Mimulus guttatus (syn: Erythranthe guttata) is an important model organism in evolutionary ecology research. However, besides a few scattered reports of a single herbivore species at a time, there has only been one published list of herbivores that attack M. guttatus. I combined literature records as well as records from over five years of field surveys to include a range-wide list of species that attack M. guttatus. These records included plant populations from the native range in western North America and the non-native ranges in the United Kingdom and Eastern North America. I recorded over 86 species that consumed M. guttatus through its native and introduced ranges. In the native range, 77 species were found. In the UK, I reported 22 species of herbivores while in the eastern North America populations I recorded seven species feeding on M. guttatus. The native western North America range shared nine species with the UK range (mostly gastropods) and shared five herbivores with the eastern North America populations (mostly generalist mammal herbivores). I expect this list to grow as more studies focusing on plant–herbivore interactions in M. guttatus are published. I hope this list starts as a foundation for these future studies.

Pinus edulis Engelm. (pinyon pine) is a tree in the Pinaceae family with wide geographic distribution throughout dry forests of western North America. Pinyon pine seed cones, which mature over a 2-year period before shedding seed, are often resinous. Conifer resin, which is a liquid-soluble mixture of volatile and non-volatile secondary metabolites, typically demonstrates significant ecological functions. In the current study, seed cones (n = 240) were collected monthly for a 1-year period from pinyon pine trees (n = 20) and separated equally into two groups, resinous and non-resinous cones, for research on the volatile compound chemistry and insect herbivory. Upon distillation, resinous cones yielded 41× more volatile oil and contained more viable seeds, compared to non-resinous cones. Chemical profiles of volatile oils were seemingly consistent between seasons but differed between cone groups. In resinous cone samples, volatile oils were largely composed of α-pinene (avg. 75.6%) and δ-3-carene (avg. 7.4%). In contrast, in non-resinous cone samples, the volatile oil profiles were not dominated by any single prominent compound. Cone inquiline insect communities varied with regard to the resinous status of the cones, the month of collection, and with overall volatile oil yield. Typically, with larger oil yields we saw more diverse and more abundant inquiline communities. Findings from this study suggest that the volatile oils, in addition to other components of cone resin and physical structures, play a significant ecological role in pinyon pine seed preservation from insect herbivory.

The agricultural industry largely relies on conventional pesticides to maintain healthy, pest-free crops. Application of conventional insecticides is the go-to method for cultivating important food crops, such as corn and sorghum, free of Spodoptera frugiperda (fall armyworm) infestations. However, conventional insecticides have purported negative environmental and health impacts. Natural plant extracts, such as essential oils, are viewed as a promising alternative to conventional insecticides. In the current study, Dysphania ambrosioides (epazote) essential oil was embedded into an artificial diet and fed at two different concentrations to fall armyworms during a 10-day period. Final weights of the 5% epazote treatment group were statistically less (F₆₃₄₃ = 136.2 p < 0.001) than control groups. The 5% epazote treatment group also experienced the highest mortality rate (62%) of any treatment group (X² = 831.4, DF = 6, p < 0.001). Findings suggest that epazote essential oil has potential as an effective, natural insecticidal ingredient. This research is of importance to the fields of agronomy and health sciences.

Rhus is a genus of shrubs that produces strong aromatic essential oils. These oils have numerous applications, including treating urinary infections, flavoring food, and alleviating gastrointestinal ailments. We conducted an experiment to track the essential oil yield and composition of two Rhus species, Rhus aromatica Aiton and Rhus trilobata Nutt., over the course of the growing season. The essential oil yield and composition were examined over four weeks from May to June 2023. We found that higher ambient temperature lowered the total yield of essential oils. Yield decreased in both species over the course of the experiment, with a yield of 0.21% in week 1 and 0.07% in week 4. The composition of oils changed as the outside temperature increased. Some of the lighter hydrocarbons, such as limonene, decreased, while other heavier hydrocarbons, including β-caryophyllene and germacrene D, increased as the outside temperature rose. Limonene was also shown to be the main component of R. aromatica essential oil at an average of 86.2% area, with >98% of that being the enantiomer D-limonene. Additionally, the effect of different drying methods on the yield and composition of the essential oils was investigated. The results show that when drying the plant material in the oven, a greater yield of 0.31% is obtained, whereas the shade- and sun-dry methods yield 0.09% and 0.02%, respectively. The main component of R. trilobata was α-pinene compared to the D-limonene in R. aromatica. This study helps to understand more of the correlation between outside temperature and essential yield/composition in the species R. aromatica, particularly during the May–June sampling period. To compare two Rhus species that get commonly grouped together as the same species, SPME Headspace was used to determine that the main component of R. trilobata was α-pinene compared to D-limonene being the main component in R. aromatica.