Survival of a Lepidopteran Defoliator of Eucalyptus is Influenced by Local Hillside and Forest Remnants in Brazil

摘要

We tested the hypothesis that Euselasia eucerus (Lepidoptera: Riodinidae) the intensities of mortality factors in eucalyptus plantations in xeric environments are greater near fragments of native forest and they diminish with increasing distance from the latter. Samples were collected along a transect crossing a 70-ha planting of Eucalyptus urophylla x Eucalyptus grandis hybrid extending from adjacent native vegetation to a hilltop. Sampling was completed along an elevation and distance gradient from the native forest in three environments, near the native forest (base), intermediate (mid way between the native forest and the hilltop) and distant from the native forest (hilltop) ones. Fungi, parasites and predators caused mortality of E. eucerus pupae. Damage to E. urophylla x E. grandis hybrid by E. eucerus was greater at the more distant location possibly because of plant water deficits and/ or increased E. eucerus survival. Mortality of E. eucerus in all ontogenetic stages was greater in areas near the native forest. Proximity to native vegetation appeared to be a key factor that influenced survival of local E. eucerus populations in E. urophylla x E. grandis hybrid plantations. The results presented here reinforce the concept that native vegetation near eucalyptus plantations exerts a local effect supporting the maintenance of natural enemies of E. eucerus, and favoring infections by entomopathogenic fungi during the pupal stage of this insect. View this article in BioOne