Evaluation of canola cultivars for resistance to Helicoverpa armigera (Lepidoptera: Noctuidae) using demographic parameters.

The cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is one of the most important pests on a wide range of crops worldwide. The antibiotic resistance of 10 canola cultivars ('Sarigol', 'Hayula420', 'Opera', 'Okapi', 'Modena', 'RGS003', 'Zarfam', 'Licord', 'Talaye', and 'SLM046') to H. arimgera was evaluated using demographic parameters including life table, reproduction, development, and adult longevity. Larval period ranged from 18.8 to 16.1 d on Hayula420 and RGS003, respectively. The longest development time of immature stages was on Sarigol and Hayula420 (36.8 d) and the shortest one was on Zarfam (34.8 d). The highest daily and total fecundity (1,082.4 and 254.8 eggs, respectively) was on RGS003 and the lowest was on Talaye (517.0 and 41.4 eggs, respectively). The r(m) values varied from 0.153 on Sarigol to 0.179 on Opera. The net reproductive rate (R0) was calculated to be lowest on Talaye (157.4) and highest on RGS003 (331.5). The comparison of demographic parameters of H. armigera on different cultivars of canola and the cluster analysis revealed that Hayula420, Talaye, Sarigol, and SLM046 were the most resistant cultivars to this insect. Such results could be useful to develop an integrated pest management strategy of H. armigera on canola cultivars.