Friday, September 26, 2008

Who Needs Males?!?


Ever since I saw Mr. Miyagi take a leaf disguised praying mantis from the tree in one of the karate movies, they've peeked my interest with their still-as-statues eating habits and graceful natures. They have a long thorax that increases their field of vision as well as granting them the ability to turn their heads 180 degrees. They are lean, green, snaring machines! Anything from flies and moths to small frogs and hummingbirds can find themselves on the menu for these strikingly fast killers!


Even though these agile hunters have a diverse diet, cannibalism is far from uncommon. In fact it's a trait that's favored! Male praying mantis' have little to no chance of mating and living to tell the tale. Sorry boy's, no bragging about that night! The mating is done in a series of three steps. First the larger female mantis meets the smaller male mantis. Then the male gets into mating position and he puts his sperm in her, fertilizing her hundreds of eggs, perhaps loosing his head at the same time. Male praying mantis' can afford to loose their heads and use it as a sacrifice because their neural messages to mate aren't located in their heads, so even after they are beheaded they will continue to breed with the larger female. Then, when the male is finished, he will try to run away, whether he's beheaded or not. The female will either try and catch the male, if she didn't already have him, or continue eating him so that he would be the first nurishing meal to the eggs he'd just finished fertilizing.

Posted By: Ada Marie Flores (2)
UPDATE (September 30, 2008)
My updates are at the end of the comment section. I wasn't 100% sure how to correctly post it on this, so I wrote it in my comments like the teacher said I could. Sorry if this inconveniences you.

30 Comments:

At 11:14 AM, Blogger PWH said...

How long do the males have before they are completely dead? I did not know they could continue mating after they are decapitated. Very interesting.

So, do we know what the average life cycle is of a male mantis? It seems that for many animals males only serve the one purpose.

-Michele Copeland (2)

 
At 2:39 PM, Blogger PWH said...

During the mating female eats male, that is pretty nasty thing to see. In a way, female are being smart because female needs that nutrient for her offspring.
However, I did not think the male run away from her especially without his head. How can he runs away? I cannot picture it. In addition, before I did not read this article, I thought male would like to devote his life for his offspring and female. It is very interesting article.

So Jin Lee

 
At 4:39 PM, Anonymous Anonymous said...

A very interesting article, I enjoyed the link to one of my favorite movies as a child.

I found it to be very interesting that the neural network for mating isn't located in the brain. Where is it located? I am also amazed that they can eat animals as large as a hummingbird


Duy Nguyen

 
At 5:12 PM, Blogger PWH said...

I was wondering if the males know they are going to be sacrificed prior to breeding. I ask this because the post mentioned (and the video showed) that the male tries to run away post mating. Since the male is such an important source of nutrients for the female I found it interesting that they haven't seemed to evolve to the point to where they understand their fate.

-Benjamin Spozio

 
At 6:40 PM, Anonymous Anonymous said...

I had previously been aware that praying mantises ate their mates as part of the mating ritual. However, I was surprised to learn that it was during the sexual act and not after. It was also surprising to learn that the males can occasionally escape without their heads.

Since they can continue to mate and move without their heads, I'm curious to know to what degree their heads are even required. Are their brains even located in their heads?

I'd also like to know how frequently the males actually escape without being devoured. Does it's survival have a detrimental affect on the developing eggs?

Allison Cornell (2)

 
At 7:26 PM, Blogger pajama said...

I knew that some spiders also ate the male after mating, however I did not know this also applied to praying mantis'. I was if the only reason that the males die after mating is for nourishment of the eggs, or if there are other reasons as well. Though i'm not certain, I think there were several reasons for the males getting eaten in spiders.

~Dan Hong

 
At 10:56 PM, Blogger PWH said...

i am glad that you chose to post about this because ever since I read about them in our animal behavior book I have been interested. I knew before that the females would consume the male after mating, but until I read it in the book I had no idea that might eat the males head before they mated. I was amazed to read in your post that they can eat frogs and hummingbirds! How exactly do they do this? Frogs and hummingbirds are larger than the praying mantis so it seems that they would have a hard time consuming them. Do they consume them all at once and have mouths that expand for this or do they eat them by picking at them? I am also interested in why they eat their mate. I know that it is nourishment for the female, but if they have so many other food options is it really critical for them to eat their mate?

