Evaluation of bio-efficacy and residual activity of pyriproxyfen against field collected aedes aegypti and aedes albopictus from Gujranwala (Punjab), Pakistan
Anjum KI, Hassan SA, Usman M
Background: Dengue disease is a major health problem in tropical and subtropical region of the world. Pakistan has also serious issues on this infectious disease in the form of DF, DHF & DSS since 1994 when it was declared the first epidemic in Pakistan. Since then, many epidemics in different cities of Pakistan have been occurring on regular basis. The ever worst epidemic was occurred in 2011 in Punjab province where more than 286857 suspected cases and 21685 confirmed cases with 350 deaths were reported by Health Department. There is an urgent need for entomological and epidemiological studies on large scale to control the disease. The best known strategy is the effective implication of Integrated Vector Management (IVM) through adaptation of alternative and viable means vector control. Methodology: The recent study was conducted in district Gujranwala-Punjab, Pakistan to evaluate the Bio-efficacy of pyriproxyfen (a juvenile hormone analogue) against field collected mosquitoes (larvae) of dengue vectors. Aedes aegypti and Aedes albopictus were collected from three different localities of Aroop Town. Collected mosquitoes were reared to get fresh larvae according to the WHO recommended rearing procedure. Larvae were treated with pyriproxyfen (Predator 0.5 WDG) at the WHO recommended dose of 0.01mg/l of a.i. The tests were conducted in triplicate form along with a control. A fresh lot of 25 larvae were added in all treated as well as in control cups on every ten days interval to determine the residual activity of the tested product. Result: The bio-efficacy of pyriproxyfen was found effective against field collected Aedes aegypti and Aedes albopictus. The complete Inhibition of Adult Emergence (EI) was observed 58 days and 47 days for Aedes aegypti and Aedes albopictus respectively. The results also show that the residual activity of pyriproxyfen against Aedes aegypti is greater than Aedes albopictus as 68 days and 59 days (up to 80 % EI) respectively. Conclusions:Pyriproxyfen can be used to control the dengue vectors (Aedes aegypti and Aedes albopictus) and it can be included in integrated vector control strategy. It is very effective and safer to use for vector control as non-conventional usage of chemical insecticides.