1 The presence and abundance of arthropods were compared in three olive orchards under organic, integrated and conventional management regimes. In each olive orchard, trees were sampled in the canopy by beating branches and soil arthropods by placing pitfall traps. Contrary to expectations, the highest abundance of arthropods occurred in the integrated management orchard. The most abundant groups were Formicidae and the species Euphyllura olivinae (Homoptera: Psyllidae). 2 Canopies and the soil under the tree canopy (interior soil) were selected as the most informative sites for sampling. The months with the strongest differences were May, June and July, especially June. In the canopy, Araneae, Coleoptera, Diptera, Heteroptera, Hymenoptera, Homoptera, Lepidoptera, Neuroptera and Thysanoptera were the most abundant, and showed significant differences in abundance among orchards with different management regimes. Moreover, in the canopies, Coleoptera and Lepidoptera showed a seasonal pattern of abundance and consistent significant differences between the organic orchard vs. the integrated and conventional ones in both years of study. In the soil, 12 orders showed significant differences in abundance among management regimes at some point of the sampling season. 3 In a search for biological indicators that could help to distinguish between management regimes, a discriminant analysis applied to the data indicated that only the samples from the canopy were classified according to their management regime in a consistent way over time. The groups selected by the analysis to establish differences among management regimes were Coleoptera, Diptera, Heteroptera, Lepidoptera and Thysanoptera. The analysis applied to compare organic vs. non-organic olive orchards, again identified Coleoptera and Lepidoptera as suitable groups. The results suggest that these two orders are potential bioindicators to distinguish, in a simple way, organic olive orchards from non-organic ones.

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A study has been made of the presence of ants in 59 olive trees in each of three orchards under di}erent agricultural management in the province of Granada "southern Spain#\ during the months of May\ July and September 0886\ using both observational methods as well as the collection of specimens from the soil and trunk and the tree canopy[ A total of 07 species of ants were identi_ed\ 05 of which were present in the orchard of Arenales\ four in Colomera 0\ and nine in Colomera 1[ The number of species varies over the survey\ being greatest before the~owering of the trees\ this period coinciding with the lowest temperatures[ The species Tapinoma nigerrimum "Nylander# was the only species present in all the samplings of the olive orchards\ and the other common species in the three zones proved to be] Messor barbarus "L[ 0656#\ Tetramorium semilaeve Andre and Plagiolepis pygmaea "Latr[#[ Most of the species found made their nests in the soil under the tree canopy\ and only four species nested exclusively in open areas[ Ten species foraged in the tree and seven foraged in groups[ The three olive orchards were similar in phenology\ temperature and humidity\ and therefore the di}erences in the myrmecofauna at the di}erent sites were attributed to agricultural practices at each site[