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Genetic variation among host plants can influence herbivore behaviour and consequently their abundance, performance and environmental impact. In the Andean‐Patagonian forest, the arboreal vegetation is dominated by species of genus Nothofagus. Previous studies of Nothofagus alpina demonstrated differences in genetic diversity among and within its populations. The native caterpillar Perzelia arda feeds on various Nothofagus sp.Our aim was to evaluate host selection behaviour of P. arda larvae towards different genetic pools of N. alpina trees.We collected leaf samples from trees growing in a common garden field trial and evaluated, by paired comparisons, not only differences among provenances but also variation between and within open pollinated families.Our results demonstrated that P. arda performed a choice between the leaves of the host plants offered. This larva was able to choose specific provenances, open pollinated families and genotypes of N. alpina.In conclusion, the larva is guided by characteristics of individuals and host plant species. These innovative results in insect–plant interaction studies demonstrate that it is important to evaluate discrimination between intra‐specific hosts. Further study is required to fully understand the use of resources by this native insect, as well as the ecological consequences. [ABSTRACT FROM AUTHOR]

Two different studies based on isozymes that include genetic structure analysis have arrived at contrasting conclusions regarding the minimum number of seed transfer zones for Patagonian cypress ( Austrocedrus chilensis) in Argentina that are required in order to avoid genetic contamination in restoration programs. Unfortunately, the more recent article lacks discussion on these controversial results, which is, therefore, the purpose of this article. The reliability of the markers used and the sampling performed in these studies are evaluated comparatively. The later study found higher levels of diversity and differentiation but paradoxically suggested that only two seed transfer zones would be enough to preserve the genetic identity of the natural populations of the species, whereas the earlier study concluded that at least five are necessary. Arguments are presented here for the case that definition of fewer than five genetically homogeneous groups is absolutely inappropriate and implies a probable risk of genetic contamination and maladaptation. [ABSTRACT FROM AUTHOR]