Invertebrate trends in an arable environment: long-term changes from the Sussex Study in Southern England
The Game & Wildlife Conservation Trust’s Sussex Study is one of the world’s longest running studies of the cereal ecosystem. We report here on fifty years of changes in invertebrate abundance, farming management and weather on the study area and review relevant research contributions arising from this work. The abundance of six groups of chick-food invertebrates all showed annual variations. Symphyta, Lepidoptera & Neuroptera increased by 26% over the fifty years, Chrysomelidae & Curculionidae and Non-aphid Hemiptera remained stable, Araneae & Opiliones, Aphididae and Carabidae & Elateridae declined by 32%, 57% and 76% respectively. Of three chick-food indices examined, the grey partridge chick-food declined by 18%, the yellowhammer index by 57% and the corn bunting chick-food index increased by +44%. Overall invertebrate abundance declined by 17%, though this was influenced by the very numerous Collembola (-1% change in abundance), Thysanoptera (+29%) and Aphididae (see above). Discounting these large groups, overall abundance of the remaining invertebrates declined by 34%. We review the results of previous research on the drivers of these changes, considering changes in cropping, use of pesticides and changes in weather.