Cycles and importance of the larch budmoth
The grey larch budmoth (Zeiraphera griseana [Hübner]) is a small moth that became internationally famous for its periodic, large-scale infestations of larch forests in the Engadine and other inner Alpine valleys in Europe. While public attention remains limited to the years when regional outbreaks occur, this moth has become one of science’s best-known examples of cyclic population fluctuations.
The first historical mention in Switzerland of a "disease" that turned extensive larch forests yellow-brown dates from 1820 in the municipality of Ardon in Valais (Coaz 1894). In the mid-20th century, when tourism in Switzerland slowly started picking up again after the Second World War, another larch budmoth outbreak was in full swing. Consequently, he tourism industry in the Engadine pushed for the application of DDT, considered a wondrous new insecticide at the time, to treat the unsightly forests.. In 1948, the pressure to apply insecticides set in motion a long-term study spanning six decades. In the course of this ongoing study, the larch moth changed in public and scientific perception from a mere pest to a ecosystem engineer and fascinating topic of study.