Studies on Microarthropods associated with pastures in Co. Ioannina

This study presents some results of a quantitative and qualitative research of the microarthropod fauna associated with pastures in Katsikas region, Co. Ioannina. These results refer to the period from November 1993 to October 1995. The quantitative analysis showed the presence of 41 mite aπd 15 insect taxa. The evaluation of these taxa, using the criteria of dominance and frequency showed that the most characteristic taxa were the following: a) grass-pasture: Entomobryidae, Lepidocyrtidae and Isotomidae from Collembola, Thripidae (especially Aptinothrips rufus) from Thysanoptera, Aphididae from Homoptera, Acaridae (especially Tyrophagus spp.) frοm Asigmata, Oribatulidae frοm Cryptostigmata, Tarsonemidae, Tydeidae (especially Tydeus kochi) and Eupodidae from Prostigmata and Phytoseiidae (especially Amblyseius graminis) fom Mesostigmata, b) broadleaved pasture: Entomobryidae, Hypogastruridae and Onychiuridae from Collembola, Thripidae and Phloeothripidae from Thysanoptera, Aphididae from Homoptera, Acaridae (especially Tyrophagus spp.) from Astigιnata, Oribatulidae from Cryptostigmata, Tydeidae (especially Tydeus kochi) and Tarsonemidae from Prostigmata, Ascidae, Eviphididae (especially Alliphis halleri) and Phytoseiidae (especially Amblyseius obtusus) from Mesostigmata. As for the seasonal fluctuation of some of the most important taxa: a)Thripidae developed high population densities during summer οn the broad-leaved pasture and during spring and winter on the grass one, b) Collembola showed population peaks on the cool and humid periods ofthe year on both plots, c) Acaridae and Cryptostigmata showed the highest population densities in spring and autumn.