Home » Posts » News and Views » Pesticides versus Hong Kong mosquitoes killing too much other wildlife
Email to director of the Food and Environmental Hygiene Department, after multiple correspondence with other FEHD officials failed to achieve progress on issue of over zealous use of pesticides versus mosquitoes killing considerable other wildlife:
I’m a birdwatcher living on Cheung Chau, and have made numerous complaints to FEHD regarding fogging and spraying insecticides for mosquito control.
Yes, I appreciate that mosquitoes – including Aedes albopictus – are important vectors for diseases including dengue fever, and now chikungunya.
Pesticide squirted, as if just for the sake of squirting by a path
However, I also believe the use of pesticides versus these mosquitoes is too often excessive, and often extremely poorly targeted
– and that this in turn kills substantial other wildlife.
Also, FEHD officers have contacted me sometimes, perhaps saying the FEHD contractors’ teams would adopt better approaches, but there has been little real progress.
Disastrous impacts on other wildlife
Numbers of moths, beetles and other insects have plummeted around our home in recent years, surely as a result of the pesticides.
This in turn has reduced numbers of insectivorous birds, which I used to find in fair numbers. Also frogs and toads.
Importantly, too, this is surely not just a Cheung Chau issue.
Pesticide fogging at Tamar Park: does not look like habitat for mosquito breeding; surely few here
Kowloon Park, for instance, was formerly a birdwatching hotspot; but has become significantly worse for birds in recent years. Birdwatchers have seen abundant pesticide being applied there – surely no coincidence.
Perhaps in response to my complaints, there was some change, from a reliance on a wide-spectrum insecticide [permethrin], to at least some use of bti toxin.
Bti toxin: not an answer in itself
At first, use of bti toxin seemed to me excellent, as I read it is specific to mosquito larvae; hence should avoid killing other species.
But, I have seen this or other insecticide readily squirted at various places with no water for mosquito breeding; like short grass, even bare earth with almost no plants.
Plus, there seems to be quite a smell after bti is applied, so it seems there are other chemicals accompanying it?
Contractors don’t care??
It appears that the contractors and some of their team members don’t really care; I believe they are just aiming for zero or near zero mosquitoes trapped in sampling places. Perhaps that’s the viewpoint of the contractors; worried that FEHD will complain if mosquitoes are detected.]
Maybe the teams are simply not really trained, educated in just what is being attempted, which should be targeting places where there may actually be mosquito larvae. So even small amounts of water, maybe in trees, but especially in lap sap etc.
Squirting pesticide at vegetation by a path; seemingly random
Alternatives???
More careful application of pesticide
I have often been told that contractors’ teams will be advised to use pesticide more carefully.
Yet seen it still applied carelessly.
An improvement here would be welcome. Including bti toxin applied where there is some water where Aedes mosquitoes may breed.
More publicity about mosquito breeding places around people’s homes
I remember Hong Kong having promotions about “No standing water. No mosquito breeding”
But nowadays, not seeing such promotions.
I’ve looked online, various places like Australia aim for eye-catching, memorable public relations campaigns.
Aussie promotion re eliminating mosquito breeding places around homes
Then, if people help by checking their homes, might also impact mosquitoes overall.
– we check around our home. Did have some water with mosquitoes breeding; after watering an indoor plant. Of course, made sure this place is now dry.
Non pesticide spraying approaches: traps
I have also seen that mosquitoes can be trapped, killed, as the females lay eggs.
Information on In2Care claims their mosquito “stations” can decrease mosquitoes within around 4300 square feet, so around 400 square metres.
I see you use these traps, but mainly for monitoring mosquitoes?
What about increasing the numbers, densities, see if these traps can have a significant impact?
No need to be over wide areas, perhaps; but along the most used sections of paths, such as by housing – where people are more likely to be bitten if there are mosquitoes.
I know a public housing area that perhaps uses such traps; has few or no mosquitoes, but also enough insects that it is a hotspot for small migratory birds.
Well, I am sure your team in FEHD can come up with better, if you agree it is worthwhile finding how to control mosquitoes with minimal impact on other wildlife.
Hope so!
Facebook Comments
I posted the above to Facebook; here are some comments:
We live on Lamma and stress about the same. Would be good to find out if we can build some sort of coalition around this as it is a HK wide issue. Any sense of whether there are any local NGOs working on this?
I have also complained about this on Lamma
We used to have bees, butterflies and dragonflies everywhere, ladybugs too. It’s quite worrying to have them spraying everyday and at every drains, along pavement and at every park in our area. Now we are left with tons of mosquitoes and cockroaches.
Couldn’t agree more that a public info campaign is needed about standing water. Trays under potted plants are seen everywhere. If people know they’re putting themselves at risk of mosquito-borne diseases there will surely be behavioural change
Auto-translated: Thank you for your efforts. Everyone knows that the work you are doing is thankless. We understand that officials, to cope with pressure from higher-ups and complaints from the public, often resort to the simplest actions to prove that they have actually done something. Widespread spraying of insecticides is one of the most direct methods. At least it shows people that something is being done, and in the short term, it seems effective in reducing mosquito problems. For officials or most citizens, other forms of life simply don’t matter, and most people, for the sake of convenience, won’t consider using sustainable or environmentally friendly methods to replace the existing system. In this regard, those of us involved in bee conservation feel this deeply. Breaking this deadlock seems extremely difficult at the current stage.
多謝你嘅付出。
次次噴完之後果日，仲多左俾蚊咬。
都唔知係唔係上一級掠食者俾殺蟲水攪掂左。
蚊又大量第二係度飛過黎。
Auto-translated: Thank you for your efforts. Every time after spraying, the next day I end up getting bitten by mosquitoes even more. I don’t know if the higher-level predators have been taken care of by the insecticide. The mosquitoes are swarming again in large numbers.
我都住長洲，以前行山頂道的確好多唔同種類昆蟲，逢夏天會見到手掌咁大既
仲有蟬，近5-6年
差不多已絕跡在路邊，蟬亦少了很多，唔想比蚊咬自己噴蚊怕水好了！
Auto-translated: I live in Cheung Chau. In the past, there used to be many different kinds of insects along the mountain trail. Every summer, you could see ones as big as a palm, and there were also cicadas. Over the past 5-6 years, they have almost disappeared along the roadside, and there are far fewer cicadas. To avoid being bitten by mosquitoes, it’s better to just spray mosquito repellent!
Thanks so much!!! Pesticides is no doubt one of the biggest environmental problem.
below data is from Cheung Chau volunteer of HKBWS (SSRG). Although we can not confirm the reasons of the rising mortality rate from year 2021, we think that it may related to decrease of all insect by increasing usage of insecticide.
