TY - JOUR JF - Acarologia T1 - The missing stase in spider mites (Acari: Tetranychidae): when the adult is not the imago VL - 52 IS - 1 SP - 3 EP - 16 PY - 2012 SN - 0044-586X SN - 2107-7207 PB - Les Amis d'Acarologia AU - Andre, H.M. AU - Van Impe, G. UR - https://doi.org/10.1051/acarologia/20122038 DO - 10.1051/acarologia/20122038 DA - 2012-03-30 ET - 2012-03-30 KW - Tetranychus urticae KW - ontogeny KW - ontogenetic trajectory KW - paedogenesis KW - stase KW - state KW - instar KW - respiration AB - Apart from a calyptostatic prelarva, the ontogeny of spider mites is limited to one six-legged immature followed by three eight-legged instars. The usage consists in naming them: larva, protonymph, deutonymph and adult. In this study, the "missing stase" and different associated hypotheses are explored using diverse approaches: light microscopy, electronic microscopy, comparative chaetotaxy, ontogenetic trajectories, and interspecific comparisons. It turns out that the imago (new name for the last stase) is missing in Tetranychus urticae and that its post-embryonic development may be summarized as follows: prelarva (calyptostase), larva (six-legged stase), protonymph (eight-legged stase), deutonymph (eight-legged stase), tritonymph (with paedogenesis, i.e. precocious development of sexual maturity). The respiratory role of the prelarva is emphasized. The current terminology of post-embryonic development is confusing as it pertains to three approaches: the state or form description, the instar standard and the stase paradigm. ER -