A look at how climate change is spreading pests around the globe

Pests on move worldwide as climate warms

A look at some other pests that are benefiting or could benefit from global warming:

—Ticks that transmit Lyme disease are spreading northward into Sweden and Canada, once too cold for them.

—Giant Humboldt squid have reached waters as far north as British Columbia, threatening fisheries along much of the western North American coast.

—Malaria-carrying mosquitoes are now found in South Korea, the Papua New Guinea highlands, and other places previously not warm enough for them.

—Bark beetles reproducing more quickly in warming climates and expanding their ranges have devastated forests across western North America. In British Columbia they have laid waste to an area twice the size of Ireland.

—A microscopic parasite is spreading a deadly disease among salmon in Alaska and British Columbia. Researchers say rising water temperatures are partly to blame.

—The U.S. government warns that such invasive plants as the common reed, hyacinth and purple loosestrife are likely to spread to northern states.