A hundred years ago, two American researchers named Marshall Hertig and Simeon Burt Wolbach had discovered that mosquitoes harboured bacteria within their cells.
Other researchers later found similar bacteria in the cells of most insects and many other arthropods.
The genus to which the bacteria belonged was named Wolbachia.
Wolbachia bacteria are also present in insect eggs but they are absent in the sperm.
This means females can transmit Wolbachia to their offspring whereas males can’t.
Encarsia formosa wasps are of interest to agricultural scientists because they provide an efficient way to control whiteflies.