Why we need a diversity of predators
Predatory insects have many different lifestyles, habitats, and diets. Ladybirds and their larvae are active on crop plants while other predators such as wolf spiders and ground beetles are active on the soil surface.
Natural predators hunt in different ways. Wolf spiders don’t build webs but instead chase down their prey. Even web-building spiders differ in the type of webs they build. Money spiders build small web sheets on the top of vegetation and their webs are frequently found catching the dew on grassland swards. Orb-weaver spiders construct classical spiral, wheel-shaped, webs and these spiders typically require structurally diverse vegetation to build their complex webs.
Natural predators also feed on different prey items. Most ground beetle species eat a wide variety of insects, but some are extremely specialised - Cychrus caraboides has long mandibles specifically designed to pull snails from their shells. Parasitic wasps also tend to be specialists with many species laying their eggs in aphids. The hatching wasp larvae consume the aphid from the inside, pupate and then emerge as adult wasps from the mummified carcass.
Providing a range of habitats helps to support a diversity of natural predators and this can result in more effective control of a wider range of pest species.
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