Spatial ecology includes research into factors responsible for observed distribution patterns of organisms. Moreover, the spatial distribution of an animal at a given spatial scale and in a given landscape may provide valuable insight into its host preference, fitness, evolutionary adaptation potential, and response to resource limitations. In agro-ecology, in-depth understanding of spatial distributions of insects is of particular importance when the goals are to (1) promote establishment and persistence of certain food webs, (2) maximize performance of pollinators and natural enemies, and (3) develop precision-targeted monitoring and detection of emerging outbreaks of herbivorous pests. In this article, we review and discuss a spatial phenomenon that is widespread among insect species across agricultural systems and across spatial scales-they tend to show "edge-biased distributions" (spatial distribution patterns show distinct "edge effects"). In the conservation and biodiversity literature, this phenomenon has been studied and reviewed intensively in the context of how landscape fragmentation affects species diversity. However, possible explanations of, and also implications of, edge-biased distributions of insects in agricultural systems have not received the same attention. Our review suggests that (1) mathematical modeling approaches can partially explain edge-biased distributions and (2) abiotic factors, crop vegetation traits, and environmental parameters are factors that are likely responsible for this phenomenon. However, we argue that more research, especially experimental research, is needed to increase the current understanding of how and why edge-biased distributions of insects are so widespread. We argue that the fact that many insect pests show edge-biased distribution patterns may be used to optimize both pest monitoring practices and precision targeting of pesticide applications and releases of natural enemies.

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Soil salinity and mineral deficiency are major problems in agriculture. Many studies have reported that plant-associated microbiota, particularly rhizosphere and root microbiota, play a crucial role in tolerance against salinity and mineral deficiency. Nevertheless, there are still many unknown parts of plant–microbe interaction, especially regarding their role in halophyte adaptation to coastal ecosystems. Here, we report the bacterial community associated with the roots of coastal sand dune halophytes Spinifex littoreus and Calotropis gigantea, and the soil properties that affect their composition. Strong correlations were observed between root bacterial diversity and soil mineral composition, especially with soil Calcium (Ca), Titanium (Ti), Cuprum (Cu), and Zinc (Zn) content. Soil Ti and Zn content showed a positive correlation with bacterial diversity, while soil Ca and Cu had a negative effect on bacterial diversity. A strong correlation was also found between the abundance of several bacterial species with soil salinity and mineral content, suggesting that some bacteria are responsive to changes in soil salinity and mineral content. Some of the identified bacteria, such as Bacillus idriensis and Kibdelosporangium aridum, are known to have growth-promoting effects on plants. Together, the findings of this work provided valuable information regarding bacterial communities associated with the roots of sand dune halophytes and their interactions with soil properties. Furthermore, we also identified several bacterial species that might be involved in tolerance against stresses. Further work will be focused on isolation and transplantation of these potential microbes, to validate their role in plant tolerance against stresses, not only in their native hosts but also in crops.

There is high demand for accurate insect sampling methods to inform integrated pest management strategies. Despite widespread application, existing sampling methods, such as portable aspirating and sweep netting, can result in overrepresentation of prominent pests, underrepresentation of natural enemies, and damage to plants. In this study, we test a novel device for insect sampling via anesthetization. Specifically, we test the effect of CO2 (application pressure and duration of exposure) on Lygus hesperus Knight (Hemiptera: Miridae) anesthetization in the laboratory and on insect community density in a strawberry agroecosystem. Carbon dioxide application proves an effective means of anesthetization compared to negative controls, and an increase in net CO2 exposure results in a decrease in time until L. hesperus anesthetization. Field results indicate the CO2 method collects more parasitoids and thrips than a portable aspirator, and at the 50 PSI application pressure and 15-s exposure, the CO2 method results in a comparable number of pests collected as the research standard, a portable aspirator with 8-s aspiration time. Benefits of the CO2 method include minimal plant damage, highly explicit spatial and temporal data, and scalability.