Macau eyes mainland smart mosquito traps as alternative to citywide chemical spraying

With mosquito breeding site indices rising in February and March, the Health Bureau (SSM) has warned that a citywide chemical control campaign may be considered if infestations worsen, though authorities have approached a mainland smart mosquito-trap manufacturer about importing trial units to Macau.

Mosquito breeding conditions have worsened significantly, authorities previously told the media, with April’s ovitrap index hitting 38% – well above last April’s 15% and the five-year average of 30% – while the February and March averages reached 2.2%, up from 0.7% and 1.2%, respectively, a year earlier.

Noting that five imported cases of dengue fever and two imported cases of chikungunya had been recorded during the January-to-April period this year, authorities acknowledged that the risk of transmission of both dengue and chikungunya is anticipated to persist.

Given Macau’s status as a tourist destination characterized by high volumes of population movement, the risk of dengue and chikungunya transmission is projected to continue rising, authorities added.

Longstanding environmental hygiene and safety concerns in Macau’s older districts – encompassing aging building stock and urban structural deficiencies, including “three-nil buildings,” vacant construction sites, neglected corners, back alleys and narrow passageways, as well as deteriorating drainage networks and roadside drains – have long been recognized as stagnant-water black spots and sanitation blind zones.

These concerns were brought before the Legislative Assembly (AL) by lawmaker Lee Koi Ian, who called on authorities to strengthen mosquito prevention and control efforts during the summer rainy season and to reinforce emergency resilience mechanisms.

Separately, other legislators inquired whether authorities would investigate and conduct trials of the so-called “Sky-Swallowing Frog” mosquito-eradication technology, a purported high-tech innovation developed in Hangzhou that claims to eliminate between 7,000 and 30,000 mosquitoes per day.

According to authorities, they have scheduled mosquito control operations at a minimum frequency of twice per month for more than 130 sanitation black spots and over 140 municipal facilities throughout Macau. During the first four months of this year, 274,000 insecticide spraying operations were carried out on street drains, alongside 5,600 site inspections and 800 chemical mosquito control treatments.

Notably, from last year through April of this year, the Municipal Affairs Bureau (IAM), operating under its established mechanism for addressing hygiene issues on private land and vacant lots, facilitated the removal of approximately 212.5 metric tons of waste and conducted inspections covering more than 900 “three-nil” buildings – properties lacking property management, residents’ associations or maintenance funds.

Addressing the Legislative Assembly during Wednesday’s plenary session, Secretary for Social Affairs and Culture O Lam announced that preliminary planning envisions the deployment of drones to target hard-to-access locations – including vacant land, high-rise platforms and remote areas – for the purpose of breeding-source inspection and monitoring, thereby mitigating mosquito proliferation risks at their origin.

She further confirmed that the Municipal Affairs Bureau has already installed novel mosquito control devices in select municipal parks and cemeteries.

These devices function on the principle of biological control, interrupting the maturation of mosquito eggs and larvae into adult mosquitoes, while infected mosquitoes perish within several days.

The government is “working on” importing a small number of “Sky-Swallowing Frog” mosquito-killing units for trial, O Lam told the AL, reaffirming the government’s strong commitment to mosquito prevention and control.

The device uses physical attraction by converting carbon dioxide in the air to mimic human breath, she explained, though the product is currently “in short supply.” Authorities added that a citywide mosquito control campaign would only be considered if a widespread outbreak occurs.