PUB releases thousands of fish in Pandan Reservoir to combat midges

Channel NewsAsia 6 Sep 19;

SINGAPORE: National water agency PUB has released "tens of thousands" of fish into Pandan Reservoir, the latest measure employed to try to control the midge pupae population, it said on Friday (Sep 6).

The release of the guppies, mollies and swordtails into the reservoir was done in a controlled manner that does not affect its ecosystem, PUB said in a Facebook post.

Midges, which are commonly mistaken for mosquitoes, are small insects which exist in and near water bodies.

"While these midges do not bite or spread diseases, they can be a nuisance when present in large numbers," said PUB.

Residents and businesses at Teban Gardens have been affected as swarms of the insects have infested the neighbourhood.

PUB biologist Tricia Poh releasing fish into Pandan Reservoir to help control the midge pupae population. (Photo: Facebook/PUB)
PUB said insect nets have also been installed at bus stops along Penjuru Road and West Coast Road.

The nets are laced with permethrin, an insecticide used in PUB’s fogging operations. It is non-toxic to humans.

An insect net installed at a bus stop along West Coast Road to help deter adult midges from entering the area. (Photo: Facebook/PUB)
Earlier, PUB said in a Facebook post on Aug 1 that it had stepped up measures to control the rising midge population around Pandan Reservoir.

These include putting more biological liquid larvicide within the reservoir, fogging and misting around the reservoir dyke and surrounding vegetation more frequently, and installing bright spotlights at the Pandan Reservoir pumping station to attract adult midges when they emerge at night. According to PUB, the bright lights deter them from flying into residential estates.

There are approximately 57 species of non-biting midges in Singapore's reservoirs.

The current dominant midge species that has recently emerged at Pandan Reservoir is a rare one that has not been studied in great detail, said Minister for Environment and Water Resources Masagos Zulkifli in Parliament on Monday.

The species exhibits different behaviours from other species, he added.

“Midges cannot be eradicated as they are part of the natural aquatic ecosystem, and will emerge to breed, especially when aided by favourable environmental conditions. Climate change will further complicate our efforts,” he said.

Pandan Reservoir midge infestation: 'You can say that we’ve given up'
Ang Hwee Min Channel NewsAsia 6 Sep 19;

SINGAPORE: For the past month, stallowners at Makan Shiokz coffee shop on the ground floor of Block 49 Teban Gardens have had to watch their regular customers turn around and go home after seeing the swarms of midges plaguing the block.

“At around 6 or 7pm, I see them walk here to buy food, and after they see the midges, they u-turn and go home,” said the coffee shop manager, who only wanted to be known as Zai.

“They don’t even want to come here and take away food. It's so sad. We couldn’t even do anything,” he added.

Located adjacent to Pandan Reservoir, the coffee shop has seen a 40 per cent dip in business over the past month, said Zai.

He told CNA that the stallowners have grown so frustrated at the swarms of midges that they decided to take the problem into their own hands.

“First we tried electric racquets. Then we bought electrical insect traps. Then we tried glue boxes. Then these weren’t working, so we bought small fogging machines to try fogging ourselves, and now we’ve put up this net.

“Every night in August, we even used a paint brush to brush the net and the columns with oil, because it is sticky and the midges get stuck.”

“The problem with (the coffee shop) being here, is because we are located at an angle and there is no HDB blocking us, the wind blows all the midges towards (the coffee shop),” said Zai.

“Whenever they do the fogging, it works for the reservoir, but then the midges come to us. You can see them sticking to the second and third floors also.”

He added: “We did email PUB asking if there’s any possibility for us to get compensation, because (the reservoir) belongs to them. But they emailed back and said no way of compensation.” According to Zai, PUB informed residents that the problem is predicted to persist until October.

“The insects really fly into your food. It makes me uncomfortable,” said housewife and regular customer Ms Normah Johan, 53.

Ms Normah stopped eating at Makan Shiokz for about a month, but recently started going to the coffee shop again as she observed that there has been a reduction in the swarms of midges.

Her husband, Mr Aziz Biat, drives a lorry for work every day, and has to wash it more often because the midges stick to the vehicle after he drives around the area.

“When it was hot in August, there were really a lot of insects flying around. Now it is a bit better,” said the 61-year-old. “Actually this is not so bad, it is just irritating. At least it is not mosquitoes, that actually can be dangerous.”

The couple has lived at Block 24 Teban Gardens for over 20 years. While their home has yet to be invaded by midges because their block is located further away from the reservoir, the family closes all their windows and sprays insect repellent before going to bed.

