Revista Chilena de Historia Natural 81 (2): 221-238, 2008
RESEARCH ARTICLE
Composition, species richness and abundance of nocturnal folivorous insects associated with
Aristotelia chilensis (maqui) in the fragmented Maulino forest
At the Maulino forest, herbivory upon Aristotelia chilensis (maqui) is
negatively affected by forest fragmentation, being higher in the continuous forest than in the small remnant fragments, particularly at the
beginning of the growing season (spring). This phenomenon may be attributable to changes in the population dynamics of herbivores,
mostly insects. In this work, the effect of the Maulino forest fragmentation on the abundance, species richness and composition of
nocturnal defoliating insects associated with A. chilensis was evaluated. The insects associated with A. chilensis
were sampled monthly, between August 2005 and February 2006, in 32 trees located in a continuous forest (600 ha) and in 32
trees located in eight forest fragments (0.4-20 ha). Insect sampling was carried out during the first five night hours. 890 folivorous
insects from 17 families and 77 species of Coleoptera, Orthoptera and Lepidoptera were collected. All species were native. The total
abundance did not vary with habitat fragmentation. Nevertheless, some species increased their abundance with fragmentation, while
others were depressed. The species richness of folivorous insects per tree did not vary with forest fragmentation, though the total
number of species was considerably higher in the forest fragments. The species similarity was higher within the continuous forest than
between the continuous forest and fragments or among fragments. At the beginning of the season (September), the abundance of
Sericoides obesa was significantly higher in the continuous forest than in the forest fragments. Later in the season,
Sericoides viridis became more abundant in the forest fragments. Because of the body size and the voracity of
Sericoides sp., these insects seem to be responsible of the herbivory patterns of A. chilensis at the Maulino
forest.
Key words:
folivorous insects,
Maulino forest, habitat fragmentation
