noneEnter An assay was conducted over 2 years (2005 and 2006) to investigate the effects of reducing deltamethrin concentrations, from 0.01 to 0.00125% a.i., in olive logs prior to colonization by the olive bark beetle, Phloeotribus scarabaeoides Bern. (Curculionidae, Scolytinae) on the population densities of the pest and its associated parasitoids. Effects were measured in terms of numbers of penetration holes in logs, numbers of insects captured in containers placed under the logs, and numbers of insects emerging from logs. The results from 2005 showed no differences, there being low insect numbers that year as a consequence of an unusually cold winter. In 2006 beetles dug negligible numbers of reproduction galleries inside logs treated with deltamethrin at different concentrations, and emergence from the treated logs was significantly reduced. A repellent effect rather than a direct effect of the insecticide is hypothesised. Parasitoid wasps were captured in low numbers in containers under the logs, both in the control and the insecticide treatments. The emergence of parasitoids from control logs was significantly higher than from treated logs. A further reduction of deltamethrin concentration is recommended in olive beetle management. BR Animals and man. Control. Reproduction. Life cycle and development. Development. Metamorphosis. Parasites diseases and disorders. Parasites. Insect parasites. Hosts. Insect hosts. Ecology. Population dynamics. Habitat. Man made habitat. Abiotic factors. Chemical factors. Land zones. Palaearctic region. Eurasia. Europe. Phloeotribus scarabaeoides (Curculionidae): Host, Parasite; Eurytoma morio (Eurytomidae): Parasite; Cerocephala eccoptogastri (Pteromalidae): Parasite; Cheiropachus quadrum (Pteromalidae): Parasite; Rhaphitelus maculatus (Pteromalidae): Parasite; Dendrosoter protuberans (Braconidae): Parasite. Cerocephala eccoptogastri, Cheiropachus quadrum, Dendrosoter protuberans, Eurytoma morio, Rhaphitelus maculatus: Emergence, prevalence, host control measures effect, Coleopteran hosts, Phloeotribus scarabaeoides, Cultivated land habitat, Olive groves, Fertilizers and pesticides, Deltamethrin treatment of logs, Spain, Granada; Phloeotribus scarabaeoides: Chemical control, Deltamethrin treatment of logs, prevalence, Reproduction, Emergence, Hymenopteran parasites, Cerocephala eccoptogastri, Cheiropachus quadrum, Dendrosoter protuberans, Eurytoma morio, Rhaphitelus maculatus, Plant hosts, Olive, Control measures effect on pest and parasites, Population density, Cultivated land habitat, Olive groves, Fertilizers and pesticides, Spain, Granada. ST Animalia, Arthropoda, Insecta, Coleoptera, Polyphaga, Curculionoidea, Curculionidae; Animalia, Arthropoda, Insecta, Hymenoptera, Apocrita, Terebrantia, Chalcidoidea, Eurytomidae; Animalia, Arthropoda, Insecta, Hymenoptera, Apocrita, Terebrantia, Chalcidoidea, Pteromalidae; Animalia, Arthropoda, Insecta, Hymenoptera, Apocrita, Terebrantia, Ichneumonoidea, Braconidae. Arthropods; Beetles; Hymenopterans; Insects; Invertebrates.