Resistance of some canola cultivars to Myzus persicae (Hemiptera

The green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), is an important insect pest of a canola crop Brassica napus L., in Ardabil, Iran. Host plant resistance is an essential component of the integrated management of M. persicae. In field experiments, the population density of M. persicae was higher on Zarfam and lower on Ebonite, Elite, Okapi, RGS003, and Opera among the 19 canola cultivars during 2008 and 2009. In a free-choice situation, the numbers of attracted aphids per plant was lowest on Opera (1.2). In the life table study, aphids reared on Opera had the shortest adult longevity (8.3 days), lowest numbers of progeny per female (15.4) and the lowest survival rate (62.5%) compared to the other five cultivars. The intrinsic rate of the natural increase (rm) and population growth rate (λ) were lowest on Opera and highest on Zarfam. The generation time (T) was shortest on Opera (11.7 d) and longest on RGS003 (13.1 d), whereas the doubling time (DT) was longest on Opera (3.58 d) and shortest on Zarfam (2.26 d). Our results clearly suggest that Opera was the highest resistant host among the tested cultivars and has the potential to be used in the integrated management of M. persicae.