Free Dr. Tatiana's Sex Advice to All Creation by Olivia Judson Page B

why even large males who are not in musth stay well away from any male who is.

    Dear Dr. Tatiana,
    Â 
    My name’s Rob, and I’m a bedbug, Xylocoris maculipennis. I’ve read that if I have sex with my friend Fergus, he’ll deliver my sperm when he next has sex with Samantha. Is this for real?
    Â 
    Making Mischief between the Sheets

    First, you’re not a real bedbug but a pirate bug, a close cousin. No use pretending. As to your question, it sounds to me like you’ve been reading too much naughty French literature (although to be fair, I’ve read the same stuff myself). The claim is that because you have a penis like a hypodermic needle—and because in species like yours, you jab it through the body wall—sperm injected into another male will migrate through his body and arrive in his gonads. Exciting though this sounds, it has always struck me as one of those facts journalists call “too good to check.” The short answer is yes, it’s possible—but it’s unlikely.
    I have two reasons, one practical and one theoretical, for being skeptical. On a practical level, the original claim is flimsy—based on poor data—and the experiments have never been repeated on your species. Moreover, experiments on a related species, the European bedbug, have found no evidence for males injecting each other. Theoretically, the situation you describe would be highly unstable: any male who could resist acting as a proxy would have a big advantage over one who could not, and genes for resistance should swiftly spread through the population. Which is exactly what has happened in the sea squirt Botryllus schlosseri.
    This creature undergoes cycles of both sexual and asexual reproduction. It lives in colonies on rocks and reefs. A sea squirt looks like a tiny barrel with two siphons on the top; in a sea
squirt colony, the barrels are embedded in a gel-like matrix. Looking at the adult, you’d probably never guess that these organisms are animals, let alone close relations of animals with backbones. Only the larvae, which look like simplified tadpoles, give the game away. When a larva settles on a new rock, it metamorphoses into a grown-up sea squirt and begins to reproduce asexually to form a group of genetically identical individuals that share a common blood supply.
    As neighboring colonies expand, they may run into each other. At this point, they have a choice. They can either join forces and become one big colony or they can reject each other, creating a physical border, a line in the sand that neither can cross. If the colonies fuse, something sinister can happen. Cells from the individuals of one colony can travel through the common blood supply and invade the gonads of all the individuals from the other colony. It’s a hostile takeover: when the time comes to reproduce sexually, members of the losing colony are forced to make eggs and sperm carrying genes that are not their own. Predictably enough, this has led to the evolution of mechanisms to avoid having your gonads hijacked. Botryllus colonies are highly particular about whom they fuse with: whether or not fusion goes ahead depends on a complex system that ensures close matching between genes of the two colonies. Colonies fuse only when they have similar genes—and therefore, are probably closely related. In pirate bugs and bedbugs, however, there is no evidence of measures to counter gonadal hijacking—and I bet it doesn’t happen in the first place.
    The males of some species do, however, have another, more plausible way of eliminating their rivals: they render them impotent. Such nastiness has been claimed for at least one spiny-headed worm, the gloriously named Moniliformis dubius, a scourge
of cockroaches and rats. Baby worms live in the guts of cockroaches; when a cockroach is eaten by a rat, the worms grow up and have sex in the rat’s intestines. Not exactly romantic, but there you go.