Valent BioSciences Introduces MetaLarv® XRP for Long-Lasting, Consistent Control in Catch Basin Mosquito Habitats


LIBERTYVILLE, Ill., May 5, 2021 – Valent BioSciences, the global leader in biorational solutions for Public Health and Integrated Vector Management programs, has introduced MetaLarv® XRP, an innovative new formulation designed specifically for extended residual control of mosquito larvae in catch basins and storm drains.

Leveraging MetaLarv’s proven Triple Release Technology™ for residual control, the new XRP (extended release pouch) formulation is designed to provide mosquito abatement professionals more reliable and consistent control of West Nile virus vectors in catch basins by pairing the flexibility of a water soluble pouch with the residual control (90-100 days) of a briquet.

“We’ve learned from our customers and the literature that the active ingredient release profile and duration of traditional long-lasting catch basin treatment options can be challenging,” said Banugopan Kesavaraju, Global Technical Manager for Valent BioSciences’ Public Health and Forest Health Business Units. “We developed MetaLarv XRP to help mosquito abatement professionals overcome these challenges by combining the flexibility and immediacy of a pouch with the long residual of an extended release briquet.”

Catch basins and storm drains are prime mosquito breeding grounds for West Nile virus vectors and can be difficult for technicians to access with certain types of products. Water soluble pouch (WSP) formulations are malleable to fit through the narrow grates that often cover these closed habitats, and release effective active ingredient immediately. The concern is that they typically provide control for only 1-2 months. For mosquito control programs that require control over a longer duration, this means more applications per season – a significant challenge in areas with hundreds or even thousands of such drains and basins.

To get a longer residual (90-120 days), many districts opt for mosquito larvicide extended release (XR) briquets, which can be dropped through grates that have openings wide enough to receive them. However, the physics of this “brick plunge” can drive briquets downward to become embedded in sludge or other debris. Such lodging reduces the amount of XR briquet surface area that comes in contact with the water column, meaning slower and diminished release of active ingredient. Water temperature also plays a role in the release profile of briquets, which lags in colder temperatures early in the season. These drawbacks often translate into inconsistent results.

MetaLarv was first introduced in 2012 as a highly functional spherical pellet (S-PT) formulation of the insect growth regulator (S)-methoprene, which disrupts insect growth and prevents the emergence of adult mosquitoes that are capable of transmitting harmful diseases such as West Nile virus, malaria, dengue fever, and encephalitis. MetaLarv S-PT provided mosquito control districts with significant operational advantages in the control of floodwater mosquitoes. Like its successor, MetaLarv S-PT combined the best features from two different formulation types; it provided the low-rate application flexibility of a granule combined with the residual control of dynamic floodwater habitats of a pellet formulation.

MetaLarv XRP now delivers Valent BioSciences’ proprietary Triple Release Technology benefits into the challenging environments of storm drains and catch basins.

When applied, MetaLarv XRP floats briefly on the water’s surface where it quickly dissolves to deposit the full volume of its Triple Release “micro briquets” into the mosquito habitat. The first release occurs immediately with a flash of active ingredient to control initial mosquito broods and is not dependent on water temperature. The second release occurs over time as a further portion of the micro briquets breaks down in standing water, allowing for control of multiple mosquito broods during a flood. The third release allows for product to withstand dry-down/reflood situations in catch basins, ensuring MetaLarv XRP is ready for the next flooding cycle. This “trifecta” approach ensures multiple point source coverage for consistent control over an extended period of time.

“We work in an industry where resources are limited and the stakes for success or failure are high,” said Kesavaraju. “When our customers make an application, they need to be able to walk away with the confidence that the resources they’ve expended are going to provide the level of control they expect. MetaLarv XRP is another example of our ongoing commitment to provide specialized solutions –based on specific mosquito larval habitats – that help public health professionals reduce the risk of vector-borne disease.”

MetaLarv XRP joins MetaLarv S-PT and the Valent BioSciences biorational mosquito larvicides, VectoBac®, VectoPrime®, VectoMax®, VectoLex®, and Bactimos®, to provide the public health industry’s most comprehensive range of target-specific, biorational larvicides for mosquito abatement professionals and health care officials around the globe.

For more information, visit or contact a Valent BioSciences technical sales representative.


About Valent BioSciences LLC

Headquartered in Libertyville, Illinois, Valent BioSciences is a subsidiary of Tokyo-based Sumitomo Chemical Co., Ltd., and is the worldwide leader in the development, manufacturing, and commercialization of biorational products with sales in 95 countries around the world. Valent BioSciences is an ISO 9001 Certified Company. For additional information, visit the company’s website at

Media Contact:
John Mandel
Valent BioSciences

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