In-Field Habitat Management to Optimize Pest Control of Novel Soil Communities in Agroecosystems

Navigating Agricultural Expansion in Harsh Conditions in Russia: Balancing Development with Insect Protection in the Era of Pesticides

As the world's population continues to increase, ensuring food security becomes a major problem. This often leads to the expansion of agricultural production, even in harsh conditions and becomes a key problem for many countries, including Russia. However, such expansion may entail certain costs, including the potential loss of insect populations, which are vital for ecological balance and agricultural productivity. The development of fallow lands in these regions is necessary to increase food production and increase food security; it is important to balance this with protection from harmful insects and sustainable farming methods. Research into the effects of insecticides on insects is an ongoing challenge, and new, sustainable farming methods are needed to ensure that protection from harmful insects and sustainable development can coexist. This article discusses the use of pesticides to protect the well-being of mankind, the problems of studying the effects of pesticides on insects and the vulnerability of insects to pesticides in regions with harsh conditions. It also discusses successful methods of sustainable agriculture and the importance of the legal framework governing the use of pesticides. The article emphasises the importance of balanced development with insect protection to ensure the sustainability of agricultural expansion in harsh conditions.

Bottom-Up Forces in Agroecosystems and Their Potential Impact on Arthropod Pest Management

Bottom-up effects are major ecological forces in crop-arthropod pest-natural enemy multitrophic interactions. Over the past two decades, bottom-up effects have been considered key levers for optimizing integrated pest management (IPM). Irrigation, fertilization, crop resistance, habitat manipulation, organic management practices, and landscape characteristics have all been shown to trigger marked bottom-up effects and thus impact pest management. In this review, we summarize current knowledge on the role of bottom-up effects in pest management and the associated mechanisms, and discuss several key study cases showing how bottom-up effects practically promote natural pest control. Bottom-up effects on IPM also contribute to sustainable intensification of agriculture in the context of agricultural transition and climate change. Finally, we highlight new research priorities in this important area. Together with top-down forces (biological control), future advances in understanding ecological mechanisms underlying key bottom-up forces could pave the way for developing novel pest management strategies and new optimized IPM programs.

Life History, Biology, and Distribution of Pterostichus melanarius (Coleoptera: Carabidae) in North America

Pterostichus melanarius (Illiger, 1798) is a Palearctic generalist predator native to Europe. It was unintentionally introduced to North America at least twice in the mid 1920s and has since become widespread in Canada and the United States. Although P. melanarius is a valuable natural enemy in many different agricultural systems, we are not aware of any effort to compile in one publication details of its life history, diet, distribution, and factors that influence its populations. Some studies in North America have investigated the effects of P. melanarius on pest species and native carabid assemblages. Moreover, given that it is an exotic species whose range appears to still be expanding, it will be valuable to predict its potential distribution in North America. Therefore, the goals of this paper are to: 1) compile information on the life history and biology of P. melanarius, 2) review the effects of various agricultural practices on this species, and 3) use ecological niche modeling to determine the potential range of P. melanarius in the United States and which climate variables are most important for range expansion. Our review revealed that P. melanarius appears to provide benefits most consistently in diverse agricultural systems managed with no-till or reduced till methods, whereas our modeling revealed that P. melanarius likely occupies, or will occupy, more of the northern U.S. than is currently recognized, particularly in the Appalachian and Rocky Mountain regions.

Ground Predator Activity-Density and Predation Rates Are Weakly Supported by Dry-Stack Cow Manure and Wheat Cover Crops in No-Till Maize

Because it keeps land in production, conservation programs that focus on in-field habitat manipulations may help farmers better support predators than by building predator habitat around fields. We investigated two in-field habitat manipulations that benefit producers and soil quality: fertilizing with dry-stack cow manure and planting a wheat cover crop. We hypothesized that, compared with inorganic fertilizer and fallow plots, both treatments augment habitat and residue and support more small arthropods that can serve as alternative prey for larger predators. As a result, we expected manure and the cover crop to increase ground-active predators. In turn, these predators could provide biological control of pests. Each year in a 3-yr field experiment, we applied manure and in 2 yr planted a wheat cover crop. We found that both planting a cover crop and applying dry-stack manure increased the plant cover in May. In the last year, this translated to greater soil mite (Acari) density. At the end of the experiment, however, neither manure nor the wheat cover crop had increased residue on the soil surface. As a result, our treatments had inconsistent effects on predator activity-density, especially for carabids and spiders. We observed strong edge effects from neighboring grass alleys on carabid activity-density. Regardless of treatment, we observed high predation of sentinel prey. We conclude that even without cover crops or organic fertilizer, the stability of no-till maize and increased weeds in fallow treatments generate sufficient habitat complexity and alternative prey to support robust predator communities.

Influence of Cover Crop Termination on Ground Dwelling Arthropods in Organic Vegetable Systems

A key aspect in cover crop management is termination before the cash crop is planted. The aim of this study was to assess the effects of termination methods on ground-dwelling arthropods. The conventional mechanical termination method-i.e., green manuring by means of a disc harrow-was compared to flattening using a roller crimper. Two different crop systems were investigated for two growing seasons; cauliflower was grown in autumn after the termination of a mixture of cowpea, pearl millet, and radish, and tomato was cropped in spring and summer after the termination of a mixture of barley and vetch. Ground beetles (Coleoptera: Carabidae), rove beetles (Coleoptera: Staphylinidae), and spiders (Araneae) were sampled by means of standard pitfall traps throughout the growing season of both cash crops. The roller crimper increased the overall abundance of ground beetles in the first growing season of both cash crops, whereas in the second year, no significant effect could be detected. Rove beetles were more abundant in plots where the cover crops were terminated by the roller crimper. Finally, green manuring increased the abundance of spiders, especially on the first sampling date after cover crop termination. Albeit different taxa showed different responses, the termination of cover crops by a roller crimper generally increased the abundance of ground dwelling arthropods. Given that most of the sampled species were generalist predators, their increased abundance could possibly improve biological control.

Balancing Disturbance and Conservation in Agroecosystems to Improve Biological Control

Disturbances associated with agricultural intensification reduce our ability to achieve sustainable crop production. These disturbances stem from crop-management tactics and can leave crop fields more vulnerable to insect outbreaks, in part because natural-enemy communities often tend to be more susceptible to disturbance than herbivorous pests. Recent research has explored practices that conserve natural-enemy communities and reduce pest outbreaks, revealing that different components of agroecosystems can influence natural-enemy populations. In this review, we consider a range of disturbances that influence pest control provided by natural enemies and how conservation practices can mitigate or counteract disturbance. We use four case studies to illustrate how conservation and disturbance mitigation increase the potential for biological control and provide co-benefits for the broader agroecosystem. To facilitate the adoption of conservation practices that improve top-down control across significant areas of the landscape, these practices will need to provide multifunctional benefits, but should be implemented with natural enemies explicitly in mind.