Diesel effects on some population attributes of Orthonychiurus folsomi Schäffer 1900 (Collembola: Onychiuridae) under laboratory conditions.

Soil contamination by hydrocarbons and its effects on population health and welfare is a growing concern, especially in urban environments with industrial activity. Indicator species complement the information obtained from the measurement of environment quality by using physicochemical variables. The objective of this study was to evaluate the response of a springtail species that could be potentially used as a bioindicator of hydrocarbon contaminated sites. We studied the effects of seven diesel concentrations on survival and other population parameters of Orthonychiurus folsomi under laboratory conditions; we evaluated the springtails response on survival, fecundity, population size, hatching and development time. Survival and fertility were analyzed by using generalized linear models (GLM). An ANOVA test was used to analyze the final population size and a Kruskal-Wallis test for oviposition, hatching, and development times. Results showed that diesel has negative effects on some population parameters. The most evident effects were recorded above 500 mg/kg concentrations. A significant decrease in survival, fertility, and population size was recorded in function of diesel concentration increase. The estimated LC50 for survival was 955 mg/kg. Oviposition and hatching time increased significantly when diesel concentrations were above 500 mg/kg, while development time increased slightly at low diesel concentrations but decreased at concentrations above 500 mg/kg. Population final size decreased as soil diesel concentrations increased. Due to the sensitive and rapid response of O. folsomi, it could be useful to detect diesel-contaminated soil, mainly in urban areas.