Entomobrya nigriventris A head chaetotaxy B labral papillae C trochanteral organ D unguis and unguiculus of leg III E Ventral tube anterior view (left side) and posterior view (right side), circles-ciliated chaetae F Manubrial plate G Th II dorsal macrochaetotaxy H Abd II dorsal macrochaetotaxy I Abd III dorsal macrochaetotaxy J Abd IV dorsal macrochaetotaxy. Abbreviations: Abd = abdominal tergite; Th = thoracic tergite. Scale bars: 0.03 mm (A, D–F); 0.02 mm (B); 0.05 mm (C, G–J).