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You’d think that after all of these years roaming Earth humans would have discovered every species possible. There’s approximately 8.7 million animals, plants, insects and bacterium on the planet, according to study published in the PLoS Biology journal in 2011. Yet more than 15,000 living things are discovered and named every year.
But how do you know if you’ve found something that’s never been identified? According to Dr Anneke Veenstra, senior lecturer at Deakin University, you need to know what you’re looking for. Her particular interest is the Cecidomyiidae – a family of flies. They’re commonly known as gall midges and they’re small enough to walk on a strand of spider’s web without getting caught in it.
There hasn’t been a lot of research into the gall midge family in Australia and there could be hundreds of gall midge species to discover, according to Dr Veenstra. She’s currently assessing a possible four new species, two of which were recently found by Deakin students.
Dr Veenstra sat down with us and explained the steps they took in making these discoveries.
Samples are collected in the field
The first step is to look for an unusual growth on a plant that’s known as a gall. That’s where gall midges grow. ‘Galls are abnormal plant tissue. No one knows precisely how the gall midge does it, but it convinces the host plant to produce galls rather than producing normal shoots, leaves or flowers,’ says Dr Veenstra. New insects develop as larvae, then pupae within the gall.
The difficulty is finding the right leaves on the right plant. Because there are still many species of gall midge to be discovered, they can be found on a number of different native plants. There are opportunities to find them everywhere. Recently Deakin science student Jess Longmuir found new galls on a snowy daisy bush in Emerald.
'Galls are abnormal plant tissue. No one knows precisely how the gall midge does it, but it convinces the host plant to produce galls rather than producing normal shoots, leaves or flowers.'
Dr Anneke Veenstra,
DNA is sequenced and assessed
If a female gall midge has laid an egg on the plant and a gall develops, Dr Veenstra puts them in a snap-lock bag until the adult emerges. Dr Veenstra collects the galls and monitors them until they have developed, which takes about 30 days, and preserves them in ethanol. She then mounts the gall midge adult that has developed on a slide, looks at their head, wings and collects the DNA using a forensic kit.
‘In the past you had to use between three and six of the same insect, now you can use part of their body,’ she says. Once the DNA has been sequenced, it can be compared to the DNA of other gall midges that have already been submitted to Genbank, an international database. If it’s a new DNA sequence, then it’s a brand new discovery.
The new species is named and documented
If the DNA proves it’s a new species, then it’s time to name it. There needs to be a logical reason for the name and it must be Latinised. For example, if the gall looks like a flower, part of the new gall midge’s name might be Floriformis (flower-like). Recently, Dr Veenstra incorporated a student’s surname into the name of a new gall midge – Asphondylia peelei – named after Colleen Peele, a Deakin student who discovered galls growing on a saltmarsh plant. But she says it’s not possible to go naming all new species after one’s self, as each new discovery must have a different name.
For the discovery to be on the record, it must be documented in a journal such as Austral Entomology. The key features – such as the antennae and wings and other distinctive characteristics – must also be drawn. Once it’s published, it’s listed in the International Commission on Zoological Nomenclature catalogue and the finder gets eternal bragging rights.
Interested in finding a new species of insect? Check out Deakin’s courses in Zoology and animal science. Dr Veenstra is part of Deakin University’s School of Life and Environmental Sciences.
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