Dating : The Crazy Mating Gifts that Insects Provide

Folks (fellas or ladies), is your partner upset at you over something, whether it’s your fault or not? Are you yearning to get some loving in, but your partner just isn’t feeling up to the act right now?

You may want to try giving her a present. After all, it works for insects.

Mating rituals include many of the strangest behaviors in the animal world, often including behaviors that don’t seem to make much sense at first:

• Male bowerbirds will build elaborate nests, including planting gardens of twigs and berries, or decorating with bright objects, such as fruit, flowers, or stolen human garbage.
• Male anglerfish will attach to the female, literally merging their bodies together until the male is little more than a vestigial organ hanging off the female.
• The female praying mantis is famously known for devouring the head of her mating partner after sex.

But praying mantises aren’t the only insects that exhibit strange mating behaviors. It turns out that a wide variety of insects and arachnids — including spiders, crickets, moths, butterflies, beetles, and houseflies — are known to give a mating, or nuptial, gift to their partner.

Why would an insect give a gift? What’s the payoff for a spider or a cricket to give a present to their mating partner?

Let’s say that you’re a male Tropical House Cricket, and you’ve got your eyes set on a hot little female, with long elegant legs, big sparking compound eyes, a slender thorax, and an abdomen that goes on for days with curves like boom BOOM…

How do you woo her? You win her over by offering her a spermatophylax.

Despite what you may guess, looking at the word, a spermatophylax doesn’t contain any sperm. Instead, this is a gelatinous mass that surrounds a smaller pouch, called an ampulla, which contains the sperm. It’s rich in vitamins, protein, and energy, and it helps protect the smaller ampulla pouch of sperm that’s inside.

You, the male cricket, form this spermatophylax and offer it to your female. It sticks to her body, and transfers the sperm to her as she eats it after sex. She has to eat through the spermatophylax before she can remove the ampulla, stopping the transfer of sperm.

Spiders, butterflies, and houseflies also provide food gifts to their partners. Spiders will wrap up bugs in silk, and mate with the female while she’s distracted by the feast. Butterflies place a nutrient-rich plug on the female’s mating organs, giving her food but also blocking any other males from mating with her. Houseflies produce regurgitated, calorie-rich spit that attracts the females and gives them nutrients and energy.

Whether you’re an insect or heading over to a prospective romantic interest’s housewarming party, food gifts are usually the way to go.

No offense to bugs, but they’re fairly simple creatures. They don’t really “think”; they have a series of mostly pre-programmed responses to external stimuli. Provide a bright light, and moths assume that it’s the sun. Place a spider in a tree, and it spins a web. Create air currents around a housefly, and it takes to the air to avoid danger (being swatted).

So when an insect provides a nuptial gift, there must be a direct payoff. Yet for the male, it seems like a bad deal. Give up vital food or calories, just to get a female’s attention? Is it worth the cost?

For insects, the answer seems to be yes. Going back to crickets, the older males produce larger spermatophylaxes with more nutrients, and thus attract more women. (They like the sugar daddies!)

These gifts also support a theory called the paternal investment hypothesis. At first glance, there’s no reason for a male to care about his children. He just drops his sperm and is out, without having to invest the energy that a female must put in.

But females, as the ones who must give up more energy to create offspring, can be pickier in choosing a mate. Therefore, the male will put in energy to impress the female, looking to prove that his genes are worthy and will yield strong, robust offspring.

By giving a gift, the male proves that he’s doing so well, he can afford to hand over tons of nutrients to the female. Just like how a human may wear a Rolex or go to a fancy restaurant to impress his date, insect males give big gifts to prove that they’re strong and capable.

Additionally, the larger the nuptial gift, the longer the female hangs around — giving the male more time to pass over his sperm. If a spider gives several captured prey as gifts, it gives him more time to mate with the female as she eats. Some flies produce hormone signals that compel the female to stick around, to give the male a chance at multiple matings.

And for some creatures, like butterflies, that mating gift also blocks the female from reproducing with others. It’s not quite a wedding ring, but it’s a way of forcing exclusivity.

Of course, not all insects play by the rules. Douchebaggery isn’t limited to humans; some bugs also pull a fast one on their prospective partners.

For example:

• Some male spiders will steal prey from the webs of another, and will present it to a female as their own.
• Spiders also will use varying amounts of silk to wrap their gifts. Only a small fly? Wrap it in more silk so that it looks larger, and is more attractive to a mate. (Ever filled an expensive wine bottle with cheap wine?)
• Some male flies and crickets will seek to re-use their gift, or offer gifts with little nutrition. They hope that the female will land and begin mating before the deception is realized.
• For some scorpion flies, a long courtship ritual, driven by pheromone secretion, takes place. The males may hold back their offering of a nuptial gift until the female has stuck around for a while, instead of risking “wasting” it on a female that leaves before copulation.

Many of these strategies are high risk, but also high reward. A spider that steals its gifts has a higher chance of failing and coming up empty-handed (empty-legged?), but also doesn’t have to invest the energy in spinning its own web and catching its own prey. A fly that provides a low-nutrient gift may have a lower rate of success with females, but has more energy to pursue more females.

These strategies are at least partially successful, as they’ve stuck around and haven’t been weeded out by evolution. However, they remain a small proportion of the total male actions — if all spiders sought to steal their gifts from others, no one would be catching bugs in the first place.