Why Doesn't My Venus Fly Trap Trap?

Last Updated (Wednesday, 03 November 2010 15:32) Written by Raymond Nakamura

I took my daughter to the Apple Festival at UBC. They didn't have any apples, so instead, we snapped up a Venus Fly Trap Dionaea muscipula in the gift shop. I thought it was supposed to be carnivorous, but it didn't seem interested in flies. What happened?

Snap

Let's start with the ideal situation. When the trap is open for business, the inner cells are taut with water and convex.

When the trigger hairs get tweaked twice within about thirty seconds, an electrical signal transforms the cell membranes. Special pores in the membranes open and the water is quickly passed out so the inner surface becomes concave and the trap closes. Other chemical transformations may also contribute to the closing but are probably slower. The overlapping spines help cage in our hapless fly.

Gurgle

When the inside surfaces meet, they form a seal, which keeps out bacteria and mold, as long as lunch isn't bigger than about a third of the trap. Digestive enzymes fill our perogy or calzone or gyoza, drowning and and digesting the insect. It also contains an antiseptic to kill off bacteria. After about a week, the insects gets digested. If the insect is bigger it takes longer. If the trap is older, it takes longer because the enzymes gets recycled and might not be as concentrated. If it's warmer, it might take less time because more energy results in faster reactions.

Plop

Once the nutrients are deleted in the acid bath, the fluids are resorbed, signalling time to open up. Leftover exoskeleton blows away. It can catch about three meals before rotting off. They keep growing new ones. It supposed to be able to go on indefinitely.

This Doesn't Bite

If the disturbance isn't a meal, the trap reopens in about a day. After about a dozen closures, the traps lose their response and focus on photosynthesis. This might be the other part of my problem. Mine seem to be only green. Also they become dormant over the winter. I guess should have read this about how growing them is not so easy.

Any Fly Trap fans out there?