Evaluation of Antixenosis Resistance of Cucumber Cultivars, Cucumis sativus L. to Vegetable Leafminer, Liriomyza sativae Blanchard (Diptera: Agromyzidae)

The use of resistant plant cultivars and parasitoids could be an effective strategy in IPM of Liriomyza sativa Blanchard. Cucumber is a preferable host for this insect. In this research, antixenosis resistance of 17 cultivars of cucumber was evaluated to L. sativae under greenhouse condition. Results indicated that there were significant differences between cultivars with regard to the number of feeding sting and larval tunnels (p<0.01). Cucumber cultivars were ranked by cluster method based on all measured characters and were classified to four groups: susceptible, semi-susceptible, semi-resistant and resistance. Density of leaf hairs and trichomes of cucumber cultivars were evaluated and the result showed that the density of glandular hairs on leaves of field cultivars was higher in comparison to greenhouse cultivars. These results suggested that the local and field cultivars are generally more resistant to leaf miner than the greenhouse cultivars. In this study, a wide range of genetic variation in traits related to leaf miner resistance was found in cucumber germplasm. Also in tritrophic level system, the effects of first level (cucumber cultivars) on third level (parasitoid wasps) were studied and the results showed no significant differences between cultivars in attracting parasitoid wasps.