Results of two-year studies on the aphids number in different uncultivated habitats (field boundaries, roadsides, field shrubs and forest margins) are presented. The analysis of data permitted to distinguish two basic types of change in the aphids number in a vegetation season.
As a result of two-years studies carried out in the Dendrological Garden in Poznań 47 aphid species representing 2 families: Adelgidae and Aphididae wwere found. Aphids were collected on 26 tree species and 38 shrubs species.
The many years’ study on species composition and harmfulness of aphids infesting perennials in the decorative plant collection Agricultural University in Poznań permited to ascertain occurrence of 23 aphid species on 66 species of decoratice perennials, representing 20 botanical families. The species that occurred in all the four study seasons in 2000, 2002, 2003 and 2005 included: Aphis fabae Scop., Brachycaudus cardui (L.) and Aphis sedi Kalt.. Very often Aphis newtoni Theob., Acyrthosiphon malvae (Mosl.), Brachycaudus helichrysi Kalt. and Longicaudus trirhodus (Walk.) were found. Spring and early summer was the period of numerous occurrence of aphids on decorative perennials. The high degree of plant infestation was resulted in decreasing the plant’ decorative value. The aphid infestation may be especially dangerous for numerous cultivars of Dahlia x cultorum, Eryngium planum, Echinops ritro, Leucanthemum maximum, Papaver orientale, Sedum aizoon, Iris sibirica, Yucca filamentosa, Achillea ptarnica, Dicentra eximia, Doronicum orientale i Geum coccineum.
In shrubbery complexes of „Biedrusko” Protected Landscape Area 43 species of Pimplinae subfamily and 2 species of Poemeninae subfamily (Hymenoptera, Ichneumonidae) were found. The species of Pimplinae subfamily constituted 31.1% of Polish fauna species and 62.3% of those reported from Wielkopolska. The following were dominant: Pimpla contemplator (D5 = 35.1%), Itoplectis maculator (D5 = 14.7%), Itoplectis alternans (D5 = 11.6%) and Pimpla turionellae (D4 = 5.3%). The most numerous group were parasitoids of Micro- and Macrolepidoptera (55.5% of the reported species) and of Arachnida (22.3%). For the first time in Wielkopolska shrubbery the following species were found: Ephialtes manifestator, Itoplectis viduata, Perithous albicinctus, Polysphincta boops and Theronia atalantae (Pimplinae) and Podoschistus scutellaris (Poemeniinae).