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Bark beetles Ips typographus (Coleoptera, Scolytidae) feed on conifers, which produce myrcene (MR) among some other defensive compounds. In order to find out whether gut symbionts of the phytophagous insect are involved in MR inactivation, intestinal microbiota from the bark beetle was cultivated on tryptone soya broth containing different concentrations of synthetic MR (2.5, 5, 7 and 10 μl MR/ml). Six bacterial strains most resistant to this bactericide compound (survived at 10 μl MR/ml) were selected and analysed. Partial sequences of the 16S rRNA gene were sequenced of six resistant strains. All the sequences were identical. Phylogenetic analysis of 16S rDNA sequences within the family Enterobacteriaceae revealed the closest relationship of the sequence established to that of Pantoea cedenensis, AF 130971. The reaction to different concentrations of MR (survival at 2; 40 and 80 μl MR/ml) in myrcene-resistant Pantoea sp. was polymorphous. The growth of one strain was inhibited at a concentration of 40 μl MR/ml, two strains were suppressed at 80 μl MR/ml, while three strains were resistant to the highest concentration tested. This study revealed a new phylotype, Pantoea sp., thus providing new information on MR-resistant intestinal tract microbiota from bark the beetles Ips typographus feeding on MR-rich plants. The 16S rRNR gene partial sequences were deposited at the EMBL data library under the accession numbers DQ309414-DQ309419. Kinivarpos žievėgraužiai tipografai Ips typographus L. (Coleoptera, Scolytidae) maitinasi po spygliuočių žieve. Mitybiniai augalai, be kitų apsauginių cheminių junginių, gamina ir mirceną (MR). Tiriant, ar vabzdžių fitofagų žarnyno simbiontai susiję su šio junginio nukenksminimu, žievėgraužių tipografų žarnyno mikroflora buvo kultivuojama triptono sojos nuoviro terpėje su įvairiomis sintetinio MR koncentracijomis (2,5; 5; 7 ir 10 μl MR/ml). Išskirtos 6 bakterijų padermės, atspariausios minėtam baktericidiniam junginiui (išgyveno esant 10 μl MR/ml). Analizuota visų 6 mircenui atsparių padermių dalinės 16S rRNR geno sekos. Visos sekos buvo identiškos. Filogenetinė 16S rRNR dalinių sekų analizė Enterobacteriaceae šeimos rėmuose parodė, jog nustatytosios sekos yra artimiausios Pantoea cedenensis AF 130971 sekai. Identifikuotosios Pantoea sp. bakterijos pagal reakciją į skirtingas MR koncentracijas buvo polimorfiškos. Vienos linijos augimą inhibavo 40 μl MR/ml koncentracija, dviejų – 80 μl MR/ml, tuo tarpu likusios 3 padermės buvo atsparios didžiausiai tirtajai koncentracijai. Pirmą kartą gauta duomenų apie MR atsparias bakterijas, esančias fitofagų, kurie minta MR gausia augaline medžiaga, žarnyne. Aptiktas iki šiol nežinomas Pantoea sp. bakterijų filotipas, jų 16S rRNR geno dalinės sekos deponuotos EMBL bibliotekoje tokiais numeriais: DQ309414-DQ309419.

Identification of Small Bivalvia Molluscs of the Family Sphaeriidae Using DNA Markers and Scanning Electronic Microscopy. Clams of the family Sphaeriidae are very small in their size. Based only on their morphological approaches it is problematic to identify their species and there are only small amount of DNA markers for Sphaeriidae species identification. The purpose of this research was to identify Sphaeriidae mollusc species by using scaning electronic microscopy and molecular methods. Shells of P.hibernicum, S. nitidum ir P.casertanum were studied by scaning electronic microscopy, shell size and comparing cardinal teeth. Inner shell pore density of these species was described for the first time. New molecular markers (mitochondrial 16S rDNA and nuclear ITS1 rDNA) for P.casertanum and S.nitidum species were obtained. Phylogentic analysis based on new obtained rDNA sequences and rDNA sequences from Genbank revealed that Sphaeriidae species are sometimes misidentified by morphological approaches, so rDNA molecular markers for some Sphaeriidae species are false.