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The history of civilization is partly one of a never-ending struggle to bend nature to our will. As we mastered agriculture and constructed buildings, we decided certain species of animals and plants were undesirable and labelled them as pests that should be excluded. Over the centuries, we have developed various strategies and tools attempting control these pest species and in the past ninety years or so, have applied the science of modern chemistry to the issue, creating highly toxic compounds that are used on crops and in buildings alike.

However, the development of these latest tools along with advances in other scientific fields such as ecology, highlighted a fundamental problem with our approach which is that we’re fighting a war with nature that we not only cannot win, but which is putting ourselves and species we don’t consider as pests at risk. This is the message that Rachel Carson gave us in Silent Spring.

Why is this a losing battle? Consider today’s conventional approach to pest control in a modern office building, which typically involves periodic spraying of chemicals inside the property regardless of whether there’s a significant pest problem. This strategy tacitly acknowledges two issues with the approach: that the toxic chemicals being applied will linger in the environment for some time, and that even after their application, the pests will continue to be a problem.

This second point is a major issue for a chemical-only approach to pest management. Pest species usually have rapid breeding cycles and individuals surviving pesticide application events reproduce and pass on their genes to the next generation, helping the population to evolve innate resistance to that chemical.Pesticide resistance, which is something Carson talked about sixty years ago, is a serious issue and many previously effective compounds are now ineffective as pesticides against resistant populations.

Because these pesticides are not specific in who they target they often raise questions about their safety to human health which can take decades to answer. Chlorpyrifos, a common pesticide that is legal in Taiwan, is a good case in point. Patented back in 1966, it wasn’t until 2016 that it was (mostly) banned in the UK, 2020 when it was banned in the EU, and 2021 when it was banned for use on food crops in the US. Even now, policymakers cannot agree on whether it should be banned completely worldwide, despite the US EPA considering it posing a significant threat to the neural development of children exposed in-utero, and evidence that the chemical has spread across the globe, even to Antarctica(1).

Placing non-toxic mosquito traps

There is a safer, more effective approach to pest control, and it’s called Integrated Pest Management (“IPM”). IPM is founded on the acknowledgement that we can’t permanently exclude pest species from a space such as an office building. Even if we could eradicate all pests in the building one week, more will come in from the surrounding environment the next, so long as there is something in the building that those creatures value, usually food or shelter.

The first step in any IPM program is knowing which species of pests pose a risk and understanding their biology to develop effective non-chemical solutions. This provides important information such as seasonal fluctuations, how pests are likely to gain access to a space, what factors attract each species, which pests are potentially more of an issue and in what numbers they represent a significant problem.

Armed with this knowledge, a species-specific IPM plan can be created, following a hierarchical approach to pest control. Priority is given to preventing access to the space, largely through better maintenance and operating procedures. For example, cracks or small holes in walls must be sealed, waste (especially food waste) must be properly stored, and spaces kept clean. This is accompanied by an ongoing program of monitoring throughout the building to check for access points, that hygiene operating procedures are being followed, and to see if there are any signs that pests are in the building.

The IPM plan will list two action thresholds for each pest species. The first is the frequency of pest sightings that require active intervention. The second is the frequency of pest sightings that require emergency intervention. These thresholds will be different for each species and based on the knowledge of their biology and potential risk. For example, the action threshold for cockroaches could be the sighting of one individual on the basis that if one cockroach is spotted, there are likely to be more that can’t immediately be seen. However, the action threshold for mosquitos may be five in one space at one time, because one or two could have simply flown in an open door or window and may not represent a larger problem.

Active intervention progresses through a series of species-specific treatment or removal methods, first physical or mechanical, then biological, and finally chemical. The chemical treatment stage is split into two sub-stages – first trying least-toxic chemical options, including inorganic compounds and natural chemicals, before finally resorting to more toxic pesticides if all else fails.

LEED has two credits that relate to IPM. The first covers the implementation of the IPM program throughout the property, including the entire building and its surrounding grounds. The second relates to how the exterior of the site is managed in a more sustainable manner and includes a provision to ensure the IPM program is followed. This is important because many buildings have a pest control contractor that implements the IPM program inside the building and a separate landscaping contractor that carries out pest control on plants outside the building.

