Imergard™ WP

A new, long-term mechanical insecticide to combat malaria

Imergard WP (wettable powder) mechanical insecticide is a perlite-based indoor and outdoor residual spray designed to provide a physical mode of action against mosquito vectors.

• Physical mode of action
• Long-term residual control
• Manages insecticide resistance
• 100% natural, safe and effective

In its 2019 annual report, the World Health Organization (WHO) reported 405,000 deaths from malaria, 67% of which were children under the age of 5 years old. Indoor Residual Sprays (IRS) have been an effective strategy to control malaria transmission and have helped reduce the number of deaths in recent years. However, mosquitos evolved to become resistant to these treatments.

A new mode-of-action IRS

Imergard WP (Wettable Powder) is a mechanical insecticide providing a physical mode of action. It can be applied to interior walls using standard backpack spray equipment. When the mosquito lands on a treated surface, there is a static transfer of Imergard WP particles that absorb the lipid layer necessary for the mosquito’s survival.

Tried and tested during an eight-month study in Tanzania

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In a 2019 community trial in Tanzania, where over 4,000 homes were treated, Imergard WP was able to control the malaria parasite as effectively as the gold standard Positive Control, a micro-encapsulated Pirimiphos-methyl IRS. 

At the end of the eight-month study, Imergard WP maintained 100% efficacy after 72 hours against a threshold target of 80% mortality. This is an impressive result for a mechanical insecticide, considering that the mosquitos in this study were susceptible to micro-encapsulated Pirimiphos-methyl.

ImerGard WP limits the spread of the malaria-carrying parasite

The primary objective of employing IRS as a strategy for malaria control is to limit the spread of the malaria parasite. After a blood meal, mosquitoes typically rest indoors prior to ovipositioning. If mosquitoes don’t live longer than 10-14 days, they will not live long enough to transmit the malaria parasite.

The advantage of Imergard WP is that it provides a physical mode of action. It will deter cross-chemical resistance development and complement existing IRS chemistry.

Nearly a year’s performance across a wide range of surfaces

We extended the cone bioassay study in the community trial in Tanzania to establish if Imergard WP can meet or exceed the new industry target of more than 12 months of residual efficacy. An IRS that has at least a 12-month residual efficacy means it can be applied at any time of the year and not just during mosquito season, resulting in increased IRS coverage.

Preliminary feedback is that Imergard WP has 11 months’ residual efficacy, exceeding the WHO 80% thresholds on the 72-hour holding, with performance equal to the gold standard on susceptible and resistant strains. 

Since Imergard WP does not heat degrade, it can be applied to tin ceilings, potentially opening up a new large surface area for residual application.

No physical, chemical, human health or environmental hazards

The active ingredient of Imergard WP is perlite which has been processed to release its insecticidal properties. Imergard WP has demonstrated efficacy against multiple anopheles, aedes and culex s.s. It has a toxicity class IV rating, which is the lowest rating, and is non-toxic to bees.

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Features & benefits

• Pending USA Environmental Protection Agency approval as a biopesticide for targeted IRS applications
• A physical mode of action offers a new resistance management tool to deter cross-chemical resistance development
• A five-year shelf life, so it can be distributed to application sites months or years in advance
• No odor and residents can enter the home immediately after application
• Visual application cues allow sprayers and home residents to see where it has been sprayed
• Applied with standard IRS backpack sprayers
• Produced from a renewable and sustainable resource

Does not heat degrade so can be applied to tin ceilings.