Weather conditions become suitable for breeding of mosquitoes’ larvae

Rawalpindi : With the rise in temperature being recorded in almost all parts of the Punjab province including this region of the country, the weather conditions have become suitable for breeding of larvae of mosquitoes including malaria and dengue fever vectors and according to experts, it is right time to take necessary measures to check breeding and growth of larvae and adult mosquitoes to avoid expected outbreaks of malaria and dengue fever.

To avoid possible outbreaks of malaria and dengue fever, individuals must destroy all possible breeding sites of mosquitoes mechanically, particularly inside homes and offices that can harbor larvae to develop into adult mosquitoes. At this point in time, according to experts, the chemical elimination of mosquitoes using adulticides is of minimal use.

It is important that in the existing weather conditions, water accumulation and even moist places can provide a favorable place for the female mosquitoes to lay eggs and individuals should look for sites and places inside or outside homes to avoid breeding of larvae of mosquitoes.

Studies reveal that mosquitoes’ eggs can last from a few days to several months in desiccation period as the eggs remain in dormant period till the availability of suitable conditions for hatching. When these eggs are submerged in water by the rainfall or the artificial man made flooding like watering of lawns, fields and water spillage, they hatch and the larvae mature through four stages.

The mosquitoes have three water dependent stages that are eggs, larvae and pupae and the last aerial stage of adult mosquitoes. The life span in each stage depends on several factors like temperature, humidity and availability of water.

After emergence and insemination, adult female mosquitoes seek human hosts to take a blood meal, rest in a sheltered place for a few days needed for the eggs to mature and then search for the sites to lay eggs where the mosquito can complete its cycle and breed. The mosquitoes need artificial containers of any type like metal, glass, stone, plastic, rubber etc even empty holes in tablet’s blister or small natural water bodies like tree holes to lay eggs.

Epidemiological findings reveal that the incidence and outbreaks of malaria and dengue fever can be avoided by avoiding breeding of mosquitoes and by controlling their growth. The dynamics of mosquitoes’ population including aedes mosquitoes, the vector for dengue fever, present a strong seasonal variability with a six months period of adult activity and a six months period of egg diapauses. Many experts believe that it is easier for individuals to check the growth of mosquitoes during the diapauses period.

Usually, the female mosquitoes lay the first eggs of the year during April or at the beginning of May depending on weather conditions and the mosquito density is maximal in early July, late August and early September. The egg laying activity remains continued until November though the larval density reaches its peak in September.

It is important that the best preventive measure to avoid spread of malaria and dengue fever for areas infested with mosquitoes is to eliminate the mosquitoes’ egg laying sites called source reduction. By lowering the number of eggs, larvae and pupae, we can reduce the number of emerging adult mosquitoes that would certainly help control the transmission of the disease.