Yellow Paper Wasp facts for kids
Quick facts for kids Yellow Paper Wasp |
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The Ropalidia romandi, also known as the yellow brown paper wasp or the yellow paper wasp, is a type of paper wasp. You can find these wasps in Northern and Eastern Australia. R. romandi wasps live in large groups called swarms. Their nests can last for many years. These nests are often called 'paper bag nests' because they look like paper bags. They are built differently depending on where they are placed. The wasp's name honors Gustave de Romand, a French politician and insect enthusiast.
These wasps often have tiny parasites inside them called strepsipterans. When they feel threatened, they can deliver a very painful sting.
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About the Yellow Paper Wasp
Ropalidia romandi was first named by Élie Jean François Le Guillou in 1841. It belongs to a group of wasps called Polistinae. There are two main types, or subspecies, of this wasp: R. romandi romandi and R. romandi cabeti.
The group Ropalidia is special. It includes wasps that start new colonies in two different ways. Some species are 'independent-founding'. This means one or a few female wasps start a new nest alone. Other species are 'swarm-founding', where a large group of wasps starts a new nest together. This group of wasps lives across Oceania and other parts of the world. There are about 180 different species in the Ropalidia group.
What Does It Look Like?
The Yellow Paper Wasp is easy to spot because it's mostly yellow. It has dark brown marks on its middle section (thorax) and its back section (abdomen). These wasps are quite small, usually around 12mm long. The first part of their abdomen is thinner than the rest. When they are resting, their front wings fold lengthwise. This is a common feature of many paper wasps.
Their nest is called a ‘paper bag nest’. It has a papery cover that surrounds several flat, horizontal combs. Both the cover and the combs are made from plant fibers. The wasps glue these fibers together with their saliva. The nest can be round or half-round. It can grow up to one meter (about 3 feet) long! You usually find these nests hanging in trees or under the eaves of buildings.
Where Do They Live?
In Australia, you can find R. romandi in the Northern Territory and Queensland. It's one of the most common paper wasp species in Eastern Queensland. These wasps live in both warm, tropical areas and cooler, temperate places. However, in areas with cold winters, their colonies become less active during that season.
Nests often hang from tree branches or building eaves. They can be anywhere from 2.5 meters (8 feet) to 30 meters (98 feet) above the ground. They often build their nests on Eucalypt trees. These trees shed their bark often. When the bark falls, the nests fall too, and the wasps leave them. Soon after, they build a new nest.
Life Cycle of a Colony
R. romandi is a 'swarm-founding' species. This means a new colony starts when a large group of worker wasps and some queens (female wasps that lay eggs) move together to a new spot. This is different from 'independent-founding' species, where just one or a few queens start a new colony alone.
R. romandi colonies can last for several years. This means the colony doesn't die off in the winter, unlike 'annual' colonies. Instead, they survive the cold months and use the same nest the next year. Because of this, swarm-founding colonies are usually larger and have more queens than independent-founding ones.
These wasps are more active in summer, when they reproduce a lot. In winter, fewer wasps reproduce, and there's less activity.
Winter vs. Summer Behavior
There's a big difference in how the colony finds food between winter and summer. In winter, workers collect flower nectar (which is full of carbohydrates) much more often. This suggests they use these carbohydrates as energy to survive the winter. These energy stores allow the wasps to stay in their nests for up to a week. This helps them avoid cold temperatures and rainy weather.
The inside of the nest also changes with the seasons. Winter nests have more stored nectar in their cells than larvae. But in summer nests, only about 1% of the cells have nectar. The rest are filled with developing young wasps. This shows that most reproduction and raising of young happens in summer. More food gathering and storing happens in winter.
How Swarms Start New Nests
The Ropalidia group is special because it has both independent-founding and swarm-founding species. R. romandi is a swarm-founding species. This means new nests are started by a large group of worker wasps and a smaller number of queens.
There are two types of swarms:
- Reproductive swarms: Some females from an old colony leave to start a new colony with a group of workers.
- Absconding swarms: All members of an existing colony move together to a new place. This happens if their old nest is destroyed, damaged, or disturbed a lot.
R. romandi seems to use both types of swarming. However, most research on R. romandi has focused on absconding swarms.
Finding a New Home
When a colony absconds, the worker wasps, not the queen, choose the new nesting site. This is unusual for wasps. Scientists think this process is guided by special scents called pheromones.
When searching for a new home, R. romandi workers do something called ‘metasomal dragging’. This means the wasp drags its metasome (the back part of its body) along surfaces like leaves, rocks, or buildings. Glands on the underside of the metasome leave a scent trail. Other workers and queens follow this scent. Wasps that aren't dragging their metasome can be seen sniffing objects with their antennae, likely following the scent. This pheromone path helps all colony members find the new nesting site.
Seeing other wasps might also be important. As wasps move to the new site, they often fly towards groups of wasps already flying around the new spot. This visual cue might be the final signal for the new nesting site.
Are They Aggressive During Swarming?
