To create further awareness of the beneficial insect diversity and community on the basis of increasing biocontrol in crops and farming systems to lead to reduced pesticide use, costs and to support our own environment, I would like to start off introducing those of you who don’t know to a species of beneficial in each newsletter.
Introducing the Ground Beetle
Firstly, which won’t come as a surprise to my clients – the Ground Beetle. The Ground Beetle is an extremely common predator for pests such as Aphids and Slugs, they also feed on various other soft bodied pests including caterpillars, beetle larvae and insect eggs.
Ground Beetle Habitat and Behavior
Their egg laying sites include crevices or in the soil profile – due to this, it is worthwhile to note that excessive cultivation and disturbance of the soil can be detrimental to increasing this highly beneficial insect into our biodiversity of farming. The larvae and adults tend to overwinter in grass clumps or in dense woody vegetation (beetle banks and grass margins are highly effective to creating a good habitat to increase beetle numbers) and when not hunting, the adults will take shelter under mulch, stones, logs and brush piles. This is another important fact to consider when increasing and looking into biodiversity as to include not only suitable habitats but also adequate needs for successful hunting by the predator. Fields without adequate stones, straw debris and plant cover (all year round), do not see the benefits of Ground Beetles as integrated pest control.
Ground Beetle Diet
Other food sources of the Ground Beetle will include some of the Omnivorous species which will consume seeds, pollen and detritus in addition to the prey stated above.
The Reach of Beneficial Insects
Beneficial insects will usually range up to 50m out from their habitat. Past this 50m it is not reasonable to assume biocontrol from insect diversity is reliable and hence in general, fields with smaller field sizes with less pesticide use and more non-crop habitat from field margins and hedgerows will have the most beneficial insects and lowest pest pressures if the supporting natural habitat is balanced.
Encouraging Ground Beetles on Your Farm
Keep an eye out for Ground Beetles, think on how we can integrate schemes and habitats to our own benefit on the farm and is there anything else we can be doing to support nature to best support our own farming systems.
Ground beetles are killed by most foliar applied insecticides and intensive soil tillage. We can encourage Ground Beetles by dividing large fields (>15ha) with beetle banks, create tussocky grass margins, use spray thresholds to control and reduce insecticide applications, reduce intensive tillage and allow uncompetitive weeds or companion crops to survive in the bottom of the crop to provide cover and alternative food source from seeds and other insects.
Stewardship Schemes for Ground Beetle Enhancement
If you are interested in looking into mid-tier stewardship schemes that would help to increase the available habitat and increase populations of ground beetles – beetle banks (AB3 – £573/ha), 4-6m buffer strips on cultivated land (SW1 – £353/ha), in-field grass strips (SW3 – £557/ha), winter cover crops (SW6 – £114/ha), management of hedgerows (BE3 – £8/100m side), undersown cereal (OP5 – £86/ha) and woodland edges on arable land (WD3 – £323/ha) would all be helpful schemes to look further into.
