Dynamics of Larch Bud Moth Populations

Abstract

+6121Ideally studies on the population dynamics of organisms should be holistic, general, precise, and realistic ( 64). Much too often, however, support for research on forest pests approximates the curve of the gradations in time and space, resulting in periodic gathering of bits and pieces of information that differ little from that gathered earlier or elsewhere (68). Therefore it is not surprising that lack of compre hensive, quantitative information on many generations of a field population has handicapped the progress of theoretical thinking on the dynamics of populations, which badly needs "more light and less heat" (86). It has been proposed that research efforts should be coordinated internationally on a few model insects in order to cope with complexity and diversity of population dynamics at a high level of efficiency (25). We consider that the larch bud moth, Zeiraphera diniana, would meet the criteria for being such a model insect (1 8).The coincidence of large-scale insect outbreaks, the availability of effective insecti cides, and economic expansion of industry and tourism after World War II pro moted several extensive control actions against such forest pests as the spruce budworm, Choristoneura fumiferana, in eastern Canada and the larch bud moth, Z. diniana, in Switzerland. Public demand to protect the subalpine larch forests in the recreation area of the Engadine (Switzerland) against the recurring defoliation by the larch bud moth triggered the present research phase. This article is the first attempt to publish the results of the research period comprehensively. In addition, information concerning previous outbreaks of Z. diniana is reviewed on a worldwide base.

Previous herbivore attack of red alder may improve food quality for fall webworm larvae

“…The reduction of food quality may occur within hours or days (Green andRyan 1972, Carroll andHoffman 1980) or may persist over several seasons (Baltensweiler et al 1977). Food quality may also deteriorate as a regular seasonal occurrence (Feeny 1970, Dement and Mooney 1974, Scriber 1977, Mooney et al 1981.…”

“…Deterioration. Herbivore attack reduces the photosynthetic productivity of plants and food quality deteriorates, possibly as a result of leaf area loss, reduced leaf water or nutrient contents, or increased fibre content (Feeny 1970, Baltensweiler et al 1977, Haukioja 1982, Myers and Post 1981.…”

An experimental test of whether pied flycatchers choose the best territory for rearing the young

“…There can be huge differences in arthropod population densities between years (e.g. Baltensweiler et al, 1977;Ruohomäki et al, 2000) with varying effects on passerines (Enemar et al, 2004;Hogstad, 2005). We have previously shown that pied flycatchers did not prefer territories with herbivore-damaged birches that had caterpillars hidden from view (Mäntylä et al, 2010).…”

Snow Avalanches in Forested Terrain: Influence of Forest Parameters, Topography, and Avalanche Characteristics on Runout Distance

“…The period of analysis ) included a L. monacha outbreak in the 1980s (Bottero et al 2013) and 2 Z. griseana outbreaks, 7 years apart (Esper et al 2007) with a duration of 3 years each (Baltensweiler et al 1977). Insect disturbance had a very low recurrence, as the insects moved to adjacent areas from year to year.…”