Crickets

[00:00:00] Alex Re: 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. Today, we're taking a look at an insect you're probably all familiar with.

[00:00:23] They may be small, but they like to make themselves heard and their sound is unmistakable. So listen closely and get ready to jump into the episode as we talk about crickets.

[00:00:52] Crickets are members of the group Orthoptera, along with grasshoppers and locusts. There are roughly 2, 400 species of crickets, and in the U. S., you can find about a hundred unique species. The most common crickets you may find in your home are field crickets, camel crickets, and house crickets. Camel crickets are also known as cave crickets, and they're attracted to cool, dark places, like your basement.

[00:01:20] And house crickets aren't native to North America. They're invasive species native to Asia. The largest species in North America is called the prairie mole cricket. They're about 5 centimeters in length and can weigh over 2 grams, which isn't much for our standards, but a lot for a cricket. They get their name from their burrowing behavior, similar to moles.

[00:01:44] These crickets are endemic to the Midwest and some of the southeastern parts of the United States. Endemic means that they can only be found in a specific area. They're mostly known for their mating songs, which the males will sing while in their burrows. They sing while the females fly overhead listening.

[00:02:04] The females will pick the male that has the best voice. And don't worry, I'll go into more detail about cricket songs, mating, and their burrows later on in the episode. Crickets are found all across the globe, but most of the species diversity, like a lot of other animals, especially insects, is focused in the tropics.

[00:02:25] They can also be found in a variety of habitats, including grasslands, marshes, and caves. Crickets are primarily nocturnal, so they're active mostly at night. This explains why their songs are mostly heard when it's dark outside. But how do crickets make their famous chirping sound? It's not through their mouths.

[00:02:46] First of all, only male crickets can sing or chirp. This gives a clue as to why they chirp in the first place. To attract females. Crickets achieve this vocalization by doing something called stridulation. Stridulation is the act of producing sound by rubbing body parts together. In particular, body parts that are textured.

[00:03:10] Crickets scrape their forewings, called tegmins, against each other to make noise. Their tegmins have a leathery texture, and if you zoom in to one of their wings with a microscope, you'll see tiny teeth that the other wing scrapes against. I like to think about it like running your fingernail along the teeth of a comb.

[00:03:31] Try it out, and you'll see that you can make different noises depending on how fast you scrape. Their songs aren't only used for mating, though. They can also be used to defend their territory from other males, and also as warning sounds. What's interesting is that there's a relationship between temperature and cricket chirps.

[00:03:51] The hotter it is outside, the faster their chirps will be. This is because crickets are ectotherms, meaning that their body temperature is determined by the outside environment. So crickets move more slowly when it's colder outside. And some scientists have actually come up with a formula that you can use to get the approximate temperature outside just by listening to the chirp speed of crickets.

[00:04:17] All you have to do is count the number of cricket chirps in 15 seconds and add 40. Supposedly, this will get you the temperature in Fahrenheit. So while you test that out, we're gonna take our first break, and when we get back, we'll talk about how crickets can hear their chirping.

[00:04:46] On this episode, I want to give a shout out to Felicia from San Antonio, Texas. Her favorite animal is the comb jellyfish. Did you know that comb jellies are thought to be the first animal to ever appear on Earth? Pretty cool that they're still around today.

[00:05:12] Making noise is only good if someone else can hear you. And you'd be correct if you thought that crickets would have incredibly strong hearing. Crickets possess tympana, which are similar in structure to our eardrums. However, crickets have their tympana on their front legs instead of inside their heads.

[00:05:32] Now, you heard me mention earlier that crickets have wings. Did you know that they can fly? You may not have known that they could because in cartoons, you'll always see them jumping but never flying. Crickets have two pairs of wings or four wings in total. They have a set of four wings, not the number four, but four meaning front, and they have a set of hind wings.

[00:05:55] Species with larger hind wings are the ones best adapted for flight, and if you ever look at their wings, you'll see that they have veins running across them. The veins move hemolymph, which is like insects, blood through the wings. The hemolymph helps to keep the wings warm and also provides oxygen. This is essential because oxygen helps make energy, and flying uses a lot of energy.

[00:06:22] We get our oxygen by taking it in through our lungs, of course. But this isn't the way to do it in the insect world. Crickets and other insects use spiracles to breathe. Spiracles are openings located on the exoskeleton that take in oxygen. They're pretty much holes that are located on their bodies. Even though they can fly, crickets main form of locomotion is jumping, and it's easy to see why.

[00:06:51] They have adapted extremely large and powerful hind legs. House crickets can jump about three feet in length, which is a huge distance for a tiny creature. And more often than not, they land on their feet because they're able to position themselves in midair at the perfect landing angle. Some scientists believe that they can use how crickets jump in order to design robots.

[00:07:17] And some cricket species are in fact flightless, so jumping is really their specialty. The aforementioned camel cricket is an example. Because crickets are insects, their bodies are segmented into three parts. The head, thorax, and abdomen. In those segments are a foregut, midgut, and hindgut, which help them digest their food.

