TESSA OH Today Online 2 Sep 19;
SINGAPORE — Residents living around the Pandan Reservoir said that the recent outbreak of midges in the area is like being “in a horror movie”, Member of Parliament (MP) Foo Mee Har said on Monday (Sept 2).
Describing it as the “most severe” outbreak that residents have witnessed, Ms Foo, MP for the West Coast Group Representative Constituency (GRC), added that the midges stick to clothes and hair, and residents have found swarms of them in corridors, lifts, bus stops and in their homes.
Responding to questions from three MPs, including Ms Foo, Environment and Water Resources Minister Masagos Zulkifli said that the sudden spike in midge activity can be attributed to the recent spell of unusually hot weather, which has hastened the growth process of the midges.
“With climate change, we will experience more extreme weather, which will have a corresponding response from nature,” he said.
Mr Masagos noted that the midges do not bite or spread disease. Outbreaks since the late 1970s had lasted for as little as two weeks, or as long as five months.
He added that national water agency PUB has implemented several measures to mitigate the impact of midges on the residents living around the reservoir since the outbreak began in the middle of July.
For instance, PUB has increased the frequency and dosage of the application of biological liquid larvicide in the reservoirs to help eliminate midge larvae. It has also increased the frequency of fogging and misting around the reservoir dyke and surrounding vegetation to kill adult midges.
These methods have been proven to be effective at killing midges at the relevant stages of their life cycle, Mr Masagos said.
PUB has also installed bright spotlights at the Pandan Reservoir's pumping station and switched them on at night to attract adult midges towards the reservoir and away from residents’ homes.
The agency will continue to monitor for midge emergence at reservoirs and conduct frequent checks for larvae in samples of reservoir sediments or for adult midges trapped around the reservoir vicinity, he said.
The dominant midge in the present outbreak is a rare one, unlike an outbreak at the reservoir in 2016, he said. This species hides in drains and culverts in the day and swarms above the drains in the evening.
To tackle this, PUB has rolled out more measures to alleviate the issue, such as greasing the drain walls to trap the midges when they land, he said.
SCREENS AND NETS
In a supplementary question, Ms Foo asked if the Ministry of Environment and Water Resources (MEWR) would consider working with other agencies to help the affected families to protect themselves against the midge outbreak by providing them with screens and placing nets in prominent areas such as bus stops.
She also asked MEWR to consider planting more trees and shrubs around the reservoir so that the midges can congregate around the vegetation rather than go into residents’ homes.
Similarly, Dr Chia Shi-Lu, MP for Tanjong Pagar GRC, asked in a supplementary question whether MEWR will consider looking into ways to change the microclimate around the banks of the reservoirs, citing studies that have shown that this can have an impact on midge outbreaks.
Mr Masagos said that the ministry will consider the proposed suggestions and will work with the relevant agencies to ascertain if such measures can help to alleviate the problem.
“We don’t want to create new problems such as people having different kinds of pests (in their homes) because of the kinds of trees that we have planted near their homes or around the reservoirs,” he explained.
MIDGES ARE HERE TO STAY
However, Mr Masagos cautioned that to expect that the midges can be completely eradicated is unrealistic, given that they are part of Singapore’s natural aquatic ecosystems and are food for fish and birds.
“At the end of the day, we have to recognise that man cannot control nature. We can only do our best to suppress (the problem) and we have to (learn) to live with nature. In fact, we are the ones intruding into their living spaces,” he said.
Mr Masagos also noted that efforts to combat the problem must find a delicate balance as relying too much on larvicide and fogging will compromise the health and safety of Singaporeans.
“There is a tradeoff between killing enough or killing so much that in the end, we kill ourselves. There is a limit to which these measures can mitigate the issues that residents are facing,” he said.
PUB stepping up measures to tackle emergence of rare dominant midge species at Pandan Reservoir: Masagos
Ang Hwee Min Channel NewsAsia 2 Sep 19;
SINGAPORE: 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 (Sep 2).
“The species exhibits different behaviours from other species. For example, they hide in drains and culverts in the day and swarm above the drains in the evening,” he added.
The minister was replying to parliamentary questions from MPs about the rise in the midge population at Pandan Reservoir and the measures being taken to address it.
Providing details, he said PUB has greased drain walls to trap midges when they land to rest, and have targeted these areas for fogging.
PUB has also explored the use of free-moving oily paper within drains to increase the capture rates of adult midges, he added.
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.
“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 added.
PUB said in a Facebook post on Aug 1 that it has stepped up measures to control the rising midge population around Pandan Reservoir.
These include increasing the frequency and dosage of biological liquid larvicide within the reservoir, increasing the frequency of fogging and misting around the reservoir dyke and surrounding vegetation, as well as the installation of bright spotlights at the Pandan Reservoir pumping station to attract adult midges when they emerge at night, said Mr Masagos.
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.
Speaking in Parliament, 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.
“Their homes have been invaded by the midges. Corridors, lifts and bus stops have been swarmed. And the midges stick to your clothes, your hair, fly around your eyes, get into your nose, get into your food, and they’re everywhere.
“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.”
Ms Foo raised concerns about the health risks of exposure to chemicals from sustained fogging, and whether residents could be supported with insect screens for their homes as such installations can be costly.
Mr Masagos said the pesticide used by PUB has been certified safe and suitable for use by the World Health Organization, and is also diluted before use.
As for the installation of insect screens, Mr Masagos noted that the residents can also protect themselves and their property.
“This situation doesn’t come all the time, not every year. And to put in something that will become a permanent feature, this may also affect the image of the reservoir or the places around the reservoir,” he added.
Mr Masagos also explained that the larvicide used in the reservoirs is a safe, biological larvicide.
“It is actually a naturally occurring soil bacteria, which produces spores that are toxic specifically to the digestive system of midge larvae.”
Underscoring the importance of maintaining water quality, he added: “There is a trade off between killing enough midges, or killing so much or everything that we kill ourselves. We can’t do that either. There is a limit to which these measures can mitigate the issues that residents are facing.
“This problem is really man versus nature, the kind of war man has never been known to win. We can only suppress it and do our best but we have to live with nature. In fact, we are the ones who are intruding into their living spaces.
"Our reservoirs supply drinking water to the population and we have to be careful to ensure that PUB’s mitigation measures, both short- and long-term, do not end up compromising water quality."
Source: CNA/hw(mn)
