Spatial distribution of Cydia fagiglandana (Zeller) in an exploited holm oak (Quercus ilex L.) forest.

Cydia fagiglandana (Zeller) (Lepidoptera: Tortricidae) is a carpophagous insect which affects the quality andviability of the fruits of beech, oak and chestnut trees. The majority of the works on this species in holm oak woodsdealt with assessing its damages. No investigations have yet been performed on the spatial distribution of this pest,although this element is one of the key features to take in account in order to develop proper integrated managementprograms. The present study, performed during a four years period in an exploited holm oak forest area in SouthernSpain, investigated the spatial distribution of C. fagiglandana integrating classic methods based on dispersion ratesand distribution fitting together with the elaboration of population density maps based on GIS. Our results showedthat the infestation rate progressively decreased from 0.339 in 2001 to 0.102 in 2004. Density maps for C. fagiglandanaalso show an heterogeneous and aggregated distribution of this insect and a spatio-temporal stability in this area. It isconcluded that during the four years of the study inter-specific competition with the weevil Curculio elephas was thefactor that most affected the spatial distribution of C. fagiglandana in the experimental plot.