The mysterious midge: is this plague of the Irish summer due some respect?

This small mosquito can be a menace to people and deadly to animals, but the little-studied insect plays a role in pollination


They are as part of the Irish summer as the cuckoo, and food for him, too – but not nearly as welcome. We have up to 80 different biting midges and those are just the ones we know about. And we don’t yet fully understand them.

Climate change and increased movement globally in goods, animals and even humans will introduce more of the thousands of species of biting midge worldwide, it is also expected.

Not all midges bite. The biting midge belongs to the family Ceratopogonidae. And while the scientific name refers to bearded horns or antennae of the male, it is the female that bites, because she needs protein from blood to produce her eggs. The rest of the time she and the male are eating nectar.

Midges can be a nuisance to many people but they can be fatal to livestock, with farmers already alert to how they spread blue tongue in cattle and sheep, says Dr Aidan O’Hanlon, entomology curator at the National Museum of Ireland.

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“Much of our information on biting midges comes from the late Dr Paddy Ashe (formerly of the Natural History Museum), who was a world expert on the non-biting midges but also published on the biting species and on the Irish mosquitoes as well.”

Mosquitoes are being monitored by the HSE at ports and airports for the arrival of the Asian Tiger and Egyptian mosquito, now an emerging invasive species across the EU

The museum is taking part in a new research project with UCD and the South East Technological University.

The Network of Insect Vectors in Ireland project, funded by the Department of Agriculture, wants to find out more about our resident midges and mosquitoes, identify what they are spreading and forecast likely effects of climate change on them.

The researchers have gathered samples from volunteers all across the country to investigate the prevalence of midges around livestock. A mosquito survey is planned for this summer, says O’Hanlon.

Mosquitoes are being monitored by the HSE at ports and airports for the arrival of the Asian Tiger and Egyptian mosquito, now an emerging invasive species across the EU. These carry serious diseases, such as malaria, yellow fever and dengue fever.

So far, only common native Irish species, of which there are 20, have been collected in the samples sent to O’Hanlon to identify. Irish mosquitoes do not carry malaria.

Covering oneself may be the only sure way to prevent bites. Cloughaneely Angling Assoication in Donegal advises anglers to cover up when there is not enough wind.

“In Donegal there is normally enough wind to keep the midges at bay. However, it is advisable to carry a midge net or midge repellent for those calm, warm days when they are active,” anglers are told.

It was only in 1940s that a midge was discovered to be the key pollinator for the cacao (coca/chocolate) plant with its “really complicated flowers”

Dr Fidelma Butler, an ecologist at the School of Biological Earth and Environmental Sciences at UCC, says the western coast is a great breeding ground for the midge but climate change may affect the distribution and spread it.

Midges breed in damp ground and they emerge in swarms at dawn and in the evening when the air is most humid. “They don’t like dry conditions,” says Butler.

There is a global lack of information on midges, which means their role as pollinators is probably not fully appreciated, she says. It was only in 1940s that a midge was discovered to be the key pollinator for the cacao (coca/chocolate) plant with its “really complicated flowers”, she adds.

The ecologist firmly believes that some people attract biting midges more than others, and says she herself is “living proof” of this. “They are attracted by CO₂ and by chemicals you give off. People do give off chemicals and [some] are more attractive than others.”

It is also the case that once bitten, more bitten. When female midges feed, they themselves give off a chemical saying they have had a good meal, and other midges arrive for their fill, says Butler.

Oil, even olive oil, on the skin can act as a barrier and prevent midges from taking a bite, the ecologist says.