Toxicity of procymidone to Bombyx mori based on physiological and transcriptomic analysis.

Procymidone is widely used in vegetables and fruits because of its broad-spectrum and high efficiency. However, it is unclear whether procymidone can affect silkworm (Bombyx mori) growth and cocoon production. This study investigated the effects of procymidone on the growth and cocoon production of silkworms. We analyzed the growth, and cocoon quality of fifth instar larvae fed on mulberry leaves saturated with different concentrations (2.5, 5, and 10 mg/ml) of procymidone and the control. Results showed that procymidone supplementation decreased the larval growth and cocoon quality compared to the control group, suggesting that procymidone had toxicity to silkworms. Additionally, after transcriptomic analysis, we identified 396 significantly differentially expressed genes (DEGs) in the presence of procymidone. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) illustrated that these DEGs were closely related to metabolism. Taken together, these results confirmed that procymidone could cause toxicity by affecting metabolism in silkworm larvae. We believed that these results could provide important materials for the effect of procymidone on silkworms and gave us some clues for pesticides used in the mulberry garden.

Effect of Lactic Acid Supplementation on the Growth and Reproduction of Bombyx mori (Lepidopteria: Bombycidae).

Lactic acid is widely used in the food, drugs, cosmetics, and other industries to maintain the microbial stability of low-pH products. However, it is unclear whether lactic acid can affect silkworm (Bombyx mori) growth and reproduction. This study investigated the effects of lactic acid on the growth and reproduction of the silkworm. We analyzed the growth, cocoon quality, and reproductive performance of fifth instar larvae fed on mulberry leaves saturated with different concentrations (0.01, 0.1, 1, and 10%) of lactic acid and the control. Results showed that 0.01, 0.1, and 1% lactic acid supplementation positively affects growth and female cocoon quality, with increased larval weight and female cocoon shell weight compared to the control group. In contrast, 10% lactic acid was toxic to the larvae and significantly decreased growth, leading to larval death. Our study provides a basic reference for the optimal amount of preservatives. In addition, this study can be a desirable intervention for sericulturists and can play an important role in getting high return from silkworm-rearing activities.

Contamination and congener profiles of polychlorinated biphenyls from different agricultural top soils in a county of the Tailake Region, China.

Hundred topsoil (0-20 cm) samples under different land use types were collected from a county in the Tailake Region, China and analyzed for 18 polychlorinated biphenyls (PCBs) including five dioxin-like PCBs. The mean concentration of total PCBs (SigmaPCBs) for all sites was 1.071 microg kg(-1) dry weight (dw) with a range of 0.016 microg kg(-1) to 4.050 microg kg(-1), and the concentration of total Dioxin-like PCBs (SigmaDioxin-like PCBs) was 0.352 microg kg(-1) about 33% of SigmaPCBs. The concentration of SigmaPCBs in paddy field (PF) soils with a mean of 1.63 microg kg(-1) was higher than that in vegetable soil with a mean of 0.882 microg kg(-1), but the concentration of Dioxin-like PCBs in PF soil was lower than that in commercial vegetable production soil. The concentration of heavier weighted molecular PCB congeners (> or = penta-PCBs) in vegetable soil accounted for 98% of SigmaPCBs, while that in Paddy field soil for 65% of SigmaPCBs.