Ecology is not a dirty word

Last week I was delighted to attend a workshop at Monash University focused on using EICAT methods to assess environmental impacts of invasive insect species. Thank you to Melodie McGeoch and her team (Dave, Chris & Rebecca), and Andrew and Carol from the Invasive Species Council, for inviting me in the first place, and for organising an excellent, productive week. We were also very lucky to have Sabrina Kumschick and Helen Roy there to share their expertise in developing and using EICAT.

It was a ‘proper’ workshop, i.e. a small group of researchers working on a project together with planned outcomes, rather than a training or upskilling ‘workshop’ (why aren’t they just called courses?!). As an early career researcher, it was so rewarding to be there. Research workshops have similar benefits to conferences, in that you have the opportunity to discuss new ideas and network outside your normal collaborative groups. But I find workshops much more fulfilling than conferences, because you have more time to develop those ideas, learn new perspectives, and really get to know people you may not otherwise cross paths with.

The EICAT method we were using is an evidence-based process focused on assessing known impacts, not potential risk. Species are assessed via collation and interpretation of published research, not hypothetical outcomes. (You can read more about it here, here, here.)

I quickly realised how hard this would be for insects. There is so little published information on the distributions, life histories, and ecology of the vast majority of insect species, even in their native ranges. For species that have been introduced outside their native range, there is often a lack of knowledge on what they are doing in that introduced range, especially if the introduction was recent, or if the species hasn’t so far been considered a threat/worth investing research funds in.

Here are a few thoughts I came home with:

~ We need more research on interactions between insects and their environments, including with other insect species, plant species, pathogens, other animal species etc., as well as more published natural history observations. There is a lot of basic knowledge available, including outside academic journals, on generalised life histories at the family and genus level, but species interactions can be unique and contextual. Life history research is still really valuable, but I think studying interactions can lead to deeper understanding of life history more often than vice versa.

~ We also need more insect taxonomists. There are many species that have been renamed multiple times and some that are still ambiguous. Many of our native species are still undescribed. It’s really hard to know what impact an alien species is having, when we don’t even know the names of the species it interacts with. Subspecies are a particularly difficult case to deal with when looking for evidence of environmental impacts, as some studies (especially older literature published before subspecies were described) refer to the standard species name without clarification.

~ Alien species sometimes have beneficial, or neutral, impacts. This doesn’t mean that we should embrace them, and this is not evidence to support introducing more species!! But, given that my current research focuses on teasing out the simplistic ‘goodie’ vs ‘baddie’ labelling we apply to nature, I found it interesting whenever I came across research showing a positive environmental outcome of an alien species. This doesn’t happen very often. But from an ecosystem services perspective, I think there is a big knowledge gap in understanding how these interaction trade-offs occur and what environmental patterns are associated with a species switching between positive and negative outcomes.

~ ‘Sleeper’ alien species are fascinating and present a valid argument for taking all alien species seriously, even if there is currently no apparent threat. Helen Roy, who is doing wonderful work growing citizen science to inform the spread of invasive harlequin ladybird (Harmonia axyridis) in the UK, talked about its introduction to the USA. It was first introduced from Asia in the early 1900s as a biological control agent for aphids, with a few more introductions after that because it didn’t establish viable populations. Then in the 1980s-90s, it suddenly took off and officially became ‘invasive’. There are other examples like this. Without baseline long-term data, how do we know when this happens, and what environmental changes drive this?

~ Citizen science is a great method for monitoring distributions and interactions of native and alien species, while also educating the community. The UK Ladybird Survey is an excellent example of this. Here in Australia, we have FeralScan and the Cane Toad Challenge for vertebrate aliens, but I’m not aware of any citizen science projects targeted at an invasive insect species (although ad hoc biodiversity recording sites like Bowerbird can track invasive species, as happened with the recent spread of the African carder bee). Most people care about their local patch, and are looking for an excuse to get outside and find out what’s going on in the undergrowth. Monitoring campaigns for targeted alien species can be a great resource for building knowledge of their spread. The challenge is to ensure accurate identification tools to avoid similar native species being knocked out by well-meaning participants!

Invasive European wasps (Vespula germanica) devouring a native tussock moth, Victoria Australia.

© Manu Saunders 2018