In what could be a game-changer not only in curbing mosquito-borne diseases such as dengue and Chikungunya which are on the rise but also save foreign exchange, the technology for India’s indigenously developed eco-friendly bio-pesticide VCRC B17 is now available for commercial sale.
It is developed by the ICMR’s lab Vector Control Research Centre (ICMR-VCRC), Puducherry after it indigenously isolated a strain of Bacillus thuringiensis var. israelensis (BtiVCRC B17) way back in 1980 from a soil sample collected from Puducherry.
After successfully holding a string of clinical trials at various locations including in India, Indonesia, and the USA all these years, the Indian Council of Medical Research (ICMR) is now seeking commercial production of the bio-pesticide also VCRC Bti B-17. It is said to have very high larvicidal activity against mosquito species belonging to Culex, Anopheles, and Aedes, as assessed by the Institut Pasteur, Paris and designated as an ‘Indian standard strain’ by the Central Insecticide Board (CIB).
Currently, Bti is largely imported in the country and hence the indigenous product of VCRC strain will be a major import substitute, saving the precious foreign exchange reserves, said an official from the ICMR.
The ICMR has now floated an expression of interest (EOI) in this regard, seeking proposals from the industry in the bio-pesticide sector to manufacture VCRC B17, which it claims is useful for the control of mosquitoes and black flies. It is found to be safe against honey bees, silkworms, mammals, and also non-target organisms occurring in mosquito breeding habitats, as per the Council.
“The isolate was further characterized by sequencing its toxin genes. A simple and low-cost pilot-scale fermentation technology for the production of this bacterium, using locally available raw materials has been developed. Two formulations viz., aqueous suspension (AS 5.0%) and water dispersible powder (WP) formulations of the larvicide have been developed.
“The formulations have been tested, both in the laboratory and under field conditions in different climatic conditions, extensively and found to be highly effective in controlling the larvae of disease and nuisance-causing mosquitoes,” said an official from the ICMR.
In laboratory tests, the biolarvicide, Bti ICMR-VCRC B17, was found to be highly toxic to larvae (water stages) of mosquitoes transmitting malaria (Anopheline sp.), filariasis, and Japanese encephalitis (Culicine sp.), dengue, chikungunya and Zika diseases (Aedes spp.).
Bti ICMR-VCRC B17 kills mosquito larvae by destroying their gut, within 10-30 minutes upon treatment. Its identity and larvicidal activity were confirmed by the WHO Reference Centre, Institut Pasteur, Paris, and rated equivalent to the global standard strain ONR 60A (WHO).
A pilot-scale (100 litres capacity) technology for the production of the biolarvicide has been perfected at ICMR-VCRC. The biolarvicide can be produced using locally available agriculture-based raw materials and hence it is cost-effective and environmentally friendly, the official shared.
Blackflies transmit river blindness in African countries. Hence, there is enough scope for its export to other countries, including the African continent for the control of mosquitoes and blackflies, he said.
As mosquitoes are developing resistance to chemical insecticides and United Nations Industrial Development Organisation (UNIDO) mandating phase out of DDT to be replaced with environment-friendly alternatives such as Bti, ICMR hopes its product will fill the gap as the focus is now on biocontrol agents.
“For almost a century, mosquito control programmes have relied mainly on chemical insecticides. This overreliance is presently being challenged due to the high costs, development of insecticide resistance, health and environmental hazards, depleting raw material resources which are mainly petrochemical-based,” said the official.
As global warming leads to rising temperatures, environments are becoming conducive for mosquitos and black flies to multiply and transmit several diseases such as malaria, filariasis, Japanese encephalitis, dengue, chikungunya, and Zika leading to heavy morbidity and mortality, as also impacting social well-being.