[00:07:40] Most of the digestive process takes place in the midgut. Because there are so many cricket species, there's a lot of variation as to what they eat. Some species are completely herbivorous, only eating plants. Others are predatory in nature, targeting larvae and aphids. But most are omnivores, basically eating whatever's available to them.

[00:08:04] Speaking of diets, crickets are a huge staple in many reptilian and amphibian diets. People who keep these animals as pets often use crickets as a food source. They're also a part of some human diets in many African and Asian countries. Research indicates that certain species of cricket are more nutritionally balanced than most plant and other animal sources.

[00:08:29] They could be used as an alternative to help with food scarcity and nutrient deficiencies. And insect protein may be the way of the future everywhere in the world if we keep producing food as unsustainably as we have been. Crickets are polyandrous, which means that female crickets have multiple mates in order to maximize offspring production.

[00:08:52] Remember when we talked about how male crickets chirp to get the attention of females? Well, females can choose who to mate with based on the speed of their chirp. They'll most likely choose a cricket with the faster chirp, because that means they have more energy and stamina, and are therefore in better health.

[00:09:12] In the Northern Hemisphere, crickets lay their eggs in the fall, and they'll hatch in the spring. Crickets are hemi metabolous. This means that there are three life stages. Egg, larva, and adult. They pass through an average of 10 larval stages, or molts, before reaching adulthood. Female crickets can lay around 100 eggs every day.

[00:09:36] In a lot of cricket species, females lay their eggs in the stems and soil bases of plants. This can cause damage to the plant structure and integrity, but it allows the larvae to hatch in a prime place with an abundant food source while being protected from the elements while in the egg. Females store the sperm from the males that they mate with in a structure called the spermatheca, and scientists believe that the females can control what specific male's sperm is stored in this organ and what isn't.

[00:10:09] This is beneficial because it can protect them from inbreeding. Basically, when two individuals are very closely related and mate, it can cause genetic issues for the offspring. With female crickets taking so many mates, it definitely comes in handy. Okay, let's take our last break. After that, we'll talk about cricket's social structure and behaviors.

[00:10:44] Time for today's trivia question. How many feathers are found on a peacock's tail?

[00:10:57] The answer is around 200.

[00:11:10] Okay, we're back. So, aside from mating, crickets are mainly solitary creatures. As I mentioned briefly, crickets can be territorial and competition between males is common. Research shows that cricket social structure impacts the severity of these face offs. Crickets were found to fight with more intensity when other crickets were around to see them.

[00:11:35] This is likely due to wanting the respect of other males and the admiration of the females. Many species rely on burrows to avoid getting eaten by predators. They use their mandibles, which are like their jaws, to push away the dirt or debris in their way and fold their antennae to avoid detection. This is also where their ability to jump far distances can help them.

[00:12:01] It makes them much harder to catch. Crickets also display cryptic coloration. This is just a fancy way of saying camouflage. They've developed colors and patterns that allow them to blend in to their environment. According to the IUCN Red List, most cricket species are listed as unknown. This could be due to lack of resources or attention placed on these species, but crickets are very important to their native environments.

[00:12:31] For instance, they're pivotal to the food chain. Tons of species prey on crickets, like amphibians, reptiles, bats, and even other insects. Crickets are also great cleaners of the ecosystem, as they like to eat plants, insects, and also decaying material. They also have some unexpected benefits as well. In 2010, a species of cricket called the raspy cricket was found to be pollinating orchids on the island of Reunion in the Indian Ocean.

[00:13:04] This is the first time in history that crickets have been seen acting as pollinators. Maybe this behavior is displayed in other species, and it just hasn't been observed yet. In any case, pollinators are crucial to the reproduction of important plant species. I mentioned earlier in the episode that the camel cricket was an invasive species.

[00:13:26] They're native to Asia and prefer cool, damp environments. Their populations are growing here in the U. S., and the main problem they cause is that they're out competing the native crickets. This could cause some serious consequences that we don't even know about yet. And because they like dark, cool environments, they'll migrate into our homes, which invites other animals as well.

[00:13:51] More research needs to be done on cricket populations so that we can figure out the risks of losing native species in our ecosystems, and also determine if there are any species that need our help. This is why you should check out the Oklahoma Department of Wildlife Conservation's The Lost Cricket Project.

[00:14:10] This is a program that inspires the public to get involved in tracking prairie mole cricket populations. You should also take a look at the Nature Conservancy and the Xerces Society for Invertebrate Conservation. Thank you so much for coming on this adventure with me as we explored the world of crickets.

[00:14:30] 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 onwildlife. podcast at gmail. com. And you can follow us on Instagram at on underscore wildlife or on Tik TOK at on wildlife. And don't forget to tune in next Wednesday for another awesome episode. And that's On Wildlife.

[00:15:02] Jess Avellino: 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.