Moles (Talpa europaea) are now very common and even small populations can do considerable damage to sports turf, playing surfaces and amenity lawns, although control may not be necessary in less intensively used or managed areas. The damage is a side-effect of moles' subterranean lifestyle - they live on a diet of worms and other soil invertebrates and although they do not eat plant material they could damage roots during their tunnelling activities.
On nurseries, the cultivation associated with open-ground or field production makes seedbeds or rows of stock attractive places for moles to dig, and their tunnelling can often follow lines of recently planted stock. This activity may damage the plants through root disturbance.
Controls are divided between deterrents, traps and poisons. On private sports and amenity areas, it is possible to use pellets containing aluminium phosphide. These generate a poisonous gas on contact with moisture. Baiting, fumigation and trapping are most effective from October to April when the moles are active but before the start of the breeding season.
Controlling earthworm populations - using proprietary pesticides - will reduce the moles' food supply but it is important to remember that earthworms are also very important for soil aeration, health and fertility.
- Moles are blackish-brown mammals that live most of their lives underground and exist on a diet of earthworms and other soil invertebrates.
- An 80g mole consumes around 50g of worms a day. Moles will also feed on soil-dwelling pests such as cockchafer larvae but not plant roots.
- They have poor eyesight and use touch, hearing and smell to detect prey and help sense danger.
- They dig two types of tunnel, both of which are 4cm or 5cm in diameter. Those immediately beneath the surface are dug by males looking for females during the breeding season (February to June). Deep holes, between 5cm and 20cm beneath the surface, are used for breeding and feeding. Tunnels can be up to several hundred metres long.
- Molehills on the surface are the means of disposing of excavated soil. Nest sites are marked by large molehills. Females produce litters of three-to-five young. Their average lifespan is three years.
- Apart from the breeding season, moles lead solitary lives so one could be responsible for the visible activity over quite a large area.
- Vacant tunnel systems are often recolonised by another mole from an adjacent area.
Molehills are heaps of excavated soil on the surface of lawns or greens or on the soil of planted areas. Tunnels beneath amenity or sports turf cause long ridges of soil a few centimetres high. The tunnels may collapse, causing an uneven, poorly performing and possibly dangerous surface.
Tunnelling can disturb the roots of seedlings or freshly planted stock in nurseries or amenity plantings, breaking root-soil contact and, in severe cases, leading to drought symptoms in the plants. Moles can also chew through buried irrigation system control cables or trickle pipes should these be in the animals' way.
Treatment: biological control
Planting caper spurge (Euphorbia lathyris) is said to deter moles because exudates from the roots have a repellent effect. Deadhead the flowers before seed set to prevent it becoming a weed problem.
Treatment: cultural control
Some turf fungicides containing carbendazim (all products have an end use date of 31 August 2017) are approved for the control of casting earthworms on managed amenity turf. Control of worms reduces moles' food supply but may have negative implications on soil health.
Electronic or mechanical devices that produce sound or vibrations to deter moles can be placed near runs. These can be effective over small areas but often only displace moles to another location.
Well-designed and maintained spring-loaded traps can kill humanely and can be effective if they are used correctly. Handle with gloves to prevent leaving human scent residues on the traps and bury them in soil for a few days before use. Place the traps in mole tunnels with minimal soil disturbance but not directly beneath molehills. Inspect traps and remove dead bodies regularly.
Live traps are available that should be used with the same precautions to prevent contamination with human scent. These should be checked at least once a day. Natural England provides advice on preventing unnecessary suffering. Control of moles on a site of special scientific interest may require permission from Natural England.
Treatment: chemical control
Active ingredient Aluminium phosphide
IRAC code 24A
Formulation Phostoxin (Rentokil); Talunex (Killgerm Chemicals)
Action(s) Fumigant pellets approved for control of moles on managed amenity turf, lawns and in farm woodland. In contact with moisture, the compound releases toxic phosphine gas. Only to be used by operators trained in the use of aluminium phosphide. Cannot be used in wet weather. Effectiveness may depend on soil conditions. Holes must be sealed to retain gas. Precautions needed to protect non-target organisms. Applications of these products have been subject to recent changes to legislation (RAMPS UK - www.ramps-uk.org). The Register of Accredited Metallic Phosphide Schemes aims to maintain best practice and the sustainable use of metallic phosphide products through training and registering of stockists and operators.
Animal Welfare Act 2006 (and Protection of Animals, Scotland, Act 1993); Pests Act 1954; Pharmacy & Poisons Act 1933; Small Ground Vermin Traps (Scotland) Order 1958; Poisons Act 1972; The Poisons (Amendment) Rules 1989; Wildlife & Countryside Act 1981; Control of Pesticides (Amendment) Regulations 1997; Control of Substances Hazardous to Health (COSHH) 2002.
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