Female Scorpionflies Judge Males By The Quality Of Their Spit
Female Scorpionflies Judge Males By The Quality Of Their Spit 
You don’t have to be an expert entomologist to know that the insect world is full of bugs that demonstrate highly unusual mating behaviors. Take for example the scorpionfly. These flying insects are already unique among insects for a variety of reasons that are not related to their sexuality. For instance, scorpionflies are among the oldest of insects that undergo a complete metamorphosis. Scorpionflies evolved from ancient insects known as Permian panorpoids that existed as far back as one hundred and ninety million years ago. These ancient insects also gave rise to butterflies, moths, and true flies. What is most unusual about modern scorpionflies is the manner in which the males advertise their reproductive fitness to females. The scorpionfly’s mating ritual involves the males making a gift of their spit to the females.
As a result of millions of years of saliva-related seduction, the male scorpionfly has evolved enormous salivary glands. Male scorpionflies may also attempt to impress potential female mates by presenting them with delicious dead insects. However, entomologists agree that this method is only secondary to the males presentation of their own spitballs, as nothing seems to impress the female scorpionflies more than an impressive pool of saliva. Females seem to respond positively to the males saliva, as the females will often return to a particular male only after they make a production out of the prowess of their overactive salivary glands, and the puddle of spit that inevitably results. It is believed that females are attracted to the pheromones that the male saliva produces.
Studies have also demonstrated that more attractive male scorpionflies produces spit-gifts, if you will, that are of lesser quality than spit produced by less attractive scorpionflies. This is likely due to less attractive males adapting to attract females with their relatively higher quality spit. More attractive male scorpionflies, on the other hand, do not require the same degree of spit-quality on account of their innate attractiveness. In any case, female scorpionflies seem to find a male’s high-quality spit irresistible.
Have you ever heard of an insect with a more peculiar mating ritual than the ritual described above? If you have, then what type of insect do you have in mind?