I’m doing a PhD on saproxylic invertebrates. I was going to say that I am ‘starting’ but I have realised that I am already two and a half months in… terrifying.
When people ask about the topic of my PhD, I usually reply ‘it is about the insects that live in mouldy wood’. I have realised that the term ‘saproxylic’ isn’t a common word in the non-ecologist’s lexicon, and so my previous explanations were met with a lot of confused nodding. Don’t get me wrong ‘insects in mouldy wood’ is still not always excellently received. It usually has people slowly backing away with an amiable smile tenuously stretched over their realisation that they are talking with a crazy person…
But I’m not crazy. Just take a look at some of these examples of saproxylic beetles and I’m sure you’ll see the appeal.
(Left to right: Anaglyptus mysticus, Hylecoetus dermestoides, Thanasimus formicarius, Rhagium mordax)
In reality, my explanation of ‘the insects that live in mouldy wood’ doesn’t cover it. The term ‘saproxylic invertebrate’ isn’t restricted to species that spend their lives living amongst and feeding on decaying wood. It can also describe invertebrates that depend on decaying wood for only part of their life-cycle (for example, many flies rely on rot holes or rotting wood sap in their immature stages). It can even be used for species that aren’t particularly interested in the decaying wood substrates at all, but instead prefer to feast on other invertebrates that are true wood-specialists.
Among the saproxylic groups of invertebrates, I will be focusing on the beetles. These have a wide diversity of saproxylic species with different ways of life. Some bore into trees, making networks of burrows underneath the bark, while others prefer to revel amongst nutritious wood-mould inside tree hollows.
The beetles are the most extensively studied saproxylic insect group. This might be because of their potential as tree pests, their ease of surveying or perhaps just the fact that there are a lot of attractive, conspicuous species. This has positives and negatives for me. On one hand I have lots of papers and books to choose from during my literature review, on the other hand, I might have to be relatively creative to make sure that I’m not walking pre-trodden ground in my experiments.
For the PhD, I am working with Natural England and Buglife to study these beetles with an ecology and conservation slant. The current main aspects are:
- understanding the amount of habitat connectivity that is important for these insects
- trialling a potential ‘artificial habitat’ (like a bird box) to help supplement the resources of one of the UK’s endangered beetle species, the violet click beetle.
So far, I have been having a lot of discussions and doing a lot of experimental planning along with the inevitable truck-load of reading. However, I have had time to squeeze in a few site visits, which have definitely been highlights of my PhD time so far. I leave you with some pretty pictures of these. Hopefully I have such good weather in the months of experimental set-up to come.