Mosquito control is a problem that is best handled by the community and public health agencies rather than by an individual, because of the complexities, says Ravi Chandra.
Mosquitoes are important vectors of numerous diseases such as malaria, yellow fever, filariasis, dengue and chikugunia.
Mosquitoes lay eggs necessarily in water therefore, an object capable of retaining water for five or more days is a potential breeding area for some species of mosquito.
The different water habitats where mosquitoes can breed can be flowing streams (including drainage ditches), ponds, streams, lake edges, swamps, natural containers (leaves, tree holes), artificial containers (flower pots, construction depressions, thrown plastic cups, rubber tyres), natural subterranean waters (holes dug by crabs, animal hoof prints) and artificial subterranean waters (septic tanks, storm and sewage drains).
Mosquito control is a problem that is best handled by the community and public health agencies rather than by an individual, because the breeding places of mosquitoes are often situated at considerable distances from the place of annoyance. However, there are some methods that the experienced pest control operator may utilise to reduce mosquito pest problem.
The best method of control mechanism for mosquitoes is prevention. The age-old techniques of closing the windows and doors during the dawn and dusk period are an excellent practice to prevent the entry of mosquitoes.
Also, screens like mesh wire gives seldom chance to enter the premises. Although hotels have very little places which have openings/entry points for mosquitoes as most of them use centralised AC’s, there are still areas like the main entrance of the automatic open doors, the corridors (back stairs areas) where the windows are opened for some fresh air or as an exhaust, the openings caused due to renovations, the exhaust openings in the kitchen/pantry areas if any, can still cause mosquitoes to enter inside the property.
Larvae may breed wherever suitable water is available. If it is not possible to eliminate this water, insecticides should be used. Suitable larvicides need to be used for the water source depending on the nature of the water body.
Rates vary according to specific environmental situations and water source. Oils are also used to kill larvae. There are chemical and biological larvicides and a new generation insect growth regulator. But whatever is used, the efficacy, environmental damage, aquatic organism’s life and human safety needs to be kept in mind before deciding on any particular product for that particular place.
Larviciding measures done in the water source take care of only the mosquito larvae and not the eggs and the pupae already present in the water body. The advanced versions of larviciding control are slowly moving from chemicals to biological larvicides and insect growth regulators as long-term effectiveness and environmental friendly measures.
Insecticides are used with fuel oil and burnt to create a fog with the help of a thermal fogging machine.
The disadvantages of thermal fogging are a hazard of reduced visibility so movement becomes difficult; the cost of using fuel oil as a carrier and majorly, the pollution of the environment with fuel oil. This method has now been almost entirely replaced by ULV application in the other parts of the world as a better and safer alternative.
Special machines are used with nozzles which break up an undiluted insecticide into microscopic droplets. With ULV application very small amounts of chemical are used.
ULV treatment remains longer than the thermal fogging as the tiny droplets hover around in the atmosphere for more time before getting dispersed. Both thermal fogging and ULV application are very temporary in nature.
This method places the insecticides on the foliage of trees shrubs, tall grass, tree trunks and the sides of structures where resting mosquitoes may come in contact with it. Diluted amounts of pesticides are used which will not harm the plants and trees, but will give better results on the mosquitoes.
The other common method used is the IRS or indoor residual spraying, wherein the odourless, safe, non-fumigant, non-staining and environmental friendly formulations are mixed in water and sprayed or done with ULV from in the indoor areas.
This sort of spraying is done on all the possible resting and hiding areas of the property like walls, false ceilings, venetian blinds, underneath the tables and chairs and in dark corner areas.
The insecticide will remain as a filmy coat on the sprayed surfaces; once the solution dries and when the mosquitoes come in contact with such areas they get killed. However, this spraying will not ensure that there will not be entry of the mosquitoes inside the property.
The understanding between the hotel staff and the treatment measures done by the pest control companies needs to be clear and perfect as to what are the efforts done and what is expected out of the same.
More often than not mosquito control measures are done for only a particular floor of the hotel building, which will only give partial results. Mosquito control measures always gives better results in an integrated approach of the prevention and the source elimination.
