NSFW? – katydid pre-mating sperm removal

August 6, 2015 • 7:45 am

by Matthew Cobb

This neat video by Ralf Jochmann, with commentary, shows katydids (or bush crickets, if you prefer) mating and above all, shows the male using his bits to remove sperm from previous males from the female. These scenes are rather detailed, so you might find them icky, or your colleagues might find you weird.

Just to explain a few things: in this video the male is the larger insect, underneath at the beginning. The female has the curled-up ovipositor at the end of her abdomen. Mating in these species is not penetrative, but instead involves the transfer of a spermatophore – the white blobby thing – from the male to the female, which the female picks up with her genital apparatus.

Spermatophores often contain substances that increase the female’s fitness, and/or which indicate the male’s fitness to the female. Before the male of this species gives up his gift, he makes sure that he has removed sperm from rival males who have mated with the female. The second half of this video features this process, in close-up. You have been warned.

[JAC: Once again, “natural selection is cleverer than you are.”]

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Reference: von Helversen D and von Helversen O. (1991) Pre-mating sperm removal in the bushcricket Metaplastes ornatus Ramme 1931 (Orthoptera, Tettigonoidea, Phaneropteridae). Behavioral Ecology and Sociobiology28.6 (1991): 391-396. Link here.

21 thoughts on “NSFW? – katydid pre-mating sperm removal”

  2. Recent research shows that the human penis will effectively remove over 90% of previously deposited sperm from a human vagina. I’m not sure what that tells us about our sexual habits in evolutionary terms but you must admit that it’s an interesting adaptation to ensure gene transmission.

  3. Sperm removal has also been suggested as a driver for the the evolution of the human penis – although I have no idea how plausible this is…

    “Semen Displacement as a Sperm
    Competition Strategy in Humans
    Gordon G. Gallup” in Evolutionary Psychology
    human-nature.com/ep – 2004. 2: 12-23

      1. Ah yes, but can we reject the hypothesis of the headline-grabbing selfish meme?

  4. I see the female does not seem to object to this sperm removal behavior. Probably the act would not have any negative effect on the female’s gene transmission since her gene contribution is unaffected.

    1. Perhaps, unless

      1. The male’s behavior damages her reproductive tract; or

      2. She chooses mates based on genetic or phenotypic quality, and this behavior by the male short-circuits her choice.

      1. Maybe this behavior by the male validates him as the female’s choice. And wouldn’t damage to her reproductive tract be non-adaptive for both of them?

        1. I think the damage in this case would be to prevent future access. This wouldn’t necessarily be non-adaptive. I would imagine there would be selective pressure for the male to “glue” the female tract shut in some way.

          1. …creating pressure for later males to evolve better scrapers and solvents. Or bypass the whole system, like bedbugs.

    2. If it bothered her she’d probably chase away the male or worse (since they seem evenly matched) so bothersome configurations perhaps didn’t work with these insects.

      1. Mating in this katydid seems similar, at least in part, to the Mormon cricket (which is really also a katydid). Males in that species also deliver a big sperm packet, but importantly, it is very nutrient rich and the female actually eats much of it. Because this meal is highly valued, female Mormon crickets seek out males for mating and will mate with multiple males if they can.
        So perhaps the above female katydid does a similar thing. Perhaps she eats much of this packet, and so does not at all object to mating with other males.

        1. Wow, those Mormons. Is there anything they do that isn’t weird? 😉

          cr

  5. Wow, this is an amazing video! Sperm removal is well-known from damselflies and dragonflies, which have elaborate penises that shovel out the sperm from the female’s previous matings. I’d never heard of it in katydids, where males usually are very choosy about who they mate with. There is generally a nutritive substance attached to the spermatophore itself, and the nutritive blob can weigh up to a third of the male’s mass, so it’s extremely costly to produce (I always tell people to imagine what it would be like if human males had to manufacture something out of their own body fluids that weighed 50 pounds or more every time they had sex). Females benefit by eating the blobs, and compete to obtain them. So in most katydids females are larger and males are selective, sometimes called sex role reversal.

    Darryl Gwynne at the U of Toronto has done lots of cool work on katydids, if anyone is interested, and his 2001 book on them is fantastic.

  6. That is some acrobatic mating. First, it is a reverse ‘doggy style’, and the male manages to stand on his head for a time.

  9. I prefer ‘bushcrickets’, since most British species don’t make a ‘katydid’ or ‘Kate did it’ sound (or Japanese species, either!). I think the term was coined by David Ragge of the Natural History Museum in London; he wrote what was I think the first book on the complete British orthoptera, complete within a small vinyl record of the vaious bushcrickets’ cries. It was one of my favourite books in youth.

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