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Cockroaches are persistent household pests and if left unattended can cause serious problems. The question becomes, can you use a Venus flytrap as a cockroach repellent? How effective would they be in keeping these insects away? Or ar you better off looking for another solution?
Venus flytraps can only eat baby cockroaches. An adult cockroach is 2-3 inches, while the average trap is only 1-1.5 inches in length. Cockroaches also have a rigid exoskeleton which Venus flytraps have a difficult time digesting.
Can Venus Flytraps Digest Cockroaches?
The average Venus flytrap is 5-7 inches tall and each trap or mouth is 1-1.5 inches long. Large flytrap variants like the B-52 can have 2 inch traps, but that is the usual limit.
Venus flytraps can digest cockroaches if they are small enough to fit in the trap. But mature roaches are too large for most variants.
Baby cockroaches are about 0.11 inch / 3mm, so it can fit into a trap. But once a cockroach reaches adulthood it can reach up to 3 inches in length, too big for the plant.
It is not just the size though, it is the exoskeleton that presents problems. Venus flytraps have a hard time eating insects with hard shells like cockroaches, beetles and some ants.
Venus flytraps produce enzymes to digest insects, similar to how other animals generate digestive fluids to dissolve food. The body of a cockroach is comprised of chitin, a very strong material which can handle 900 times the insect’s weight.
This super strong exoskeleton is the reason why cockroaches are so hard to kill. So you can imagine how much digestive enzyme a Venus flytrap has to produce to dissolve its body.
Venus flytraps use large amounts of energy to trap and digest insects. But it is worth the risk because the plant receives nitrogen and other nutrients in return.
A cockroach however, presents two problems. It is too large and the body is too hard. If the cockroach is small enough, the enzymes might be able to dissolve it. But adult roaches will take a lot of effort that only the largest Venus flytraps can do it.
Cockroaches are a good source of nitrogen, something Venus flytraps need. But there are other insects that can provide the same nourishment but will not require as much effort.
What Happens if a Venus Flytrap Catches a Cockroach?
A small cockroach caught in a Venus flytrap will be digested. If it is an adult, the roach will probably be able to eat its way out.
Venus flytraps use the same technique to lure all insects, by producing nectar in the trap. If a baby roach wanders off into the trap and triggers the sensors, the lobes will come down on its prey.
Once trapped, the Venus flytrap will secrete enzymes to digest its prey. A baby cockroach has not yet fully developed its exoskeleton so it will be easier for a Venus flytrap to digest.
It is a different story with adult cockroaches. Even if the insect lands in the trap, its size and physical composition makes it hard for a Venus flytrap to eat.
Venus flytraps will reopen if an insect is too small as it is not worth bothering about. If the cockroach is too big however, the flytrap will not be able to close properly.
If the cockroach is too large, parts of it will hang out of the trap. These will eventually rot and spread throughout the plant. While Venus flytraps do not feel pain they will become aware of the damage. This is not going to be good for the plant in the long term.
Venus flytraps will not eat prey unless the trap is completely shut. If the cockroach is too big for the trap, the plant will not digest it. At some point the trap will reopen and let the cockroach go.
If the traps manages to close over the cockroach it will secrete the enzymes. But its exoskeleton might be too much for an average sized Venus flytrap. And in any case, adult cockroaches are just too big. The enzymes are better used for other insects.
Can Venus Flytraps be Used to Control Cockroaches?
Venus flytraps are not effective cockroach repellents because their traps are too small and limited in number. A Venus flytrap might have 5-10 traps at a time, but it takes about a week to digest a single cockroach.
If you have a cockroach infestation the best solution is an insecticide. It will get rid of those pesky roaches fast. But going back to why Venus flytraps are not potent roach killers, there are many reasons.
We have already discussed how the traps of a Venus flytrap are too small for adult cockroaches. We have also pointed out that cockroaches have a very hard exoskeleton which makes them hard to kill.
But even without those two factors, Venus flytraps are still not good cockroach killers. The reason is each trap takes two weeks or more to digest a prey.
Venus flytraps can grow several traps at a time. But only one needs to be fed. A single trap eating a single prey requires a lot of energy.
The odds of all the traps catching cockroaches simultaneously is very low. And even if it does happen the plant probably does not have the energy to digest them all.
You can reproduce Venus flytraps easily, and several of these along with pitcher plants and other carnivorous plants may catch some small cockroaches. Large pitcher plants can digest large insects, so if you want to use plants to control vermin, you will need several of these.
A better method of dealing with cockroaches is to find out the source. These insects are attracted by food and standing water. They are also looking for shelter and humid, warm, dark places to settle in.
Now that you know why they are cockroaches in your home, you can keep them out without depending on Venus flytraps to catch them.
Can I Feed Dead Cockroaches to My Venus Flytrap?
Venus flytraps are known for eating flies and spiders, but they can consume any insect if it is small and soft enough. You can even give them mealworms, tiny fish food bits like TetraCichlid Crisps and yes, dead insects. There are also products like Jessi Mae Venus Flytrap Food which are specifically for these carnivorous plants.
You can feed dead cockroaches to Venus flytraps but you have to cut the insect into small pieces and place them in the trap. Stimulate the trap so it closes, and the Venus flytrap will start eating it.
Venus flytraps do not care if an insect is dead or alive. Either way it contains the nutrients the plant requires to grow. Once a cockroach is digested, its nitrogen is absorbed by the plant and used to enhance its growth.
Because Venus flytraps require stimulation to shut, you have to tap the leaves lightly with a stick. First chop the cockroach into small bits. Place the bits into one trap only.
Once the trap is one third full, prod it gently with a stick. Tap it a couple of times and the trap will lose. The hair triggers are sensitive so it will not take a lot to get them to close.
Once the trap closes over the cockroach bits, the Venus flytrap’ digestive mechanisms will take over. The plant cannot tell if the insect is alive or dead, only that its trap has caught something.
Its digestive enzymes and antiseptic fluids will dissolve the cockroach. Usually this would be a problem due to its rigid shell. But if you cut it into tiny bits, it will be easier for the enzymes to do their work. The trap will remain shut until the cockroach is eaten.
So the bottom line is Venus flytraps are not roach killers or controllers. You are better off using other means to manage cockroaches and let Venus flytraps consume flies and other smaller insects. Of course if the trap snares a small cockroach every now and then, that is always welcome.
My fascination with carnivorous plants began many, many years ago with Venus Fly Traps. Now I am more than happy to impart what I know with other enthusiasts and those who are curious about meat eating plants.