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NEWS RELEASE No: 1644316 MARCH 2016

Exploring future trends in pest damage to forests in a changing climate

GREAT SPRUCE BARK BEETLE (Dendroctonus micans)

Future trends in insect pests’ effects on Britain’s forests as the climate changes are explored in a new Forestry Commission Research Note.

Entitled ‘Influence of climate change on forest insect pests in Britain’, the research note was written by entomologists Dr Daegan Inward and Dr Dave Wainhouse at the Commission’s Forest Research agency.

It outlines the main changes projected for the British climate over the coming decades, and how forest insects, grouped according to similarities in their ecology and life history, are likely to be affected by climate change. Specific examples within each insect group are discussed briefly.

It is intended to help woodland managers, foresters and researchers with long-term forest management planning decisions. Dr Inward said,

“The key messages arising from the review we’ve conducted for this research note are that:

  • managing and mitigating the risks of pest damage is an important aspect of sustainable forest management;
  • climate change will affect the abundance and geographical distribution of forest insect pests and the severity of damage they cause; and
  • climate change will also affect host trees (in some cases making them more susceptible to attacks by pests) and the natural predators of pests.”

In addition, Dr Inward added, the effects on pests are likely to be complex, influencing not only their rate of development and number of generations per year, but also the seasonal timing of life-cycle stages. Changes in rainfall and the frequency of extreme weather events also have the potential to influence pest damage.

“Although it is not possible to predict the future impact of forest pests with any precision, some generalisations are possible based on the ecological characteristics of different insect types,” Dr Inward continued.

“Overall, the damage caused by aphids and related insects is likely to increase as the climate warms. Higher temperatures will increase reproductive rates, with species having multiple generations each year likely to benefit most.

“Drought stress on host trees caused by rainfall changes is likely to be favourable for some pests. The impact of bark beetles and related insects is also likely to increase, due to factors such as increased frequency of windblow, drought stress and, for some species, a shorter generation time.”

This Research Note is an unpriced publication available to download from the Forestry Commission’s on-line publications catalogue at

Media contact: Charlton Clark, 0300 067 5049