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The bean beetle, Callosobruchus maculatus (Coleoptera, Chrysomelidae), has become a widely used insect species in undergraduate laboratory education. This species is particularly suitable for course-based undergraduate research experiences (CUREs) due to its short generation time, ease of handling and culturing in the laboratory, and sexual dimorphism in its sedentary phase. Bean beetles complete their growth and development inside a host seed (bean) with at least eight different host species. However, conducting manipulative experiments with bean beetles would be enhanced if it were possible to readily prepare artificial beans on which the beetles could complete their lifecycle. Here, we report on the use of a mechanical pill press (LFA Machines Model TDP-0) to make artificial beans. We prepared artificial beans by making whole blackeye pea flour (Vigna unguiculata) using a coffee grinder. That flour was used in the pill press to make 8mm diameter x 5-9mm thick disk-shaped pills with and without additives. Adult female bean beetles readily laid fertilized eggs on the surface of these artificial beans. Offspring emerged 4-5 weeks later at 25°C, the same development time that would have occurred in natural intact blackeye pea seeds. No special treatments of the artificial beans were required to induce females to lay eggs on them nor for the pills to remain intact during the period of larval and pupal development. This mechanical pill press can produce 30-50 pills per minute, so artificial beans can be produced rapidly in sufficient numbers to conduct meaningful experiments. This simple and effective method for making artificial beans creates the opportunity to conduct studies that have been difficult or impossible in the past.For example, future studies may evaluate treatments such as plant secondary compound concentrations, nutrient content, and antibiotic exposure on bean beetle life history and microbiome communities. 

Recent calls for increased inclusion in & access to authentic course-based research have been building on the momentum of support for Course-Based Undergraduate Research Experiences (CUREs). However, these courses can be very challenging to implement at scale or with low resources. To equitably provide these critical science process skills to the largest possible cohort of students, we have developed a new student research project within our first-year biology lab. Our student team research project is integrated throughout the semester, building authentic science process skills from start to finish. Students start from a research idea, develop a multi-site experimental design, do hands-on data collection at home, analyze quantitative data, and present their findings in a conference-style format. We have also embedded structured time for building collaborative skills. This novel change to our lab curriculum runs online, hybrid or face-to-face; it has no lab budget costs; and it has been well-received in multiple offerings of our course of ~200-600 students. It also has allowed us to improve our assessments: we evaluate writing (graphical abstracts) and/or oral presentation skills. Further, our lab exam can now be more cognitively challenging because our new curriculum better prepares students to analyze, evaluate, and synthesize. This article demonstrates that we can reduce barriers to doing authentic research, at scale in introductory courses; and we include here all materials needed to adapt this project to your own context. 

ABSTRACT A pervasive pest of stored leguminous products, the bean beetle Callosobruchus maculatus (Coleoptera: Chrysomelidae) associates with a simple bacterial community during adulthood. Despite its economic importance, little is known about the compositional stability, heritability, localization, and metabolic potential of the bacterial symbionts of C. maculatus . In this study, we applied community profiling using 16S rRNA gene sequencing to reveal a highly conserved bacterial assembly shared between larvae and adults. Dominated by Firmicutes and Proteobacteria , this community is localized extracellularly along the epithelial lining of the bean beetle’s digestive tract. Our analysis revealed that only one species, Staphylococcus gallinarum (phylum Firmicutes ), is shared across all developmental stages. Isolation and whole-genome sequencing of S. gallinarum from the beetle gut yielded a circular chromosome (2.8 Mb) and one plasmid (45 kb). The strain encodes complete biosynthetic pathways for the production of B vitamins and amino acids, including tyrosine, which is increasingly recognized as an important symbiont-supplemented precursor for cuticle biosynthesis in beetles. A carbohydrate-active enzyme search revealed that the genome codes for a number of digestive enzymes, reflecting the nutritional ecology of C. maculatus . The ontogenic conservation of the gut microbiota in the bean beetle, featuring a “core” community composed of S. gallinarum , may be indicative of an adaptive role for the host. In clarifying symbiont localization and metabolic potential, we further our understanding and study of a costly pest of stored products. IMPORTANCE From supplementing essential nutrients to detoxifying plant secondary metabolites and insecticides, bacterial symbionts are a key source of adaptations for herbivorous insect pests. Despite the pervasiveness and geographical range of the bean beetle Callosobruchus maculatus , the role of microbial symbioses in its natural history remains understudied. Here, we demonstrate that the bean beetle harbors a simple gut bacterial community that is stable throughout development. This community localizes along the insect’s digestive tract and is largely dominated by Staphylococcus gallinarum . In elucidating symbiont metabolic potential, we highlight its possible adaptive significance for a widespread agricultural pest. 

Over the past decade, laboratory courses have made a fundamental shift to inquiry-based modules and authentic research experiences. In many cases, these research experiences emphasize addressing novel research questions. Insects are ideal for inquiry-based undergraduate laboratory courses because research on insects is not limited by regulatory, economic, and logistical constraints to the same degree as research on vertebrates. While novel research questions could be pursued with model insect species (e.g., Drosophila, Tribolium), the opportunities presented by non-model insects are much greater, as less is known about non-model species. We review the literature on the use of non-model insect species in laboratory education to provide a resource for faculty interested in developing new authentic inquiry-based laboratory modules using insects. Broader use of insects in undergraduate laboratory education will support the pedagogical goals of increased inquiry and resesarch experiences while at the same time fostering increased interest and research in entomology. 

ABSTRACT Calls for early exposure of all undergraduates to research have led to the increased use and study of course-based research experiences (CREs). CREs have been shown to increase measures of persistence in the sciences, such as science identity, scientific self-efficacy, project ownership, scientific community values, and networking. However, implementing CREs can be challenging and resource-intensive. These barriers may be partly mitigated by the use of short-term CRE modules rather than semester- or year-long projects. One study has shown that a CRE module captures some of the known benefits of CREs as measured by the Persistence in the Sciences (PITS) survey. Here, we used this same survey to assess outcomes for introductory biology students who completed a semester of modular CREs based on faculty research at an R1 university. The results indicated levels of self-efficacy, science community values, and science identity similar to those previously reported for students in the Science Education Alliance-Phage Hunters Advancing Genomics and Evolutionary Science (SEA-PHAGES) full-semester CRE. Scores for project ownership (content) were between previously reported traditional lab and CRE scores, while project ownership (emotion) and networking were similar to those of traditional labs. Our results suggest that modular CREs can lead to significant gains in student affect measures that have been linked to persistence in the sciences in other studies. Although gains were not as great in all measures as with a semester-long CRE, implementation of modular CREs may be more feasible and offers the added benefits of exposing students to diverse research fields and lab techniques.