Two new species of flies discovered in island's mangroves

Two new species of flies with quirky characteristics were discovered in the mangroves of Pulau Ubin in 2018 and 2019.

The offspring of one fly dwells in dung, while the other fly feeds on sandflies - a known pest and bane of many beach-goers.

The insect-gobbling fly, found in May 2018, is called the long-legged fly, and its scientific name - Trigonocera ubinensis - was inspired by the island.

For the April 2019 discovery of the new sepsid fly with a faecal connection, it was a double victory.

Not only is the insect a new species, but its discovery also saw the creation of an insect category, or genus, new to science.

The National Parks Board (NParks) announced the twin discoveries on Ubin Day yesterday.

Both flies were found by Dr Patrick Grootaert - an NParks research fellow and head of entomology at the Royal Belgian Institute of Natural Sciences - while he was doing fieldwork on Pulau Ubin.

The findings underscore the rich biodiversity in Pulau Ubin, which is home to more than 530 known species of birds, butterflies, mammals and reptiles.

The flies were discovered during a survey of insects, where traps were placed at different parts of the mangroves on the island.

During the process of sorting the various insects caught, new species may be discovered, and that was what happened in 2018 and 2019.

The long-legged fly was found in the mangroves on the western side of Pulau Ubin, and the sepsid fly was discovered in the mangroves of Sungei Teris.

The sepsid fly's larvae reside in dung, which likely comes from wild boars.

As for the long-legged fly, it was found to be a predator fly that devours smaller insects such as midges and sandflies.

NParks and researchers are excited by the discovery of a new predator fly in Pulau Ubin mangroves, because it indicates that the mangrove ecosystem is thriving, with a healthy number of insects and plants to sustain the food chain.

NParks' group director of conservation, Mr Lim Liang Jim, explained: "Predators are at the top of the food chain, which means that they have a lot of prey insects to feed on, and the prey insects also have flowers, leaves and the sap of plants to feed on."

However, further surveys are needed to get a complete picture of the fly's population.