# Understanding the Venus flytrap through mathematical modelling

Venus flytrap is a carnivorous plant that catches its prey mostly insects and arachnids through snap-trap movement. It has a trapping structure that is triggered by tiny hairs in the inner surface of the plant leaves.  When insect crawling along, the plant trigger to close only if it caught a live insects worthy of consumption. This unique trapping mechanism drawn attention to scientific interest and called it “one of the most wonderful in the world”. However, only recently that snap-trap closure mechanism of the Venus flytrap fully understood. On the other hand it is also been studied the trade-off investment in snap-trap structures and its energetic benefits. But a little information has been established about prey selection and why the traps allow prey to escape. This paper provides the first mathematical cost-benefit model for carnivory in the Venus flytrap and understanding its ecology.

### 3 Stages of Venus flytrap prey captures and digestion

Venus flytrap captures and digests its prey into three stages.  Firstly, trap is open and the lobe stand at approximately right angle to each other waiting for prey to enter. In this stage when prey moves across the trap it generates stimuli a receptor potential then action potential. Secondly, after the signal for closure the trap shut and enters in a semi-closed state. It will remain semi closed until further mechanical stimuli to make sure that live prey has been caught. Thirdly, while the prey is struggling inside the trap it will further stimulate and cause the lobes to close tighter. In fully closed state the trap has essentially transformed into a stomach and start digesting.

The investigation reveals that Venus flytrap non- prey sources such as raindrops or wind caused trap closure. This mechanism is triggered once every two days and the trap wait for more than a month for a meal. However, bigger insect around 29mm will trap fully but smaller size less than 14.2mm can escape eventually. This carnivore plant is prey selective wherein the average size of prey is 20mm. Meaning, it utilizes 68.9% of its maximum potential. Moreover, optimal trap allows 76.8% of captured prey to escape indicating that Venus flytrap is highly selective in prey capture.

Indeed, the ecology of Venus flytrap is not understood well that is why investigating capturing and digestion of prey is important. This research provides the building blocks on modelling its ecological mechanism which could incorporate various stages of trap. Since the plant is highly adaptive to its habitat the traps grow quickly.

Source: Prepared by Joan Tura from Journal of Theoretical Biology

Volume 444, 7 May 2018, Pages 1-10