Symptoms
How to tell if leatherjackets are a problem in your garden:

• Leatherjackets have elongate tubular bodies, up to 30mm long, and are greyish brown. They have no legs or obvious head
• Lawns develop patches where the grasses turns yellowish brown and often dies.
• Crows, magpies, rooks and starlings will search for leatherjackets in turf. These birds leave small round holes in the turf where they have inserted their beaks.

There several species of leatherjackets (larvae of crane flies) that feed on the roots and stem bases of lawn grasses and other plants.
The adult crane flies or daddy-longlegs mostly emerge and lay eggs in the turf or soil surface from August to October. Dry soil conditions at that time can result in many of the eggs failing to hatch.

The eggs hatch a few weeks after they have been laid and the young leatherjacket begin feeding on plant roots. In cold winters, they overwinter as small larvae and do not grow large enough to cause significant damage until mid-summer. Mild winters allow the young larvae to continue feeding and they can be large enough to cause lawn problems by late winter.

Symptoms
Some species of chafer grub eat the roots of grasses and other plants. Evidence of their activities can be seen in a number of ways:

• Damage to lawns is most obvious between autumn and spring when the grubs are reaching maturity
• Patches of the lawn may become yellowish
• Birds, particularly of the crow family, tear up turf in order to access the grubs to feed on them
• Damaging infestations can be highly localised and sporadic
• Chafer grubs can be found in the soil under the loose turf. They have white bodies curved in a C shape, light brown heads, with three pairs of legs at the head end. They are bigger than the adult beetles and, if straightened out, can be up to 18mm long.
• Other less troublesome species of chafer grubs can also occur in turf and garden borders, such as the cockchafer, summer chafer and brown chafer. These can have larvae up to 30mm (over an inch)
• Similar root damage in lawns can also be caused by leatherjackets but churning up of the turf by other animals is less likely where leatherjackets are the problem.

Symptoms
Earthworms are soil-dwelling animals that have elongate cylindrical segmented bodies. Adult earthworms have a distinctive thickened band about one third of the way down the body from the head end, this is part of the reproductive system of the worm.

In general earthworm activities are beneficial in gardens, for both soil structure and in nutrient recycling. Earthworms feed on dead plant material and in doing so ingest a certain amount of soil. As a consequence, an earthworm’s excrement has a muddy consistency and appearance. Most earthworm species void waste material underground but a few species deposit casts on the surface. This can spoil the appearance of fine lawns, particularly if the casts get squashed and spread over the surface by trampling feet or lawnmowers. This can create places where mosses and lawn weeds can establish.

Worm casts can be distinguished from soil brought up to the surface by other lawn animals, such as ants, mining bees and moles, by the fine muddy nature of the excreted soil. Freshly deposited worm casts often have a coiled appearance.

The worm casts, if left untreated, can also form a good seed bed for weeds to establish in.