A moth outbreak has killed off forests across Siberia, now the flammable wood is causing wildfires

An insect outbreak has left Siberia's forests dead while also transforming the region into a tinderbox where wildfires are now spreading beyond human control. The trees burning across Krasnoyarsk this year were, in a lot of cases, already dead. Not from the fire or the drought, but because of a small moth.Dendrolimus sibiricus, the Siberian silk moth, has spent the last several years stripping needles from fir, spruce, larch and pine across huge stretches of central Siberia and a tree that loses its needles for numerous consecutive seasons simply dies where it stands. It will not decompose, but stand upright in the cold, dry climate until something eventually sets it alight. This year, it was the flame of an unusually hot, dry stretch of Siberian summer.Striking a fireThe Siberian silk moth has burned up the forests, without ever touching the fire. Its caterpillars are defoliators, meaning they eat needles rather than wood, bark or roots and a single bad outbreak year can strip hundreds of thousands of hectares. A 2026 research study into the moth's life cycle published in Frontiers in Insect Science examined why some populations follow a one-year larval cycle while others take two...