Written evidence submitted by Professor Sara L. Goodacre (INS0002)

Insect decline and UK food security: Science and Technology Committee Inquiry

About me

I am a Professor of Evolutionary Biology and Genetics based in the School of Life Sciences at the University of Nottingham. I have spent the last 20 years working in the area of spider genetics. I have been on the Council for the European Society for the study of Arachnology since 2014 and its vice-President since 2018.

Submission content

One focus area of my research has been the distribution of spider populations across agricultural areas and studies of the way that these populations are influenced by human activity. My research clearly shows why this group of animals needs urgently to be included in all debates on invertebrates and food security. Their ecosystem service role as pest-controllers may be as significant to us as that of other, more well-publicised groups, such as bees and other pollinators. Their potential as a food source for particular groups of other animal, such as birds, is also likely incompletely understood and valued.
Spiders offer potentially significant pest-controlling1 potential within agricultural settings, thus reducing our reliance on insecticides. But spiders are heavily influenced by insecticides, including those from both the pyrethroid and neonicotinoid groups, and they are thus continually removed from agricultural landscapes by modern farming methods.
Spiders can return rapidly to a farmer’s field by aerial dispersal, using their silk as sails that are picked up by the wind2. They form a significant part of the aerial fauna travelling around our landscapes, in this way potentially repopulating areas emptied by previous insecticide application. In addition to controlling pests where they land, they also provide sources of food for species such as birds, and leave silken trails that can help bind soil.
Spiders are heavily influenced by insecticides (including the much-debated neonicotinoids3) and are in some cases several orders of magnitude more sensitive than a similarly-sized insect. Their populations are thus often devastated by farming activities that involve these agents. We do not yet fully understand what the physiological basis is for the increased sensitivity, but as spiders are several hundred million years diverged away from the insects it is not a surprise that their nervous systems and physiologies respond differently. We need to increase our understanding of the underlying mechanisms for spiders’ response to insecticides if we want to do more to try to help conserve this natural biological capital.
Conclusion: We need spiders to provide food for other species, to limit the abundance of pest-species, and to provide the natural balance in terms of the presence of predatory arthropods in both our urban and native ecosystems. This needs to be reflected in Government policy, which should prioritise spiders as much as insects as part of a healthy ecosystem for future food security.

5 March 2023