When CNA visited Teban Gardens between 4.30pm and 7pm on Thursday afternoon (Sep 5), midges were swarming above drains in large numbers, and dead midges had accumulated in crevices on walls and pillars, appearing to be dirt or dust at first glance. Standing still resulted in midges swarming around and getting into one's eyes, mouth, nose and hair.

At about 4.30pm, Block 31 and Blk 33 Teban Gardens, which directly face the reservoir, were washed down with water jets. And at about 6pm, PUB officers carried out fogging around the reservoir, as well as drains surrounding the blocks next to the reservoir.

PUB said in a Facebook post on Aug 1 that it has increased the frequency of fogging and misting around the reservoir dyke and surrounding vegetation, frequency and dosage of biological liquid larvicide within the reservoir, as well as the installation of bright spotlights at the Pandan Reservoir pumping station to attract adult midges when they emerge at night.

According to PUB, the bright lights deter them from flying into residential estates. Midge egg masses attached to floating structures and rocks along the edges of the reservoir have also been removed.

Residents and passersby were spotted wearing masks, swatting the insects away and avoiding drainage areas where huge swarms of midges were gathering.

Mr Lim Thiam Chye, who works in a provision shop in the industrial area near Pandan Reservoir, has worn a mask and a cap to work every day since the midge emergence began in July, to prevent the insects from flying into his eyes, nose and mouth.

“It rained the other day, and the midges disappeared for a while. A few days later, they were back and there was even more of them,” said the 57-year-old in Mandarin.

“I don’t think the fogging has helped. The number of midges hasn’t decreased at all, and the wind is so strong, it just blows them back to the HDB area,” he added.

After the fogging on Thursday ended, CNA observed swarms of midges returning to the drains and the surroundings just 15 to 20 minutes later.

Resident Xavier Lopez, who has lived at Block 40 Teban Gardens for over 40 years, said the midges emergence happens most years.

“But this is the first time it is like that. It’s been going on for more than a month, last time is at most one week. It’s probably the most insects I’ve seen,” he added.

Mr Lopez said he closes all his windows at home, but this does not prevent midges from flying through the bathroom windows. He told CNA that dead midges accumulate on the floor, walls and mirrors, and he washes the toilet every day. He also does not turn on any lights, even at night.

Student Zena Seah and her family have adopted similar habits, choosing to leave all windows closed at all times. They also avoid turning on the lights, as they have observed that midges swarm around their bright kitchen lights.

Zena, who stays in Block 25 Teban Gardens, said she encounters swarms of midges in the lift when she leaves and returns from school. “I don’t even dare to open my mouth,” she said.

When she eats at the nearby hawker centres, she has also noticed midges landing on tables and chairs.

“There was once I went to the hawker centre to get food, and I saw a table full of black marks. Then the cleaning aunty wiped the table, and I realised it was all dead midges,” she added.

But Zena said that while the midges are a nuisance, they have not affected her family’s daily routines. “We don’t really care. Even if we see them, they’ll die in one to two days anyway.”

The current dominant midge species that has recently emerged at Pandan Reservoir is a rare one that has not been studied in great detail, said Minister for Environment and Water Resources Masagos Zulkifli in Parliament on Monday.

The species exhibits different behaviours from other species, like hiding in drains and culverts in the day and swarm above the drains in the evening, he added.

PUB has greased drain walls to trap midges when they land to rest, and have targeted these areas for fogging, he said. It has also explored the use of free-moving oily paper within drains to increase the capture rates of adult midges.

The netting on the reservoir dyke has also been extended by 1km, said Mr Masagos, acting as a barrier to trap adult midges and reduces the number of adult midges that would otherwise be blown to residential estates.

Speaking in Parliament on Monday, MP for West Coast GRC Foo Mee Har said residents who live near Pandan Reservoir have “suffered greatly” from the mass emergence of midges since July this year.

"This year’s outbreak is the most severe we have witnessed yet and also persisted for the longest time, impacting the daily lives of our residents. Some have likened it to being in a horror movie. If you visited it's really scary," she added.

READ: PUB stepping up measures to tackle emergence of rare dominant midge species at Pandan Reservoir: Masagos
READ: PUB to carry out fogging, checks as midges multiply near Pandan Reservoir
As for Zai, returning home is not an escape from the midges at work. The 46-year-old lives in a unit in the same block.

He spends his free time looking on the Internet for solutions that might work against the midges, but has not found any other options yet. “I do not know what to do anymore. Seriously, I do not know what to do anymore,” he said.

He added that while he, along with other stallowners, used to paint the insect net and columns with oil by hand every night, they have since stopped doing so.

“You can say that we’ve given up. There are just too many.”

Source: CNA/hw