@drsammygrams 

University of Colorado professor Samuel Ramsey has just completed a PHD on varroa mite and the results could determine if eradication in Australia is possible. Ramsay explains 

"You guys are the largest land mass to keep varroa out since the 1950s and it's quite remarkable that you've been to remain varroa free”

“It is worth considering if you’ve had this organism here for more than a year and that’s really concerning, that means the population could be officially established in the environment, when it is officially established in the environment when we think of an organism as a normal part of the environment, at that point it is unlikely that the organism will be eradicated, it would be a worthwhile endeavour to transition to management"

The mites are also able to hold their breath for long periods.
That is important for beekeepers because varroa mites may be surviving fumigation because of it.
"If the mites are able to hold their breath for long periods of time they may be able to escape some mechanisms of the treatments," Professor Ramsay said.

One of the issues with varroa is that they are adept ecosystem invaders, they make really effective invasive species because it only requires one, for a lot of other organisms if you’re going to have an invasive population of it develop, you need at least two individuals, the introduction of a male and a female, and that’s harder to do, but it makes it that much easier that you only have to introduce a single female because the moment she starts walking around outside of the small little cell she was born, she’s already pregnant and any new location where she is located, she can start a new population.

https://www.abc.net.au/radio/programs/vic-country-hour/canvarroabeerradicated/102393302

Photo @natgeo