Gut content analysis of extra- and intraguild prey in ground dwelling predators and field densities of prey and predators

The experiment took place in 10 organic and conventional spring barley
fields in south-central Sweden located in pairs during the early barley
tillering ('Early' period) and at barley stem extension/heading stage
('Late' period).

3680 generalist ground-dwelling predators (carabids and spiders)
were collected for gut content analysis with primers targeting:
- extraguild prey: aphids, thrips, dipterans, springtails and earthworms
- intraguild prey: Carabids: Harpalus, Pterostichus, Poecilus, Bembidion; and Spiders: Lycosidae, Linyphiidae, Pachygnatha spp; other: Coccinella septempunctata and lacewings.

Extraguild prey density and intraguild prey activity density were recorded at Early and Late period.