Multiple applications of hydrophobic kaolin particle film in apple orchards suppressed numbers of blossom weevil (Anthonomus pomorum), brown leaf weevil (Phyllobius oblongus), attelabid weevil (Caenorhinus pauxillus), leafhoppers (Empoasca vitis and Zygina flammigera) and green apple aphid (Aphis pomi) colonies. The kaolin treatments reduced the apple sawfly (Hoplocampa testudinea) fruit infestation on cultivar J. Grieve, and the fruit damage caused by oyster scale (Quadraspidiotus ostreaeformis), mussel scale (Lepidosaphes ulmi), early caterpillars, leaf rolling moths (Tortricidae), fruitlet‐mining tortrix moth (Pammene rhediella) and codling moth (Cydia pomonella). There was no effect on the number of colonies of rosy leaf curling aphid (Dysaphis devecta), nor on the fruit damage caused by common earwig (Forficula auricularia) and apple sawfly on cv. G. Delicious. The level of infestation of rosy apple aphid (Dysaphis plantaginea), leaf miner moths (Phyllonorycter blancardella, Lyonetia clerkella), and agromyzid flies (Phytomyza heringiana) increased in the kaolin‐treated plots. Kaolin treatments promoted woolly apple aphid (Eriosoma lanigerum) infestation, which became severe, while it reduced the abundance of polyphagous predators like F. auricularia, predaceous Heteroptera and Coleoptera, the red velvet mite (Allothrombium fuliginosum), spiders (Araneae) and the abundance of common black ant (Lasius niger). The treatments also reduced parasitism of the apple sawfly by the ichneumonid Lathrolestes ensator. Many weeks after ending the kaolin treatments, the number of predaceous Coleoptera and especially the number of spiders remained low in the kaolin‐treated plots.
Spider communities (Araneae) inhabiting the canopy, the herbaceous layer and the borders, as well as the populations overwintering on the tree trunks of different aged IPM and conventional apple orchards were investigated in Hungary. Abundance and species richness of entire spider communities in IPM plots were significantly higher than in conventional plots, probably owing to the lower toxicity of pesticides used and higher prey densities. In the case of abundance, similar tendencies were observed in web-building and hunting spider guilds. Age of plantations can significantly influence spider density in the canopy, acting through the prey density. In young plantations, where size of the canopy was smaller and density of the pear lace bug (Stephanitis pyri L.) higher, significantly higher numbers of hunting spider communities were present than in old plantations which had been similarly treated. This relationship was not observed for web-building spiders. Diversity of canopy-inhabiting spider communities was higher in old plots, regardless of the treatments. The effect of the border of the orchard on spider communities was investigated and it was found that when selective insecticides were used, migration of spiders into orchards was increased significantly. When broad-spectrum insecticides were applied, spider densities in the canopy did not differ between outer and inner rows of the orchards. The effect of the treatments and orchard age, both on abundance and species richness of overwintering spider communities on the trunk, showed the same result as for canopy spiders, namely significantly larger spider communities were found in IPM plots and in the young plantation than in conventionally-treated plots and in the old plantation. Broad-spectrum insecticides reduced abundance and species richness of spider communities in the herbaceous layer of the conventionally-treated plot. At the same time, the spider communities of the herbaceous layer of the IPM plot did not differ significantly from adjacent herbaceous plants. A significant overlap exists between spider communities of the canopy and herbaceous layer. Despite chemical treatments, migration from the herbaceous layer into the canopy occurs. The effects of chemical treatments on the dominant species are discussed. There were no significant differences between the differently treated plots in abundance of one of the dominant species Oxyopes heterophthalmus Latreille. However, the other dominant species, Cheiracanthium mildei L. Koch, was more abundant in the IPM plots.
1 The composition of pome fruit orchard inhabiting spider assemblages was investigated at different geographical scales (Holarctic, European, inter-and intraregional levels within Hungary) using previous faunistic studies and data collected in Hungary between 1995 and 1997. Samples in Hungary were taken from the canopy and herb layer of apple and pear orchards in ®ve markedly different fruitgrowing regions by beating and sweep-netting methods. 2 The composition of canopy spider assemblages of apple orchards was analysed for the Holartic region and found to be determined by latitude at family level, and by the main zoogoegraphical regions at genus level. At the European scale, both the genus and species composition changed along a north±south gradient. 3 A comparison among apple and pear orchards located in different regions in Hungary, showed that both foliage-and grass-dwelling spider assemblages varied considerably in species composition and dominance order. 4 Within the same region, both the foliage-and grass-dwelling spider assemblages showed moderate differences in apple and pear orchards submitted to different treatments. Although the assemblages of spiders inhabiting the canopy and the herbaceous layer can be unambiguously distinguished, some overlap still occurs. 5 We conclude that the composition of spider assemblages is basically determined by geographical location. Although both pesticide treatments and available prey densities can in¯uence the population of spiders, such factors are of moderate importance when compared with the effect of regionality, even when considered at smaller scale. However, most members of the family Theridiidae and the large orb-weavers (Araneidae) decreased considerably in treated plots. Scale-speci®c differences are thus relevant in determining the composition of prey±predator systems in orchards, and should be taken into account when designing integrated pest management (IPM) programs for apple and pear orchards.
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