-Tara Quist

 
At 11:54 PM, Blogger PWH said...

Very interesting..but I wonder how this mating ritual evolved in this species and if females have genetically evolved over time have come to be larger than the males in order to maintain this ritual.

-Joanne Philippeaux

 
At 1:53 PM, Anonymous Anonymous said...

I was wondering if any of the males have successfully gotten away and lived to see another mating? And i was wondering if any of the males did not try to run away, just knowing that this was how it is and accepts the part of the species. This was extremely interesting and i would like to find out how many other species sacrifice themselves in the mating process


-Amanda Joyce

 
At 2:23 PM, Anonymous Anonymous said...

So if males are killed after or during mating who protects the female from predators? Do the females protect themselves?

-Sasha Rogers

 
At 2:29 PM, Blogger PWH said...

This is a very interesting article. It's odd that the male can loose it's head while in the process of mating. Does the male ever escape the female and live to mate with another? If the male were to get away, would the offspring be at a large disadvantage without the nutrients of the male to help nourish them?

Rob Lubenow

 
At 4:37 PM, Anonymous Anonymous said...

I'm glad I'm not a male preying mantis. It's interesting to see a role-reversal where the females seem to be more in charge.

What's happens when the female mantis are not able to catch the male mantis after mating or is a 100% chance?

- David Huynh

 
At 5:35 PM, Anonymous Anonymous said...

I knew the females at the males, but I've never actually read up on their mating process. How does the male stay alive without a head? Why does his head come off in the first place? This was really interesting.

Amy Kawazoe

 
At 5:35 PM, Anonymous Anonymous said...

I knew the females at the males, but I've never actually read up on their mating process. How does the male stay alive without a head? Why does his head come off in the first place? This was really interesting.

Amy Kawazoe

 
At 5:59 PM, Blogger PWH said...

Wow. This is indeed a very interesting article. It is interesting to see the way we interact with each other and compare it to species and how they interact with each other in a natural environment. I am wondering whether the beheaded male will survive after it runs away.

 
At 6:45 PM, Anonymous Anonymous said...

I love the way you presented this article with humor, sometimes it gets boring reading so many scientific articles! Great job presenting the data and making it fun!

But I wonder... Why would males want to mate if they get eaten afterwards? I mean I know that passing your genes are one of the most important things but i'd think males would mate less, if it means dying. So does the male only mate once ALWAYS? Also does the male wait until he is older to mate so that he can live longer?

By: Brena Sena

 
At 7:37 PM, Anonymous Anonymous said...

This is a nice blog. I thought it was very interesting that the mantises evolved to the point where they will continue to mate after being decapitated. I am curious as to how they try to run away afterward if they have been decapitated. The one thing I might change is the title "Who needs males?" as I found it a little misleading. Still, very enlightening and a fun read.

Comment by Alex Jackson

 
At 8:28 PM, Anonymous Anonymous said...

Wow, if we as people think relationships can be cruel this definitely sheds light on that idea. I have heard that this kind of thing happens with insects, are there others that practice this same behavior in mating? I think I heard that certain spider females will kill the male after breeding as well.
-Alicia Stein

 
At 9:27 PM, Anonymous Anonymous said...

I vaguely remember something like this in my evolution class. Where a male would present a gift to a female to court her, and this seems like this is an extreme case. Do you know if the female selects the male that seems like he would be the best meal, so she gains more nourishment to pass on to her young?

Stephen Lee

 
At 9:28 PM, Anonymous Anonymous said...

I liked this article a lot. I was wondering if the male always loses the fight though, or if the female is ever consumed by the male. Is cannabalism only a trait of females?

Jen Kodela

 
At 9:30 PM, Anonymous Anonymous said...

Very interesting and well written. Do the males always die right after they mate or do some escape? Nice work.

