Wasps

Alex Re (00:00): Hello, welcome to On Wildlife. I'm your host Alex Re. On this podcast, we bring the wild to you. We take you on a journey into the life of a different animal every week, and I guarantee you, you're going to come out of here knowing more about your favorite animal than you did before. The animal that I'm going to be talking about in this episode might freak you out, especially if it flies close to you, but I promise you'll come away with a better appreciation for them. You might have already had a bad experience with one of these animals, but they're really important to the ecosystems that they live in and they have some pretty cool behaviors, and as summer is in full effect, you're going to start seeing them around more. So try not to get stung because this week we're talking about wasps.

(01:04): Wasps are insects that belong to the order, and this is the same order that ants and bees are a part of. So we know that all three had a pretty close common ancestor, and because there are many different species of wasps, it's not easy to classify them all in a single category that's separate from bees. Although there are some differences between the two, which we're going to talk about later on in the episode because there classification can get messy. There's conflicting information on how many species of wasp there actually are. Some sources say that there are around 10,000 species, while others say there are over a hundred thousand species. Either way, the huge amount of species causes there to be a lot of variation in their sizes. One of the largest known wasps is a type of hornet. And yes, every species of hornet is classified as a wasp.

(01:58): The Asian giant hornet can grow to be over one and a half inches long, and the queen can get even bigger than that. They're also one of the fastest wasps in the world because they can fly at over 25 miles per hour. Some people also claim that the tarantula hawk is the largest wasp. It's said to grow over two inches long and they get their name because they prey on tarantulas and it's also thought that they have one of the most painful stings of any animal. Wasps have two sets of wings and six legs, and when you think of a wasp, you're probably thinking of a yellow jacket, which is one of the more common types of wasp in North America. According to the University of Illinois, yellow jackets are believed to mount to half of all insects stings on humans. They can be found pretty much anywhere in the world except for Antarctica.

(02:54): Wasps are most successful in forested areas, but you can them building their nests on or near your house too. Now what's the difference between a bee and a wasp? Bees are usually more rounded and hairy, and this is a characteristic that helps them collect and distribute pollen. This works by attracting the pollen with static electricity generated by the fuzzy hairs of the bee. Wasps are more slim bodied and they have slender legs and they appear more shiny because they don't have that fuzz that the bees have, they're also able to sting you multiple times. While many bee species will die after one sting, and this is because of how their stingers work, bee stingers are barbed. So once the bee stings its target, the stinger is built to stay inside. When the bee tries to pull the stinger out, it will usually rip off part of its abdomen.

(03:48): Wasps stingers are still barbed, but they have a sheath that covers the barb, which allows the barbs not to get caught in the flesh of their target. Both bees and wasps deliver a dose of venom when they sting you. Chemicals in the venom break down cell membranes, and when this impacts your nerve cells, they send pain signals to your brain and to make sure the pain keeps coming. Other substances in the venom like norepinephrine stop the flow of blood. This is why the pain of a wasp sting can last for several minutes until the bloodstream can carry the venom away. But with wasps, that one sting probably won't be the worst of your problems When they sting you, they also release a pheromone which signals other wasps in the nest that they should attack the enemy. And this is why wasps will swarm you. More stings mean more pheromones being released. The venom of the sting is usually not dangerous, but several stings can cause a problem. It's either used to stun prey that's carried back to the nest or as a defense mechanism. Okay, let's take our first break, but don't worry, we've still got a lot more stuff to talk about, including how wasps make their nest and what they eat.

(05:13): The science word that I want to talk to you about today is cytosis. Here's another long but important word. Your white blood cells help to protect you from foreign invaders by engulfing and destroying them. That process is called phagocytosis.

(05:38): Okay, welcome back. Another difference between wasps and bees is how they make their nests. Bees make theirs out of honeycomb and wasps make theirs out of paper. They chew up strips of bark and spit it out again to make a paper-like substance that's then patched together to create the hollow shape of the nest. These nests can be built pretty much anywhere, but they usually favor dark and cool locations away from predators. The diet of a wasp varies greatly between species. Many of them are classified as either carnivores or omnivores. Most wasps capture and eat other insects, though some of their prey items include grasshoppers, aphids, flies, and bees. And also, as you heard before, in some cases even tarantulas. Wasps like yellow jackets will eat insects because they're high in protein, so they have ample stores to feed their larva in order to catch their prey.

(06:37): They'll use their stinger to paralyze it first so that it's easier to eat. They also like to eat nectar, tree, sap and fruit. Yellow jackets have really long tongues that they can stick into flowers to obtain nectar. So even though we think of bees as pollinators, wasps help pollinate too. Occasionally they've been seen going to bees hives to steal honey if they need to. Some wasps will even swarm around trash cans and eat our food scraps. They'll usually only do this or steal honey when they're desperate for food. It's definitely not their first option. And like I mentioned before, wasps don't eat wood, but some chew it up to make their nests when feeding their larva. Wasps chew the food into a paste to make consumption easier, and this next part may sound weird, but the worker then begins to tickle the larvae, which causes their salivary glands to release a sugary liquid.

