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Expert comment on new research into insect numbers

Prof CollierProfessor Rosemary Collier from Warwick Life Sciences and the Warwick Crop Centre comments on new research into insect numbers:

"My career has been based on finding novel ways of outwitting and eradicating insects that infest food crops, and vegetable and salad crops in particular. I and my colleagues are focused on doing this, as far as possible, in environmentally friendly ways that have minimal impact on other species (Integrated Pest Management).

"The new paper, ‘Meta-analysis reveals declines in terrestrial but increases in freshwater insect abundances published in Science, by van Klink et al. confirms, what to me is very obvious, that through terrestrial land-use change, we have altered and reduced the size of habitats that are suitable for a good number of species of insect.

"In particular, this study suggests that urbanisation has an important negative effect on insect abundance. The contrasting increase in insect abundance in fresh water ties in with other evidence that the quality of freshwater bodies in some parts of the world has improved; this has been reflected in the ‘return’ of other non-insect species to our rivers, for example the River Thames, although other aquatic species are still threatened.

"The finding that the trends in spatiotemporal patterns of insect abundance are more nuanced than previously suggested provides some hope that if we can understand better the requirements of species and have the will to ‘make space for nature’ then we can make a positive difference.

"Incidentally, one potential effect of the COVID-19 pandemic may be a reduction in maintenance activities, such as the mowing of road verges, that will allow wild plants to flourish, providing more resources for other wildlife, including insects.

"To return to the pest insects. Land use change for agriculture, to feed the human population, has meant that we grow large areas of a single plant species, such as wheat, which allows the specialists (pests) to flourish. Our areas of monoculture have replaced the more diverse habitats containing the resources required by many other insect species. Cropped areas are likely to contribute to insect biomass but not contribute so much to biodiversity.

"It’s estimated that potential losses world-wide due to damage by animals (mainly insects) are around 18% and that pest management activities reduce this by about 40% (Oerke, Journal of Agricultural Science (2006), 144, 31–43). This obviously varies from location to location and crop to crop, but one recent example of a severe threat to food security by insects is the current locust plague in East Africa

"With a growing global population we can’t afford to lose our crops to pest insects, but there is a pressing need to investigate how we can adapt our living landscape (crops and other habitats) in future to make room for other, often beneficial, insect species."

24 April 2020


Sheila Kiggins

Media Relations Manager

07876 218166