Introducing New Dung Beetles to Australia: Battling the Cane Toad’s Legacy
Last week, the Commonwealth Scientific and Industrial Research Organisation (CSIRO) announced that they were going to import Moroccan dung beetles into Australia. The purpose being ostensibly to combat the fact that local Australian dung beetles have not evolved in step with marsupials instead of cattle, and are therefore pretty ineffective when it comes to breaking down the dung of sheep and cows. The introduction of the new beetles (specifically the Moroccan dung beetle, Gymnopleurus sturmi) is therefore intended to aid in the breakdown of cattle dung, returning nutrients to the soil, reducing the populations of the flies which follow cattle around and just generally cleaning the joint up. Sounds great. We’ve never had problems with species introduced to clean up our own mess before.
Ok but didn’t you introduce the cane toads to sort out your problems and now they’re everywhere?
YES YOU’RE DAMN RIGHT WE DID. For those less familiar with the poster child for biological controls gone wrong, the cane toad (Bufo marinus) was introduced to Australia mid last century to deal with the cane beetle, which was destroying sugar crops. Australian species, having no experience which a poisonous frog of this type, have been heavily affected ever since, and the toads spread like lightning.
So this is a bad idea?
Well not exactly. While many people are comparing this directly to Australia’s previous mistakes, there are some marked differences. Exotic dung beetles have actually already been in Australia for decades. We do have 500 native species of dung beetle (accounting for about 10% of discovered species worldwide), yet scientists from the CSIRO introduced new species in the mid 60s to combat the same problem they’re trying to combat now.
This initial project is not exactly a great look for the CSIRO. In a paper from 2018, Bernard Doube of Dung Beetle Solutions International and formerly of CSIRO pointed out that of the 53 species that scientists attempted to introduce, ten were never introduced and 20 never successfully established. Doube attributed some of this to poor understanding of dung beetle breeding biology, which is worrying, given that we should really know as much as possible about a species before we go dropping it into a new ecosystem. The remaining 23 have spread to varying degrees throughout what was thought would be their natural range in a country like Australia. So far, they don’t appear to have posed a problem for native species, and have done their job in some areas.
So why will these new ones make a difference?
According to the CSIRO, the dung beetles that they have introduced don’t seem to get much work done during the spring. That’s why they’re introducing the new species. They’re not hyperfunctional crazy shitrolling juiced up beetle monsters, they just work a different shift.
This seems… fine?
Yeah ok, BUT IT’S NOT. I don’t actually have a problem with the science, it SEEMS pretty solid and anything that sequesters carbon needs to be given a look-in these days. But the way the CSIRO seems to have ignored the obvious questions that come with this irritates me. Even without reading into this too much, it is perfectly natural for anyone with a passing knowledge of the cane toad debacle to question it. The CSIRO needs to, right off the bat, acknowledge that this might sound like a bad decision, and then be abundantly clear about why it’s not.
This whole thing brings to mind the recent decision to introduce genetically modified mosquitoes into Florida to deal with the Zika virus. The science appears sound, but goddamn the concept of human-made super mosquitoes suddenly being released sounds like the start of a horror film we don’t want right now. As an example of how this sort of communication SHOULD be handled, mosquito ecologist Kara Fikrig posted a fantastic explanation of why the mosquito introduction should work, linked below.
I genuinely believe that science communication is getting better all the time. And I think this project sounds promising. I just wish that in articles like this one, and the one linked below (both of which do a pretty good job of communicating the science behind the project), both the media and the scientists would do a better job of addressing people’s valid concerns about the use of exotic species as biological invaders.
Sam Perrin is a freshwater ecologist who completed his PhD at the Norwegian University of Science and Technology who didn’t make a single poo joke for this entire article and deserves your respect because of it. You can read more about his research and the rest of the Ecology for the Masses writers here, see more of his work at Ecology for the Masses here, or follow him on Twitter here.