New "pests", in the form of flora and fauna or diseases (human or animal), which were previously rare or unknown in the UK, could appear as a result of a variety of external factors. Perhaps most notable among these are climate change and increasing migration and transport of people, livestock and food products.
In the case of climate change, a number of studies have been made of the possible effects of global warming on the distribution of wild plants and animals within the UK and some predictions made as to which new species might be expected to gain a foothold in the country. For example, the Royal Horticultural Society notes that:
In addition, the UN’s Intergovernmental Panel on Climate Change states in its report "Climate Change 2001: Working Group II: Impacts, Adaptation and Vulnerability" that:
"Pests, diseases and weeds that currently are of minor significance may become key species …. The distribution and intensity of current key pests, diseases, and weeds may be affected, leading to changed effects on yield and on control measures such as pesticides and integrated pest management."
and suggests that the prevalence of water-related illnesses and a wide range of food-, tick- and rodent-borne diseases could all increase as a result of the climate changes, which are predicted over the coming decades.
HSE has responsibility for providing mandatory approvals for biocides in 4 categories, namely:
Pesticides for plant protection are the responsibility of the Pesticides Safety Directorate within Defra.