Abstract:
Poratrioza sinica (Hemiptera: Psyllidae) is a highly destructive pest that infests of wolfberry. To screen biodegradable and safe insecticides, 12 representative monoterpenoids in essential oils were evaluated for their acute toxicity, synergistic or antagonistic efects on adult P. sinica. The modified residual film method was used to test the toxicity of individual and binary mixture of these monoterpenoids against adult P. sinica. The efects of these monoterpenoids on acetylcholinesterase (AChE) and glutathione S-transferase (GST) activities in P. sinica were assessed in vitro. Correlation between numbers of synergistic or antagonistic binary mixtures and AChE or GST activities was analyzed. The results showed that 2-ethylimidazole had the strongest acute toxicity against P. sinica adult, with a median lethal concentration (LC50) value of 0.52 g/L. Among the 66 binary mixtures, 19 showed strong synergistic efects, while 21 showed antagonistic efects. The most profound synergistic efect was the mixture of l-carvone and dihydrocarvone, with an expected mortality of 35.2% and actual mortality of 98.4%. Estragole had the highest frequency of antagonistic efect (7 combinations), and the most significant antagonism was observed when combining ß-pinene and estragole, with an expected mortality of 29.0% and actual mortality of 3.8%. Furthermore, AChE inhibition was observed with estragole, cuminaldehyde, and 1,8-cineole displayed high potency. L-carvone showed the highest GST inhibition activity, followed by cuminaldehyde. Pearson correlation analysis revealed a significant negative correlation between GST inhibition rate and number of antagonistic binary mixtures. In conclusion, our findings suggest that 2-ethylimidazole and cuminyl alcohol have high toxicity against P. sinica. L-carvone was the best synergist, and binary mixtures of l-carvone with dihydrocarvone, cuminaldehyde, cuminyl alcohol, d-carvone, and estragole showed potential as control agents against P. sinica. This study provides insights for identifying safe and biodegradable insecticides and potential solutions for controlling P. sinica.
Keywords:
acute toxicity
,
Acute toxicity
,
Monoterpenoids
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Acute toxicity
,
Binary Mixtures
,
GST inhibition
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AChE inhibition
,
Synergistic efect
,
Poratrioza sinica