[The effects of chitin synthesis inhibitor, diflubenzuron on the larvae of Culex pipiens (L.) and Culiseta longiareolata (Macquart) (Diptera: Culicidae)]

Abstract

Objective: The aim of the present study was to detect effects of diflubenzuron on Culex pipiens and Culiseta longiareolata larvae, and determine the weekly mortality rate and most effective dose of diflubenzuron during the study.

Methods: The lower and higher doses (0.016, 0.032, and 0.064 mg(ai)/cm(2)) than 0.05 mg(ai)/cm(2) which are brecommended for granular formulation of diflubenzuron by WHO (World Health Organization) was applied against 1st, 2nd, 3rd and 4th instars under laboratory conditions and mortality was recorded.

Results: According to our data, diflubenzuron was more effective against early instars, and it was found most effective in the 4th and 3(th) week post-treatment in the application for Culex pipiens and Culiseta longiareolata larvae respectively. In addition, the most effective dose of diflubenzuron was obtained as 0.064 mg(ai)/cm(2) (LC50 > 4640 ppm, LC90 = 0.0034 ppm). Furthermore Culiseta longiareolata was more sensitive than Culex pipiens larvae.

Conclusion: Knowing the specific mortality rate of diflubenzuron in different mosquitoe species and larvae stages, plays an important role in determining the resistance against diflubenzuron.