Male wasps’ lengthy genital stings may save their lives

Fending off an attacker with two reproductive stingers is a moderately useful form of self-defense for male wasps, according to an unusual study. The mason wasps’ tail spines might be useless in delivering sperm, but they saved his life.

Male wasps (and bees) do not grow stingers that inject venom. It is a female weapon that evolved with spawning equipment. Instead, the males of mason hornets fight off swallowing tree frogs (and collecting entomologists) by deploying a pair of spines on the wasp’s rear that evolved with male genitalia.

Thorns are just pseudo-thorns. There is no venom, but male wasps can sting aggressive frogs in the face and mouth.

“Our study is the first to demonstrate the defensive role of the pseudo-stinger as a wasp’s counterattack device,” says ecologist Shinji Sugiura of Kobe University in Japan. Biologists have long known about the existence of stingers, but the study, published Dec. current biologyTest how they work.

Inspired by Sugiura’s student and co-author Misaki Tsujii, who was stabbed while collecting men gibbon Mason Hornet.

Female mason wasps use their veritable stinging apparatus to paralyze multiple caterpillars for fresh baby food while still alive. A mum has sealed zombie caterpillars in the private nursery she built for each offspring.

Sugiura said that while males don’t have the actual ability to sting, they can still deliver a “tingling” sensation. To see how much protection this piercing afforded, the researchers placed the wasps near various hungry frogs in the lab.

Each of the 17 male wasps was trapped by pond frogs (black spotted grouper) was eaten despite being punctured.Confrontation with Tree Frogs Japanese xerophytesHowever, is a different story.

The male wasp resisted, this time with some success. Their reproductive spines were “often observed to impale the frog’s mouth,” the researchers report. Lab video shows a tree frog kicking a wasp with its skinny toes as it forcefully spits it out of its wide frog mouth. The frogs eventually rejected 6 of the 17 wasps. However, when offered sting-removing wasps, the tree frogs ate them all.

Judging by Tsujii’s own reaction to being falsely stung by one of the male wasps, they don’t sound like a pleasant snack.She rated her pain as a 1 on the 0-4 Schmidt Pain Scale for classifying stings Increased from nothing to, non-technically, being bound in hot lava (Serial Number: 7/24/16). A bee sends out 2 stings.

“I can attest from personal experience that the male false wasp stings … for defense,” says wasp expert James Carpenter of the American Museum of Natural History in New York City. “I’ve been stung by them a few times and they can be so painful that they trigger a startle response and then you just give up.”

Despite being located on the rear, “the spines don’t appear to be used for copulation,” Carpenter said. In that case, “they’d be removed.”

Sugiura and Tsujii even examined whether a male who was rejected by a female during courtship somehow used his spines to overcome her objection. No, the researchers said after observing 10 matings and seven matings: the spines of this species appear to be merely defensive.

Male spikes, called parameral spines, also occur in other species of wasps, but their defenses have not been tested in those species. The possibility that the spines still have some sexual function should be considered, says Menno Schilthuizen, an evolutionary ecologist at the Naturalis Center for Biodiversity in the Netherlands and Leiden University.

“The male genitalia of many insects have such appendages, whips or drumstick-like structures,” he said. Remaining “outside the female” during mating…doesn’t mean they don’t play a role in reproduction. In many species, they tap or stroke the female’s belly during what’s called ‘coital courtship’, which increases the male’s true take advantage of their sperm’s chances of fertilizing an egg.”

Few studies, even in non-wasps, have documented defensive genital behavior. Another example given by Sugiura and Tsujii comes from the horn moth.These large nocturnal foragers Use genital structures to create ear-piercing static interfered with the echolocation frequency of moth-catching bats (Serial Number: 7/3/13).

The researchers believe it’s important to study genital structure from a perspective of defense rather than sexual attraction, in large part because it’s uncommon. Finding the death-avoiding aspect of genital evolution could encourage “new perspectives,” the researchers propose. And there is astonishing diversity in the evolution of genital forms.