TURF PESTS

INTRODUCTION

Groundsmen in this country are relatively fortunate in having a limited number of pests which cause serious damage to turf.

The following can be considered to be the major pests affecting turf grass:-

Worms

Leatherj ackets

Moles

Less common pests – Fever fly

Frit fly

Also some other miscellaneous insects and animals, e.g. bitch urine damage.

1. WORMS

Worms are the most common pest of intensively managed turf. They are a pest because they cause unsightly casts which can create a muddy and uneven playing surface: these smother the turf and create a seedbed for weeds.

Of the 25 or so British species of earthworms, there are only two that produce casts on the surface.

Worms feed on dead and decaying organic matter in the soil and are present in larger numbers in humus rich soils. They will not thrive in very acid or very dry soils.

Worms are most active in moist, warm weather, particularly in the autumn and spring, and it is during these periods when the worms are nearer the surface that worm killing materials should be applied if indeed their activities are so disruptive that they must be eliminated.

It must be pointed out that worms do carry out a very good job of aerating the soil and breaking down fibre and are welcomed by gardeners. However, where sports turf is concerned, the disadvantages of earthworms far outweigh their advantages. Having eliminated earthworms from the turf, the groundsman will need to compensate by increasing the aeration of the sward.

Control

i) Cultural method

a) Maintain an acid soil.

b) Avoid excessive use of organic fertilisers and top dressings.

c) Box off clippings.

ii) Chemical methods

Chemical worm killers:-

These kill the worms below the surface. No clearing up is required and their action is long term.

a) Carbaryl – available as a wettable powder and is a relatively safe material to use, but will only last for about 12 months.

b) Carbendazim (MBC)

c) Gamma HCH + Thiophanate Methyl

2. LEATHERJACKETS

These are the larvae of the crane fly or ‘Daddy long legs’. Each female fly lays about 400 eggs into the turf in late summer and these soon hatch out into small grubs. The grubs feed on the roots and basal shoots of grass plants.

Some grubs are killed by winter cold, but in a mild winter many survive to give a second outbreak of damage in the spring. Damage is noticeable as yellow patches of grass and can be confirmed by lifting a turf to reveal the grubs beneath.

(Control chemicals as for worms.)

3. OTHER INSECTS

Very few other insects cause significant damage to turf, but Cockchafer grubs, Fever fly and Frit fly grubs may cause damage.

For Cockchafer grubs and Fever fly use gamma HCH.

For Frit fly grubs use Chlorpyrifos. Ants – HCH dust can help.

4. ANIMALS AND BIRDS

Moles can cause serious damage to fine turf areas. Moles are more common in fertile soils with a high worm population on which to feed. Therefore, a control of worms will help eliminate moles. If control measures are required, the following methods are possible:

Trapping

Poisoning with Warfarin – Professional operators only.

Gassing – aluminium phosphide – very nasty stuff –

Professional mole killers only. Smokes – the mole fuses are not always effective. Deterrents – moth balls in the run.

Others – There are sonic mole deterrents which work off batteries and will drive moles away from a locality.

Rabbits – can be a nuisance on newly seeded areas. Aluminium ammonium sulphate – an inorganic animal repellent.

Birds – can eat newly sown seed, or damage the surface of turf looking for insects. (Starlings look for leatherjackets.) Quassia – an animal repellent of vegetable origin.

TURF PESTS AND THEIR CONTROL

Worms Expfillants Rotenone (Derris)

Poisons Carbaryl (Sevin) In autumn In autumn Up to 12 months 1 season

Leatherjackets Carbaryl

Gamma – HCH ) Chlorpyrifos ) Late autumn Early winter

Chafer Grubs, Fever fly and Frit fly grubs Carbaryl (chafer grubs only) When required

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