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drdoug March 14 2016, 07:57:09 UTC
introducing a ton more bats into the area would probably be more effective and have less of a potential for long term environmental problems.

I don't think we know that without a lot more information about the ecosystem involved.

My guess is this would be unlikely to help for more than a few seasons, if that, and even has a chance of causing a disastrous collapse of the bat population, which would probably end up with way more mosquitos. And it may also have all sorts of other terrible effects, which are hard to predict without knowing the ecology of the area really well.

As you say, there are bats there already. The key question is why there aren't more than that. If the bat population is limited by persecution or roosting spaces, there's an easy and cheap way available to increase the population and decrease the population of prey insects. Hooray! (Except, of course, there will be reasons for the persecution and the lack of roosting spaces, which may be hard to overcome.)

Chances are, though, that the bat population is limited by availability of food. Introducing more bats will mean fewer mosquitos ... until the bat population crashes from starvation. The mosquito population then booms, unchecked, until the slower-breeding bats can catch up. Predator-prey cycles are not pretty. Even worse, an artificially-induced one like this runs a risk of driving the bat population below a sustainable level in the crash phase and wiping them out. Oops.

Also, what else are the bats eating? Or what do they turn to in desperation when the mosquitos turn scarce? They might eat important pollinating insects. Hell, some bats are significant pollinators themselves. They might eat some other food source that's currently relied on by some other important species. And so on, rattling round the food web.

This latter effects are, of course, a possibility if the mosquitos are wiped out entirely with the release of gene-driven GM mosquitos. Ecology is rarely simple. But the first-order effect will be to reduce or wipe out the mozzers. If this technology works, it can be used around the world.

Mosquitos worldwide cause such a massive amount of suffering that it's well worth a try at eliminating them. Although we can do a lot of desk research on it, there's no way of knowing perfectly in advance what'll happen when they're released in the field. Trying it out first in a first-world country where we can monitor what's going on thoroughly - and have far more resources to deal with unexpected adverse consequences - seems a great plan to me. I don't bank on it happening, though. Deep-pocketed nimbyism (entirely understandable) is a greater barrier, especially given that mosquitos are less of a problem in first world contexts, partly because of those deep pockets. Protecting just people's sleeping areas (with mosquito-proof bednets) is more than we can manage in some parts of the world; I remember when I went to Florida seeing these huge black mosquito-netting cages covering the gardens at the back of most of the suburban houses.

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