Mosquitoes: A necessary evil

Let me make this clear. I hate mosquitoes. They are noisy, irritating and somehow manage to find your ears and buzz next to them even when you cover yourself up completely. Also, I’m not a fan of itching every part of my body they decide to have their meal from. Thankfully, I haven’t faced any serious diseases because of them, but I know people who have. Mosquitoes are responsible for the spread of deadly diseases like malaria, chikungunia, yellow fever, dengue and others that kill over 1.5 million people every year. Those who survived these diseases probably loathe these tiny flying monsters.

But no matter how useless you find these creatures, nature doesn’t keep anything alive if it has no use. Today, mosquitoes are found in every corner of the world; they are invasive in many of the countries. They have found a niche for themselves in all of these ecosystems and do play an important role…

mosquito के लिए चित्र परिणाम

There are 3500 named species of mosquitoes; only a few hundred have any relationship with humans. They have been present for 100 million years on Earth; they are extremely specialized and in many cases, they have co-evolved specifically as prey or predator for a few species. The major roles mosquitoes play are in the form of prey, predator and pollinator.

Prey

The mosquitoes are fantastic things to eat in their larval form, if you are a fish. Many birds, insects and even some bats are also known to have mosquitoes in their diet. Larvae especially are important food source in aquatic ecosystems.

mosquitofish के लिए चित्र परिणाम
The mosquitofish.

The mosquitofish (Gambusia affinis), for example, is a specialized predator — so effective at killing mosquitoes that it is stocked in rice fields and swimming pools as pest control. Eradicating all mosquitoes from the world would require all the fishes that feed on them to switch their diets; the ones that can’t will go extinct. The chances of extinction are greater, since many of these fishes have mosquito-feeding embedded in their genes. That cannot be changed within a year.

For birds and insects, mosquitoes are only a part of a varied diet. It is possible that they could rely on alternatives even if mosquitoes were eradicated, but that is not the case in the Arctic tundra.

In the Arctics, mosquitoes possibly have the largest biomass. During their peak season, you can actually see swarms of mosquitoes flying with the wind. Certain estimates show that population of migratory birds from this region could fall by 50% if mosquitoes like Aedes impiger and Aedes nigripes became extinct. 

Predator

Mosquito larvae are filter feeders, feeding on decaying organic matter and microorganisms. Hence, they are an important link in aquatic food chains as a predator as well. It is as yet unclear if other filter feeders would step in if mosquitoes are eradicated. Some people are of the opinion that other filter feeders will step up. “If you pop a rivet out of an airplane, it’s not going to crash”, says insect ecologist Steven Juliano, of Illinois State University in Normal. But today, we have already popped many rivets in our ecosystems unknowingly. It is sheer luck that they have not been catastrophic. Do we really want to risk killing off mosquitoes without knowing the all the consequences?

mosquito inside pitcher plant के लिए चित्र परिणाम
Mosquito larvae inside the pitcher of the pitcher plant.

An interesting relationship exists between mosquitoes and the pitcher plants of North America. The plant has very, very small ponds inside their pitchers. When other insects die, the mosquito larvae digest them and release important nutrients like nitrogen for the plant to use. Extinct mosquitoes would affect plant growth, in this case. Protozoa population, which also exists in the pitchers of these pitcher plants, are more diverse in the presence of these larvae, according to one research published by ecologist John Addicott, now at the University of Calgary.

Pollinators

Many mosquito species are pollinators in the tropic regions, even for plants like cocoa. Imagine, without mosquitoes, you might have no chocolate to eat! The thousands of these plant species could become extinct if these pollinators were not present. Even if they are not important for “crops humans depend on”, it’s not right that we exterminate mosquitoes in this regard.

But still, mosquitoes are a pest…

One of the animals that might be happy if these pests were exterminated, apart from humans, is the caribou. During peak seasons, mosquitoes can even asphyxiate caribou in their thirst for blood. Herds of caribou are known to flee opposing the wind to escape these swarms.

For humans, the problem is well documented. The economic burden of fighting mosquito-spread diseases is so huge in some countries that people estimate that the economic growth of these countries could increase by up to 2% if mosquitoes were eradicated. Forget economic growth, simply put, more humans will live without mosquitoes.

Does that justify our plan to exterminate them?

No, not really. Killing off mosquitoes is an active research area and in many places, people have started implementing them. Without the proper research on how important mosquitoes are,  this could spell disaster. Also, the mode in which we are killing mosquitoes is an issue. Many of the insecticides used kill similar sized insects as well. They are also part of the food chain in aquatic ecosystems. If mosquitoes and the alternatives are killed, you cannot expect the fishes that survive on this diet to live for long.

Also, out of 3500 species, if only a few hundred even bother humans (maybe a few tens are vectors for diseases), how can you go ahead and eradicate all the mosquitoes in the world?

The solution (at least, for the moment)

I completely understand why people would want the world to be rid of mosquitoes. But until our research is complete and we figure out ways to compensate the loss of mosquitoes in their ecosystems, we cannot do that. The solution to their vector behavior is active pest control; control their populations in places with high human populations. The research, meanwhile, continues…

 

 

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