The ladybirds Coccinella septempunctata and Harmonia axyridis are important biocontrol agents for the small walnut aphid Chromaphis juglandicola, a key walnut pest. C. juglandicola outbreaks occur in walnut orchards, and walnut yields have declined. Intraguild predation (IGP) is prevalent among natural enemies that coexist in shared habitats and prey upon the same extraguild prey. We designed laboratory experiments to evaluate the potential for IGP between these two ladybirds at different temperatures and extraguild (EG) prey densities, and the ability of IGP to control EG prey under different conditions. We measured IGP rates in first instar larvae, female adults, and male adults (both starved for 24 h) in the vulnerable immature life stages of two ladybird eggs. Intraguild (IG) prey (H. axyridis eggs or C. septempunctata eggs) and EG prey (C. juglandicola) consumption were tallied after 24 h. Temperature and EG prey density influenced IGP rates, with temperature contributing the most to the variance. IGP increased with increasing temperature (15–35 °C), with both factors interactively influencing the EG prey consumption rate and exhibiting highly significant effects. EG prey consumption increased with temperature and density. This research provides theoretical support for the rational use of H. axyridis and C. septempunctata in the joint biological control of C. juglandicola

As an important ecosystem, the wild fruit forest in the Tianshan Mountains is one of the origins of many fruit trees in the world. The wild fruit forest in Emin County, Xinjiang, China, was taken as the research area, the spatial and temporal distribution of the wild fruit forest was inverted using random forest and PLUS models, and the 2027 distribution pattern of the wild fruit forest was simulated and predicted. From 2007 to 2013, damage to the wild fruit forest from tourism and overgrazing was very serious, and the area occupied by the wild fruit forest decreased rapidly from 9.59 km² to 7.66 km². From 2013 to 2020, suitable temperatures and reasonable tourism management provided strong conditions for the rejuvenation of wild fruit forests. The distance of the center of gravity of the wild fruit forest increased, and the density of distribution of the wild fruit forest in the northwest direction of the study area also increased. It is predicted that the wild fruit forest in the study area will show a steady and slowly increasing trend in places far away from tourist areas and with more complex terrain. It is suggested that non-permanent fences be set up as buffer zones between wild fruit forests, ensuring basic maintenance of wild fruit forests, limiting human disturbance such as overgrazing, and reducing the risk of soil erosion.

The globose scale (GS) (Sphaerolecanium prunastri Boyer de Fonscolombe) is a sucking insect that feeds on saps of wild apricot tree (Prunus armeniaca L.) in the Xinjiang Uygur Autonomous Region of northwestern China. It feeds on branches of wild apricot leading to poor growth, leaf yellowing and leaf drop, and sometimes mortality. Since the initial infestation in 2018, all the main valleys of wild apricot trees have been affected, but there is little research on the host’s physiological response to GS infestation. We measured the differences in growth between infested and non-infested wild apricots. The results showed that the diameter of shoot branches, the fresh weight, dry weight, length, width, area, and chlorophyll content of leaves, and the longitudinal diameter of fruit, were all significantly less for infested wild apricot trees than for un-infested wild apricot. The branch length of shoots, cross diameter, and weight of fruit also decreased, although the differences were not significant. Overall, GS infestation significantly reduced the growth of wild apricot trees, and may accelerate the damage by GS to wild apricot over time.