## 1 Introduction  
Crop yields have dropped over the last few years owing to the scarcity of cultivated land, lack of irrigation water, climate change, and the low utilization of soil nutrition [1]. However, in the region of southern Xinjiang, which is located in northwest China, farmers have extensively practiced the alley cropping system not only to alleviate the contradiction between the relatively low income of grain monocropping and the increasing requirement of grain yield, but also to maximize the advantages of light, temperature, water, and other essential production factors utilized under the 'cash tree-grain crop' system [2; 3; 4]. In the agroforestry system, previous studies had focused on the interaction of subterranean organs as well as on the competition of nutrient utilization between both component plants. For instance, [PERSON] et al. (2019) identified that the yield of the aerial part, and the parameters to evaluate subterranean roots such as LER or RD of both species, had decreased significantly under the alley cropping system. On the contrary, the alley cropping pattern increased the root length [5]. Under drought conditions, [PERSON] et al. (2013) reported the biomass, yield, and number of grains per spike higher than monocropping [6]. But, [PERSON] et al. (2019) had found no substantial differences between the narrow crop alley, wide crop alley, and traditional patterns [7]. As a remarkable agroforestry practice, alley cropping enhances the capability of soil nutrients, the abundance of soil microbial communities, the presence of landscape species, as well as reduces carbon emissions to a significant level [8; 9; 10; 11]. More specifically, walnut trees bring many important ecological functions, such as light interception and windbreak [12; 13; 14]. But, some reversed conclusions were also drawn by other researchers. They discovered that tree/wheat mixture shows a low photosynthetically active radiation and are affected significantly by the tree age [3; 15; 16]. All these alterations induced varying degrees of impact to the microclimate factors (temperature, humidity, light intensity, wind strength, etc.) on the participant plants in the system. It differs significantly as compared to the monocropping system. Cereal aphids (including _Sitobion avenue_, _Riopalosiphum padi_, _Metropoldium dirdoum_, etc.) are commonly observed wheat pests which reside in major ecological niches under both patterns at locality, and harm wheat production in China [17; 18; 19]. The insects generally suck phloem sap through their mouthparts from wheat stems, leaves, and ears [20]. During the process of sap sucking and saliva injection, the transmission of barley yellow dwarf virus (BYDV) and other plant viruses occurs. The infection has huge negative impacts on wheat production. In pandemic years, virus infestations can cause yield losses of up to 40% of total wheat production [21]. With the concept development of integrated pest control, reasonable agricultural method application has received much attention from researchers. The alley cropping pattern can attenuate pest harm by decreasing entomic immigration, survival rate, and fecundity and build a temporary shelter for predators to maintain the population before the crop pests' outbreak [22; 23; 24]. Some researchers have explored relationships between pest dynamics and the intercropping patterns of several horticultural crops and cash trees. In this regard, the intercropping system of pear orchards and aromatic plants is beneficial for orchard intercropping systems [25]. Similarly, when cultivating rosmears (_Rosmarinus officinalis_) and sweet pepper (_Capsicum annum_) simultaneously in the same field (intercropping), the densities of the sampled _Franklinella intonsa_, _Myzus persicae_, and _Bemisia tabaci_ in this system are significantly lower than that observed in a monoculture field of sweet pepper [26].