The aim of presented investigation was to determine the composition of scale insects species and intensity of their occurrence on some greenhouse’s ornamental plants. The investigations were carried out in the greenhouse of Maria Curie Skłodowska Botanical Garden in Lublin in years 2002–2004. Eight species belonging to seven botanical families were observed: Abutilon striatum cv. Thomsoni, Cyrtomium falcatum Presl., Dizygotheca elegantissima (Veitch), Hedera helix L., Hypoestes phyllostachya Presl., Nerium oleander L., Passiflora guadrangularia L., Ruscus aculeatus L. The quantitative analysis of the studied material was performed making use of the following ecological indicators: number and density. Identification of the scale insects species was performed on the basis of microscope slides. Three species of the scale insects belonging to three families were observed on ornamental plants: Pseudococcidae [Pseudococcus maritimus (Ehrh.)], Coccidae [Saissetia coffeae (Walker)] and Diaspididae (Aspidiotus nerii Bouchè). The scale insects were noted on all species of studied plants. Observed scale insects are typical polyphagous and all of them are considered as harmful pests in greenhouses. Among scale insects inhabiting this group of plants distinctly numerous on particular host plants were S. coffea and A. nerii. On the studied plants scale insects were stated at four degree of density.

Obviously, the moment has come in agriculture and forestry when we must decide to gradually abandon (where possible) non-selectively acting chemical insecticides, taking into consideration the overall decrease in the total biomass of insects, especially pollinators, and the increased number of diseases and human deaths directly or indirectly associated with chemical insecticides. Yet with the world facing the rapid growth of human populations, the annual reduction of cultivated areas, and substantial losses from insect pests, most experts believe that no serious alternative to chemical insecticides exists. However, there is definitely room to create more well-tailored chemical insecticides. And there is hope, in the form of effective DNA insecticides able to provide an adequate level of safety for non-target organisms. In this short communication describing experiments carried out on the larvae of Ceroplastes japonicus Green (feeding on Ilex aquifolium Linnaeus), we show for the first time the enormous potential for the use of DNA insecticides in the control of soft scale insects and how they could replace non-selective organophosphate insecticides.