More Than an Annoyance – Mosquito Population Set to Increase

Mosquitoes have turned into a menace that is under-discussed despite inflicting massive harm upon human civilization since its beginning. Research suggests that over 200,000 years, 108 billion people have lived on Earth. And out of that 108 billion, 52 billion – close to half – have died because of mosquitos. 

According to Timothy C. Winegard, writer of the book The Mosquito: A Human History of Our Deadliest Predator, mosquitoes have been there on this planet for more than 100 million years now. Their global population was 110 trillion in 2019. 

Why Timothy C. Winegard terms mosquitoes as ‘our deadliest predator’ because of the range of diseases it can cause us. Some of these diseases include malaria, West Nile virus, Dengue, Zika, Chikungunya, etc. If we look at the magnitude of the damage-causing potential of these diseases, the numbers appear no less than mind-boggling. 

Every year, the world witnesses approximately 247 million malaria cases. The incidence of dengue virus infections is even more widespread, totaling around 390 million infections annually. Since 2005, there have been over two million reported cases of Chikungunya globally. Vector-borne diseases, which include those transmitted by mosquitoes, result in over 700,000 deaths each year.

More concerningly, the mosquito menace is increasing. It is now spreading its wings to parts of the world where its impact was not that severe earlier.

According to Andrea Ammon, the director of the European Centre for Disease Prevention and Control:

“In recent years, we have seen a geographical spread of invasive mosquito species to previously unaffected areas in the EU/EEA.”

She went on to say that if this trend continued, the erstwhile unaffected areas would see increased prevalence of diseases such as Dengue, Chikungunya, and Zika viruses and, under certain circumstances, West Nile virus.

She stressed the need to focus “on ways to control mosquito populations, enhancing surveillance and enforcing personal protective measures.” However, controlling the mosquito population would require us to know why mosquito populations are surging. 

Why is the Mosquito Population on a Surge?

The World Mosquito Program points towards climate change as one of the primary factors responsible for increasing mosquito populations across the world. 

Climate Change

According to scientific data available to us, anthropogenic greenhouse gas emissions have caused the mean global temperature to rise by 1 degree centigrade above pre-industrial levels. If the current patterns of greenhouse gas emissions continue, the mean global temperature of our planet may increase by 4 to 5 degrees centigrades before we hit the next century of this millennium. 

This rise in temperature will have severely encouraging effects on the global mosquito population. The geographic range of A. aegypti, the most popular vector of Dengue, is limited by cooler ambient temperatures. A warmer ambiance will facilitate the spread of these mosquitoes. An increase in ambient temperature implies mosquitoes and the viruses they carry expanding to higher latitudes and altitudes.

Not only will their incidence increase, but it will also result in the lengthening of the transmission season in endemic areas. The world is already seeing an increase in Dengue rates. Scientific research shows that the age-standardized DALY rate for this disease increased by 26% between 2007 and 2017. 

A study published in the Journal of the Ecological Society of America found that warmer climates help accelerate the development time of mosquito larvae. It means less time to curb them, resulting in nearly twice as many mosquito larvae in the same breeding time in an area. 

Climate change has also disrupted our traditional weather patterns. The number of extreme incidents and natural calamities, such as droughts, heatwaves, floods, and heavy rainfall, has increased substantially. These irregularities and increased severities act in favor of the mosquitos by allowing them more breeding grounds. 

According to Dr. Katie Anders, an epidemiologist and director of impact assessment at the World Mosquito Program:

“When households store water in response to drought, this can increase local mosquito breeding sites and disease risk. Land use changes can also drive migration to cities, increasing the population at risk of explosive outbreaks of Dengue and other mosquito-borne diseases.”

As we speak of migration to cities, rapid and often unplanned urbanization has also led to growing mosquito populations across the world. 

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Urbanization

Urbanization alters the species composition of an area, resulting in encouraging mosquitoes that thrive in proximity to humans and feeding on them. The increase in trade and migration in rapidly growing urban areas also contributes to the growth of vector-borne diseases. Scientific studies have identified the dispersal of pathogens into non-endemic localities through travel, trade, and migration.

For instance, in Europe, the increase in the number of Dengue cases is highly correlated with the number of travelers arriving from endemic zones. Linkages between urbanization and mosquito population growth are empirically proven facts. 

Back in 2016, reports showed an increase in mosquito populations by as much as ten times over five decades in the highly urbanized cities of New York, New Jersey, and California. In these areas, during the same period, the number of mosquito species increased by two to four times. 

According to Marm Kilpatrick, associate professor of ecology and evolutionary biology at UC Santa Cruz, “In Florida, urbanization and mosquito control efforts are more likely to be the dominant drivers of mosquito populations.” 

As Professor Kilpatrick mentions, inadequate mosquito control efforts are another factor driving the growth of the mosquito population. 

Inadequate Mosquito Control Efforts

There are several roadblocks to effective mosquito control. Some of these challenges are failures on the part of the governing authorities, and some are incumbent upon the citizenry and the communities living in the mosquito growth areas.

The authorities often suffer from a lack of funding and political will, which manifests as poor vector control facilities and mechanisms on the ground and insufficiently trained personnel. Poor facilities are also the outcome of inadequate partnerships between concerned parties, lack of innovative technologies and coordination, and insufficient standardization, leading to poor replicability. 

