Fig. 4.

Prompt Chl a fluorescence. Prompt fluorescence transients of Dionaea muscipula traps dark-adapted for 20 min and transients, measured with M-PEA induced by red actinic light of 3500 µmol photons m^–2 s⁻¹ and plotted on a logarithmic time scale from 0 to 300 s normalized at t = 50 µs (F₀); the steps O (‘origin’ at 50 µs), J (at 2 ms) and I (at 30 ms), peak P (between 200 ms and 1 s) and ‘terminal steady state’ T (at about 300 s) are marked. (A–E) Green open circles, open traps at t = 0; downwards filled triangles, closed traps mechanically triggered to close; filled squares, traps fed with insect powder and mechanically triggered to close; at different times after trap closure. Time: (A) dark blue symbols, t = 1 min; (B) light blue symbols, t = 20 min; (C) purple symbols, t = 4 h; (D) pink symbols, t = 9.5 h; (E) red symbols, t = 24 h. In (F) closed traps fed with insect powder at t = 48 h (orange filled squares); t = 72 h (brown filled squares) and 96 h (black filled squares). Data shown are mean values based on eight individual measurements.