting it out!
Question: Our lawn in general looks pretty healthy, green with not many weeds to worry about. However, it seems that all of a sudden there will be patches which get a very unhealthy looking gray-green. What could be the cause? Gloria, Alpharetta, Georgia
Answer: Gloria, let’s sandwich a segment of lawn (mentally) between two pieces of glass, much like a scientist would do in studying the habits of insects and growing patterns of grass.
This gives us a cross section of earth, top grass, searching roots, and the insect enemies. With lawns a struggle is constantly going on, and survival of the fittest is an ever-present law.
Leading the insect enemies are lawn grubs, curiously C-shaped grass-eating vegetarians.
In the grub’s somersault-like tunnelings through the earth, just below the surface, it is like a soldier advancing toward its goal of destruction.
The grub is powered for movement. Upon its head are two sickle-like jaws which thrust forward, moving earth for its passage, and a set of eating jaws.
Three pairs of slender legs. tipped with single claws, extend from the body, enabling it to burrow through the earth. Its almost transparent body is lined with firm muscles. The bristles on its back help move the grub along.
About one-fourth to one inch in length, the grub is one of the most dangerous insects to lawns. It curls up just below the soil’s surface, eating away at roots.
When earth becomes springy to your step and the grass is no longer green, but a dead brown so dead that it can be rolled back… you know the grub has struck, for the roots have been cut below the surface.
Ants, Wireworms, Rootworms and Root Maggots
Beside the grub are wireworms, rootworms and root maggots. Their “meat” is the small roots of grass, but they’ll chew away at vegetables and flowers also.
Another enemy is the ant. Its great numbers make it one of the most common of the insects. In its perpetual digging and depositing of earth upon the surface, the ant destroys grass.
Another digger is the mole cricket, a close relative to the grasshopper. Its shovel-like front legs have one purpose only… the digging of earth. There’s a goal to this digging… the roots of grass, upon which the mole cricket feeds.
Our look into the earth would also reveal the round and fat sowbug or pillbug, which attacks plant stems and roots near the ground.
Beneath the graceful flight of the lawn moth is its larva, the sod webworm. These larvae become eager and mobile green caterpillars. Surface grass is the victim of the sod webworm.
Then there are the cutworms, grassworms and armyworms… caterpillar larvae of other moths which hit plant stems just below or just above the ground level. You know they’re there by the ragged and uneven appearance: of what was once smooth and level grass.
Another enemy is the lawn chinch bug. They suck vital juices from a plant and inject a toxic salivary substance. Their mark is the dried and dead patch of grass.
Having pincers like the grubs are the earwigs, brown beetle-like; insects with strong pincers at the end of their abdomens. They go for ornamental plants and vegetables, and they work exclusively at night. During the day they rest in the grass.
There are others…
- Leaf miners
- Flea beetles
- Fuller’s rose beetles
- Lace bugs
- Black vine weevils
- Lygus bugs
- White fringed beetles
- Night crawlers
- Spider mites
- Beetle grubs
… to name a few.
All have a damaging effect on a fine lawn.
Today’s homeowner has few options to control the “battle zone” going on beneath the soil line. Fortunately we have lawn care professionals who can analyze your lawns needs and provide a solution. If your lawn is having problems call a lawn professional in your area today.