Plant essential oils, as biological pesticides, have been reviewed from several perspectives and play a key role in chemical ecology. However, plant essential oils show rapid degradation and vulnerability during actual usage. In this study, we conducted a detailed analysis of the compounds present in the essential oils of A. stechmanniana using gas chromatography–mass spectrometry (GC-MS). The results showed seventeen terpenoid compounds in the A. stechmanniana oil, with four major terpenoid compounds, i.e., eucalyptol (15.84%), (+)-2-Bornanone (16.92%), 1-(1,2,3-Trimethyl-cyclopent-2-enyl)-ethanone (25.63%), and (-)-Spathulenol (16.38%), in addition to an amount of the other terpenoid compounds (25.26%). Indoor toxicity assays were used to evaluate the insecticidal activity of Artemisia stechmanniana essential oil against Aphis gossypii, Frankliniella occidentalis, and Bactericera gobica in Lycium barbarum. The LC₅₀/LD₅₀ values of A. stechmanniana essential oils against A. gossypii, F. occidentalis, and B. gobica were 5.39 mg/mL, 0.34 mg/L, and 1.40 μg/insect, respectively, all of which were highly efficient compared with azadirachtin essential oil. Interestingly, A. stechmanniana essential oil embedded in β-cyclodextrin (microencapsule) remained for only 21 days, whereas pure essential oils remained for only 5 days. A field efficacy assay with the A. stechmanniana microencapsule (AM) and doses at three concentrations was conducted in Lycium barbarum, revealing that the insecticidal activities of AM showed high efficiency, maintained a significant control efficacy at all concentrations tested, and remained for 21 days. Our study identified terpenoid compounds from untapped Artemisia plants and designed a novel method against pests using a new biopesticide on L. barbarum.

It is well known that human activities and climate change have increased steppe habitat loss and fragmentation in Northwest China. Carabid beetles are often used as bioindicators of environmental change because they are extremely sensitive to disturbance. We chose 42 landscapes (18 fragmented and 24 continuous) in both desert and typical steppes of Northwest China to examine the influence of habitat loss and fragmentation on carabid beetle communities. The results showed the largest correlation coefficient between carabid communities and landscape compositions within a 7-km spatial scale in both desert and typical steppes. Further, the response of carabid communities to habitat fragmentation was species-specific in both desert and typical steppes. Habitat fragmentation in the desert steppe had positive effects on the richness and abundance of carabid communities, while in the typical steppe, the effects were negative. Additionally, habitat fragmentation significantly decreased the abundance of two common carabid species in the desert steppe. Therefore, the effects of habitat fragmentation on carabid biodiversity differ with species characteristics and habitat traits, where plant communities, soil structure, and microclimate vary in the different steppe types. The results of this study provide experimental evidence and technical support for biodiversity conservation management in the steppes of Northwest China.