European paper wasp facts for kids
Quick facts for kids European paper wasp |
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The European paper wasp (Polistes dominula) is a very common type of social wasp. It belongs to a group of wasps called Polistes. These wasps are special because they can eat many different kinds of insects. This helps them survive better than other wasps when food is hard to find.
In a wasp nest, the main female, called the queen, lays most of the eggs. Other females, called workers, mostly go out to find food. They usually do not lay eggs. But if the queen is gone, the next most important female will take over as the new queen.
How important a female wasp is can be seen by the black marks on her face (called the clypeus). More scattered marks mean she is more dominant. For male wasps, their importance is shown by the spots on their bellies. European paper wasps are found all over the world. They are good at surviving because their colonies grow well, their young wasps develop quickly, and they can handle attacks from predators.
These wasps have a special way of finding mates, called a lek-based mating system. What's interesting is that about 35% of the wasps in a colony are not related to each other. This wasp is considered an invasive species in places like Canada and the United States. This means it has spread to new areas and can sometimes cause problems for local species.
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What is a European Paper Wasp?
The European paper wasp was first described in 1791 by Johann Ludwig Christ. He called it Vespa dominula. The name dominula means "little mistress." This name does not change even if the wasp is put into a different group (genus). Some people used to misspell the name as "dominulus."
This wasp is often called the European paper wasp because it comes from Europe. Also, its nests are made from paper-like material mixed with wasp saliva. In older books, you might see it called Polistes gallicus. This is a different species that was often confused with the European paper wasp.
How to Spot a European Paper Wasp
It's hard to see big differences between individual European paper wasps. The wings of male wasps are about 9.5 to 13.0 millimeters long. Female wasps have wings that are about 8.5 to 12.0 millimeters long. Their bodies are bright yellow and black. They look a lot like Vespula germanica, which is another common and aggressive wasp.
Female wasps have black jaws (mandibles), sometimes with a yellow spot. They also have a black mark below their antennae, which sometimes has two small yellow spots. Females might also have two small yellow spots behind their eyes. They also have yellow, comma-shaped spots on their backs.
Unique Marks on Wasps
Even though they look similar, each wasp has unique features. For example, the spots on the bellies of male P. dominula wasps are different in size, place, and pattern. These spots help them attract mates and show their social rank in the colony. Males with smaller, regular spots are usually more aggressive and dominant.
Female wasps also have unique features. The larger and more scattered the black marks on a female's face (clypeus), the more likely she is to be the dominant one in the nest.
Where Do They Live?
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The European paper wasp naturally lives in southern Europe and North Africa. It also lives in warmer parts of Asia, as far east as China. These wasps have also been brought to new places like New Zealand, Australia, South Africa, and North and South America.
Since the mid-1980s, European paper wasps have spread to cooler areas, especially in northern Europe. Scientists think that global warming might be making some places warmer. This allows the wasps to move into areas that used to be too cold for them.
The first time P. dominula was seen in North America was in Massachusetts in the late 1970s. By 1995, they were found all over the northeastern USA. They are probably in other states too, but just haven't been reported yet. We don't know exactly how they spread so far. But some wasps, including queens, might have hidden in things like shipping crates or boats. These items are used for international trade between countries.
Their Favorite Places to Live
European paper wasps usually live in mild, land-based places. These include areas with chaparral (shrubs), forests, and grasslands. They also like to live near human towns and cities. This is because man-made buildings offer great shelter. They are also close to resources like food.
How They Spread in North America
European paper wasps have special behaviors that helped them spread outside their home areas. This allowed them to invade the United States and Canada. Most Polistes wasps in the United States only eat caterpillars. But P. dominula eats many different kinds of insects. They also build nests in safer places, which helps them avoid predators.
North America has a climate and environment very similar to Europe. This helped the wasps settle in quickly and successfully. P. dominula also seems to be more productive than Polistes fuscatus, a wasp native to the United States. P. dominula produces worker wasps about a week earlier. They also start looking for food earlier in the day than P. fuscatus.
