Plant-pathogen
Guides
Chrysolina quadrigemina
greater St. John's wort beetle, St. John's wort beetle
Chrysolina quadrigemina is a leaf beetle introduced to North America as a biological control agent for the invasive weed Hypericum perforatum (St. John's wort). Native to Europe and North Africa, this beetle has established populations across western North America and has been introduced to Australia. Adults and larvae feed exclusively on Hypericum species, with documented spillover onto native congeners such as H. punctatum in the eastern United States. The beetle exhibits a univoltine life cycle with adults active in summer, and shows evidence of post-colonization adaptation to colder climates in northern populations.
Cicadellinae
sharpshooters, leafhoppers
Cicadellinae is a subfamily of leafhoppers (family Cicadellidae) within the order Hemiptera. Members of the tribe Proconiini within this subfamily are commonly known as 'sharpshooters.' The subfamily currently contains five tribes: Cicadellini, Makilingiini, Phereurhinini, Proconiini, and Tungurahualini. Cicadellinae leafhoppers are globally distributed and are significant agricultural pests due to their role as vectors of plant pathogens, particularly the bacterium Xylella fastidiosa, which causes diseases including Pierce's disease of grape, phony peach disease, and citrus variegated chlorosis.
Leucostoma
Leucostoma is a genus of ascomycete fungi in the family Cytosporaceae (order Diaporthales). Species in this genus are plant pathogens that cause canker diseases, primarily affecting woody hosts. The genus produces both sexual (perithecia) and asexual (pycnidia) fruiting bodies, with the asexual stage formerly classified under the name Leucocytospora. Leucostoma species are distributed across temperate regions of North America, Europe, and Asia.
Neoaliturus tenellus
Beet Leafhopper
Neoaliturus tenellus, commonly known as the beet leafhopper, is a significant agricultural pest in western North America. This leafhopper species is a documented vector of Candidatus Phytoplasma trifolii (CPt) and beet curly top virus (BCTV), pathogens that affect potato, sugar beet, and other vegetable and seed crops. The species exhibits complex seasonal movement patterns between crop and noncrop hosts, utilizing weedy vegetation for overwintering and summer development. Its population dynamics and pathogen transmission ecology have been studied extensively in the Columbia River Basin and southern New Mexico to improve pest management forecasting.
Stigmina
Stigmina is a genus of fungal plant pathogens in the family Mycosphaerellaceae, established by Saccardo in 1880. Species in this genus cause leaf spot diseases on a wide range of woody hosts, including conifers and broadleaf trees. The genus is characterized by superficial sporodochia that develop through stomata, with conidiophores arising laterally from the lower outer cells. Transmission occurs primarily via airborne conidia.