New Horsehair Worm from Peru

The Nematomorpha, those long, thread-like parasites of arthropods are found all over the world and can be relatively common in some places. Peru is something of a blackhole for them though, and until recently no species were known from this hotbed of biodiversity. This is just down to a lack of collecting rather than a lack of species. These animals are actually fairly easy to collect, especially for entomologists. The likely hosts, e.g. Orthoptera, Mantodea, Blattodea, Coleoptera can be dunked in water and if there’s a mature nematomorph present it will make a sharp exit from the host. In certain hosts, you don’t even have to go to these lengths as the parasite can often be seen through the integument of the abdomen.

In 2018, during an expedition to Peru, a Eubliastes bush-cricket came to our MV light trap and got accidentally squashed. Sensing that its host was doomed, a nematomorph forced its way out and into a collecting tube. It turned out to be a new species of Acutogordius and we called it. A. olivetti after the stream near where it was found.

Here’s a link to the PDF of the full description of the new species by Andreas Schmidt-Rhaesa and I.

The meagre records of these animals is not limited to Peru. They’re very poorly known from the Neotropics in general, so if you find yourself in any Central American or South American country soon, notwithstanding Covid, then please keep your eyes peeled for them.