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“Remarkable” Spider Eats Mostly Mosquitoes—Could It Fight Malaria?

Hate spiders? The Malaysian jumping spider might just win you over. New research reveals that Paracyrba wanlessi preys almost exclusively on a despised human foe: the mosquito

Perhaps a little respect is in order for an arachnid that gobbles up swarms of mosquitoes, the disease-transmitting insects responsible for millions of deaths a year due to malaria and other illnesses—not to mention endless annoyances on summer nights. (Related: “New Mosquito Repellent Made, ‘Better Than Anything Else.'”)

A photo of a mosquito-eating spider.
A male jumping spider, Paracyrba wanlessi, in Ulu Gombak Forest Reserve, Malaysia. Photograph by Daiqin Li

“Many other animals, including other spiders, may sometimes eat mosquitoes,” study co-author Fiona Cross, a biologist at New Zealand’s University of Canterbury and the International Centre of Insect Physiology and Ecology, said by email.

“But this spider is different, because this is a species that loves mosquitoes more than anything else!” said Cross, whose study appeared October 1 in the online journal Royal Society Open Science. (Read more about how jumping spiders travel.)

In fact, when Cross and colleagues reared spiders in the lab on non-mosquito diets and then gave the arachnids various options on the menu, they still chose mosquitoes. “This active preference for mosquitoes is highly unusual,” she said.

All Mosquitoes, All the Time

In fact, so far only one other animal is known to be such a strong mosquito specialist: another jumping spider from tropical Africa called Evarcha culicivora. This arachnid also happens to prefer Anopheles mosquitoes—the worst offenders in spreading disease, particularly malaria.

This is an example of convergent evolution; the two distantly related spiders evolved very similar traits—in this case, eating mosquitoes—independently, according to the study. (Also see “‘Surreal’ Vegetarian Spider Found—A First.”)

But at mealtime, the two spiders enlist quite opposite strategies.

Evarcha feeds indirectly on blood by choosing blood-carrying mosquitoes as prey,” study leader Robert Jackson, also at Canterbury, said by email. “You could say the mosquito is a syringe with wings that delivers the blood to Evarcha.”

A photo of a spider that feeds on mosquitos
Evarcha culicivora eats a mosquito at the International Centre of Insect Physiology and Ecology field office in Mbita, Kenya, in 2007. Photograph by Remi Benali, Corbis

Paracyrba, on the other hand, isn’t focused on the blood content. If there’s a mosquito, empty or full, the spider targets it, said Jackson, who received funding from National Geographic Society’s Committee on Research and Exploration.

Most remarkably, the spider will eat mosquitoes of various species at all stages of life—even though juvenile and adult mosquitoes are distinctly different animals, looking almost nothing alike. A juvenile lacks wings, a proboscis, large compound eyes, and legs, and it lives in wet habitats much different from adults’ dry environs.

“Juvenile mosquitoes live in water and they are of no interest to Evarcha, but Paracyrba scoops juvenile mosquitoes out of the water,” Jackson said.

So really, Paracyrba has two kinds of preferred prey, he noted. “It chooses adult mosquitoes away from water and juvenile mosquitoes in water. This kind of double-barrel specialization on mosquitoes has never been demonstrated for a predator before.”

“Like a Miniature Cat”

The spider also has to adjust its capture style depending on the mosquito’s habitat—stalking adults on land but ambushing and repeatedly attacking juveniles from the water’s edge.

Paracyrba [like other jumping spiders] has extraordinarily good eyesight and hunts for its prey like a miniature cat,” Cross said. (Watch a video of a jumping spider attacking a bee.)

“But even when the spider has never seen, let alone eaten, a mosquito before, and even when it has only been reared on a diet of terrestrial prey or on a diet of aquatic prey, it still knows what to do” in either scenario presented to it, she said, suggesting that the Paracyrba’s preference for mosquitoes is hardwired.

“Whether the mosquito is a juvenile or an adult, it doesn’t stand much of a chance,” she added.

