How vampire spiders could help in the war against malaria

 

A creature known as a “vampire spider” sounds like the last thing that could be good for your health, but the authors of a recent study in the Journal of Arachnology claim that they may be a valuable ally in the fight against one of the world’s deadliest diseases.

As reported recently by The Guardian and The Washington Post, the arachnids in question are a species of jumping spider known as Evarcha culicivora, which are adapted to specifically target the female Anopheles mosquitoes capable of transmitting the malaria parasite.

Native to East Africa, these mosquito-gobbling spiders could help combat malaria, which World Health Organization statistics claim is responsible for about 500,000 deaths each year and primarily affects children in Africa. That fatality rate fell by more than 54 percent between 2000 and 2013, thanks in part to biological control methods like these spiders, reports indicate.

Could these spiders be released to combat malaria?

RedOrbit posed that question to the authors of the study, Dr. Fiona Cross from the International Centre of Insect Physiology and Ecology (ICIPE) and Professor Robert Jackson of the University of Canterbury via email, who said that it was “disconcerting” that people “want to know whether we plan to release millions of these spiders into the wild, especially throughout Africa and Asia, without considering any of the potential consequences on local ecosystems.”

However, while it may not necessarily be a great idea to flood an ecosystem with this invasive species, Dr. Cross and Professor Jackson said that since E. culicivora willingly enters homes and kills malaria-carrying mosquitoes, “encouraging people to welcome these guests into their homes sounds like a good idea.” Unfortunately, as they note, “it is hard to be optimistic” about this plan gaining widespread acceptance when even some entomologists are repulsed by spiders.

Whether we like them or not, these so-called vampire spiders are our allies in the fight against malaria, the researchers noted. While they have a taste for blood, they are unable to bite humans due to the structure of their mouths. However, they are attracted to the smell of people, which is one of the reasons they target mosquitoes that have recently dined on human blood.

On an interesting side note, Dr. Cross and Professor Jackson told redOrbit that E. culicivora is attracted to the odor of smelly socks. Experiments they conducted in 2011 found that the spiders spent a significantly longer period of time breathing air blown over stinky socks than they did air blown over clean ones. This indicates that they actively seek out human odors, and that this ability may help them track down mosquitoes that had recently fed on people.

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(Image credit: Robert Jackson)