Chrysomelidae

Chrysomelidae, or leaf beetles, is a large and diverse family of beetles (order Coleoptera). Described species number in the thousands, with many more likely undiscovered, and members occur in nearly all habitats worldwide. Adults vary from a few millimeters to over a centimeter and are often oval or rounded in shape. Many species are brightly colored or metallic, and most are herbivorous, feeding on leaves, stems, seeds, or roots.

Taxonomy and diversity: The family includes several subfamilies, notably Chrysomelinae, Galerucinae (which contains the flea beetles, sometimes treated as Alticinae), Cryptocephalinae, and Cassidinae. Classifications differ, but these groups are generally recognized as major lineages. Habits range from leaf grazing to mining, seed feeding, and wood boring, depending on lineage.

Ecology and economic importance: Leaf beetles occupy many plant communities and, in agricultural settings, many species are pests of crops such as potatoes, canola, beans, and vegetables. Notable pests include Leptinotarsa decemlineata (Colorado potato beetle) and Diabrotica spp. Some species are used in biocontrol against invasive weeds, such as Zygogramma bicolorata on Parthenium hysterophorus.

Life cycle and morphology: Chrysomelidae undergo complete metamorphosis. Eggs are laid on or near host plants; larvae are often legless or grub-like, while adults resemble miniature beetles. Development timing varies with species and climate, and some lineages exhibit seasonal diapause.

Distribution and evolution: Leaf beetles are globally distributed and have diversified in concert with flowering plants. They are a frequent subject of study for systematics, ecology, and integrated pest management.