Introduction
Arthropods being haematophagous (blood sucking) have the ability to behave and demeanor as vector; found to transmit human diseases, where many viruses, bacteria, protozoa and helminths parasites make use of such species for transmission between the vertebrate hosts. Historically, major vector born diseases viz., malaria, dengue, chikungunya, yellow fever, and plague were responsible for most life threatening pathological conditions in humans (Gubler, 1991). Not long after the discovery in 1877 that mosquitoes transmitted filariasis from human to human, malaria (1898), yellow fever (1900) and dengue (1903) to have similar transmission cycles. By 1910, other major vector-borne diseases such as African sleeping sickness, pwere shown lague, Rocky Mountain spotted fever, relapsing fever, chagas disease, sandfly fever and louse-borne typhus had all been shown to require a blood-sucking arthropod vector for transmission to humans (Philip & Rozenboom, 1973).
 
Vector born Dengue viruses are flaviviruses and its four serotypes DEN-1, 2, 3 and 4 sequentially causes infections and are responsible for Dengue Haemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS) in humans. The viruses are transmitted to man by the bite of infective mosquitoes, mainly Aedes aegypti and secondarily by Aedes albopictus. DHF is characterized by increased vascular permeability, hypovolaemia and abnormal blood clotting mechanisms. Due to rapid growth of urban centers the rainwater harvesting in diverse types of containers resulting in multiple storage practices and provided the place for breeding vector species. Before the advent of DDT in 1939, vectors were controlled by environmental sanitation and with non-synthetic chemicals especially plant products. However, in the past few decades a galaxy of synthetic residual insecticides flooded the field of public health and agriculture. Later with the development of organophosphorus compounds, a new era of insect and pest control began (Hassal, 1982). Unfortunately, problems and backlashes have emerged; indiscriminate use of insecticides in the control of insect pests has led to resistance development by the target species and also eliminated natural enemies. Large quantities of four classes of insecticides viz., organochlorines, organophosphates and carbamates, are applied annually to fields or indoors in China, directly or indirectly bringing heavy selection pressure on vector populations. One among the seven major species of vector mosquito in China was Ae. aegypti wherein all have evolved resistance to all the above types of insecticide except the carbamates (Feng et al., 2006). The degree of resistance varies among mosquito species, insecticide classes and regions. To overcome such problems and in the background of the failure of organochlorides and organophosphates in many foci, search for new compounds have been undertaken throughout the world. With the result, more safe and degrada