Why euthanise some moths?

Moths are euthanised in order to create reference collections. Dr Barbara Anderson from Ahi Pepe MothNet, and Dr Robert Hoare from Manaaki Whenua – Landcare Research explain the value of reference collections for species identification and monitoring.

Transcript

DR BARBARA ANDERSON

One of the reasons that it’s really important to sacrifice them is in order to make a reference collection because it makes identification easier. So if they have a three-dimensional moth specimen here in the school, then it’s much easier to compare a live moth with that one.

DR ROBERT HOARE

We simply don’t have photographs of live moths of a lot of these species. It would take an awful lot of work to go out there and find live specimens of all these species and to get standard photographs of all of them, whereas in the collection, we have all these species nicely spread out and we can make standard photographs.

DR BARBARA ANDERSON

From the science point of view, reference collections and museum collections are really important, because they are a bank of information that is curated and it’s kept safe for future generations. And right now, we have a lot of environmental change that’s happening and has already occurred in New Zealand and across the world. But we can’t go back in time and sample there. The only way we can look at species interactions or even distributions of species – moths and plants and herbarium – is from museum collections.

Robert has this amazing story of this moth that was once very common across New Zealand, and we know this because it’s in museum specimens. It’s now very rare. But the other interesting thing about that moth is that we thought that it was one species. When Robert went back through all the museum collections, he could see very clearly that it was in fact two species. And the one that we thought was common everywhere has declined to the point that it’s actually very rare now, and we don’t know why. It might be that its host plant has gone, it might be that it’s just the favourite snack of a mouse or a hedgehog. But we wouldn’t even know that that moth was declining if we didn’t have the reference collections, if we didn’t have those biological collections there.

Acknowledgements Tiahuia Kawe-Small Dr Barbara Anderson Dr Robert Hoare The tamariki of Te Kura Kaupapa Māori o Ōtepoti

Ahi Pepe MothNet Manaaki Whenua – Landcare Research Museum of New Zealand Te Papa Tongarewa National Institute of Water and Atmospheric Research (NIWA)