Individual clutch sizes and body length

The collembolans are maintained in the laboratory in polyethylene vials (diameter 52mm, height 65mm) filled with a 30 mm width layer of a plaster of Paris mixed with Indian ink to facilitate detection of the individuals. Food is provided weekly in the form of small dried pellets of a mixture of agar and dried yeast in standardized concentration and volume (Tully and Ferrière, 2008). The rearing boxes are maintained in incubators at 21+/-0.5°C and the plaster is kept wet to have a constant humidity within the boxes (~100% RH). We monitored 220 isolated individuals and regularly measured their body size and fecundity (clutch sizes).