Some musings on insects...

The UCL Conservation Group’s ‘Insect Insights II’ which happened this week got me thinking about the smaller organisms we share the planet with. Whilst I’m not sure they’re any less likely to go out of the window when I come across them in my bedroom (sorry, arachnophiles, learning about their ecological roles has made me appreciate them a bit more. Conservation does seem to focus on characteristic fauna and larger organisms, quite obviously since they provide more visible action to be taken, and also are easier to track in case of loss.

But insects have an important role in global biodiversity, making up a massive proportion of global species - they account for more than 2/3 of terrestrial species. And like other terrestrial species, their decline is significant and concerning – with this study reporting losses in 71 species of more than 30% in the last decade, which would cause them to be considered as ‘threatened’ using IUCN definitions.

Bees are the posterchild of insect conservation, perhaps due to their significant contribution to ecosystem services, but their risk from climate change is very high. Changing phenology of plants and flowers associated with shifts in temperature risks causing difficulties for these crucial pollinators. Despite the speed of climate change, many species around the world have been able to shift their range in an attempt to adapt, but the humble bumblebee (Bombus) has shown an inability to respond to changing temperatures by altering its northern and southern ranges (Kerr et al 2015). Human land use is further damaging their ability to adapt, with the use of pesticides and removal of natural land contributing to species declines. The potential loss of bumblebees is worrying both in terms of their importance as pollinators in symbiotic relationships with plants, and also in terms of their role in ecosystem services that aid agriculture – a role that we take for granted, but is essential with 84% of Europe's crops having some dependence on pollinators.

Furthermore, insects are a key example of one of the caveats to measuring and monitoring biodiversity. It’s difficult to accurately say how many terrestrial mammals we are losing as we can’t be 100% sure how many there are, and with insects this is only magnified, with an estimated 10 quintillion (10,000,000,000,000,000,000) individuals present. Each year 15,000 new species are reported and due to the size of insects it’s likely there are many that we haven’t yet discovered.

We have little quantitative data for insects and so conservation is difficult, with the only practical solutions being to maintain known habitats. Perhaps it’s likely that insect biodiversity loss will be just another consequence of climate change that we underestimate.