Larvicidal Effect of Zingiber officinale and Cyperusrotundus Oils on The third Instar Larvae Cephalopinatitillator (L.)

Abstract

C ephalopina titillator (C. titillator) [Clark, Diptera: Oestridae] only attacks camels and damage tissues causing economic losses and reduction of fertility. The present work evaluated two common essential plant oils from Cyperusrotundus (C. rotundus) (Cyperaceae) and Zingiber officinale (Z .officinale) (Zingiberaceae), which are considered ecofriendly and have the ability to kill larvae. Scanning electron microscopic examinations were done to demonstrate alterations of the respiratory spiracles after exposure to the essential oils. Three different concentrations 30, 50, 100 µl/ml of oils in distilled water were prepared. Few drops of Tween 80 were added as an emulsifier to the used essential oils. Five 3 rd instar larvae were used in each treatment then dipping procedure was applied five times. Each group of larvae was immersed for 60s in each dilution for each oil and the solution was continuously stirred. Dead larvae were counted after 24 hrs. Samples of treated and control larvae were fixed for Scanning Electron Microscope (SEM). The essential oils were very toxic to C. titillator larvae. Results of dipping bioassays showed that mortality of treated larvae was concentration-dependent. At the 100µl/ml concentration, there was 100% mortality of larvaefor both oils. The posterior spiracles were damaged and showed severe distortion of both lips. C. rotundus and Z. officinale oils have great potential to be developed as a novel larvicidea gainst C. titillator larvae and they could be used as nasal drench .They may be an effective, inexpensive control for this pest.