Dynamics of the predatory arthropod community in Spanish olive groves

1 A survey of the predatory fauna of olive pests, particularly the olive moth, Prays oleae, was undertaken in Granada, Spain, from May to September 1994–95. 2 At both experimental sites similar patterns of emergence were observed for all predatory species with peaks occurring in June, both in 1994 and 1995. More individuals and species were captured in the morning than in the evening. 3 A weak inverse relationship existed between the mean monthly temperatures and the total number of predators caught. 4 The number of predatory species and of individuals caught at both sites was, respectively, two and three times larger in 1994 than in 1995; This difference is assumed to have been due to the accumulated affect of 6 years of drought. 5 Synchrony between P. oleae and predator phenology was suggested by the coincidental timing of peak predator numbers with the oviposition and subsequent emergence of the most vulnerable stage of the olive moth’s lifecycle, i.e. the flower generation. 6 There were more individuals of ants caught, whilst more spider species were captured than all other groups; predatory Coleoptera and Heteroptera were poorly represented. 7 Ants appeared to have a detrimental affect on the number of all other predators.