When it comes to communities, general apathy towards domestic efforts to control mosquitos and lack of awareness play a crucial role in empowering mosquitoes with rampant breeding grounds. 

The banning of DDT as an insecticide also helped mosquitoes grow, especially in the United States. Studies showed that DDT was incredibly effective in curbing mosquito population growth, and, in some areas, it took three to four decades for mosquito populations to recover after the use of DDT was banned in the United States in 1972. However, it had to be banned because of DDT’s adverse impact on the environment, birds, and wildlife nearby. But it had undoubtedly helped decrease the population of mosquitoes, both in numbers and species types. 

The reasons for mosquito growth are many, and they require immediate and effective redressal. There are companies working towards devising efficient solutions. We will look at some such instances in the segments below. 

Companies Combating Mosquito Menace

#1. VDCI: Vector Disease Control International 

VDCI claims to be a global leader in Integrated Mosquito Management (IMM) services. Its service comprises a team of entomologists, biologists, environmental health and mosquito control specialists, etc., working towards the common objective of supporting public health initiatives in cities, countries, states, and other mosquito abatement programs in the United States. 

It offers emergency response mosquito control services after major flood events or increased mosquito-borne disease spreads. 

In 2016, VDCI initiated a collaboration with the CDC to assist United States territories in defending their population against the threat of Zika. According to Dr. Brrox Broze, the VDCI Operations Manager in Northern Colorado:

“Our team provided Ministry of Health and Public Works employees with education in the field and the classroom as well as donated application equipment to aid in further management efforts.”

The company was also in charge of another integrated mosquito management program in Guam. 

VDCI is a member of the Rentokil family of companies in North America, known for its pest control operations all over the world and for providing high levels of service to commercial and residential customers everywhere. 

In 2022, Rentokil registered an annual revenue of more than 3.7 billion pounds sterling, with a profit (before tax) of 296 million pounds sterling. The company witnessed a pest control organic revenue growth of 5.6%. 

#2. Terminix

Terminix has an elaborate mosquito control program that starts with a thorough inspection to identify the level of mosquito population and potential mosquito breeding sites. After assessing the risks and potential vulnerabilities, it offers regular mosquito control services during mosquito season. 

Capable of combating and eradicating all mosquito species found in the United States, its services include both liquid and granular mosquito treatment outdoors, creating a highly effective barrier against mosquitoes.

Headquartered in Memphis, Tennessee, with more than 11,400 teammates and 2.9 million customers in 24 countries and territories, the company claims to conduct mosquito and other pest management and protection visits at more than 50,000 homes and businesses every day. Since October 12, 2022, Terminix has been a part of Rentokil following its acquisition.

According to the latest available financial reports, the company reported a year-over-year revenue increase of five percent to $496 million for the first quarter of 2022. However, the net income for the quarter decreased year-over-year by $8 million to $19 million, or $0.15 per share.

#3. Clarke

Clarke’s mosquito population control services have reached over 50 countries so far, with six WHO PQ-listed products and fourteen proprietary mosquito control product lines. It claims to have worked with the ministries of health and NGOs across four continents, who rely on Clarke’s products and services for control and surveillance of mosquito populations in the area. 

Clarke’s protections are effective against a host of vector-borne diseases, including Dengue, Zika, Chikungunya, and Yellow Fever viruses, etc. Its Natular larvicides are a proven tool in the market for curbing mosquito populations. Its patented active ingredient, Qalcova brand spinosad, is a product derived from a naturally occurring soil bacterium. It is also the first IRAC Class 5 active ingredient used for vector control.

According to Clarke’s latest sustainability report, the company earns 48% of its revenue from its next-generation products and services, and it has 7 OMRI Listed® products in its next-generation portfolio for the mosquito control market. 

Menace of Growing Mosquito Population: The Road to Victory

A complete victory against mosquitoes does not look feasible in the near future since they have been a part of our environment for ages. However, effective curbing measures and initiatives to discourage the driving factors for mosquitos to prosper would go a long way in keeping vector-borne diseases under control. 

The United States Environmental Protection Agency advocates for a scientifically tested and proven comprehensive approach to controlling mosquitoes effectively. It has put up a model to replicate. Known as Integrated Pest Management or IPM, the program believes the best approach to controlling mosquitoes is to have control over each life stage of a mosquito. 

IPM leverages a range of pest management techniques, including pest prevention, pest reduction, and the elimination of conditions that lead to pest infestations. It also stresses the need for adequate resident education and pest monitoring. Although insecticides like DDT have been banned in the United States, both the CDC and EPA believe there is a legitimate and compelling need for the use of chemical interventions, under certain circumstances, to control adult mosquitoes. 

The four-step structure that the current mosquito control strategy relies upon includes:

• The removal of mosquito habitats.
• Using structural barriers to mosquito growth.
• Controlling mosquitoes at their larvae stage and then at their adult stage. 

An effective collaboration between academia, industry, and government is what we need at present to put a stop to the surging mosquito population. Once we achieve a deceleration, only then could we think of a reversal.

Click here to learn how lasers might prevent mosquitoes from biting humans.