WHY ARE INSECTS DECLINING IN THE UK?

 

INSECTIFICATION OF AGRICULTURE.

The intensification of agriculture has had a multitude of impacts on insect populations. Land conversion to agriculture has resulted in the loss and fragmentation of many vital habitats.

The expansion of monoculture farming has reduced the diversity and availability of habitats and food sources.

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The increased use of pesticides (inc. insecticides, fungicides and herbicides. Pesticides are not target specific, so they do not just harm the insect species being targeted, but many other insects that come into contact with the pesticides as well. Many pesticides can persist in the environment for considerable time or when it rains runoff into other habitats including waterways, so their impact goes
beyond just agricultural land. Pesticides do not just kill insects, but they can also have sub-lethal impacts on insects, including changing behaviour or damaging the immune system. Sub-lethal impacts are not usually considered in environmental impact assessments, so the long term impact on insects is not well understood outside of a research setting.

 

CLIMATE CHANGE

Changing temperatures as a result of climate change is believed to be a significant contributor to insect decline. Many insect species have adapted to specific, stable temporal conditions, so they cannot adapt quickly enough to keep up with the changing climate. Temperature change is also leading to the decoupling of pollinating insects emerging with plants coming into flower. This loss of synchronicity could have a devastating impact on both the pollinating insects and the flowering
plants.

 

There is also emerging evidence that climate change is causing the range of some insects to shift, possibly due to shifting habitats as a result of changing temperature. The loss of these insects from their original ranges could
lead to changes in the ecosystem community structure, which will have unknown impacts.

 

URBANISATION

Similar to agricultural intensification, urbanisation and the expansion of urban infrastructure such as roads, housing estates and shopping centres has led to extensive habitat loss and fragmentation. The management of urban green spaces can actually have a negative impact on biodiversity. For example, tightly mown grass may look neat and tidy, but it is devoid of plant diversity and flowers which can attract different insects.

The use of pesticides in gardens and urban green spaces has also increased considerably over the years, further contributing to the accumulation of pesticides in the soils and waterways of the UK.

 

Urbanisation has also contributed to increases in light pollution caused by artificial lights. Light pollution has the greatest impact on nocturnal insects, such as moths, whose behaviour has been disrupted by the presence of artificial lights at night.

 

CHEMICALS (OTHER & NEONICOTINOIDS)

Pesticides are not the only chemicals that are having a negative impact on insects.

Fertilisers, heavy metals and different types of chlorinated hydrocarbons such as polychlorinated biphenyls (PCBs) have been found in freshwater habitats. Many insects rely on freshwater habitats not only as a source of water, but will spend part of their lifecycle in water. The use of neonicotinoids is also highly contentious.
Neonicotinoids are systemic; they travel to all parts of the plant. Even the smallest amount can kill pollinators. In 2013 the use of neonicotinoids was severely reduced due to overwhelming evidence that they seriously impact bee pollinators. However, their use is allowed in emergency situations and in January 2022 the UK government authorised the use of the Cruiser SB pesticide, which contains neonicotinoid, on sugar beet seed. There is a common misconception that coating seeds is less damaging than spraying directly onto crops. The Labour Government in 2025 agreed to maintain the ban on Cruiser SB which is a huge win for the bees. But we will continue to monitor the situation.