The cost–benefit model for the evolution of botanical carnivory assumes that the traps represent a significant cost for the plant, and that this is outweighed by the benefits from increased nutrient uptake from prey. Pavlovič & Saganová summarize results from a wide range of studies and conclude that traps have lower rates of photosynthesis than leaves, and that leaves have higher rates of photosynthesis after feeding. They also note that prey digestion, water pumping and electrical signalling in the traps represent additional carbon costs via increased rates of respiration and decreased rates of photosynthesis. Against these, jasmonate signalling and the inducibility of digestive systems optimize enzyme production in response to prey capture. The similarities between inducible defence mechanisms and botanical carnivory are highlighted.
