Beneficials on farmland: identification and management guidelines (HGCA Summer 2008)

'SAFE' principles to encourage beneficials

Beneficials need Shelter, Alternative prey, Flower-rich habitat and an appropriate Environment (SAFE) to thrive in farmland and keep pests in check naturally.

Shelter


Tussocky grasses support high densities of predators

Hedgerows, associated margins and other areas protected from insecticides and intensive tillage, provide habitats that enable beneficial insects to repopulate nearby crops. Strips of tussocky grasses and flower-rich grassland support high densities of some species.

Beneficials that only live for part of the year within a crop need other habitats in which to forage, breed or survive dormant periods.

Alternative prey


Dolichopod fly eating a springtail

Pests may only be present for short periods of the crop’s growing season. Prey, on which beneficials feed for the rest of the year, can be provided by:

  • other crops
  • uncropped areas
  • undersowing
  • weeds – deliberately left in the crop
  • minimum tillage
  • organic manures.

Minimum tillage and application of organic manures are especially valuable in providing suitable conditions for detritus-feeding invertebrates which serve as alternative prey for predators.

Flower-rich habitat


Flowers in margins support predators

Pollen and nectar – essential for parasitic wasps and hoverflies – are important food for other natural enemies including beetles and predatory flies. Alternative prey can live in vegetation with a varied habitat structure. Annual and perennial flowering plants found in woodlands, hedges, margins and crops can supply pollen and nectar.

Environment


Weeds beneath crops provide diverse vegetation. Herbicide programmes should focus on yield-robbing weeds.

Beneficials thrive in diverse vegetation that has not been treated with insecticides, such as field margins. All approved insecticides affect them to some degree, so it is important to minimise usage by adopting Integrated Pest Management (see Pest management in cereals and oilseed rape – a guide, HGCA (2003)) and only treating when thresholds are reached. Other pesticides may adversely affect beneficials, directly or indirectly, eg removal of weedy habitats.

Correct management will help create a habitat structure, providing beneficials with cover and a suitable microclimate.

The first step to maximise benefit from beneficials is to manage habitats so that they:

  • are spread across the farm – some beneficials tend to remain close to margins
  • are diverse – this encourages a range of beneficials providing robust biological control.

Landscapes

On some farms, a diverse landscape with many existing hedgerows and rough grassland provides beneficials with adequate habitat.

Elsewhere, especially in open simple landscapes and where there are large fields, extra provision is needed.

Making the most of agri-environment schemes

The costs of enhancing habitats can be recovered through some options in each national agri-environment scheme.


Diverse landscape – many non-crop habitats

Simple landscape – few non-crop habitats

Resources provided for beneficials by environmental schemes

Habitat type Option availability ^ Shelter Alternative prey Flowers Environment
Hedgerow management ELS, OELS, HLS, RSS, TG *** ***  *** ? ***
Protection/creation of uncultivated ground flora ELS, OELS,  HLS, TC *** ? ***  * **
Wild bird seed mixture ELS, OELS, HLS, RSS, TC, TG * ? ** ? * ? **
Pollen and nectar ELS, OELS, HLS, TC ** *** *** ***
Floristically enhanced grass HLS, TC ** ? *** *** ***
Overwintered stubbles ELS, OELS, HLS, TG ** *   *
Grass margins/buffer zones ELS, RSS, TC, TG *** *** N *
Beetle banks ELS, OELS, RSS, HLS *** *** N **
Skylark plots ELS, OELS, HLS N * ? * N
Fallow plots HLS N * * *
Conservation headlands ELS, HLS, RSS N *** * ***
Low input crops ELS, HLS, RSS, TG, TC ** *** * ***
Undersown spring cereals ELS, OELS, TG, HLS *** ** N  
Uncropped, cultivated margins ELS, OELS, HLS, TC, TG N ** ? ** ***
Ditch management ELS, RSS, TC, TG *** ***? *? **?
Non-inversion tillage   *** ** N **

ELS = Entry Level Scheme in England
OELS = Organic Entry Level Scheme in England
HLS = Higher Level Scheme in England

^ = As at spring 2008 

RSS = Rural Stewardship Scheme in Scotland
TC = Tir Cynnal in Wales
TG = Tir Gofal in Wales
*** = High benefit
** = Moderate benefit
* = Some benefit
N = No benefit
? = Potential benefit but not tested

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