Moths, beetles and spiders might seem like innocuous household pests, but in a global warming world they have the potential to wreak havoc on crops, forests and human health. We are already seeing signs of pest population explosions:

November 1991:

• A plague of whiteflies attacks southern California's winter fruit and vegetable crops, prompting the declaration of a state of emergency.

1992:

• The succession of warmer-than-usual summers encourages a proliferation of spiders, cat fleas, head lice and other insects.

December 1992:

• Intense drought-breaking rain across eastern Australia induces the worst locust plague and maggot swarms in sheep flocks in recent years.

1992-1993:

• Three successive warm summers encourages the worst infestation of bark beetles in living memory, devastating thousands of hectares of Austrian and German forests. Voracious populations of alien moths denude forests and croplands in southern England, Scotland, and central Europe.

July 1993:
• Mild winters and drought are blamed for the first locust plague in 60 years in Hungary.