These wasps are a problem for cherry and grape farmers in British Columbia. They damage the fruit by biting off the skin. They can also spread yeast and fungi that harm the fruit. And they can be a bother to workers picking the fruit.
Taking Over Native Wasp Areas
Before 1995, P. fuscatus was the only Polistes wasp species in Michigan. In the spring of 1995, a single P. dominula colony was found nesting in a Polistes nestbox. This was at the Oakland University Preserve in Rochester, Michigan. In 2002, about one-third of the P. dominula colonies there were removed. This was done because people worried about losing the native P. fuscatus population.
Even though removing P. dominula slowed them down, by 2005, 62% of the colonies at the Preserve were P. dominula. Many researchers believe that P. dominula is replacing P. fuscatus. This happens because P. dominula is much better at finding and using resources. This matches findings that P. dominula is much more productive than P. fuscatus.
Life Cycle of the Wasp
Overwintering queen wasps, called foundresses, spend about a month in spring building a nest. They also gather food for their young. The first young wasps become worker daughters in the growing colony. One or more foundresses start the colonies in the spring. If there are many foundresses, the one that lays the most eggs becomes the dominant queen. The other foundresses become subordinate workers and help the colony.
Male wasps are born later in the season. When males start to appear, some female daughters might mate. They then leave their nest to become foundresses for the next year. The colony breaks up in late summer. At this time, only males and future foundresses are born, not workers. These wasps often gather in groups to spend the winter, a place called a hibernaculum. They usually do not hibernate in their old nests.
The social order in the colony also affects how long individual wasps live. Queens live longer than males or workers. This is because workers protect the queens from predators. The queen starts laying eggs in late March or early April. This is right after the "founding phase" of the new nest.
Most non-reproducing males and females do not survive the winter. Their lives are shorter than a year (about 11 months). They survive best in warm temperatures. Queens can survive the winter by hibernating.
Why They Survive So Well
Many areas that used to be home to P. fuscatus are now home to P. dominula. Several things help P. dominula be more successful than P. fuscatus in new areas. These include a productive colony cycle, fast development, warning colors, a varied diet, and the ability to live in new places.
Colony Growth
P. dominula colonies are started by females who have left their old nests to mate and find new homes. These "foundresses" use three main ways to start new colonies. They can build a nest by themselves. They can find other "associate foundresses" to build a nest together. Or they can wait for an original foundress to leave a nest and then take it over. Once the foundresses settle, the "founding phase" ends. Then comes the "worker phase," where the first young wasps are born and grow into workers.
P. dominula colonies seem to grow faster than other Polistes species. In studies in Michigan, colonies started by a single P. dominula queen were four to five times more productive than P. fuscatus colonies. In North America, P. dominula was much more productive than similar colonies of the native Polistes metricus.
What They Eat
P. dominula eats a wider variety of food than many other Polistes species. This gives them more choices for prey. A study in Europe found that P. dominula brought back prey from three different insect groups to their nests. In contrast, North American Polistes mostly only use caterpillars to feed their young.
Some scientists think that individual wasps don't have a wider diet. Instead, they believe colonies are more flexible about using available food. For example, P. dominula uses more workers to find food. They also use eggs to feed their young. They even reduce how much protein they use for nest building. This helps them use lower quality prey when food is scarce. In Kentucky, P. dominula has been seen hunting Monarch butterfly caterpillars.
Strong Defense Against Predators
Another reason P. dominula survives so well is that their nests are attacked less often by predators. Birds don't like to eat P. dominula as much. This is mainly because of their bright warning colors. Also, their nests are very strongly attached to surfaces like tree branches or human buildings.
Unlike P. fuscatus, which is brown with faint yellow stripes, P. dominula is bright yellow with black stripes. This is similar to the warning colors of Vespula germanica, a common and aggressive yellowjacket. Besides their warning colors, the strength of P. dominula nests also helps them survive better. P. dominula might have an advantage over P. fuscatus against birds. Their nests are harder for birds to pull off the surface.
Wasp Social Order
In social insects, a social order helps one individual become the main reproducer. It also helps keep other individuals from reproducing in the nest.
