益達胺對於蜜蜂複眼視覺光感度之影響

Abstract

益達胺 (imidacloprid) 為一種系統性農藥，作用於昆蟲的菸鹼乙酰膽鹼受體 (nicotinic acetylcholine receptors)，造成神經系統過度興奮而死。然而過去的研究顯示益達胺會影響工蜂的覓食行為與視覺學習能力。另一方面蜜蜂幼蟲接觸亞致死劑量的益達胺後仍能正常羽化，但是羽化後成蟲的學習能力會降低，蕈狀體 (mushroom body) 內突觸的密度也會降低。這些研究顯示，蜜蜂幼蟲接觸到益達胺可能會影響神經系統的發育。本研究以非侵入性視網膜電位圖譜 (electroretinogram) 技術記錄蜜蜂複眼的電生理訊號，探討益達胺對於蜜蜂光敏感度 (visual sensitivity) 的影響。結果顯示幼蟲接觸益達胺並不會影響羽化後成蟲的光敏感度，而益達胺對於成蟲光敏感度可能有影響。同時0.1% 的二甲基亞碸(dimethyl sulfoxide) 會影響蜜蜂成蟲的光敏感度。

Imidacloprid is a systemic pesticide, acts on nicotinic acetylcholine receptors of insects and causes hyperexcitation in the nervous system. However, the previous study showed imidacloprid would affect honey bee workers’ forage behavior and visual learning ability. On the other hand, honey bee larvae exposed to a sub-lethal dosage of imidacloprid would decrease its learning behavior and the density of synaptic units in mushroom bodies after they eclosed. These studies imply that imidacloprid may affect the neural system of honey bee if the bee is exposed to the pesticide during its larval stage. In this study, the light sensitivity of honey bee’s compound eye was electrophysiologically measured with a non-invasive ERG recording technique to investigate the effect of imidacloprid. The results show that the larvae feeding with imidacloprid would not affect its visual sensitivity in the adult stage. However, imidacloprid may have an acute effect on the sensitivity of bee adult. In addition, 0.1% of DMSO would affect honey bee’s visual sensitivity of compound eyes.