Cereal leaf beetles are serious animal pests of crops in many areas of western and eastern Slovakia. Research was carried out in these areas in order to receive knowledge on occurrence of natural enemies of <I>Oulema gallaeciana</I>. We were detecting particular species of parasitoids parasitising <I>Oulema gallaeciana</I> and their spreading in particular area. The results showed that dominant parasitoid was <I>Necremnus leucarthros</I>. Other parasitoids with bigger proportion on parasitisation were<I> Pteromalus vibulenus</I> and <I>Diplazon</I> spp. with parasitisation up to 30%. In respect of significant parasitisation of <I>Oulema gallaeciana</I> by parasitoid <I>Necremnus leucarthros</I>, it would be appropriate to use this species for biological control of cereal leaf beetle.

The effects of ploughing and previous crop on winter wheat pests and their natural enemies under an integrated farming system was investigated in an experimental area in Slovakia. The experiment consisted of 4 small plots (50 m2 each) to which both organic and inorganic fertilisers were applied. Moreover, there was one application of herbicide and a fungicide on each plot. The ploughing was either deep or shallow, and either silage‐maize or pea was used as a previous crop. The effects of the ploughing and previous crop was studied by means of multivariate redundancy analysis (RDA) and subsequent Monte‐Carlo permutation test. The results showed that there was a considerable temporal variation in the abundance of insect pests and their natural enemies. Of the two husbandry treatments, only ploughing caused significant difference in the composition and abundance of both pests and natural enemies. However, while most of the pests favoured deep ploughing, the majority of natural enemies occurred more abundantly on shallowly ploughed plots. The previous crop did not affect numbers of either pests or natural enemies. Two systems, integrated and organic, which have been surveyed previously, were mutually compared with respect to the abundance of insect pests. The organic farming system turned out to be more sustainable.

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