Department of Entomology, University of Maryland, College Park, Maryland 20740, United States.
J Agric Food Chem. 2012 May 9;60(18):4449-56. doi: 10.1021/jf205393x. Epub 2012 Apr 3.
Neonicotinoids are systemic insecticides widely used on many pollinated agricultural crops, and increasing evidence indicates that they move to some extent into pollen and nectar. This study measured levels of neonicotinoid residues in pollen and nectar from a pumpkin crop treated with formulated products containing imidacloprid, dinotefuran, and thiamethoxam using different timings and application methods. Environmental conditions have a significant effect on overall residue levels; nectar residues were 73.5-88.8% less than pollen residues, and metabolites accounted for 15.5-27.2% of the total residue amounts. Foliar-applied treatments and chemigated insecticides applied through drip irrigation during flowering resulted in the highest residues of parent insecticide and metabolites, which may reach average levels up to 122 ng/g in pollen and 17.6 ng/g in nectar. The lowest levels of residues were detected in treatment regimens involving applications of insecticides at planting, as either seed dressing, bedding tray drench, or transplant water treatment.
新烟碱类杀虫剂是一种广泛应用于多种授粉农作物的内吸性杀虫剂，越来越多的证据表明，它们会在一定程度上转移到花粉和花蜜中。本研究使用不同的时间和施药方法，测量了用含有吡虫啉、噻虫嗪和噻虫胺的配方产品处理的南瓜作物花粉和花蜜中的新烟碱类杀虫剂残留水平。环境条件对总残留水平有显著影响；花蜜中的残留量比花粉中的残留量少 73.5-88.8%，代谢物占总残留量的 15.5-27.2%。在花期通过滴灌施用叶面处理和化学灌根的杀虫剂处理方法导致母体杀虫剂及其代谢物的残留量最高，在花粉中的残留量可能高达平均水平 122ng/g，在花蜜中的残留量为 17.6ng/g。在种植时施用杀虫剂的处理方案中，无论是种子包衣、床盘灌根还是移栽水培，检测到的残留水平最低。
