Alfalfa weevil, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae), is a pest of concern in alfalfa (Medicago sativa L.) fields throughout the western United States. This introduced pest is most problematic in the early season causing defoliation and reduced hay yield and quality. Both adults and larvae feed on alfalfa, damaging terminals, foliage, and new crown shoots, but the larvae cause the majority of the damage. Three strains of alfalfa weevil, all H. postica, can be found in the western United States: the Western, Eastern, and Egyptian alfalfa weevil, H. brunnipennis (Boheman). Cultural, chemical, and biological control options are all viable strategies to include in an integrated management plan for alfalfa weevil, regardless of strain. We highlight research findings to best inform effective use of early harvest, grazing, insecticides, intercropping, and conservation biological control in alfalfa production systems.
Timing of insecticide application can impact efficacy, given variation in both weather and development of the crop and its insect pests. Both target and nontarget insects may vary in life stage and abundance at the time of application. In alfalfa Medicago sativa L. cropping systems, producers have interest in early-season insecticide applications to eliminate last-minute decisions about preharvest applications for alfalfa weevil Hypera postica (Gyllenhal) (Coleoptera: Curculionidae). The standard recommendation is based on scouting larvae close to the first harvest time. We compared early and standard timing of application of a lambda-cyhalothrin pyrethroid on alfalfa pest and beneficial insects. Field trials at a university research farm were conducted in 2020 and 2021. In 2020, early application was as effective as the standard timing against alfalfa weevil, as compared to the untreated control, but less effective than the standard timing in 2021. Effects of timing against Lygus bugs (Hemiptera: Miridae), grasshoppers (Orthoptera: Acrididae), and aphids (Hemiptera: Aphididae) were inconsistent between years. We observed the potential for early application to reduce negative impacts on ladybird beetles (Coleoptera: Coccinellidae) and spiders (Araneae), however, damsel bugs (Hemiptera: Nabidae) were similarly reduced by insecticide application regardless of timing. Overall arthropod community composition differed by both year and treatment. Future research should explore potential trade-offs of spray timing at larger spatial scales.
Various strategies incorporate floral resources into agricultural landscapes to support beneficial insects. Specialty cut flower production offers a rarely explored approach to offer floral resources while yielding a marketable product for growers. We characterized insect visitation to six species of specialty cut flowers. Due to Wyoming’s growing conditions, the flowers were grown in high tunnels, thus offering insight into insect abundance in this unique semi-controlled environment. The flower species tested were Calendula officinalis, Celosia argentea, Daucus carota, Helichrysum bracteatum, Matthiola incana, and a Zinnia elegans-Zinnia hybrida mixture. At least four species were in bloom from early June through late September. The flowers attracted diverse pollinator groups including Diptera, Hymenoptera, Coleoptera, and Lepidoptera. Bees most often visited Ca. officinalis, H. bracteatum, and Celosia spicata whereas flies most often visited D. carota. Bombus were the most oft-collected bees from the flowers and were found on all six cut flower species. Wasp abundance varied little across the cut flowers, but wasp community composition was distinct. The highest diversity of wasp families was collected from the Zinnia mixture (seven families) in contrast to less diverse collections from Ce. spicata (two families). The most abundant wasp families collected were Crabronidae and Sphecidae. Our experiment documented that ornamental cut flower species attract pollinator insects into high tunnel environments. All cut flower species tested were visited by multiple types of beneficial insects. Planting a mixture of specialty cut flowers can support insect diversity while also diversifying on-farm agricultural products through sale of cut flower stems.
As food companies have adopted sustainability metrics to quantify the environmental impacts of supply chains, we need data-driven decision support tools that represent organic management practices. Decision support tools such as COMET-Farm and the Cool Farm Tool have been developed to estimate management practice impacts on soil carbon and greenhouse gas emissions from agricultural systems, but these tools have primarily been developed and used to evaluate conventional management systems. We provide an overview of the research, outreach, and educational activities used to improve these tools to better integrate organic management practices with a focus on cover crops. We summarize our previously published findings from a meta-analysis of the average potential soil carbon benefits of cover crops in temperate climates that identified planting window, biomass production, and soil texture as important predictors of cover crop soil carbon outcomes. We demonstrate how these findings were applied to improvements in process-based models and the parameterization of empirical models. In addition, we solicited feedback from organic community members on the utility of these tools and identified barriers to adoption. Finally, we evaluated both tools as resources for teaching undergraduate students about organic management systems and their impacts on greenhouse gas emissions. While both tools contain a range of customizable, organic amendment options, grazing management options still need further improvement. These improved decision support systems can help identify opportunities for enhancing the sustainability of organic systems.
Global food systems contribute to greenhouse gas emissions, and the mitigation of these emissions is a critical component of addressing the challenge of climate change. A variety of decision‐support tools are available for agricultural producers to use to estimate how their management decisions affect emissions. These tools, often free and online, can be incorporated into agriculture and natural sciences courses, providing an engaging and interactive way for students to learn about climate change mitigation in online courses. Here, we focus on three tools: COMET‐Planner, COMET‐Farm, and Cool Farm Tool. Each of these tools link agricultural management with estimated emissions but differ according to the scope of analysis and type of functionality. Our case study navigates how to best incorporate each tool into undergraduate courses ‐ providing detailed examples focused on crop production. Teaching notes provide guidance on pairing these activities with lessons related to agricultural policy, science communication, and farm nutrient budgets. Instructors have considerable opportunity to incorporate agricultural decision‐support tools into courses to support students connecting scientific concepts to real‐world application.