Leaf ammo to repel mosquito menace

HYDERABAD: The use of chemicals as mosquito repellents in neighbourhoods has raised health concerns, but researchers at the Environment Protection Training and Research Institute (EPTRI) Plant Tissue Culture laboratory have a solution. EPTRI is cultivating mosquito repellent plants via micropropagation and using tissue culture technique to propagate Indian Wormwood, a plant that has mosquito repellent properties.
“Currently , we are propagating mosquito repellent, aromatic and ornamental plants through micropropagation.Plants can be propagated using seed, stem cuttings or micropropagation. Seed propagation has a low germination percentage. Fresh seeds show around 25-40% better germination, but they lose viability after a few days of storage. Vegetative propagation (using stem cuttings) produces fewer plantlets. Micropropagation (also called in vitro propagation) appears to be the best method and has the potential to produce a lot of plantlets in a short time. It is carried out by using leaf, nodal and internodal segments as explants and can be used to produce disease-free plants,“ Dr M Suneela of the EPTRI tissue culture lab told TOI.
According to researchers at Prof Jayashankar Telangana Agriculture University , aromatic plants contain repelling compounds such as alkaloids, terpenoids, phenolics, proteinase inhibitors and growth regulators to prevent an attack of plant-eating insects.
Currently , GHMC entomologists are depending on tested methods such as releasing gambusia fish in water bodies, spraying larvicide in lakes and ponds, and fogging the streets with dangerous chemicals. The civic body has re eased 80,000 gambusia fish in 85 lakes, 541 wells, quarries and ponds so far this year. It has also cleaned up 31 lakes of water hyacinth, which supports mosquito breeding.
“Excessive use of chemical mosquito repellents, particularly in rooms without ven ilation, is harmful to human beings,“ said Venkatesh Vavilla, GHMC's chief entomo ogist. “Many aromatic plants repel insects. Citronella, Tu asi and Marigold also repel mosquitos. When the leaves are crushed and placed in the house, it releases an aroma hat keeps mosquitoes away .GHMC has not taken up promotion of Indian Wormwood on a large scale. We will con act EPTRI and see if we can promote it,“ he told TOI.
Almost 65% of Hyderabad's mosquito population is Culex species that transmits filariasis, 14% is Anopheles that carries the malarial parasite, 7% is tiger mosquito that carries dengue and chikungunya and 12% is Armegeris mosquito.
“Tiger mosquito Aedes aegypti breeds in containers.Though the Culex population is more, filariasis is not seen in the city as the pathogen is seen in coastal Andhra. Culex also transmits Japanese Encephalitis. Armegeris mosquito breeds in organic pollutants such as septic tanks.Usually , mosquito density is high from January to March.GHMC has formed 50 teams, each with three members, to carry out inspections in households for water stagnation,“ Venkatesh added. GHMC spends around `4 crore every year on mosquito control.