Itching With Promise

Such an innate, rather extreme behavior certainly has researchers swatting around big-picture possibilities.

“Any predator that singles out mosquitoes as preferred prey has to be of exceptional interest,” said Jackson. “Mosquitoes are not just a nuisance that keep you awake at night by buzzing around your ears. These insects are also notorious vectors of malaria, dengue, and other diseases,” especially in the tropical environments where the jumping spiders live.

Of course, no one would advocate simply turning spiders loose in places where mosquitoes and the infections they spread are problematic, especially if the spiders aren’t normally there. (Also see “Hitting Mosquitoes Where It Hurts.”)

And no spider, no matter how hungry, will be a magic bullet that will rid us of mosquito-borne disease. But further study and creative thinking might suggest a role for them in solving a major public health problem. “And they are out there in nature for free,” Jackson said.

For now.

Even with big animals like lions and elephants, “it can be hard to determine how many are out and about in their natural habitat,” Jackson said.

“It’s even harder with a spider. Paracyrba is believed common in its Asian bamboo-forest habitat, but habitat destruction is happening now on such a massive scale, sometimes it’s hard to be optimistic.”

Follow Jennifer S. Holland on Twitter.

Comments

  1. wil lones
    Nashville, Tennessee
    March 11, 5:30 pm

    I once teamed, as a photographer, with a writer to do an article on Florida’s wild spiders for a magazine. Besides being great fun and getting a few wonderful shots i learned much about these amazing creatures. What struck me the most from all that I read was the comment made by Aleena. Thank you for your purpose ans vision and I wish you all the best on your journey. For all the mistakes made by my generation and before me, I was encouraged by your words. People do not understand the small and invisible things of the world , yet they matter.

  2. Alamnyak Thaddeus Ole Orpiay
    Loiborsoit, Maasailand, TANZANIA
    October 20, 2014, 5:01 am

    I like and love Invertebrate preservation due to their roll on ecology. without this invertebrate many species like birds who depend insect as a source of food to them they will be in a group of endanger species years to come so us wildlife mangers we suppose to take action in a right time. My self i appreciate you project because i know how its very important worldwide also my self i was establish a new project concerning a increase bees colony by rase up beekeeping in Maasailand to help rural people who live adjacent National parks area to improve their live hood through invertebrate at the same time to improve a pollination action by increase pollinators agents to help the acacia woodland which is a source of food to Elephants found in Africa know as Loxodanta africana africana very popular in Eastern Africa. included Tanzania.

  3. Kalani
    Halawa Valley, Molokai, Hawaii
    October 15, 2014, 1:18 pm

    Lots of spiders here, Cane spiders, Crab spiders, and web-less smaller Wolf spiders. After years of living among them, there seasonal influx re-occurs around the same time each year. The Crab spiders are numerous during the winter months and catch a wide variety of insects in their webs.

  4. Sesu
    October 12, 2014, 2:27 am

    The University of Canterbury is not in the U.K.. It’s in New Zealand.

  5. Pedro Saul Castillo Carrillo
    October 9, 2014, 11:44 pm

    An article on spiders very interesting. Here in my region spiders are very importants in cultures of rice

  6. TREVOR RAPS
    AUSTRALIA
    October 9, 2014, 8:23 am

    OUR DISASTROUS AERIAL SPRAYING OF ALL MANGROVE AREAS WILL PUT PAID TO THAT, MOSQUITOES BOUNCE BACK QUICKLY, BUT ALL THE OTHER LIFE DOES NOT. <3 <3 <3 .

  7. nancy brownlee
    October 8, 2014, 5:13 pm

    That spider is wearing teeny little boxing gloves…

  8. Aleena
    October 8, 2014, 9:20 am

    When I get older I want to be able to find cures and help save peoples lives. With the help of many insects including this spider I think my dream will be a success.

  9. Lester
    October 8, 2014, 8:45 am

    An article that may be of interest