No Males Need Apply: Parthenogenesis in Gall Wasps

In some gall wasp species there is reproduction without males!

The title might sound scholarly, but what does it mean?  Parthenogenesis in animals is the development of an embryo from an unfertilized egg cell– in other words, no males involved.  This can happen among some invertebrate species, and even in some reptiles and amphibians.  With gall wasps, the males and females reproduce in the conventional way in the spring, but in the fall the females manage it all by themselves.

Of course, the practice of parthenogenesis decreases genetic diversity, as you would expect, but it has some advantages too.  For one thing, it usually results in production of much larger numbers of offspring, possibly because less energy is expended in looking for a mate.  Imagine being free of those pesky mating rituals!   The time and energy you’d save by not dating!

And here’s a cultural  aspect to consider:  a friend who is a member of the Coast Miwok tribe told me the tribe used to carefully time their controlled burns to hold down populations of these insects.  Clever.

Find out more about gall wasps and all other things related to oak trees in this wonderful book:  “Secrets of the Oak Woodlands” by Kate Marianchild.

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