Why houseflies and fruit flies are vital to global ecosystems

To many, they’re just nuisances, but houseflies, fruit flies and other maligned flying insects are major migratory players that deserve further study, according to new research that calls them a “vital” part of global ecosystems.

The analysis looks at the order Diptera, which includes more than 125,000 species of what the insect world calls “true flies.” Despite their abundance and diversity, the researchers write in the journal Biological Reviews, the flies’ migratory behavior is not as well studied as that of more “charismatic” insects such as butterflies.

In a literature review, the researchers found evidence of migration behavior in 47 percent of all 130 families of Diptera. Some families in the order have a higher percentage of migrants than better-studied butterflies, the researchers found.

These migrating flies use everything from the wind to the sun and polarized light to aid their migrations, enhancing their migratory abilities by increasing their fat store and even growing so they can sustain long-distance flight. Likely migrants migrate along “flyways” across the globe, even flying to Antarctica.

Along the way, migrating flies act as crucial pollinators for valuable crops, help break down the waste of other organisms, and carry nutrients and diseases. They’re also threatened by the same ecological threats that affect other types of animals, with climate change, pollution and habitat loss contributing to declines in some species.

Overall, the researchers write, migratory flies “play an unsurpassed range of ecological roles” - and there’s much more to learn about them.

“What we’ve uncovered is that Dipteran migrants are vital to the planet’s ecosystems, yet they are hugely underappreciated,” study co-author Myles Menz, a senior lecturer in zoology and ecology at James Cook University, said in a news release. “This review will hopefully inspire many more studies into this fascinating and important world of fly migration.”