RESUMEN
@#This research was undertaken to evaluate the nematicidal activity of various concentrations of aqueous tinctures of 80 plant species towards L1–2 of S. papillosus. For the experiment with larvae of S. papillosus, there were used 0.19%, 0.75% and 3.00% aqueous tinctures of plants. Out of 80 tested species, nematicidal activity against L1–2 of S. papillosus was displayed by 20 plants. The greatest activity (LC50 = 0.060–0.069%) towards larvae of S. papillosus was exerted by Teucrium polium, Achillea millefolium, Genista tinctoria and Ulmus laevis. Less expressed nematicidal activity (LC50 = 0.070–0.079%) was recorded for Thalictrum minus, Stachys recta, Falcaria vulgaris, Lavatera thuringiaca. Even lower effect (LC50 = 0.080–0.089%) was shown by aqueous tinctures of Mentha × piperita, Achillea millefolium, Salvia nutans, Eryngium campestre and Cerasus fruticosa. The following plants could be arranged in declining order of effectiveness of nematicidal activity (LC50 = 0.090–0.165%) Malus sylvestris, Tragopogon orientalis, Erigeron annuus, Grindelia squarrosa, Urtica dioica, Daucus carota, Medicago sativa, Carduus acanthoides, Ulmus minor and Hieracium umbellatum. A far weaker effect on the nematodes was displayed by Bromopsis inermis and Tragopogon podolicus. Aqueous tinctures of 60 other studied species of plants exhibited low nematicidal activity in 3.00% aqueous tincture, while in 0.19% and 0.75% aqueous tinctures, no nematicidal activity was seen. The results of the research suggest that in the conditions of natural ecosystems, some species of plants of the Apiaceae, Asteraceae, Fabaceae, Lamiaceae, Malvaceae, Rosaceae, Ulmaceae and Urticaceae families could reduce vitality of free-living L1–2 larvae of S. papillosus.
RESUMEN
The entomopathogenic nematode Heterorhabditis sp. SL0708 (Rhabditida: Heterorhabditidae) isolated from soil in Alcalá, Valle del Cauca (Colombia) was characterised ecologically using Galleria mellonella larvae (L) (Pyralidae: Galleriinae) as hosts. The effect of temperature on the viability, infectivity and reproduction, and of moisture on infectivity and storage in liquid were evaluated in infective juveniles (IJs). Significant differences were found in the viability, infectivity and reproduction of the IJs at different temperatures. No nematodes were recovered at 5 °C and 10 °C, and at 35 °C no infectivity was observed. Average daily nematode recovery was best at 25 °C, and survival of the IJs was low in substrates presenting 13% moisture. The optimal storage temperature for Heterorhabditis sp. SL0708 was between 20 °C and 30 °C, keeping its infectivity for up to 8 weeks.
O nematoide entomopatogênico colombiano Heterorhabditis sp. SL0708, isolado do solo de Alcalá, Valle del Cauca (Colombia), foi caracterizado ecologicamente utilizando-se como hospedeiro lagartas de Galleria mellonella (L) (Pyralidae:Galleriinae). O efeito da temperatura na viabilidade, na infecção e na reprodução, e da umidade na infecção e do armazenamento em líquido foi avaliado em juvenis infectantes (JIs). Diferenças significativas na viabilidade, na infecção e na reprodução dos JIs foram observadas nas diferentes temperaturas. Não foram recuperados nematoides a 5 °C e 10 °C, e não se observou infecção a 35 °C. A maior média diária de recuperação de nematoides foi a 25 °C. Por outro lado, a sobrevivência dos JIs foi baixa nos substratos com unidades de 13% e a melhor temperatura de armazenamento para SL0708 foi entre 20 °C e 30 °C, mantendo a infecção até oito semanas.