Site, Tree and Silvicultural Factors Influencing the Infestation of Xylophagous Insects on Nothofagus Forests

Abstract

This study assessed infestation of Proholopterus chilensis in Nothofagus obliqua trees in the Valdivia Province, Chile. P. chilensis is a native xylophagous insect that produces internal galleries in the stem during larval stage, decreasing value recovery in the most profitable log of the tree. The objectives of the study were to evaluate the current infestation of P. chilensis in Valdivia Province, to investigate the relationships among infestation, trees, site and flora attributes, to increase information about P. chilensis infestation patterns, and to make suggestions about silvicultural practices that could reduce damage. Results indicated that the level of infestation was low, compared with previous data. Hierarchical logistic regression models showed that estimated tree height and stand density were significant to explain probability of a tree being attacked by P. chilensis. Site altitude, flora diversity and Importance Value Index of Chusquea quila and Shannon-Weaver index were not significant predictors of infestation.