![]() ![]() Here, scientists saw an adaptation that would force males to be gentler by making coercion unviable and leaving seduction as their only means to reproduction. This adaptation is of particular importance to fend off annoying suitors because male water striders have the ability to blow up their penis to (if they achieve intromission) physically anchor their body to a female until it concedes to mate. In this evolutionary tug of war, scientists thought, females of the Asian water strider Gerris gracilicornis seemed to have come up with the ultimate trump: a genital shield to completely block access to their vagina. ![]() In the ensuing competition to be the greatest (literally) pain in the neck for females, evolution has granted them with all sorts of special clasps, to which females have responded with their own structural changes to thwart pestering males. They will mount females and ride on their backs for hours in an attempt to coerce them into mating. Water striders of the genus Gerris, common dwellers in our European ponds, are amongst nature’s most famous harassers. «Sexual cannibalism, anaesthetizing drugs and blackmail have shattered an old paradigm: that of reproduction as a cooperative endeavour between the sexes» The moment mating starts, he will transfer a chemical substance that will anaesthetize the female, allowing many lucky suitors of this species to live to mate another day. However, little does our femme fatale suspect that this particular male has a different plan in mind. Its cautiousness is hardly surprising, for females of this species enjoy devouring their partners after mating (sexual cannibalism). Hidden in the tall grass, a male funnel-web spider ( Agelenopsis aperta) tentatively approaches a huge receptive female. The sun of a crisp spring morning gently casts its warmth over the immaculate green of a remote North American prairie. ![]()
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