Changes of Feeding Behaviors of Myzus persicae (Homoptera: Aphididae) Depending on Inflow Concentrations of Imidacloprid

After treatment with imidacloprid, there were clear differences in the time to the first reaction of Myzus persicae among the concentrations treated. The time taken for the proboscis of the aphids to penetrate, during the recording plants increased as the imidacloprid concentration increased. Imidacloprid concentration inflow into a leaf was investigated using high-performance liquid chromatography, and the residues of the imidacloprid varied slightly with the different concentrations treated. However, the inflow rates of this insecticide into a leaf increased as the dipping times increased. Furthermore, it was shown that there was no relationship in inflow concentration between the concentrations and times of treatment. However, the concentration in the leaf differed according to the dipping time. Judging from the fact that the first reaction behavior against imidacloprid displayed at an inflow concentration of 0.32-0.35 mg/L, we concluded that inflow concentrations causing the first reaction of the aphids to the insecticide were much lower than the concentration treated. The general feeding characteristics of the aphids indicated that xylem and/or phloem feeding behavior continued after a series of probing behaviors and stylet activity during the first 3 h from the start of EPG recording. After 90 min treatment with imidacloprid, feeding behavior over the next 30 min indicated a significant increase in the withdrawal of the stylet from the plant at all treated concentrations. Xylem and/or phloem feeding patterns were significantly decreased during this time. In particular, the proportion of xylem feeding differed according to the concentration of imidacloprid.

Imidacloprid를 처리한 후에 복숭아혹진딧물의 처음 반응은 처리농도에 따라 차이를 나타내고 있다. 복숭아혹진딧물의 구침이 식물체에 머무는 시간은 imidacloprid의 농도가 증가함에 따라서 증가하는 경향을 보였다. 잎에 침투한 imidacloprid의 농도는 HPLC를 이용하여 측정하였으며, imidacloprid가 잎에 잔류하고 있는 잔류량은 처리농도를 달리함에 따라서 약간의 차이를 나타내고 있다. 그렇지만, imidacloprid의 침투이행 비율은 침지시간이 길어질수록 높았으나, imidacloprid의 농도와 침지 시간사이의 잔류량은 상관관계가 없었다. 복숭아혹진딧물이 imidacloprid에 대하여 처음 반응하는 잔류량은 0.32-0.35mg/L에서 볼 수 있었다. 따라서 아마도 복숭아혹진딧물은 imidacloprid의 추천 농도보다 매우 적은량을 처리하더라도 인식할 것으로 생각된다. 복숭아혹진딧물은 EPG 기록을 시작하고 처음 3시간 동안 활발한 기주탐색행동을 한 후에 물관부와 체관부에서 흡즙행동을 보이고 있다. Imidacloprid를 처리한 후 90분 후부터 30분간 진딧물이 구침을 식물체로부터 빼는 행동이 늘어나게 되며, 물관부 혹은 체관부에서의 흡즙행동은 현저히 감소하게 된다. 특히 물관부에서의 흡즙하는 행동의 비율은 imidacloprid의 처리농도에 따라서 매우 달라지게 된다.