Al Naggar Yahya, Estrella-Maldonado Humberto, Paxton Robert J, Solís Teresita, Quezada-Euán J Javier G
General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, 06120 Halle, Germany.
Zoology Department, Faculty of Science, Tanta University, Tanta 31527, Egypt.
Insects. 2022 Oct 22;13(11):972. doi: 10.3390/insects13110972.
Stingless bees are ecologically and economically important species in the tropics and subtropics, but there has been little research on the characterization of detoxification systems and immune responses within them. This is critical for understanding their responses to, and defenses against, a variety of environmental stresses, including agrochemicals. Therefore, we studied the detoxification and immune responses of a stingless bee, , which is an important stingless bee that is widely distributed throughout Mexico, including urban areas, and has the potential to be used in commercial pollination. We first determined the LC of the neonicotinoid insecticide imidacloprid for foragers of , then chronically exposed bees for 10 days to imidacloprid at two field-realistic concentrations, LC (0.45 ng/µL) or LC (0.74 ng/µL), which are respectively 2.7 and 1.3-fold lower than the residues of imidacloprid that have been found in honey (6 ng/g) in central Mexico. We found that exposing stingless bees to imidacloprid at these concentrations markedly reduced bee survival and food consumption, revealing the great sensitivity of this stingless bee to the insecticide in comparison to honey bees. The expression of detoxification (GSTD1) and immune-related genes (abaecin, defensin1, and hymenopteacin) in also changed over time in response to imidacloprid. Gene expression was always lower in bees after 8 days of exposure to imidacloprid (LC or LC) than it was after 4 days. Our results demonstrate that stingless bees are extremely sensitive to imidacloprid, even at low concentrations, and provide greater insight into how stingless bees respond to pesticide toxicity. This is the first study of its kind to look at detoxification systems and immune responses in Mexican stingless bees, an ecologically and economically important taxon.
无刺蜂是热带和亚热带地区具有重要生态和经济意义的物种，但对其体内解毒系统和免疫反应特征的研究却很少。这对于理解它们对包括农用化学品在内的各种环境压力的反应和防御至关重要。因此，我们研究了一种无刺蜂的解毒和免疫反应，这种无刺蜂是一种重要的无刺蜂，广泛分布于墨西哥各地，包括城市地区，并且有用于商业授粉的潜力。我们首先确定了新烟碱类杀虫剂吡虫啉对该无刺蜂觅食者的半数致死浓度（LC），然后将蜜蜂在两个符合田间实际的浓度下长期暴露于吡虫啉10天，这两个浓度分别为半数致死浓度（0.45纳克/微升）或半数致死浓度（0.74纳克/微升），分别比墨西哥中部蜂蜜中发现的吡虫啉残留量（6纳克/克）低2.7倍和1.3倍。我们发现，将这种无刺蜂暴露于这些浓度的吡虫啉下会显著降低蜜蜂的存活率和食物消耗量，这表明与蜜蜂相比，这种无刺蜂对该杀虫剂具有极高的敏感性。该无刺蜂体内解毒（GSTD1）和免疫相关基因（abaecin、defensin1和hymenopteacin）的表达也会随着时间的推移对吡虫啉产生变化。暴露于吡虫啉（半数致死浓度或半数致死浓度）8天后的蜜蜂基因表达总是低于4天后。我们的结果表明，即使在低浓度下，这种无刺蜂对吡虫啉也极其敏感，并为无刺蜂如何应对农药毒性提供了更深入的了解。这是同类研究中首次考察墨西哥无刺蜂的解毒系统和免疫反应，无刺蜂是一个具有重要生态和经济意义的分类群。
