Laboratory evaluation of chitin synthesis inhibitors (Diflubenzuron and Buprofezin) against aedes aegypti larvae from Lahore,Pakistan

Dengue fever is a serious problem in pakistan from the last few years. it is important to develop new control measures for the effective control of dengue vectors. laboratory evaluation of two insect growth regulators,diflubenzuron and buprofezin 25% wp (wettable powder),chitin synthesis inhibitors,was carried out against aedes aegypti (early 4 th instars) larvae collected from natural containers (used tiers and plastic jars) at lahore pakistan. the primary objective was to determine the minimum effective dosage of each for larval mortality along with pupae reduction and adult emergence inhibition (ei). laboratory bioassays with buprofezin indicated lc 50-lc 95 ranged 0.341-2.54ppm at 48h post exposure. pupae formation was completely inhibited at 48h and 120h post exposure against 10 and 1 ppm respectively while 80% pupae reduction was observed against 0.0001ppm one week post exposure. no adults emerged against upto 1ppm,and 96% adult emergence was inhibited against 0.1ppm one week post exposure. in contrast lc 50-lc 95 ranged 29-83ppm at 48h post exposure against diflubenzuron indicated less effect at larval stages as compared to buprofezin. maximum pupae inhibition (100%) and adult emergence inhibition (ei) was observed against 1ppm and 0.1ppm diflubenzuron respectively at one week post exposure. results indicated buprofezin cause high larval mortality while the effect of diflubenzuron was more toxic to pupae and adults emergence. further studies in natural conditions are in progress to control dengue vectors in pakistan. © 2011 zoological society of pakistan.