Insect Damage as a Function of Climate

Robert E. Child

Successful insect development is dependent on a number of factors. The availability, quality and quantity of suitable food is a primary one, but other factors such as light, access to undisturbed areas, proximity to other insects of the same species, are others. Fundamental to insect growth however are environmental factors of temperature, relative humidity and moisture content of food materials. When a combination of favourable factors leads to increased insect development there is a co-related increase in the damage to materials through eating, despoiling, burrowing and other activities.

Museums and other institutions holding historic and artistic collections have seen a rapid increase in insect damage in the last ten years. Some of the increased attack is due to the banning of powerful pesticides, but other factors have increased the number and variety of insect pests attacking collections. External warming of the environment, through global warming and high internal temperatures in buildings, have energized insect pests to eat and breed faster, thus increasing their propensity to cause more collateral damage. Additionally, the higher ambient temperatures have allowed warm and hot climate insect pests to migrate and thrive in countries and buildings formerly too cold for them to survive.

The changing internal and external climate with increasing temperatures, and its effect on relative humidities and the moisture content in organic material, requires a review of Integrated Pest Management policies in museums to accommodate current changes and future predictions.