Long life at low temperatures – The life-history of Folsomia candida at ecological relevant temperatures

Collembola are among the most abundant terrestrial microarthropods and are widely used in ecotoxicological testing since they are important for soil ecosystem processes (Fountain and Hopkin 2005). In their natural environment, these arthropods are often exposed to varying temperatures (Smit and Van Gestel 1997; Fountain and Hopkin 2005; Bindesbøl 2008). However, when applied as a model organism for ecotoxicological testing, experiments are performed at 20 °C; Smit and Van Gestel 1997; International Organization for Standardization (ISO) 1999; OECD 2009). The temperature choice might be beneficial concerning the timeline of these 28-day experiments (e.g., covering juvenile phase, first reproduction, and first generation hatching) but does not reflect the reality in the field. Variable climate can influence the functioning of organisms and thereby induce changes in susceptibility for toxicant stress (Smit and Van Gestel 1997; Bindesbøl 2008; de Boer et al. 2010). The presented study aims to investigate: (1) longevity of F. candida at different temperatures; (2) reproduction of the species also under different temperatures. Two different test designs were developed, each aiming to analyse a different aspect of the life cycle of F. candida. The results showed that temperature has a significant impact on the life-history traits, longevity, and reproduction of Folsomia candida. Temperatures below the standard of 20 °C significantly increased the life span up to 922.5 days at 4 °C. Furthermore, our results highlight the effect of temperature on developmental processes, such as hatching time and maturation.