Oviposition preference of Helicoverpa armigera on 10 canola cultivars under laboratory and semi-field conditions

Oviposition preference of Helicoverpa armigera on 10 canola (Brassica napus) cultivars (Talaye، Opera، Licord، Modena، SLM046، Hayula420، Zarfam، Okapi، RGS003 and Sarigol) was determined under laboratory and semi-field conditions. The first experiment was carried out under laboratory conditions using the leaves of 10 canola cultivars and the second one was done under semi-field conditions using the mesh cages. The results of the laboratory experiment of no-choice oviposition preference showed that the proportion of eggs laid on the plants to total oviposited eggs during total time period of the experiment was highest 0. 760) for Talaye، and lowest (0. 288) for Okapi. Moreover، the results of the laboratory experiment of choice oviposition preference indicated that the mean oviposition rate of H. armigera was the highest (112. 37 eggs) on Opera and lowest (27. 80 eggs) on RGS003. The results of choice oviposition preference under semi-field conditions showed that the oviposition of H. armigera was the highest (76. 67 eggs) on Zarfam and the minimum number (14. 42 eggs) was obtained on RGS003. Based on the results، RGS003، Okapi، Sarigol and Hayula420 were the less preferred cultivars for oviposition of H. armigera.