Ben Amor T, Jori G
Department of Biology, University of Padova, Via U. Bassi 58B, 35121, Padova, Italy.
Insect Biochem Mol Biol. 2000 Oct;30(10):915-25. doi: 10.1016/s0965-1748(00)00072-2.
Several photosensitizing agents, which are activated by illumination with sunlight or artificial light sources, have been shown to be accumulated in significant amounts by a variety of insects when they are administered in association with suitable baits. The subsequent exposure of such insects to UV/visible light leads to a significant drop in survival. Of the photosensitizers tested so far, xanthenes (e.g. phloxin B) and porphyrins (e.g. haematoporphyrin) appear to be endowed with the highest photoinsecticidal activity. In particular, porphyrins absorb essentially all the UV/visible light wavelengths in the emission spectrum of the sun; hence they are active at very low doses. Thus, 1 h irradiation of Ceratitis capitata, Bactrocera oleae (also known as Dacus oleae) or Stomoxys calcitrans which ingested a few nanomoles of porphyrin per fly with light intensities of the order of 1000 microE s(-1) m(-2) causes about 100% death in laboratory tests. Present evidence suggests that such photosensitizers act on the membranes of the midgut with consequent feeding inhibition, as well as on the neuromuscular sheath. No apparent onset of photoresistance has been observed. The rapid photobleaching of xanthenes and porphyrins when illuminated by visible light, as well as the lack of significant toxicity of such compounds in the dark, minimizes the risk of an important environmental impact of such photoinsecticidal agents.
几种光敏剂在与合适的诱饵一起施用时，已被证明能被多种昆虫大量积累，这些光敏剂可通过阳光或人造光源照射激活。随后将此类昆虫暴露于紫外/可见光下会导致存活率显著下降。在目前测试的光敏剂中，呫吨类（如荧光素B）和卟啉类（如血卟啉）似乎具有最高的光杀虫活性。特别是，卟啉能吸收太阳发射光谱中基本上所有的紫外/可见光波长；因此它们在非常低的剂量下就有活性。例如，在实验室测试中，用强度约为1000微爱因斯坦秒-1米-2的光照射每只摄入几纳摩尔卟啉的地中海实蝇、油橄榄实蝇（也称为油橄榄果实蝇）或厩螫蝇1小时，会导致约100%死亡。目前的证据表明，此类光敏剂作用于中肠膜，从而抑制取食，同时也作用于神经肌肉鞘。尚未观察到明显的光抗性。呫吨类和卟啉类在可见光照射下会迅速光漂白，而且此类化合物在黑暗中没有明显毒性，这将此类光杀虫药剂对环境产生重大影响的风险降至最低。
