Raw data: The combined effect of herbicide and Bacillus thuringiensis exposure delays development in the red flour beetle

The use of herbicides and their long persistence in the environment have raised concerns about potential harm to ecosystems and human health. However, there is a gap in the knowledge regarding the effects of continuous exposure to residues or admitted field doses on non-target organisms such as insects that inhabit croplands and play key ecological roles. This study adopted an eco-immunological perspective, investigating the influence of herbicides on an organism’s interaction with natural pathogens. The impact of this combination of multiple stressors was studied in larvae of the red flour beetle, Tribolium castaneum Herbst, 1797, previously treated with a pendimethalin-based commercial formulation (PND) and exposed to the natural entomopathogen Bacillus thuringiensis (1x10^9, 1x10^10 cells/mL). The effects of three PND concentrations (i.e. a recommended field rate, a soil contaminant concentration and the maximum residue limit admitted in grain in EU countries: 4L/ha, 13 and 0.05 ppm, respectively) on life history traits such as developmental time, pupation rate and survival rate and the expression levels of antimicrobial peptides (AMPs) were assessed. The results showed that even at doses considered safe for human consumption or field application, exposure to PND had an impact on beetle larvae, affecting their vulnerability to B. thuringiensis. The combined experience of exposure to PND and B. thuringiensis at the larval stage resulted in a delay of larval development, a reduction in the number of pupae and emerging adults, and alterations in their body conditions. Moreover, changes in the expression levels of the analysed AMPs, including Attacin 1, Defensin 2 and Coleoptericin 2, were recorded as markers for immune activity against bacterium. The findings of this study highlight the general need for further studies on the effects of commonly used herbicides on the physiology of non-target organisms and on host-pathogen interactions at the community level. Additionally, there is a need for the establishment of revised residual levels that are deemed non-toxic to soil organisms and humans.

Vommaro et al., 2024 The combined effect of herbicide and Bacillus thuringiensis exposure delays development in the red flour beetle, Journal of Invertebrate Pathology, Volume 207, 108227, ISSN 0022-2011, https://doi.org/10.1016/j.jip.2024.108227

除草剂的使用及其在环境中的长期持久性引发了对其对生态系统和人类健康潜在危害的担忧。然而，关于连续接触残留物或允许的田间剂量对非靶标生物，如栖息在农田并扮演关键生态角色的昆虫的影响，知识上存在空白。本研究采纳了生态免疫学的视角，探究除草剂对生物与自然病原体相互作用的影响。本研究通过研究受哌啶草嗪类商业配方（PND）处理的红褐菌（Tribolium castaneum Herbst, 1797）幼虫在暴露于自然昆虫病原体苏云金芽孢杆菌（Bacillus thuringiensis，浓度为1x10^9，1x10^10细胞/毫升）时，多重应激源组合的影响。评估了三种PND浓度（即推荐的田间施用量、土壤污染物浓度以及欧盟国家粮食中允许的最大残留限量：分别为4L/ha、13和0.05 ppm）对生命史特征如发育时间、化蛹率和存活率以及抗菌肽（AMPs）表达水平的影响。结果显示，即使在被认为对人类消费或田间应用安全的剂量下，PND的接触也对菌类幼虫产生了影响，影响了它们对苏云金芽孢杆菌的易感性。在幼虫阶段同时接触PND和苏云金芽孢杆菌的联合经验导致幼虫发育延迟、化蛹和成虫数量减少以及身体条件的变化。此外，分析出的抗菌肽，包括Attacin 1、Defensin 2和Coleoptericin 2的表达水平变化，被记录为对抗细菌的免疫活动的标志。本研究的结果突出了进一步研究常用除草剂对非靶标生物生理学以及群落水平上宿主-病原体相互作用影响的必要性。此外，有必要建立修订后的残留水平，这些水平被认为对土壤生物和人类无毒。Vommaro等，2024年，《除草剂与苏云金芽孢杆菌暴露的联合效应延迟红褐菌发育》，《无脊椎动物病理学杂志》，第207卷，108227号，ISSN 0022-2011，https://doi.org/10.1016/j.jip.2024.108227。