For her PhD research, Pauline had to breed her own tropical fire ant colonies, while making sure that the ants could not escape from their controlled environment. “I looked after dozens of newly mated queens, and they were laying eggs and looking after the first generation of workers,” she says. “I found that after the first workers of the colony have hatched, the queen no longer needs to look after the brood.”
Pauline says that when invasive ants move to a new region, they become isolated from other colonies in their native range. “They go through what we call a ‘genetic bottleneck’, which means that genetic defects can develop. For instance, I would see that some of a queen’s offspring would be very fat larvae. I called them the ‘fat babies’,” she says. “They were not meant to have such big larvae at this early stage in the life of the colony.”
Pauline also noticed that, after a while, some queens would simply eat all larvae that were too big. “Witnessing in tropical fire ant colonies was quite surprising and unexpected,” she says. These were also published in , one of the world’s premier science journals.
Exploring the blueprints of behaviour
One of the skills Pauline learned during her PhD research was to interpret DNA data collected from invasive ants. She says that this skill is very helpful in her current role as a Project Officer for Invasive Invertebrate Biosecurity at the .
“I can be that conduit with people working in different areas. First, I read the DNA reports, and then I can explain what it means to other stakeholders. So it's a very useful skill in general,” she says. “For example. I can explain how ant colonies are related to each other by looking at their genetic relatedness.”
Pauline is also one of the first contacts when there is a response to invasive ants. Given that she has examined the behaviour of invasive ants for almost ten years, she is one of the top specialists in responding to ant infestations in Australia.
“I look at suspect ant reports for fire ants in New South Wales. If I think the report is suspect, I will organise for someone to obtain a sample and take it to one of our microscopes,” Pauline says. “These microscopes can be accessed remotely by other specialist entomologists (ant experts) in New South Wales and Queensland.
“If the ant is confirmed to be a biosecurity risk, such as a red imported fire ant, I provide expertise in the biosecurity response for everything from ecology to biology,” she says. “But I also conduct risk assessments and work in the policy space.”