(07:35): After the wasp consumes this liquid, the larvae receives the food paste. This process is called prophylaxis, but there are a lot of wasps that have a much more disturbing way of growing their larva. They're called parasitoid wasps. They'll inject their larvae into an insect host, usually a caterpillar, and allow it to grow inside of them while the larvae feed off the host. Sometimes they'll also inject venom to paralyze them. Eventually, the larva will hatch out of the host and then find another caterpillar to infect. Now let's talk a little bit more about their lifecycle. Wasps have four stages in their lifecycle, egg, larva, pupa, and adult. After the queen mates with a male, she'll start a new colony every spring. In the winter, all of the wasps in the colony die because of the cold except for the queen. She hibernates during the winter to protect herself from freezing temperatures so that she can emerge to start building a new nest in the spring.

(08:38): First, she chews up some wood to use to build the nest. After finding a safe place, she starts making hexagon shapes just like the ones found in a beehive. Each hexagon is called a cell. Inside one of the cells she'll kill and chew up a caterpillar and then lay eggs inside of that cell. A few days later, the larva hatch from the eggs and remain in the cells to feed on the remainder of the caterpillar. She raises a few worker individuals first to make the nest larger and bring food, and then she starts laying more eggs. The workers are always sterile females. They really do most of the work throughout the colony. A colony can grow to over 50,000 wasps in one summer. If an egg laid by the queen is unfertilized, the wasp will hash as a male. If the egg is fertilized by a male, the wasp will hatch as a female.

(09:36): As larva eat and mature, they outgrow their skin, grow a new skin layer and shed the old one. And this process is called molting. Wasps have a hierarchy made up of different types of individuals that live in the colony. There's the queen, a few drones, which are males used for breeding purposes only, and then the sterile females called workers. The nest is mainly made up of the workers, and like I said before, they're doing most of the heavy lifting in the colony, including expanding the nest, getting food for the larvae and protecting the nest. But although their lifecycle seems like something from another world, they do have some qualities that are similar to humans, and we'll talk about that right after the break. Okay, time for a trivia question, and this is a tough one. What is the only type of venomous snake found in the uk? The answer is the adder, but if you live there, you don't really have much to worry about. The last fatal adder bite was in 1975.

(11:05): All right, welcome back. Wasps communicate with each other by releasing certain chemical compounds called pheromones. These chemicals can signal danger, alert their hive mates and call others to collect food, and you'd think they detect these chemicals through a nose, but they don't have one. Instead, they have chemoreceptors, which are like cells that pick up scents and tastes on their legs and their antenna. Basically, their main mode of communication is through smell, but they also have pretty good eyesight. Wasps have five eyes. They have two compound eyes and three simple eyes. The compound eyes are there to detect movement while the simple eyes are there to detect changes in light. Some wasps can even recognize different faces almost as well as we can. They can even learn to identify different human faces, which is pretty mind blowing. There's also a type of paper wasp that has specific facial markings, and these wasps are able to identify individuals in the colony based on those markings.

(12:13): That's really amazing, but it kind of makes sense when you look at another study that figured out that wasps actually use landmarks in their surroundings to locate where their nest is. In this study, researchers placed pine cones in a circle around a wasps underground nest. After a while, they moved the circle of pine cones over so that it wasn't surrounding the nest, but still in the same area. Surprisingly, the wasps didn't go towards their nest. Instead, they looked for the nest in the middle of the pine cone circle. This shows us that they'll use landmarks to understand their surroundings and they can also communicate through sound. Certain species will drum their abdomens after finding food, which sends a signal to others that there's food in the area, and they've had a lot of time to evolve all of these amazing communication strategies. The earliest wasp fossil dates back to over 240 million years ago.

(13:14): We oftentimes label wasps as pests because they like to buzz around you when you're eating something and they'll build their nest right on the side of your house, but they actually do a lot of good for their environment because they hunt insects. They're really good at controlling different populations like flies, spiders, and caterpillars. And by regulating these populations, wasps actually save us hundreds of billions of dollars in agricultural damage every year. And the United Kingdom wasps eat around 30 million pounds of insects every summer, and according to the I U C N Red List, they're listed as least concern. So their populations are doing fine. Some species are invasive in areas that they're not native to, like the Asian Hornet that's invasive to South Korea, but just because their populations are doing well doesn't mean we shouldn't support wasps and other pollinators in their native habitats. If you want to help pollinators and the places they live in, you should check out the Xerces Society Pollinator Partnership and the Garden Club of America. Thank you so much for coming on this adventure with me as we explored the world of wasps. You can find the sources that we use for this podcast and links to organizations that we reference at onwildlife.org. You can also email us with any questions at On Wildlife dot podcast@gmail.com, and you could follow us on Instagram at On Wildlife, or on TikTok at Wildlife. Don't forget to tune in next for another awesome episode, and that's On Wildlife.

Jess Avellino (15:01): You've been listening to On Wildlife with Alex Re. On Wildlife provides general educational information on various topics as a public service, which should not be construed as professional financial, real estate, tax, or legal advice. These are our personal opinions only. Please refer to our full disclaimer policy on our website for full details.