Key Laboratory of Animal Resistance Biology of Shandong Province, College of Life Science, Shandong Normal University, 88 East Wenhua Road, Jinan 250014, People's Republic of China.
Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, College of Life Sciences, Huaibei Normal University, Huaibei, China.
Pestic Biochem Physiol. 2021 Feb;172:104756. doi: 10.1016/j.pestbp.2020.104756. Epub 2020 Dec 13.
Boric acid, a well-established chemical insecticide, has a good control effect on various types of cockroaches. In this study, we investigated the oral virulence effect of boric acid on German cockroach (Blattella germanica) of various instars and characterized its effect on the gut microbiota by high-throughput sequencing technology. The results of an oral toxicity test showed that the toxicity of boric acid was positively correlated with its concentration and negatively correlated with the instar of cockroach nymphs. The 1-3 instar nymphs showed the strongest sensitivity to boric acid, which exhibited a median lethal time of only 3.16 d, while the 6-7 instar nymphs showed the weakest sensitivity, and exhibited a median lethal time of 10.15 d. There was no significant difference between male and female insects regarding their sensitivity to boric acid. Oral treatment of boric acid resulted in severe dysbiosis in cockroaches, the relative abundances of Bacteroides, which can degrade a variety of complex macromolecules, and Enterococcus, which can inhibit pathogenic microorganisms, were significantly reduced, while the relative abundance of the opportunistic pathogenic bacterium Weissella was significantly increased. It was speculated that dysbiosis of gut microbiota might accelerate the toxicity of boric acid on German cockroaches.
硼酸，一种成熟的化学杀虫剂，对各种类型的蟑螂具有良好的控制效果。在这项研究中，我们研究了硼酸对不同龄期德国蟑螂（Blattella germanica）的口服毒性作用，并通过高通量测序技术表征了其对肠道微生物群的影响。口服毒性试验的结果表明，硼酸的毒性与其浓度呈正相关，与蟑螂若虫的龄期呈负相关。1-3 龄若虫对硼酸表现出最强的敏感性，其半数致死时间仅为 3.16 天，而 6-7 龄若虫表现出最弱的敏感性，半数致死时间为 10.15 天。硼酸对雌雄昆虫的敏感性没有显著差异。硼酸的口服处理导致蟑螂严重的微生态失调，能够降解各种复杂大分子的拟杆菌和能够抑制病原微生物的肠球菌的相对丰度显著降低，而机会性病原体魏斯氏菌的相对丰度显著增加。据推测，肠道微生物群的失调可能加速硼酸对德国蟑螂的毒性。