IPM is a relatively new concept in Taiwan, especially in the commercial real estate industry, and it’s proving slow to gain popularity. There are several reasons for this.

There’s a sense that property managers can’t be faulted for following commonplace industry practices such as periodic spraying of pesticides, even if the pests are still seen in the building afterwards. However, if they try something radically different, such as IPM, and pests are also seen in the building, then they risk criticism for not doing their jobs properly, even though this is purely a matter of perception.

This follows on from a lack of general understanding about the downside of pesticide use, that regular repeated application leads to resistance, and that these pesticides will linger wherever they are applied, presenting a potential health hazard

Our greatest challenge in implementing IPM has been introducing the concept of balanced application of pesticides with our tenants. Previously, they would call the customer service center to request spraying as soon as they noticed pests in their offices because they didn’t understand the impacts associated with pesticide application. Excessive use of pesticides makes pests resistant, requiring increasingly higher chemical concentrations to be used as the compounds become less effective, but this causes serious environmental problems, including air pollution with more harmful chemicals lingering in the air.
Patrick Chen, Head of Building Operations at Hung Kuo.

IPM is also more work intensive because it requires constant monitoring and remedial action to prevent pests entering the building. The founder of Hung Kuo Building’s IPM contractor, In and Out(2), Mr. Zhu Zheng Qiang 朱正強, also notes that business-as-usual chemical-only pest control is easy. You don’t have to actively monitor anything, you just come along as scheduled, spray pesticides and leave. But IPM represents a challenge because it requires the development of innovative, non-toxic control methods in addition to regular building inspection, says Zhu.

Addressing mosquito incursion into the building is a great example of this. With thousands of people coming in and out of the building every day and a carpark entrance that’s always open to flying insects, it’s impossible to keep mosquitos out of the building entirely. But, based on the understanding of mosquito biology, Mr. Zhu and his team have developed a multi-prong approach to minimizing the number that get through to bother building occupants.

A collection of mosquitos collected from near a building entrance.

Mosquitos like to find places to rest and hide while they wait for the scent of someone to bite. The planters at the building entrances are good examples of such places and so In and Out place open canisters wrapped in black paper that contain water and along with a secret recipe of non-toxic ingredients that produce carbon dioxide. Mosquitos use carbon dioxide to track their way to someone to bite, and they lay their eggs in water where their larvae hatch and grow into adults. This trap not only captures mosquitos but also ensures those that lay eggs here don’t successfully reproduce.

There is a secondary battery of mechanical carbon dioxide producing traps placed near the entrances along with a special webcam that allows Mr. Zhu and his team to remotely monitor mosquitos caught, enabling them to identify the species and alert the building management team if any are potential vectors of dangerous diseases, such as Dengue Fever. All the traps are regularly emptied by the In and Out team, and the bodies of the captured mosquitos are taken back to their lab for sorting and identification which provides valuable information to improve the IPM plan over time.

Non-chemical mosquito traps and remote species detection device.

With this level of attention to detail, the IPM program at Hung Kuo Building has been a resounding success. Since its implementation in 2021 there hasn’t been the need to use any pesticides in the building. We’ve had one emergency application of pesticides on the ornamental trees around the building due to the sudden appearance of a host of an invasive species of moth that has no natural predators in Taiwan and whose caterpillars would have quickly stripped the trees of their leaves and killed them. Patrick Chen, an experienced building manager, is more than convinced about the benefits of IPM; “It’s the right thing to do, and we’re not going back to conventional pest control methods.”

Despite its clear effectiveness and obvious suitability for facilities where pesticide application poses a risk, such as hospitals, schools, and buildings in which food is stored, the uptake of IPM in Taiwan remains disappointingly limited. But In and Out’s Mr. Zhu sees a brighter future for this important practice, particularly because of the surge in interest about ESG in Taiwan, which he feels will help more organizations understand the multiple environmental, social, and governance benefits of this pest management system.

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