There are only small physical differences between the queen and the other wasps in a colony. But their behaviors are very different. A female wasp's role depends on how she interacts with others in the colony. Dominant females, the queens, lay most of the eggs. Queens stay in the nest, lay eggs, and rarely go out to find food.
In contrast, auxiliaries (the workers) or subordinate females mostly find food. They do not lay eggs. Some workers, called autumnal helpers, show a unique behavior. They leave their home nest to overwinter and start new colonies in the spring. These helpers are more active than other workers. They give more food to others (trophallaxis), attack more, and receive more dominant behaviors. Other workers receive more food and perform more dominant behaviors. About 14% of helpers survive, while about 59% of non-helpers survive.
These roles are not set in stone. For example, if the main queen is removed, another female, usually the second most dominant, will take her place. She will start acting like the queen. If larvae were removed from the nest, workers started laying more eggs. This shows that workers lay eggs when they think the queen's power is weakening.
The way females interact in the nest can affect which daughters become workers and which become future queens (gynes). Even if a female is meant to be a queen, she can become a worker if placed in a younger colony. The opposite is also true. This shows that the wasp's social system is very flexible.
Female Dominance
The main female (alpha female) usually controls all other wasps in a colony. She lays most of the eggs and sometimes eats the eggs of other wasps. The alpha female spends a lot of her time interacting with others. Subordinate wasps spend more time finding food and caring for the young.
The clypeus (face) of the wasp has many black spots that vary in number, size, and shape. These spots show how dominant a wasp is. More dominant wasps have more black spots. Wasps that join the nest later are rarely dominant.
P. dominula wasps react differently to face markings. Scientists painted dead wasps to change the number of facial spots. They used these dead wasps as guards for food sources. Then they watched a third wasp choose which food source to go to. The third wasp chose the food source guarded by the wasp with fewer spots 39 out of 48 times. This means that facial coloring predicts dominance in wasps of the same size. Wasps with more spots are more dominant.
Scientists also experimented to see if there's a cost to "lying" about dominance with facial signals. They changed the facial coloring of wasps and then had them fight. The painting didn't change who won the fight. But it did affect behavior after the fight. Losers that were painted with more spots were attacked six times more than wasps that weren't painted. This shows that wasps who don't "signal honestly" (by having more spots than they deserve) face social consequences.
Male Dominance
The spots on a male wasp's belly show his dominance. Smaller, oval-shaped spots mean a more dominant male. Females prefer these males, and they win fights with other males. This is different from males with larger, irregular spots, who are usually less dominant. Males cannot sting. Their only defense is their jaws.
Abdomen Rubbing Behavior
Female P. dominula wasps rub their bellies during the egg stage of the colony. This happens more in colonies with many females than in colonies with just one. There are a few reasons why females might rub their bellies. One idea is that they are putting chemicals on the nest surface to protect it from predators. Another idea is that they are telling the young wasps about the female's dominance. Alpha females rub their bellies more than subordinate females. If the alpha female is removed, the subordinate females will start rubbing their bellies more often. The chemicals released during rubbing might also stop the young wasps' ovaries from developing. Or they might tell the young which adult female is the dominant one.
Wasp Family Ties
P. dominula is a social insect that lives in colonies. Like other Polistes species, they are haplodiploid. This means that males have one set of chromosomes, and females have two. In most social insects, colonies are made of related individuals. They are thought to help close relatives, following a theory called kin selection.
However, in P. dominula, about 35% of the wasps in a nest are not related. In many other species, unrelated wasps only help the queen if they have no other choice. But in P. dominula, subordinate wasps work for unrelated queens even when they might have other options. No other social insect does this. This behavior, which seems unhelpful, is similar to some animal groups with backbones. This unrelated help might be a sign of altruism (selfless behavior) in P. dominula.
Most nests had one or more females that were not related. This was especially true in winter, before nests are formed and workers are born. Nests tend to form from foundresses from different nests from previous years. Foundresses are also found spending winter with other wasp species. This explains why unrelated wasps are found together in winter. However, after winter, when nests start to form, there are more related wasps in the nests. This might be because foundresses look for more related sisters instead of unrelated wasps.
