Social status in paper wasps is established earlier in life than scientists thought, says a study published this month in the journal PLoS ONE.
While many social insects have distinct social classes that differ in appearance and are fixed from birth, paper wasp society is more fluid -- all castes look alike, and any female can climb the social ladder and become a queen. Now, molecular analysis reveals that paper wasp social hierarchy is less flexible than it appears. Queens diverge from their lower-status sisters long before they reach adulthood, scientists say.
Slender reddish-brown wasps with black wings, Polistes metricus paper wasps are a common sight throughout the Midwestern and Southeastern U.S. Hidden in papery umbrella-shaped nests in the eaves and rafters of your house, a complex society is hard at work.
Female wasps develop into one of two castes that take on different roles within the nest. While young queens don't work and eventually leave the nest to reproduce and rule colonies of their own, workers forego reproduction and spend their lives defending the nest and raising their siblings.
"All offspring look alike but some work and some don't," said lead author James Hunt, currently a visiting scholar at the National Evolutionary Synthesis Center in Durham, NC. "The workers are the ones that fly out and sting you if they feel their colony is threatened."
Hunt and his colleagues wanted to find out if hidden molecular mechanisms set some paper wasps on the path to becoming workers, and others to becoming queens. "Many scientists think that paper wasp social status isn't decided until they are adults, but some think there is more to it than that," said Hunt, also a biologist at North Carolina State University.
With co-authors Amy Toth and Tom Newman at the University of Illinois and Gro Amdam and Florian Wolschin at Arizona State University, the researchers measured gene activity and protein levels in young paper wasp larvae before they took on different roles.
Although all wasp larvae look and act alike, the researchers discovered several differences during development that predispose them to one caste or the other.
The larvae that become queens have high levels of a group of proteins that enable them to survive the winter and reproduce next year, whereas the ones that become workers are much shorter-lived and have low levels of these proteins, said Hunt. "There's less upward mobility in the ones that become the workers. They may look just like the future queens, but they are strongly biased toward the worker role."
Future queens also showed higher activity of several genes involved in caste determination in other, more recently evolved insects that have more visible distinctions between castes. "Paper wasps and honey bees are separated by 100 million years of evolution, but we see some of the same gene and protein patterns in paper wasps that lead to different types of adults in bees," he explained.
The results help shed light on how insect social behavior comes to be, Hunt explained. "It is sometimes argued that adult wasps actually choose to become workers in order to help their mother reproduce and raise their sisters -- hence the term 'altruistic,'" he said. "What we found is that really the choice is limited by how they develop as larvae."
Michael Henshaw of Grand Valley State University was also an author on this study.
FAQs
According to lead researcher James Hunt, the larvae that become queens have high levels of a group of proteins that enable them to survive the winter and reproduce next year, whereas the ones that become workers have low levels of these proteins.
What happens to wasps when you kill the queen? ›
If it happens that you've killed the queen wasp and you're wondering what happens when you kill the queen wasp, the answer is that the colony continues. If the nest has already been built, and the colony exists, killing the queen wasp won't really offer a solution to a wasp problem.
What is the queen in a wasp colony? ›
Paper wasps are semisocial insects and live in colonies. The queen establishes a nest in order to lay her eggs. When the first batch of eggs develops into adults, they assume all of the nest-building, food-gathering and larva-tending responsibilities. The queen continues to lay eggs and the colony grows.
What do wasps do without a queen? ›
If the queen dies, the workers will feed royal jelly to some of the newly hatched larvae and they will grow into new queens. The first of the new queens will go on her maiden flight to mate with drones and will return to replace the dead queen. She will also go around the hive and kill the other developing queens.
Is there a Queen paper wasp? ›
Paper wasps are semi-social insects with a caste made up of workers, queens and males. Fertilized queens overwinter in protected spaces beneath tree bark or in cracks and crevices in homes. When spring arrives, they select a nesting site, begin building a nest and lay their eggs.
How many queens do paper wasps have? ›
These wasps operate in a caste system similar to ants where there is usually one queen, although some colonies may have more than one queen, and several non-reproductive workers that are in charge of foraging for food and tending to the queen and her progeny.
Is it OK to kill wasps? ›
Wasps are predators, and their prey are the types of insects and bugs that you also don't want around. Wasps happily kill flies, caterpillars, and the enemy of every gardener or farmer, the aphid. In other words, if wasps aren't bothering you, then there's no need to get rid of them.
Do wasps remember faces? ›
Before you become aggressive towards a wasp, you better think twice. That wasp may be able to recognize your face and come after you if it sees you again! While it may sound like something out of an old sci-fi movie, a new study suggests that the brains of wasps can process faces all at once.
Can queen wasp sting? ›
Just like her workers, the queen wasp has a sharp sting which she'll use when she feels threatened.
Can wasp queen fly? ›
Queen wasps fly low to the ground, searching for any round, dark object or depression. If it is a hole, they fly in to see if it is suitable and if not, move on to the next hole. This can be a void, crack or crevice within buildings.
Queen wasps also have a distinct colouration. They are usually darker than other wasps in the colony, with a black or dark brown body and yellow or orange markings on the abdomen. In addition to size and colour, queen wasps can be identified by their behaviour.
How do you know if a wasp is the queen? ›
The shape of the wasp can also help you identify whether it is a worker or a queen. Queen wasps have a more rounded body shape, while worker wasps are slenderer. Queen wasps also have a more extended abdomen than worker wasps.
What happens when a wasp dies? ›
If you kill one, it will warn the rest of its colony to be on the alert. A dying wasp will release chemical signals that tell others in the vicinity to be on the defensive. "Try not to move suddenly or do anything that could seem threatening.
What attracts queen wasps? ›
The queen wasps will be attracted by the sweetness of the apple as well as the honey, vanilla essence and jam.
What is the white stuff in a wasp nest? ›
The dark brown parts of the nest are likely made from chewed up tree bark, while the white parts are built from cotton fibers. Brightly colored building material like this table cloth can result in neon wasp nests.
How do wasps decide who is queen? ›
The traditional way to tell the social status of a paper wasp is based in part on the reproductive state of the wasp larvae workers are born with their reproductive genes turned off, while queens had their genes turned on.
How to tell if a wasp is a queen? ›
The shape of the wasp can also help you identify whether it is a worker or a queen. Queen wasps have a more rounded body shape, while worker wasps are slenderer. Queen wasps also have a more extended abdomen than worker wasps.
How long do paper wasp queens live? ›
How Long Do Paper Wasps Live? Most paper wasp colonies are dead by the first hard freeze of the year except for hibernating queens, who may live just over a year. The average worker might live between 12 to 22 days.
Are queen paper wasps aggressive? ›
Paper wasps are social creatures and will vigorously defend their nests. They are most likely to sting when their nest is disturbed. They aren't aggressive when they're away from their nest.
