RESUMO
The antibacterial activity of secretory materials present in the scale cover and produced materials of certain scale insects were examined against Gram negative and Gram positive bacteria. The scale insect included two soft scales insects; Icerya aegyptiaca Douglas and Ceroplastes rusci L. and three hard scales insects; Aonidiella aurantii Maskell, Lepidosaphes beckii Newman and Parlatoria zizyphus Lucas. Secretions of the scale insects were extracted with ethanol, acetone and DMSO. The antibacterial activities of extracted secretions of insects were investigated against Gram positive and negative bacteria. The Gram negative bacteria included Escherichia coli and Pseudomonas aeruginosa. The Gram positive bacteria included Staphylococcus aureus, Streptococcus dysgalacticae and Corynebacterium pseudotuberculosis. It was obvious that no antibacteria! activity of all insect secretions extracted with DMSO against all pathogenic bacteria except secretion of A. aurantii which showed activity against Staphylococcus aureus. But the extraction of the secretion of the scale insects extracted with acetone and ethanol were varied according to the type of insect secretion and type of pathogenic bacteria. Results of the experiments showed that the ethanol was the most suitable solvent for extraction of scale insect secretion. The antibacterial activity was varied according to the species of the scale insects