Later in the nest's life, more unrelated wasps are found. This could be because new wasps join already established nests.
How Wasps Recognize Each Other
Using Body Chemicals
Female P. dominula wasps can tell the difference between wasps from their own nest and wasps from other nests. Groups of three wasps show more aggression towards wasps from other nests than groups of two. In groups of three, aggression increases because defending the nest can be shared. But for one wasp alone, the cost of fighting is greater than the benefit of defending.
Insect bodies are covered with chemicals called cuticular hydrocarbons (CHCs). These chemicals help keep water out. They also help wasps recognize each other, their relatives, and their nest mates. The same chemicals found on adult wasps are also on the nests. This allows wasps to recognize their home.
Scientists found that the CHC differences between dominant and subordinate females are not clear when nests are first started. But these differences become obvious once worker wasps appear. The dominant female's CHC profile has more unique chemicals that are longer. When the queen is removed, the new queen's CHC profile becomes similar to the original queen's. Scientists believe CHCs are a signal for dominance, not just fertility. This is because subordinate wasps with developed ovaries still had different CHC profiles from dominant ones.
Visual Signals of Status
Black facial patterns are linked to dominance and health in male P. dominula. Male facial patterns can be "unbroken" (one big black spot) or "scattered" (several spots). An unbroken spot means "low quality," while scattered spots mean "high quality." Males generally avoid fighting "high quality" males. They prefer to fight for resources that "low quality" males are protecting. This reduces the cost of aggressive fights. This behavior leads to a social order where males with more spots are at the top.
Just like belly spots show fighting ability and mating success in male P. dominula, the clear patterns on a female's face show her dominance. These patterns help wasps judge their rivals.
Wasp Behavior
Foundress Behavior
In the first 12 days of building a nest, 75% of foundresses leave their first nests. They travel to about three nests before settling permanently. They choose the nest that will give them the best chance of having many young. Foundresses choose nest sites by balancing the benefit of a large colony with the risk of being attacked by predators. Nests with multiple foundresses have a better chance of surviving and producing young than nests with a single foundress. Foundresses generally start nests with other wasps they spent the winter with.
Nest Arrangement
The nest, which is a single comb, is the heart of the colony. Food is stored there, and young wasps are raised. It's also the main place where most wasps spend their time. P. dominula wasps do not just sit randomly on the comb. Each wasp spends most of its time in a small area of the comb, about 12% of it. This small use of space is normal, no matter how many wasps are on the nest. Sometimes, this area can cover up to 50% of the comb. Dominant females use a smaller area than subordinate foundresses and workers. Wasps don't overlap their spaces much, which suggests they limit each other's areas. Workers prefer to share areas with other workers. Foundresses prefer to share areas with other foundresses. About 70% of workers are active and use a small area of the comb. The rest don't have specific areas. They spend most of their time away from the nest or staying still behind it. Alpha females are affected by what's in the cells. They rest more often on cells with caps and avoid empty ones.
Working Together
Cooperation helps wasps survive. Groups of multiple foundresses are more likely to survive and produce young than groups of single foundresses. Also, individual foundresses in multi-foundress colonies are less likely to disappear before workers emerge. So, working together gives foundresses big advantages in productivity and survival. Cooperation helps them survive only if individual foundresses in a multi-foundress nest have a better chance of survival. Or if the foundress's contribution to the nest is kept even after she leaves.
When the Queen is Lost
Losing a queen is a big problem for a social insect colony. It can lead to more aggression and less efficient work. Also, if the colony can produce a new queen, it might take a long time for her to lay eggs. After a queen is lost, new queens do not mate in the first 12 days. Few have mature eggs in their ovaries. After a month, most new queens develop ovaries and mate. Nest growth slows down in colonies that lose their queen. This can happen if increased dominant behavior gets in the way of other important behaviors. Or if the new queen is not good at laying eggs. In queenless P. dominula colonies, wasps showed more chewing and climbing. But not more lunging and biting. These are all dominance behaviors. There was no difference in foraging behavior between colonies with and without queens. Subordinates are kept from reproducing enough so they are not a threat to the current queen. This is shown by the high cost of replacing a queen.
