Eco-friendly pest control is the best way to protect yourself from nuisance insects while minimizing your impact on the environment. Plant-based bug sprays and repellents have been on the market for years, and some are highly effective against mosquitoes. But what if the plants themselves could take over the task of reducing insect numbers?
Most plants subsist on sunlight and nutrients from the soil, but a small number of plants go one step further and actually eat. Carnivorous plants are specially adapted to catch and digest insects, and many also eat mosquitoes – but how effective are they as a method of pest control?
What are carnivorous plants?
Carnivorous plants (AKA insectivorous plants) are plants with special adaptations that allow them to catch and digest insects and other small creatures. There are over 600 known species of carnivorous plants, and they use a wide variety of trapping mechanisms to capture their prey.
In most cases, the traps of carnivorous plants are made from modified leaves. These include pitfalls (hollow structures for prey to fall in to) ‘flypaper’ leaves (covered with a sticky substance to trap insects) bladder traps (which suck insects to their doom) and snap traps (leaves that rapidly close around bugs).
Carnivorous plants are usually found in places with nutrient-poor soil, which cannot fulfill the nutritional needs of the plant.
Which plant species eat mosquitoes?
Venus Fly Trap
The Venus Fly Trap (a carnivorous plant native to the subtropical wetlands on the East Coast of the USA) uses a ‘snap trap’ mechanism to capture prey.
The leaves of the plant are wide and flat, with sensitive ‘trigger hairs’ covering their insides. When an unsuspecting bug (attracted to the scent or color of the plant) lands on those leaves, they will stimulate the trigger hairs, causing the leaves to close around the insect and trap it inside.
Venus Fly Traps grow to all different sizes, which allows them to trap a wide range of insects – including mosquitoes! Insects as small as mosquitoes don’t weigh enough to stimulate the trigger hairs of larger traps, but some Venus Fly Traps have developed ‘mini-traps’ that can sense even tiny bugs.
Once the plant has an insect in its clutches, it secretes digestive enzymes to kill and liquefy its victim. This eventually creates an insect soup from which the plant can absorb nutrients.
The Pitcher Plant is a passive predator that captures insects using a pitfall trap. They are found in a wide range of habitats, and (like the Venus Fly Trap) use their carnivorous adaptations to compensate for nutrient-poor soil.
The pitfall is made from specially-adapted leaves, which often form a long, tubular structure. They attract their prey using a series of nectar-secreting glands, which begin at the mouth of the pitcher and extend down into the interior of the trap.
The unsuspecting bugs follow the trail of sugary secretions until they reach the smooth ‘throat’ of the pitcher. At this point, they lose their footing and fall into the liquid pool at the bottom of the pitfall, where they drown. Once dead, they are digested by enzymes secreted and absorbed by the plant.
Pitcher plants primarily ‘eat’ insects (including mosquitoes). However, some species (like the 1.5-meter-tall Attenborough’s Pitcher Plant) is large enough to capture and digest rodents and other small animals.
The Common Bladderwort is a species of aquatic carnivorous plants found in lakes and streams all over the world. Using small, hollow sacs, they capture and consume a variety of small creatures including insect larvae, water fleas, and aquatic worms.
The Common Bladderwort doesn’t simply wait for bugs to wander into its traps. Those hollow sacs also feature a trapdoor, which is covered in tiny bristles. When a prey animal comes into contact with those bristles, the door swings open. This creates a sudden inflow of water, and the bug is sucked inside. The trapdoor closes behind it, and the critter is digested by enzymes before being absorbed by the plant.
Common Bladderwort can also be used to control mosquitoes, despite their watery habitats. This is because mosquitoes begin their lives as aquatic creatures, and the larval portion of their life cycle plays out in ponds, lakes, and other bodies of standing water.
Can mosquito-eating plants be used for mosquito control?
There are hundreds of species of carnivorous plants, and most of these are capable of killing mosquitoes. But does that make them a suitable form of insect control?
Keep in mind!
Unfortunately, carnivorous plants are unlikely to result in a significant reduction in mosquito numbers – especially if you have a heavy infestation.
Venus Fly Traps and Pitcher Plants are unlikely to capture mosquitoes at a high enough rate to effectively control mosquitoes and, as they naturally grow in tropical and subtropical environments, will not thrive everywhere.
However, for people with a pond on their property, Common Bladderwort may help to effectively reduce mosquito numbers. The Common Bladderwort feeds on small, aquatic prey, and can consume large numbers of insect larvae. This effectively breaks the mosquito life cycle and significantly reduces the number of mosquitoes that reach adulthood.
Carnivorous plants are plants that have evolved features that allow them to capture and digest live prey. These plants use a variety of traps to ensnare insects and other small invertebrates, before digesting them and absorbing their nutrients.
Several carnivorous plant species (including Venus Fly Traps, Pitcher Plants, and Common Bladderwort) eat mosquitoes as part of their insect diet. Unfortunately, most carnivorous plants are unlikely to have a significant impact on mosquito numbers around your home.
One species that may make a difference, however, is the Common Bladderwort. These aquatic plants capture insect larvae in ponds and lakes, and can effectively reduce numbers of mosquito larvae. Planting a few in your garden pond may, therefore, help to break the mosquito life cycle and reduce the number of mosquitoes on your property.