Larch- and pine-feeding host races of the larch bud moth ( Zeiraphera diniana) have cyclic and synchronous population fluctuations.
Résumé
Population cycles of many forest-defoliating insects often show synchronous fluctuations at both intra-specific (spatial synchrony) and inter-specific levels. However, population dynamics of different host-associated biotypes of the same species, such as those of the larch budmoth (LBM), Zeiraphera diniana (Lepidoptera: Tortricidae), have never been compared. This species causes extensive defoliation of larch forests every 8 to 9 years in the Alps, but it consists of two genetically-differentiated host races, the first one developing on European larch, Larix decidua, and the other one developing on Swiss stone pine, Pinus cembra. The dynamics of Zeiraphera populations have been extensively studied on...