Adopting Nests
Wasps adopt nests in three situations. First, when queens lose their nests and "make the best of a bad situation." Second, when workers leave nests with multiple foundresses. Third, when subordinates use a "sit-and-wait" strategy. They wait for nests to be abandoned. Nests become orphaned when the adult wasps die while caring for their nest, leaving young wasps behind. Orphaned nests allow a new wasp to become queen without a fight.
Females that adopt nests are less cooperative. They also use less energy than those that start new nests. In spring, foundresses sometimes start colonies alone. They might form groups with others. They can also take over existing colonies of their own species. Or they might even adopt abandoned nests. Females would adopt an abandoned nest if they lost their own nest due to predators or damage. Or if they waited to adopt an orphaned nest instead of starting their own.
Females using the "sit-and-wait" strategy chose the most developed nest. They did not choose the nest most likely to have relatives. Females prioritize the quality of the nest over saving possible relatives from another abandoned nest. Females prefer mature nests and nests with many older larvae and pupae. When a female adopts an orphaned nest, she destroys the existing eggs and young larvae. But she allows older larvae and pupae to finish developing. Adopting a nest helps a wasp get a mature colony without using too much energy to start a nest. It also means they don't have to cooperate in building the nest.
Once a nest is built, it can be used by many generations and for many seasons. Nests left empty during winter are almost always used again the next spring. With each new group, the nest keeps growing. Some have been recorded at 8 inches wide. Several nests might be located in the same area, just inches from each other.
Mating Behavior
P. dominula wasps have a lek-based mating system. This means males gather in certain spots to show off. Males compete fiercely for the best spots in these areas. Females are very careful when choosing their mates. Males form groups on the highest parts of things like fences, walls, roofs, and trees. Males often fight other males in the air or on these structures. Males that lose fly away from the lek.
Females fly through these lek areas or sit near them. They watch the males before choosing a mate. Females use the very clear spots on the males' bellies to help them choose. These spots vary a lot in size and shape. Males with smaller, more oval spots are more dominant. Females prefer them over males with larger, more irregular spots.
Male social insects are often seen as just wanting to mate with anyone. But males do use energy when mating doesn't work out. So, P. dominula males can tell the difference between female types. They prefer to mate with females who can reproduce, rather than workers, no matter their health or age.
Smart Wasps
P. dominula is the first insect to show it can do something called transitive inference. This is the ability to figure out a relationship between things that weren't directly compared. For example, if you know Tom is taller than Alice, and Alice is taller than Pat, you can figure out that Tom must be taller than Pat. This mental skill is common in animals with backbones.
Scientists trained P. dominula wasps using five pairs of choices. One choice in each pair gave the wasp a small shock. The shocks were in a series: A (shock) vs. B, B (shock) vs. C, C (shock) vs. D, D (shock) vs. E. When tested on a pair they hadn't seen before, like B (shock) vs. D, the wasps chose D more often than random chance. This shows they used transitive inference. They organized the pairs into a series in their minds. Then they used that knowledge to choose when faced with a new pair.
Wasp Parasites
P. dominula nests can have parasites and parasitoids living in them. These include hungry Lepidoptera larvae (caterpillars), other Hymenoptera (like other wasps), Diptera (flies), and Strepsiptera (twisted-wing parasites).
P. dominula is also attacked by Polistes sulcifer. This is a social parasite that doesn't have workers. P. sulcifer females take over a host colony by getting rid of the dominant queens. They then change their body chemicals to match the host wasps. P. sulcifer females get these chemicals by grooming and licking the host queens and workers. Or they get them from the nest material, which is covered in chemicals important for recognizing nest mates. This chemical mimicry helps foreign P. sulcifer females be accepted by the host insects. The first clear case of this parasitism in the North American population was reported in 2010. P. dominula wasps are also often infected by Xenos vesparum. This is a permanent parasite that lives inside insects.
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See also
In Spanish: Avispa de papel europea para niños
