Contact toxicity of Stachys byzantina C. Koch against Sitophilus granarius

Abstract

Aim of the study: To figure out the contact toxicity of organic extract from the aerial part and leaf of Stachys byzantina in growing Turkey.

Material and Methods: Air dried and powdered aerial parts and leafs of the Stachys byzantina were macerated with methanol:dichloromethane (1:1; v/v). Each extract was concentrated under reduced pressure to give solvent free residue. The obtained extracts were diluted with acetone to obtain 10% (w/w) stock solution. 1 mL of each plant extract was applied to every insect with a microapplicator and acetone was used as the blank in the control. The insects were incubated at 27 ºC in a dark climatic chamber and the mortality was recorded every 24 h for 3 days. The whole experiment was repeated three different times.

Results: The aerial part (50.00±1.01%) and leaf (39.86±1.05%) extracts of Stachys byzantina showed contact toxicity against S. granarius. When compared with blank control (acetone) 00.00 ± 0.00% after 24, 48 and 72 h, the aerial part extract showed significantly higher activity (p<0.05). The results obtained suggest that the aerial part extract could be considered as a potential source of natural insecticides.

Acknowledgements: I.H Geçibesler would like to express his sincere thanks to Prof. Dr. İbrahim Demirtaş, Department of Chemistry, Science Faculty, Çankırı Karatekin University for his supervisor. Author also thanks Assist. Prof. Dr. Omer Cem Karakoç Department of Crop and Animal Protection Yapraklı Vocational School, Çankırı Karatekin University for contact toxicity studies.