جستجوی مقالات مرتبط با کلیدواژه « population variations » در نشریات گروه « گیاهپزشکی »

Aphids in urban ecosystems, damage host plants directly by feeding on leaves, sucking up nutrients, and weakenig the host, resulting in yield reduction. The results of a study conducted in 2016 and 2017 on the interactions between population of the rose aphid, Macrosiphum rosae and the parasitoid wasps, Aphidius rosae and Lysiphlebus fabarum indicated that in all cases, there was a positive and significant correlation between the numbers of both species of parasitoid wasps and the population of the rose aphid. As the population of aphid raised, the density of parasitoid wasps increased as well, and these parasitoids exhibited an aggregative behavior to different densities of the aphid host. The relationship between the number of rose aphid and the percentage of parasitism by A. rosae and L. fabarum wasps showed that there was a positive correlation between percentage of parasitism by these two parasitoids and aphid density. In 2016, during the spring, the highest percentage of parasitism of aphid nymphs by A. rosae wasp was 42.17 and the highest percentage of parasitism by L. fabarum wasp was 21.15. In 2017, during the spring, the highest percentage of parasitism of aphid nymphs by A. rosae wasps was 41.89 and the highest percentage of parasitism by L. fabarum wasps was 21.02. Therefore, considering the positive correlation between the population of rose aphid and the population of parasitoid wasps and the effective performance of these parasitoids in parke-shahr in Tehran, these useful agents can be efficiently employed in biological control of rose aphids.