عنوان مقاله [English]
نویسندگان [English]چکیده [English]
The prey stage preferences of the second and third instar larvae of syrphid fly species Eupeodes corollae (Fabricius) on different nymphal instars of Brevicoryne brassicae (L.) were studied in no-choice and choice conditions (25 Â± 2Â°C, 65 Â± 5% R.H. and 16L: 8D photoperiod). In no-choice test, the second and third instar larvae of E. corollae were separately supplied with a total of 40 nymphal instars of B. brassicae. In choice test, 10 nymphs from all nymphal stages of B. brassicae were simultaneously offered to the second and third instar larvae of E. corollae. In no-choice test, the highest larval feeding of the second (25.00 Â± 2.61) and third (38.2 Â± 0.58) instar larvae of E. corollae were observed on the first and second nymphal instars of B. brassicae, respectively. However, there were not significant differences in their feeding behavior on the first to third nymphal instars of B. brassicae. In choice test, the highest feeding rate of second instar larvae was 5.00 Â±0.84 aphids on third instar nymphs of B. brassicae. No significant differences were observed in feeding rates of the predatorâs third instar larvae. Switching behavior was not observed for the third instar larvae of E. corollae, while different second: third instar ratio found to be 10:50, 20:40, 30:30, 40:20 and 50:10.