Myrmecomorphy in early nymphs of Acontista concinna (Perty) (Mantodea: Acanthopidae: Acontistini), with notes on a new chromatic form

Summary Ant resemblance is common among praying mantis nymphs but switching the model of resemblance across the post-embryonic instars has been previously recorded only for Mantoida maya Saussure & Zehntner and Acontista aurantiaca (Burmeister). This work describes in detail the myrmecomorphy of early nymphs of Acontista concinna (Perty), based on ample material reared from oothecae collected in the field. Mimic models are proposed, and the possible occurrence of transformational mimicry is discussed. The 1st instar nymphs are defended as mimics of Pseudomyrmex gibbinotus (Forel) (Formicidae), but sudden and intense changes in colour and size during the transition to the 2nd instar make them similar to larger ants, namely Camponotus Mayr. This is maintained throughout the 3rd instar, but disappears on the 4th instar, giving place to typical mantid nymphs. A dark brown chromatic form for females of A. concinna is recorded for the first time, and its existence casts further doubts about the value of overall body colour in separating Acontista Saussure & Zehntner from Raptrix Terra.