At first, eusociality was seen only in insect species whose reproductive biology makes fertilized eggs grow into females, and unfertilized eggs into males.
It only infects unfertilized ovaries, so self-pollination and fertilization can decrease the presence of the disease, but male-sterile lines are extremely vulnerable to infection.
These half-identical twins are hypothesized to occur when an unfertilized egg cleaves into two identical attached ova and which are viable for fertilization.
The plant often reproduces vegetatively via tillers, or via apomixis with unfertilized seeds, and some populations are made up only of female individuals.