Although mosquitoes are not a pest that can harm your bromeliads, they can become very annoying to everyone around them.
Mosquitoes are currently a topic of conversation as common sense and the facts often give way to rumor and sensationalism. Some officials in the Florida community and the media have even gone as far as blaming bromeliads for the spread of disease, killing and removing thousands of plants and asking bromeliad owners to do the same.
With a little education and prevention, this is completely unnecessary.
Mosquitoes breeding in bromeliads – is it a concern?
Of the 3000 types of mosquitoes that we know to exist, only 3 types are known to lay eggs in bromeliads. The most common are the Wyeomyia vanduzeei and Wyeomyia mitchellii. Neither of this type are known to carry any diseases and are typically harmless except for the slight swelling and itching that comes with a bite.
The other two types are of the Culex and Aedes genera. Unfortunately these are known to carry some diseases, but prefer laying their eggs in darker waters and containers.
The Mosquito Lifecycle
To understand how to prevent any mosquito problems, it’s important to understand the mosquito life cycle and how they breed.
Mosquitoes go through four separate and distinct stages of its life cycle: Egg, Larva, Pupa, and Adult. Each of these stages can be easily recognized by its special appearance.
Egg: Female mosquitoes bite and take in blood for more energy to produce and lay more eggs. They will land on or hover over the cup of bromeliads to lay their eggs which only hatch when moist. Eggs can be seen either singularly or as small clumps or ‘rafts’ on the surface of standing water. Hatching times differ but typically take about 3 days once they are in contact with the surface. Eggs that are laid on the leaf surface can survive for months until the cups are full enough to make contact with the top of the surface.
Larvae: After the eggs hatch, the larvae live entirely submerged and feed on nutrients in the water. These look like little wiggling worms swimming up to the surface to get air, and back down in the water column to feed. Only larvae that get enough nutrients in this stage will mature to the next, so limiting the amount of matter in the cup of bromeliads is important.
They live for about 7 days in this stage if they get enough nutrients. Wyeomyia species can extend their development even longer if their isn’t enough nutrients in the water, which makes management even more important.
Pupae: Once larvae get enough food and store enough nutrients, they develop into pupae, where they lay mostly dormant submerged in the bottom of the cup. Much like a caterpillar spins a cocoon, the mosquito builds a casing where it develops into an adult. This development takes 3 or 4 days.
Adult: Adult mosquitoes live for about 3 weeks and spend most of their time alive eating and breeding. A female mosquito can lay anywhere between 1,000 and 3,000 eggs in its lifetime, which is why populations can grow to nuisance levels quickly.
Most adult mosquitoes don’t travel far from where they were hatched so once populations are under control it is generally easy to keep them under control.
Because Mosquitoes live almost half of their harmlessly in water, this is is the best place to start in mosquito prevention.
Maintaining healthy plants and environments
Most mosquitoes lay eggs in dark, dirty water, ensuring that their are enough nutrients for the larva to feed on. Keeping the water in your bromeliads fresh and free of any organic matter on a regular basis will keep them “unattractive” to most mosquito types.
If possible, dumping out the water and lightly misting the leaves to keep them hydrated will eliminate any water in the cups and remove any standing water entirely. Otherwise using a hose to flush the cups of any eggs, larvae, and/or organic matter every few days is enough to keep populations down or eliminate them.
Also look around your yard for any other standing water that could attract mosquitoes. It’s easy to jump to the conclusion that your bromeliads are the source of breeding, but often there are other sources that are causing the bulk of the problem. Bromeliad cups may only be responsible for a small percentage of hatchlings.
Turn over any buckets or containers that may be collecting rain water. Fill in areas in the yard where water may pool and not drain properly. Pick up any trash or debris. Make sure to look carefully. A lot of breeding grounds can be under leaf piles or in trees hidden from plain view.
Utilizing a biological control agent
Chemical agents such as fogs are not recommended for several reasons. Not only could they harm your plants, but they will also kill all other insects and microorganisms in your plants that are healthy. If these are removed from the ecosystem, mosquitoes that survive will actually thrive because of the reduced amount of competition for nutrients.
Instead it recommended to use a biological control agent such as Bacillus or Bti. This is a spore-forming bacteria that has been develop to release toxins that kill mosquito larvae, but won’t harm your plant or other insects.
You can find different products some nurseries but we use and recommend Mosquito Bits which can be purchased easily online. These are kernels of corn that have been coated with Bti. Only one kernel is needed per bromeliad and these can be dropped directly in the cup.
We recommend starting out doing this once a week until populations are under control. Once treatment can be adjusted to every other week or as necessary after.
There are a lot of predators that eat mosquitoes, and can be considered if native to your area.
Natural predators that eat adult mosquitoes include some birds, bats, dragonflies, frogs, and other spiders and insects. Having these animals around will not be enough to completely control mosquito populations. They will feed on mosquitoes but eat other insects as well.
Adding fish like goldfish or guppies to fountains or water troughs can greatly reduce the number of larvae in these areas. These are known to be voracious eaters and will likely eat any larvae hatched in the water.
While tadpoles are thought to eat mosquito larvae, they are actually mostly herbivorous and feed on plant matter and algae. They will however compete with larvae for food and cause many to starve, so they should be kept when appropriate.
You can find more information at wbrcouncil.org
There are some homemade recipes that have been known to help control mosquito populations. The most common are using a soap spray or a small amount of cooking oil inside of the bromeliad cup.
Using a small amount of environmentally safe detergent or organic cooking oil lowers the surface tension of the water. This makes it difficult for mosquitoes to land on the water to lay their eggs. It also blocks the larvae from being able to get air, ultimately suffocating them.
If using a soap mix, dilute it enough to create a small amount of suds when sprayed. You can use a canister sprayer to water your plants like normal.
If using oil a small drop in each cup is usually enough depending on the size of the plant. A small amount of oil won’t harm the plant, but using too much can cause the leaves to become greasy. This can lower it’s water absorption and/or cause it to burn more easily.
Do you know any other remedies that work for you? Let us know if you have any to add or have any questions in the comments below.