A new study found that worker wasps sometimes kill their queens – which are also their mothers – so that they can lay their own eggs.
Wasps are social insects that live in a nest with non-reproducing workers and an egg-laying queen. The colonies are usually found by a single queen in the springtime. The queen lays eggs, giving birth to female workers, male drones and female queens. The queens mate with males in the fall and then hibernate during the winter, until spring comes.
Worker Wasps normally devote their lives to their queen. They take care of the nest, collect food, defend the colony, and raise the offspring. However, previous research found that workers sometimes kill the queen (aka their mother), an act which is known as matricide.
In the new study – published October 29 in the journal Current Biology – Kevin Loope, a behavioural ecologist at the University of California, Riverside, observed 18 yellow jacket wasp colonies in a lab. Using video cameras, Loope recorded the wasps’ behaviours and saw a total of three matricides.
He also looked at 31 other colonies in the wild and found that 13 of the wasp colonies had no queen – meaning that they had committed matricide.
After analysing the genes of 21 wasps of the 31 wild colonies, Loope found that worker wasps tend to kill their queen when they are part of colonies with a lot of full siblings. The queen was not killed by the workers when the colonies had more half siblings.
A possible explanation could be that if all the worker wasps in the colony were sibling, the males that they would give birth to would be closely related to the all workers – being sons or nephews. The chances of passing their genes to future generation would improve for each worker in the colony.
If the colony had more half siblings and was not so closely related, the resulting males would be sons or distant relatives to the worker wasps, meaning that not each worker would improve the chance of passing on their genes.
“Workers are not mindless automatons working for the queen no matter what. They only give up reproduction when the context is right, but revolt when it benefits them to do so,” Loope explained.
Image Source: proofpest