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On Wasps and Matricide

First, think of a wasp colony as a monarchy, where workers diligently provide for their queen.  Assume the queen is unsatisfactory, what would happen? A violent revolution perhaps?  This article on a study done by Kevin J. Loope explains how wasps are fully capable of committing matricide under the right conditions.

Matricide is not particularly uncommon in the insect world.  Many species such as crab spiders take part in matriphagy, or mother eating.  Wasps, on the other hand, depend on the queen to forage for food to feed their larvae.  Normally, fully grown workers are the ones that turn on their mother.

Source: Marjan Smeijsters on Flickr Commons

New wasp nests are formed in the spring after fertilized queens have finished hibernating.  Solitary queens construct the nest, lay eggs, and care for her larvae.  Only after the larvae have matured into workers, all of which are female, do the queen focus on reproduction and leave the other duties to her offspring.

An average wasp queen lays around 100 eggs each day.  Some workers are capable of laying eggs, but only for drones, or male wasps, and are discouraged by the queen through attacks or egg eating.   While in most cases wasps let their mother be responsible for passing on their genetic data, workers may get rid of the queen if being able to produce their own offspring outweighs the loss of new siblings.

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The queen’s mating practices are an important factor.  Queens normally only mate once or twice, but that does not imply an even distribution of full siblings.  In single-father colonies or colonies skewed to have many full siblings, workers are more closely related to their nephews than their brothers.  Loope noticed that because workers are willing to take care of closely related nephews, females will kill the queen to have the colony raise their young instead.  Wasps are believed to be capable of identifying its relatives.

Past research also reference low queen productivity or queens producing only males as reasons for matricide.  From this we can hypothesize that while wasps may work for the greater good on the colony, the queen is not necessarily vital to the continued welfare of the collective.  It puts a new light on what some would believe to be mindless workers.

Here is a basic video on the various stages of a yellow jacket wasp’s life:

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credit to ScienceOnline on Youtube

blog by Ivan Lan