Ethanolic extract of propolis exerts a strong anti-bacterial activity, in addition to antifungal. antiviral and antiprotozoal properties. In previous studies from these laboratories we have demonstrated that the intensity of the bactericidal activity of E E P is correlated with the virulence of the mycobacteria tested, and that E E P has a synergistic effect with antibiotics on growth of staphylococcus aureus. In the present study we investigated whether the same synergism and correlation exists between E E P and some anti-tuberculosis drugs on tubercu losis mycobacteria with different degrees of virulence. Six standard strains and 11 wild strains of mycobacteria were exposed for 30 days to EEP, with or without streptomycin, rifamycin, isoniazid or ethambutol. Out of the 17 strains, 8 were resistant to at least two standard antibiotics, and were considered "multi-resistant strains". The rest were either susceptible or resistant to only one of the antimycobacterial drugs. Antagonism was recorded only in one case, when Staphylococcus aureus were treated with a mixture of E E P and ethambutol, sug gesting that a chemical bond could have been formed between this anti-tuberculosis anti biotic and one of the active components of the ethanol extract of propolis.

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Extracts prepared from 2 medicinal herbs (common sage Salvia officinalis L. and German chamomile Matricaria chamomilla L.) were used in this study for biological control of spider mites. Their effect on mortality, fecundity, and development of Tetranychus urticae Koch on English ivy (Hedera helix L.) was studied under laboratory and greenhouse conditions. The extracts were prepared by soaking fresh Salvia leaves or dry Matricaria flowers in ethanol for 24 h, followed by evaporation, and finally suspension of the pellets in water. Full extracts and extracts without phenols were tested. The Salvia extracts had a higher acaricidal activity than Matricaria extracts, but the toxicity of both extracts to spider mite eggs was low. The toxic effect of full Salvia extracts on larval stages and females of T. urticae was evident. More than 50% of larvae and females were killed by this treatment in 4 days. Besides, total fecundity of survived females was evidently lower. Mortality and low fecundity after full Salvia extract application decreased the spider mite population by 76%.The toxicity of Salvia extracts after removal of phenols strongly declined, so the negative effect of the full Salvia extract on spider mites was connected with a high concentration of phenolic compounds. The toxic effect of Matricaria extracts in all tests was much lower and no evident role of phenolic compounds in its extracts was observed.

Leaf-dwelling mites often prefer to feed on young leaves and also are more likely to inhabit the abaxial leaf side. The aim of our study was to examine whether leaf age may affect production and distribution of eggs on black locust leaves by females of Aculops allotrichus. The eriophyoids were tested for 2.5 days on 'trimmed' compound leaves (with only two opposite leaflets left), which were maintained in vials filled with water. For the experiments we used leaves of three categories: (1) the 'youngest', in which both halves of the adaxial side of leaflets still adhered to each other (and usually remained folded for the next few hours), (2) 'young' with already unfolded leaflets, and (3) 'mature' with fully expanded leaflets. The tested females laid significantly more eggs on developing leaves than on 'mature' ones, although they deposited the highest number of eggs on the 'young' leaves. The distribution of eggs on adaxial or abaxial leaf sides also depended on leaf age. On the 'youngest' leaves, eriophyoids placed similar numbers of eggs on both sides of a blade. However, the older the leaf, the more willingly females deposited eggs on the abaxial side. Our biochemical and morphometrical analyses of black locust leaves indicated significant changes in the contents of nutrients and phenols within leaf tissue, and in the density of trichomes and thickness of the outer epidermal cell walls, correlated with leaf age. Their possible effects on the production and distribution of eggs on leaves by A. allotrichus are discussed.

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