Abstract
A large number of insecticides are used for the control of agricultural pests as well as household pests, such as mosquitoes,
cockroaches and house flies with the application of over and under doses in Punjab, Pakistan. Moreover, after the dengue
epidemic that occurred during 2010, insecticides were sprayed in huge quantity at high doses in major cities of Punjab to
control mosquitoes. This resulted in insecticidal resistance in mosquitoes. Mosquitocidal assays of larvae (in beakers) and
adults (impregnated papers) were evaluated after 24 (hr.). The larvicidal LC50 value of temephos ranged from 0.007 to 0.416
ppm. In the case of adulticides, three groups of insecticides were applied by filter paper method and used against twelve
different populations collected from urban, agricultural and industrial areas of Lahore (LHR), Rawalpindi (RWP), Sialkot
(SKT) and Faisalabad (FSD). Pyrethroids demonstrated the lowest effective concentrations among the tested pesticides
(organophosphates OP & carbamates). Among the pyrethroid group, deltamethrin was recorded as being the most toxic with
LC50 (0.483–9.245 ppm), followed by cypermethrin (1.839 – 33.139 ppm) and permethrin (5.145 – 101.533 ppm). The chisquared value showed no heterogeneity between all the experiments. Moreover, the obtained results indicated that the LHR
population was highly resistant, followed by the RWP, SKT and FSD populations. In addition, the mosquito populations from
agricultural areas were more resistant than those from urban and industrial areas. The biochemical analysis showed the elevated
activity of enzymes (esterases, mixed-function oxidases, glutathione S-transferase and acetyl-cholinesterase) in resistant
populations of mosquitoes. LHR population showed the maximum activity of enzymes, like esterase (0.54), mixed-function
oxidase (0.72), glutathione S-transferase (0.16) and acetyl-cholinesterase (0.13) from agricultural areas. It was concluded that
the injudicious application of chemicals in such areas caused the potential risk of resistance and resurgence of certain
mosquitoes. Thus, further research is needed to identify health and environmental risks and to devise an effective programme
through the use of selective and specific insecticides
