Xie Xinyi, Hou Jiayin, Li Meng, Liu Zhiyu, He Mengai, Li Chenxi, Du Xiaohua, Chen Liezhong
College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China.
State Key Laboratory for Quality and Safety of Agro-Products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
Toxics. 2025 May 23;13(6):427. doi: 10.3390/toxics13060427.
Phoxim is a pesticide extensively applied in mulberry fields, and residues may persist on leaves even after the recommended pre-harvest interval. However, the potential risks of these residues to L. (Lepidoptera: Bombycidae) have long been overlooked. The results demonstrated that chronic low-dose exposure from the second to fifth instars significantly impaired silkworm development and silk production. Specifically, larvae in the 0.316 μg/mL treatment group (1/2 LC) exhibited a significant reduction in body weight, while the cocoon shell ratio was significantly decreased in both the 0.079 μg/mL (1/8 LC) and 1/2 LC groups. Cocoon deformities were observed in the 0.032 μg/mL (1/20 LC), 1/8 LC, and 1/2 LC groups. Histopathological analysis revealed silk gland damage in the treatment groups, with severity increasing with higher phoxim concentrations. Biochemical analyses indicated elevated malondialdehyde (MDA) levels accompanied by increased superoxide dismutase (SOD) and peroxidase (POD) activities. Notably, phoxim exposure selectively reduced juvenile hormone (JH) titers without affecting ecdysone titers. JH-regulated genes including the receptors and , and transcription factors and were downregulated, accompanied by suppressed expression of the fibroin synthesis gene . These results collectively indicate that chronic low-concentration phoxim exposure disrupts endocrine regulation, damages silk gland integrity, and ultimately reduces silk production in silkworm.
辛硫磷是一种广泛应用于桑园的杀虫剂，即使在推荐的收获前间隔期过后，其残留物仍可能残留在叶片上。然而，这些残留物对家蚕（鳞翅目：蚕蛾科）的潜在风险长期以来一直被忽视。结果表明，从二龄到五龄的慢性低剂量暴露显著损害了家蚕的发育和蚕丝产量。具体而言，0.316μg/mL处理组（1/2LC）的幼虫体重显著降低，而0.079μg/mL（1/8LC）和1/2LC组的茧层率均显著下降。在0.032μg/mL（1/20LC）、1/8LC和1/2LC组中观察到茧畸形。组织病理学分析显示处理组的丝腺受损，且随着辛硫磷浓度的升高，损伤程度加剧。生化分析表明丙二醛（MDA）水平升高，同时超氧化物歧化酶（SOD）和过氧化物酶（POD）活性增加。值得注意的是，辛硫磷暴露选择性地降低了保幼激素（JH）滴度，而不影响蜕皮激素滴度。包括受体和、转录因子和在内的JH调节基因被下调，同时丝素合成基因的表达受到抑制。这些结果共同表明，慢性低浓度辛硫磷暴露会破坏内分泌调节，损害丝腺完整性，并最终降低家蚕的蚕丝产量。
