Friday Weird Science: Thought you could go long? Our sex has nothing on stick insects.

Jul 27 2012 Published by under Friday Weird Science, Uncategorized

Today's Friday Weird Science comes to you courtesy of Bug Girl, who never fails to send me all the completely crazy entomology stuff she comes across. And she sees...a lot. And insects have some truly amazing mating systems. Including this one.


(Source)

Yup, that's a walking stick. And boy can those sticks go at it! Very...very...slowly...

Sivinski, John. "INTRASEXUAL AGGRESSION IN THE STICK INSECTS DIAPHEROMERA VELIEI AND D. COVILLEAE AND SEXUAL DIMORPHISM IN THE PHASMATODEA*" Psyche, 1979

It's no secret that walking sticks are slow moving creatures. So if I told you that a pair of walking sticks can take FIFTY-NINE days to get it on...what do you think they'd be doing? I have visions in my head of sticks humping in extreme slow motion, but that's in fact not what they're doing. Instead what the males are doing is mate guarding, remaining in contact with the female to make sure no other male gets to have any fun and win the race for Darwinian glory.

But of course, if the male walking sticks have to undergo mate guarding...this must mean that they FIGHT. Or compete at least. But this had never been observed before. Apparently previous observations had just seen one attempt, with the intervening male giving up and walking away. Kind of lame for 1400 hours of mate guarding, you know?

But the author of this paper wanted to see if the males really did fight for their lady loves. He caught a whole bunch of walking sticks, from two different species, and crowded them together in tanks. He saw mating pairs form, and then watched very, very carefully.

And the sticks fight!

Observe:

That's a female stick with two male sticks duking it out over her charms. It's kind of hard to tell, so I help you out a bit.

The female's in pink and the two males are in blue. They have their claspers attached hard to the female's vulva, and are hanging down and having what I can only assume to be a very slow motion boxing match. Whoever gets knocked off the lady loses.

Now I may have mentioned above that some animals mate guard for 59 days. But it actually depends on the species. The author of this paper also did some size calculations on the mating sticks. It turns out that mating duration in walking sticks varies as a function of size. Not the size of the stick, but the dimorphism between the males and the females. If the males are much smaller than the females, mating gets kind of short, only 11 days. But as the males approach the females in size, the mating length expands, to up to 5 weeks or more. No word on whether they need cigarette breaks. And you start gettin' tired after 30 minutes!

So remember, if you're a walking stick, slow and steady wins the race. Very slow. Very very slow.

Sivinski, John (1979). INTRASEXUAL AGGRESSION IN THE STICK INSECTS DIAPHEROMERA VELIEI AND D. COVILLEAE AND SEXUAL DIMORPHISM IN THE PHASMATODEA* Psyche DOI: 10.1155/1978/35784

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