Pygmarrhopalites sietae sp. nov. A head chaetotaxy B Ant I–II (* means that this chaeta has been observed only in one specimen) C Ant III (the arrows point to chaetae that are noticeably thinner than the others and the sensory organ are included in a rectangle with the chaetae in black) Ant IV (the arrow points to the knobbed subapical organite). Scale bar: 0.05 mm.