Tag Archives: B. rapa

191-196 K. Hiiesaar, L. Metspalu and K. Jõgar
Attractiveness and susceptibility of Brassica rapa, B. napus and Sinapis alba to the flea beetles (Coleoptera: Chrysomelidae)
Abstract |

Attractiveness and susceptibility of Brassica rapa, B. napus and Sinapis alba to the flea beetles (Coleoptera: Chrysomelidae)

K. Hiiesaar, L. Metspalu and K. Jõgar

Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences,Kreutzwaldi St. 64, EE51014 Tartu, Estonia; e-mail: kylli.hiiesaar@emu.ee

Abstract:

The attractiveness and susceptibility of three different cruciferous plant species – turnip rape, Brassica rapa, oilseed rape, B. napus var. oleifera subvar. annua and white mustard, Sinapis alba – to flea beetles of genus Phyllotreta (Coleoptera: Chrysomelidae) was studied. Despite the fact that the number of flea beetles on S. alba was almost the same as on the other plant species, damage to B. rapa and B. napus exceeded damage to S. alba throughout the observation period, P < 0.05. Flea beetles preferred to forage on B. napus:100% of the plants exhibited holes from eating both in cotyledon and in the first true leaf stage. Although 100% of plants of B. rapa were also damaged in seedling stage, in true leaf stage damage extended only to about 70%. Significantly less feeding damage occurred on S. alba, where eating traces were counted on about 70% of seedlings and less than 50% in true leaf stage. The mean damage score of S. alba was the lowest, 1,5 at the cotyledon stage and only feeding punctures, not shooting holes, were found on the leaves; the majority of the true leaves were undamaged or had single superficial holes. Most severely damaged was B. napus: the mean damage rating, 2.7 in the cotyledon stage and somewhat less, 2.4 in true leaf stage. B. .rapa had intermediate damage rating 2.2 in cotyledon stage and 1.9 in true leaf stage.

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