R. romandi and other swarm-founding wasps can be quite aggressive when they are swarming. They might be aggressive towards humans, wasps from other nests, and even each other. Aggression towards humans can lead to stings. Aggression towards other wasps involves biting their bodies, legs, or wings.
Worker wasps are usually the ones that attack, while queens are more often the victims. Interestingly, R. romandi workers don't always attack wasps from other nests. If different colonies meet during the absconding process, they might group together with little fighting. But if a queen from another colony tries to join after a new colony has formed, she will be attacked fiercely. This suggests that R. romandi workers might "test out" different queens during the swarming process.
Wasp Parasites
A common parasite of R. romandi is a type of insect called a strepsipteran, often from the family Stylopidae. Female strepsipterans live inside the wasp's body. They create a protective sac from the wasp's own tissue. They can take up to 80% of the wasp's abdomen!
These parasites can make the wasp unable to reproduce. They can also change the wasp's body shape and behavior. However, they usually don't kill their host. Some scientists even think they might help the wasp live longer. R. romandi wasps often have more than one of these parasites inside them at a time.
Also, young R. romandi wasps in the nest can be attacked by hornets. Hornets will take larvae from the nest, sometimes over a few days or weeks. Scientists think the papery cover of the nest helps protect the young wasps from these parasites and predators.
How Nests Are Built
R. romandi nests are called ‘paper bag nests’. They have a papery cover over several horizontal combs. They are made from plant fibers glued together with saliva. The nests can be up to one meter long and are usually found in trees or under building eaves.
To start a nest, many wasps gather at the chosen spot. They begin building several combs at the same time. This leads to a semi-spiral shape inside the nest. The papery cover is built either after the first few combs are made or while they are being built. The timing depends on how big the swarm is and where the nest is located. More combs are added, and the cover is completed to surround all of them. The number of entrance holes depends on the nest's size. R. romandi never builds combs that are used on both sides. The cells in each comb are all about the same size.
Nests on Flat Surfaces
When R. romandi nests are built under building eaves, they are completely covered by an envelope. They form a flattened half-sphere with many flat, horizontal combs. The largest comb is usually near the bottom. These combs are connected to each other inside the cover by ribbon-like stalks. The cells are hexagon-shaped and neatly arranged.
The outer cover is usually a single layer, but some parts can be double-layered. It's made of plant fibers and is a uniform light gray color. Sometimes, the cover is so heavily coated in saliva that you can't even see the plant fibers! There's a round entrance hole at the bottom of the half-sphere-shaped nest.
Nests in Trees
When nests are built among tree branches, their shape changes because of the uneven surface. The biggest difference is that nests in trees are round, not half-round. They are also mostly double-layered, with only a few single-layered parts. The cover is a creamy brown color, not gray. This suggests they use different plants to build the nest.
The saliva coating on the cover is thicker when built in trees. This might be because tree nests are more exposed to rain. Instead of a roof, the nests often use leaves from the tree, which are built into the cover, to protect the top of the nest. Nests built in branches have almost twice as many combs as those on flat surfaces. However, these combs are much more irregular in shape and arrangement.
Why Are They Important to Humans?
While all wasp stings are unpleasant, the sting of R. romandi is known for being very painful. Since it's a paper wasp, it can sting many times without dying.
R. romandi wasps are most aggressive if they are swarming, if their nests are disturbed, or if they feel their nest is threatened. If wasps feel threatened, they might swarm out of the nest and chase the person who disturbed them. If you ever get swarmed by wasps, it's best to stay as still as possible and move away slowly. Sudden movements can make them think you are attacking, leading to more stings.
If you get stung, the area will turn red and might be itchy and swollen for several days. The best way to treat a sting is to wash the area with soap and water first. Then, use an antiseptic. If swelling continues, apply an ice pack.
Some people are very allergic to wasp venom. For them, a sting can cause a severe reaction called anaphylactic shock. Symptoms include swelling of the mouth, lips, and tongue, trouble breathing, dizziness, and chest tightness. If someone shows any of these symptoms after a sting, get medical help right away.
Since R. romandi nests are often found on buildings, they can be in areas where many people live. Their nests don't cause any damage to buildings. So, if a nest is in a quiet, out-of-the-way spot, it's usually best to leave it alone. Trying to knock it down will make the wasps aggressive. Also, R. romandi often rebuilds nests in similar places.
Paper wasps also help gardens! They feed their young on caterpillars, which are common garden and farm pests. If you really need to remove a nest, it's best to have a professional exterminator do it. Or, use a fast-acting can of insecticide. The best time to remove an R. romandi nest is at dawn or after dark, when the wasps are usually calmer.
What Do They Eat?
Paper wasps like R. romandi feed their young on caterpillars. Adult wasps also drink nectar from many flowering trees, such as Syzygium cormiflorum and Acacia oraria. They collect more flower nectar during the Australian winter. This is because the nectar's high carbohydrate level helps the colony survive the cold months.
R. romandi also does something interesting in winter: they collect honeydew from scale insects. They have even been seen protecting these scale insects from other wasps.
