Composition and classification of insect damage on Nothofagus glauca (Fagaceae), Maule Region, Chile

Abstract

The Maulino forest, where the “hualo”, Nothofagus glauca, dominates, is one of the Chilean plant formations least studied for its entomological fauna. This endemic tree of Chile is distributed from the regions of Metropolitana and Bío-Bío, in environments very fragmented by deforestation in previous decades and by the introduction of exotic trees. The assessment of damage by insects is a necessary tool for decision-making about integrated pest management. Given the scarce knowledge in this matter on this species, periodical samplings were made of foliage, bark, wood, fruits and roots and insect collections associated with N. glauca during the 2001-2002, 2002-2003, and 2003-2004 spring-summer seasons to analyze their insect composition and classify their damage, in second growth sectors located in Empedrado County, Maule Region, Chile. The insects associated with N. glauca were grouped in three orders, 13 families and 25 species, predominantly coleopterans (seven families, 19 species), followed by lepidopterans (three families, three species) and hemipterans (three families, three species). Foliage insects were the most abundant (16 species), causing moderate damage, followed by those on wood and bark, with seven and six species each, two of which caused significant damage. Of the species found, eight are new records for N. glauca, with five extending the geographical distribution toward the north of the country. Nearly 60% of collected fruits presented damage by Perzelia sp. (Lepidoptera: Oecophoridae), an insect that affects the regenerative processes of N. glauca.