Termite colonies have always been assumed to be a mix of males and females; not only reproductives but also workers and soldiers of both sexes. Researchers have found colonies of a drywood termite in Japan that have thrived and survived for millions of years, without males!
Image credit Sydney University: All-female (asexual) colony of the drywood termite (Glyptotermes nakajimal)
Whereas honey bee and ant species are known to exist as all female colonies, termites colonies have always been assumed to consist of both males and females – not only male and female reproductives, but workers and soldiers of both sexes exist. However, a joint research team from Kyoto and Sydney Universities, including Professor Nathan Lo, have discovered that all female termite colonies exist.
The team analysed colonies of the drywood termite, Glyptotermes nakajimal, in Japan. Analysing 74 mature colonies from ten separate populations, the team found that all the colonies from 6 of the populations consisted of all female individuals. The remaining populations consisted of mixed sex colonies. Aside from a lack of males, the colonies’ queens contained no sperm in their sperm storage organs and their eggs remained unfertilised. Furthermore, there was no significant difference in the hatching rate of these unfertilised eggs and that of fertilised eggs among mixed-sex termite populations.
The researchers estimated the asexual variant evolved from a mixed sex colony some 14.1 million years ago. They have clearly managed to survive and thrive as all female societies.
“These results demonstrate males are not essential for the maintenance of animal societies in which they previously played an active social role,” said Professor Lo.
Professor Lo says asexual reproduction could allow termites to successfully adapt to a range of new environments.
“All else being equal, asexual populations grow at twice the rate of sexual populations because only females are required to reproduce. This increased growth rate of colonies makes it easier for populations to entrench themselves in new environments.”
With some of the 276 termite species in Australia, among the most primitive and ecologically diverse in the world, it is possible some may be able to reproduce asexually, but further research will be required to determine this.
Loss of males from mixed-sex societies in termites. Yashiro et al (2018)
Based on original article from Sydney University website