Treesearch

Diease in spruce budworm, Choristoneura fumiferana (Clemens), caused by the microsporidian Nosema fumiferanae (Thomson), increase larval susceptibility to mortality by bacillus thuringlensis (Berliner) treatments compared with larvae free of N. fumiferanae disease. The median lethal concentration (LC50) of B. thuringiensis as determined by the diet incorporation bioassay method, was significantly lower for larvae infected transoverially with N. fumiferanae, but the similar slope obtained for intitially healthy larvae indicated an independent and additive interaction. The median lethal time...

Critical temperature (Tc), defined as the highest temperature at which freezing injury to plant tissues can be detected, provides a biologically meaningful and statistically defined assessment of the relative cold tolerance of plant tissues. A method is described for calculating critical temperatures in laboratory freezing studies that use electrical conductivity as a viability assay, using analysis of variance as a means of partitioning variance and estimating error. Evidence presented indicates that critical temperatures are strongly correlated with field assessments of winter injury,...

Thirty-four papers on biology and population dynamics of lymantriid moths presented at an international conference, plus a summary and discussion of research issues.

This publication provides current and historical information on primary and secondary hardwood product production, prices, international trade, and employment.