Expert Tips to Get Rid of Lawn Insects and Lawn Pests

Lawn Insects and Lawn Pests

lawn insects and lawn pests

One of the contributing factors to the reputation of the good turf grasses which we can grow in the British Isles is the fact that we seldom suffer from extremes of weather, such as excessive heat or continued drought. However, one of the first lines of defence against lawn pests, as with all other plants, is to produce strong healthy growth.

Although turf is a continual attraction for lawn insects, it can support a large population without serious harm particularly if it is in good condition, poor or hungry turf is vulnerable and likely to get worse. Damage can take several forms, some indirect such as root disturbance by ants and moles. Cutworms and similar lawn pests may bite the stems through at soil level, wireworms and chafer grubs damage the roots causing large bare patches to appear whilst others may merely suck the sap from the leaves.


Ants can be a nuisance on the lawn where the soil is light and dry. They may be controlled, without using insecticides, merely by seeing that the lawn has plenty of water applied, preferably using a sprinkler; they just do not like the moisture and move out. In practice this can present difficulties because the ground is too wet for children to play or people to sit on whilst the sprinkler is operating. The alternative is to use one of the various proprietary insecticides of which chlordane or carbaryl is the active ingredient. Where the grass is used as a play area as distinct from a purely ornamental lawn, carbaryl is probably the most desirable to use.

Ants may be all over the lawn but they have nests and these can be located by sprinkling a little granulated sugar around. The ants will seize the sugar and can be visibly traced as they carry it to their nest. This is then treated in a more concentrated fashion rather than dusting or spraying all over the lawn.

Malathion or derris are suitable for this task, the latter can be used either as a liquid or powder. What usually happens in the case of ants on the lawn is that their tunnels allow the soil to dry out around the roots of the plants, often causing the grass to die. They can also prevent it from germinating by feeding on the seeds or by storing them in their nests. Personally I mix sugar with any of the powders I use for this purpose so that the ants can carry the insecticide down into the nest.


During a dry spell wasps may often damage lawns by their nest-building habits. They are very energetic and they dig holes about 3/4 inches in diameter and mound up the excavated soil around the entrance. The holes are usually about 6 inches deep and then branch out terminating in round cells. If a powder insecticide is used, push the powder down into the hole with a little bit of stick through a small funnel and smooth out the soil. Apply a liquid with a small hand sprayer that can be pumped with the finger.

In most cases it is the grubs or larvae of the insect, be it moth or beetle, which damage the grass. Wireworms, the larvae of click beetles, can cause a great deal of damage to newly-sown lawns. They are sometimes found on established lawns too, usually near the edge of a flower bed from which they migrate to eat the tender grass roots. Here again, carbaryl will give good control. To make the treatment more effective it pays to prick the soil with a fork to a depth of about 2 inches as they seldom go deeper than this.

In some areas, leatherjackets, the larvae of the daddy-longlegs, cause quite a lot of damage and there may be as many as 200 to the square metre. Where use of an insecticide is not desirable then they can often be controlled by the use of a garden roller which literally squashes the soft grubs. On a fine evening on a badly infected patch you can see these larvae pop up through the soil; you can actually see the mature insects emerging and after a few minutes rest and drying out, pump up their wings and fly away.

Nematodes cause more damage to turf than is generally realised. They are tiny insignificant worm-like creatures which live at different depths in the soil and are thus virtually impossible to control. They seem fonder of foreign grasses than our native varieties and hybrids. In America, where grass farms may be anything up to two thousand acres in extent, nematodes cause millions of pounds worth of damage every year to cultivated turf. There is no effective control yet.


Worms can cause both damage and annoyance and in particular the types of worm which voids its casts on the surface. The control of these earthworms has been a controversial subject ever since I can remember, some people arguing that they drain the soil and should be encouraged and preserved. The facts are these: the burrowing worm passes soil through its body and voids it in the form of the familiar worm casts. In the process of being digested, toxic substances are added and for just over a week this substance is capable of killing grasses. After exposure to sun, wind and rain it becomes fertile. In the meantime, however, due to the plastic nature of the cast, air is excluded and the grasses beneath can die out over an area sometimes 3 inches in diameter. Nature being what she is, attempts to fill this in, often very quickly with weed seeds.

worm casts - lawn pests and lawn insects Worm casts also clog up the rollers of mowers and if you don’t want to destroy the worms then at least destroy the worm casts by brushing.  Worms also encourage moles. Worms themselves can be encouraged by heavy dressings of organic materials such as bonemeal or dried blood which they use as part of their diet. So if you want worms, then feed them and if you want moles then encourage the worms.

Most of us, however, want a smooth weed-free lawn composed of fine grasses and anything that we can do to eliminate the worms is desirable. Worms are most vulnerable in the spring and autumn, when they come up from the depths to the surface in April and before they descend in October anything up to 2 feet to avoid the severe winter weather conditions. There are several proprietary substances available for destroying worms and sometimes one can be found incorporated in fertiliser compounds. Ornamental turf grass lawns can grow quite happily, and indeed better, without the assistance of worms.

Lawn pests and lawn insects can be controlled, but sometimes it is just better to live and let live – some of these pests and insects are so small and do little harm ultimately.

05. August 2010 by Dave Pinkney
Categories: Lawncare, Lawns | Tags: , , | Comments Off on Expert Tips to Get Rid of Lawn Insects and Lawn Pests


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