Academia Sinica’s Biodiversity Research Center has discovered a social chromosome that determines different types of colony organization in fire ants (Solenopsis invicta), part of international research that may contribute to more effective pest control.
The center said fire ants have two types of colony organization — monogyne, with one primary reproductive female; and polygyne, with more than one active queen — and the individual features, behavior and social relations of the ants in these two types of colony vary greatly.
The team, which included John Wang (王忠信), an assistant research fellow at the center, has discovered that the control mechanism of these two types of social form is determined by a specific genomic region that contains more than 600 supergenes and resides in a pair of heteromorphic chromosomes, which have many of the key properties of sex chromosomes X and Y.
The two combinations of social chromosomes determine the characteristic and behaviors of the individual ants in the two forms of colony.
Wang said that because queen ants of the two forms develop different odors, worker ants in a monogyne colony will kill the queen ant from other colonies.
Similarly, worker ants in a polygyne colony will only accept queen ants from other polygyne colonies and kill a queen ant from a monogyne colony.
The center said there have been many reported cases of massive fire ant infestations in Taiwan and throughout the world. Bites by the highly aggressive ants not only cause painful itching or swelling of the skin, but may also lead to death for individuals who are allergic to the bites.
However, to date, pest control methods have not been very effective in eliminating fire ants, the center said.
Wang said although the research is still in its initial stages, if scientists can further identify which specific genes determine the odors of the fire ants, and use genetic engineering methods to alter the odor of queen ants, then perhaps workers ants could be fooled into killing queen ants, destroying a colony’s reproductive ability.
The research results were published in last month’s issue of Nature magazine.