| Abstract:
The predators Syrphidae flies form an important group of natural enemies of aphids in canola crop. These play a main role in controlling cabbage aphid Brevicoryne brassicae (L.). Among them a number of larve feed on aphids, while adult fly feeds feed on nectar. These flies are known as flower fly. This investigation was conducted during 2002-2004 on canolafarms of West Azerbaijan province. Aphids and syrphids larvae were collected and reared into Growth chamber of temperature in the range of 25±2°C, RH %65± 5 and 14: 10 L/D. Results indicated that six species: Episyrphlls balteatus (Degeer), Eupeodes corollae (Fabricus), Scaeva albomaclllata (Macquart), S.latimaclllata (Brunetti), S.pyrastri (Linnaeus) and Paragus compeditlls Wiedemann had been collected from aphid colony on rapeseed. As study of population dynamism of species collected was carried out. E. balteatus with the highest frequency of 29/75% and 33/48% for the year 2003 and 2004 respectively, and P. compeditus with the lowest frequency of 4% and3/35%wererecoreded. Such information is useful to proper spray timing and method programming as well as to support and preserve the natural enemies in the area plantations.
|