Ericka Adey

 
At 9:59 PM, Blogger PWH said...

Very interesting blog. Is this cannabilistic process always been the way females treat the males after they have mated with them? Or is this process one that has changed over time. Also, what happens to the headless male if he does manage to escape? Is he eventually eaten by either a female or a predator, or can he escape and continue to live?

Ahmed Sandakli

 
At 10:34 PM, Anonymous Anonymous said...

I wasn't aware that happened during the mating of praying mantises. I know that in spiders the female eats the male after he placed his sperm in her so that she will have nourishment for herself and also the young they have created but I didn't know it also happened in the mating process of the praying mantis.

What baffles me is the fact that the males continue to live after they has been beheaded. I wonder how does the male praying mantis still continue to live after its head has been eaten off? And if it does escape the clutches of the female praying mantis what happens after that?

- Debbie Theodat

 
At 10:51 PM, Anonymous Anonymous said...

I am just curious as to why they have to eat the male? Is there any other reason than the fact that its nourishing? Because like you said they do have the ability to capture other species/animals.

Tazneena Ishaque

 
At 11:48 PM, Blogger PWH said...

It be interesting to find out where the information to keep mating is coming from and if this is just localized to the praying mantis or other organisms act similar.

Charles Scondras

 
At 12:10 PM, Anonymous Anonymous said...

Over the summer I saw a preying mantis for the first time. As I was crouching down to get a closer look it spread its wings out, put up its front legs in a karate-like pose and hissed at me! It was small, only two inches or so, but I still jumped back. I'm sure it spread it's wings in order to look bigger and I was really impressed by it. I didn't even know we had mantis's in Massachusetts until I saw this one for the first time. I enjoyed reading your post about this fascinating creature.

Rachel Carboni

 
At 11:21 PM, Anonymous Anonymous said...

wow i was watching this on animal planet it is amazing to watch as the males literally sit their and get eaten sometimes not giving a fight at all. that is sacrificing for your young! -matthew sousa

 
At 12:10 AM, Blogger PWH said...

Hi, it's me the Blogger. I wasn't 100% sure how Houlihan wanted us to post on our own pages, and I didn't want to do it wrong and get points deducted, so I chose door number two and decided to comment on my own post and answer some of the more frequent questions in this section. Plus this is easier.

First off, female mantises are larger than male mantises because, depending on the species, they have the ability to lay from 3-10 cacoons with about 300 eggs in each cacoon. So I don't know about you, but if I had that in me, I'd be pretty large myself!
The lifespan for mantises in general isn't that long considering that siblings will eat each other, if given the chance, so that only the toughest really survive. Going with eating behaviors, a mantis can, and will, try to catch and eat organisms twice their size. Also mantises, like many other insects (ex: cockroaches), don't really have what a scientist would call a "brain". They are driven instead by a bunch of neural networks. So when the head is eaten either during or after mating, the male preying mantis still has the signal firing for sex, and then to get away from the female as quickly as possible so he can hope to live a bit longer. The reason that female mantises catch and devour their sperm doners, is because they will be the first non-costly nourishing meal that their recently fertilized eggs will be fed, so they can grow and develope healthily. So in effect, male mantises bodies are forcibly sacrificed by the female mantis so that she is guaranteed that her offspring will have gotten some sustenance before they are to be born.
P.S. No. There is not a 100% chance that any part of the male preying mantis will be caught and eaten by the female mantis, it is just a more likely ending for him after mating, though he (a preying mantis) doesn't live for that long anyway.

Posted By: Ada Marie Flores

 
At 12:15 AM, Blogger PWH said...

P.P.S. If a male loses his head, he won't be able to live anyway because he has no way to see or eat his prey, or watch out for predators or find a place to camouflage himself from both prey and predator.

Posted By: Ada Marie Flores

 
At 1:05 PM, Blogger PWH said...

That's insane, I heard about this before in a movie. How do they ensure they're species will continue if the females are eating the males after they only mate 1 time! How is there enough males?

Jennifer Smith

 

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