Essential oils obtained from Gomortega keule, Laurelia sempervirens, Origanum vulgare, Eucalyptus globulus, and Thymus vulgaris were analyzed by gas chromatography and gas chromatography-mass spectrometry and evaluated for their toxicity against adults of Sitophilus zeamais (Motschulky) and Acanthoscelides obtectus (Say) (Coleoptera). Contact toxicity was assayed by impregnating filter paper discs with the oils. The amount of essential oils applied in each desiccator (4 l capacity) was 4, 8, 16, or 32 µl, corresponding to 1, 2, 4, or 8 µl/l air. The results showed significant differences between the tested dosages and exposure periods of the essential oils. Although desirable insecticidal activities against A. obtectus were achieved with the essential oils of all five plants, the oils from G. keule and L. sempervirens were the most effective at 96 h. On the other hand, the essential oils of E. globulus and T. vulgaris were most effective against S. zeamais. In all plant species, higher doses or longer exposure periods were more effective against both insects. No mortality was observed in the control group (acetone only) of each species. Therefore, these results suggest that essential oils from the studied plants may be used against insect pests in grain storage.

Components of essential oils from the Chilean Monimiaceae, boldo (Peumus boldus Mol.), tepa (Laureliopsis philippiana (Looser) Schodde), and laurel (Laurelia sempervirens (Ruiz & Pav.) Tul.) were determined using Gas Chromatography-Mass Spectrometry (GCMS) and fungistatic activity of the essential oils was tested against Rhizoctonia solani Kühn (Donk), Pythium irregulare Buisman, Ceratocystis pilifera (Fr.) C. Moreau, Phragmidium violaceum (Schultz) G. Winter, and Fusarium oxysporum Schltdl. The essential oils of the Monimiaceae species shared some common components; all three had the 3-carene, α-phellandrene, and α-pinene terpenes. L. philippiana and L. sempervirens also had safrole.The main components were ascaridol in P. boldus oil, 3-carene in L. philippiana, and safrole in L. sempervirens. The essential oil from L. sempervirens showed the highest fungistatic activity with significant differences in dose as well as exposure. P. violaceum was the most sensitive strain and P. irregulare the most resistant of all the essential oils (P. boldus extract affected growth by only 19%). Therefore, essential oils from these three plants could be used to control the fungal strains studied.

No abstract

RESUMENLa aracnofauna chilena ha sido parcialmente estudiada a través de los años, pero no en forma continua, lo que ha determinado un escaso conocimiento de los taxones presentes en nuestro país. La ausencia de textos y manuales que faciliten la identificación, y determinación taxonómica de las arañas presentes en Chile, hace aún más difícil el estudio de este grupo. Para Chile se han descrito 55 familias, de las cuales 6 pertenecen a Mygalomorphae y 49 a Araneomorphae, lo que representa aproximadamente el 50% de las familias conocidas a nivel mundial. En este estudio se reconocen 51 familias. Es importante destacar la necesidad de continuar con estudios sistemáticos de las arañas presentes en Chile, y determinar su biología, distribución geográfica y diversidad. Se entregan antecedentes biológicos y una clave dicotómica para las familias de Araneomorphae más comunes para el país. En la clave no se han incluido las familias de araneomorfas: Amphinectidae, Clubionidae, Desidae, Synotaxidae, Tengellidae y Titanoecidae, por presentar problemas taxonómicos, como tampoco las familias de migalomorfas. ABSTRACTThe studies of the chilean arachnofauna have been scarce during the past years and there is a lack of texts and identification keys to help taxonomical and biological studies in Chile. Therefore the knowledgment is still poor. A total of 55 families are reported for Chile, 6 belonging to Mygalomorphae and 49 to Araneomorphae, which represents around the 50% of the world known families. Only 51 are reconized for Chile in this study. It is important to develop new systematic studies of the spiders present in Chile to determine their biology, geographical distribution and diversity. Biological information and a dicotomic key for the more common families of Araneomorphae are given. Mygalomorph families and the araneomorph families Amphinectidae, Clubionidae, Desidae, Synotaxidae, Tengellidae y Titanoecidae and are not included in the present key due to taxonomical problems of the later ones.

En este trabajo se presenta el estudio de la prevalencia e intensidad de artrópodos ectoparásitos recolectados en 90 ejemplares de Tadarida brasiliensis (Geoffroy Saint-Hilaire, 1824) capturados en la ciudad de Concepción, VIII Región-Chile (36º40'S; 73º04'O), desde noviembre del 2000 a marzo del 2001. Los ectoparásitos recolectados fueron una especie de pulga, Sternopsylla distincta (Rothschild, 1903), y tres especies de ácaros, Chiroptonyssus robustipes (Ewing, 1925), Ewingana inaequalis (Ewing, 1938) y Notoedres lasionycteris (Boyd & Bernstein, 1950). El 100% de los murciélagos se encontraron parasitados y se les extrajo un total de 3.185 ectoparásitos. C. robustipes fue la especie más común con un 100% de prevalencia, seguida de N. lasionycteris, E. inaequalis y S. distincta con prevalencias de 40, 32,24 y 8,89% respectivamente. También la intensidad de infestación promedio fue mucho mayor para C. robustipes con 34.25 ácaros/murciélago, comparado con las otras especies en que la intensidad fue menor al 2%. La prevalencia e intensidad de E. inaequalis y N. lasionycteris fue significativamente mayor en machos, mientras que para S. distincta sólo la prevalencia fue levemente mayor en hembras, con lo que se pudo concluir que la prevalencia e intensidad de ectoparásitos aparecen como dependiente del sexo del hospedero en algunas especies de ectoparásitos.