Tuesday, June 28, 2011

Why Mosquitoes

Why mosquitoes?  Of all the amazing and beautiful rain forest animals to study, why would anyone want to work with this lowly, annoying bug that drives us crazy while sitting on porches on summer evenings?  They spread disease, too.  Why would anyone want to mess with that?

True.  Mosquitoes can spread disease. That is itself a reason to study them.  They have been responsible for countless deaths throughout the centuries and, sadly, continue to be responsible for millions today, mainly in the world’s tropical zones.  Malaria alone causes nearly one million deaths each year.  

As a student of biology, I have learned through my courses that the world’s “maneaters” and “creepy crawlies” often get a biased treatment from those that may not be so familiar with them.  I hope to change that perspective a little bit.  Yes…even the “lowly” mosquito gets a little love here.

I remember when it surprised me to learn that not all mosquitoes suck blood.  Both males and females feed on plant juices and nectar.  Given that they feed on nectar, they act as pollinators.  Some may not feed at all.  It is the female that takes in blood, and she does this to lay eggs.  Blood provides iron and protein, which allows her to lay a batch of eggs larger than what would otherwise be possible on a diet of nectar alone.  Of course, being a bloodsucker has its drawbacks – Bzzzz…SLAP! –, and many species of mosquito don’t take in blood at all.  The mosquito genus Toxorhynchites includes unusually large mosquito species – none of which suck blood.  Their larvae are actually predatory (unusual for mosquito larvae) and feed on other mosquito larvae, earning them the nickname, “mosquito hawk.”  In fact, this behavior of mosquito larvae-eating has earned them the honor of being introduced into regions where the disease-carrying species, Aedes aegypti, lives.

My project asks two questions: What species are there? Where are they going?  The first part is pretty straightforward, as I collect specimens around CICRA to get an idea of what mosquito diversity is in this area.  So far, much of the diversity information comes from the areas around Iquitos, Peru, a city located in the northeastern section of the country.  Being located in the southeastern portion of the country, CICRA is a good location to sample the diversity at the opposite end.  

The “Where are they going?” portion will be tackled at the KU Natural History Museum after the specimens are identified and mounted for examination.  All life forms require certain biological parameters for them to thrive (ie. temperature, rainfall, soil content, etc.) and the regions where these parameters exist can be mapped.  This provides a picture of potential habitats for any species.  We can then track how these parameters change in response to things like climate shifts and urbanization, and therefore the change in a species distribution.  If we know that areas of a wet habitat will become dry in response to climate change, for example, we can track the potential shift in distribution of a species that requires a wet environment.  As portions of the rain forest become urbanized – such as by the construction of the transatlantic highway – it affects the distributions of its inhabitants.  This has additional consequences to human health in the case of disease-carrying mosquitoes, as an increased human presence means more opportunities for infection and for outbreaks to occur.  Such outbreaks of diseases like yellow fever and malaria (mosquito-borne diseases once eradicated from Peru) have sprung up in recent years.  These are reemerging diseases.