Abstract
The characteristics of faecal pellet deposition by Trhypochthoniellus setosus were observed in laboratory cultures, especially in relation to temperature and food type. T. setosus is panphytophagous and is the most dominant species of oribatid mite communities in a moor at Yachidaira, Northeast Japan. The mean volume of faecal pellets per individual in each developmental stage was estimated to be: 27×10-3mm3 (larva), 53(protonymph), 95(deutonymph), 257 (tritonymph)and720(adult). The number of faecal pellets deposited per individual per day increased with temperature but the total amount of faecal matter in the protonymphal stage varied little in the range20-29°C. Mites deposited more faecal pellets when fed on decayed leaves of Moliniopsis japonica, compared with fresh leaves of M. japonica or Sphagnum tenellum.Overall gut residence time in adults was only4hours at22°C. The abundance of faecal pellets and the short gut residence time of T. setosus are discussed with reference to feeding habit and habitat.
