Featured Research

from universities, journals, and other organizations

Vampire jumping spiders identify victims by their antennae

Date:
June 7, 2012
Source:
Journal of Experimental Biology
Summary:
Ravenous Evarcha culicivora jumping spiders -- vampire spiders -- have very specific tastes: they prefer to dine on blood-engorged female Anopheles mosquitoes. So how do they pick out female Anopheles from all other insects? Biologists have discovered that the spiders identify their victims by their antennae alone, even though the details of the antennae are too tiny to be seen by humans.

Evarcha culicivora jumping spiders, also known as vampire spiders, are picky eaters by any standards. Explaining that the arachnid's environment is swamped with insects, Ximena Nelson from the University of Canterbury, New Zealand, says, 'You can see from the diet when you find them in the field that there is a high number of mosquitoes in what they eat'. And when Robert Jackson investigated their diet further, he found that the spiders were even more selective. The delicacy that E. culicivora prize above all others is female blood-fed Anopheles mosquitoes, which puzzled Nelson.

How could these picky spiders pick out blood-engorged Anopheles mosquitoes from the swarms of similarly sized insects infesting the area? Nelson and Jackson decided to do some jumping spider psychology to find out how the arachnids pick out blood-fed female Anopheles mosquitoes from the crowd and they publish their discovery that the spiders identify the females by their antennae in The Journal of Experimental Biology.

According to Nelson, identifying Anopheles mosquitoes (males and females) is quite straightforward. 'The bodies of Anopheles mosquitoes rest on a 45deg angle from the substrate but most others rest parallel', she explains. But what other distinguishing features could the famished spiders use when selecting the females specifically? 'Obviously, blood-fed females have an engorged red abdomen and the other difference that comes to mind between males and females is the antennae', says Nelson. Explaining that male Anopheles have luxuriant fluffy antennae, while the female's are less elaborate, Nelson decided to see which mosquito features E. culicivora fixate on.

Collecting male and female Anopheles and Culex mosquitoes at the International Centre for Insect Physiology and Ecology in Kenya, Nelson, Godfrey Sune and other helpers painstakingly constructed hybrid mosquitoes. Combining the head and thorax of one insect with the abdomen of another, the team was able to produce Frankenstein mosquitoes with blood-engorged female abdomens and male antennae, slender male abdomens and female antennae, and every other combination in between. Then, they mounted the hybrid mosquitoes in their correct postures and tested the spiders' preferences.

'The great thing about jumping spiders is they're very decisive', recalls Nelson, who could clearly see that the spiders preferred intact blood-engorged females over everything else, even females engorged with transparent sugar solution. And, when Nelson offered the spiders the choice between a Frankenstein female (made from the head and thorax of one female fused to the blood-engorged abdomen of a second female) and a hybrid constructed from a male head-and-thorax and a blood-engorged female abdomen, the spiders usually selected the hybrid with the female antennae, even though both hybrids were packed with blood. Also, when she tempted the spiders with animated simulations of blood-engorged mosquitoes with either male or female antennae, the spiders consistently pounced on the simulated female.

The spiders weren't just picking out Anopheles mosquitoes with abdomens full of blood; they were able to identify the mosquitoes by their antennae. 'The thing that really amazed me is that I couldn't actually see the difference when I was looking at the screen', recalls Nelson. Even when she got down to the spider's level, the mosquitoes were too small for Nelson to discern the insects' minute antennae.

Having found that picky E. culicivora can identify the tastiest mosquitoes by their antennae, Nelson is curious to find out how they process this visual information: whether they assess all of the mosquito's characteristics simultaneously or systematically tick features off a check list before deciding to attack. Nelson also adds that she is baffled by how the spider's tiny brain processes all of the sensory information that they must handle when making their decision.


Story Source:

The above story is based on materials provided by Journal of Experimental Biology. The original article was written by Kathryn Knight. Note: Materials may be edited for content and length.


Journal Reference:

  1. Ximena J. Nelson and Robert R. Jackson. The discerning predator: decision rules underlying prey classification by a mosquito-eating jumping spider. Journal of Experimental Biology, 2012 DOI: 10.1242/%u200Bjeb.069609

Cite This Page:

Journal of Experimental Biology. "Vampire jumping spiders identify victims by their antennae." ScienceDaily. ScienceDaily, 7 June 2012. <www.sciencedaily.com/releases/2012/06/120607092756.htm>.
Journal of Experimental Biology. (2012, June 7). Vampire jumping spiders identify victims by their antennae. ScienceDaily. Retrieved September 23, 2014 from www.sciencedaily.com/releases/2012/06/120607092756.htm
Journal of Experimental Biology. "Vampire jumping spiders identify victims by their antennae." ScienceDaily. www.sciencedaily.com/releases/2012/06/120607092756.htm (accessed September 23, 2014).

Share This



More Plants & Animals News

Tuesday, September 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Cat Lovers Flock to Los Angeles

Cat Lovers Flock to Los Angeles

AFP (Sep. 22, 2014) The best funny internet cat videos are honoured at LA's Feline Film Festival. Duration: 00:56 Video provided by AFP
Powered by NewsLook.com
Washed-Up 'Alien Hairballs' Are Actually Algae

Washed-Up 'Alien Hairballs' Are Actually Algae

Newsy (Sep. 22, 2014) Green balls of algae washed up on Sydney, Australia's Dee Why Beach. Video provided by Newsy
Powered by NewsLook.com
Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins