Saxinis saucia

Red-shouldered Leaf Beetle

Family: Chrysomelidae · Class: Insecta · Order: Coleoptera

The red-shouldered leaf beetle (Saxinis saucia) is a small chrysomelid beetle belonging to the diverse family of leaf beetles. This species is classified within the subgenus Boreosaxinis and is part of the tribe Clytrini. Like other chrysomelids, adults are typically small to medium-sized beetles with oval to elongated bodies and antennae of moderate length. The common name suggests the presence of reddish coloration on the shoulders or pronotum, though detailed morphological descriptions for this species remain limited in accessible literature. The species occurs in North America, with the U.S. Fish and Wildlife Service maintaining taxonomic records for multiple subspecies including S. s. bisignata, S. s. monoensis, and S. s. saucia (USFWS Taxonomic Database). The exact geographic distribution of the nominate subspecies within California and other western states requires further documentation, as specific range maps are not readily available in current databases. Related subspecies suggest the species complex may have a broader western North American distribution. Habitat requirements for Saxinis saucia have not been well documented in the scientific literature. As a member of the Chrysomelidae, this beetle likely inhabits areas where its host plants occur, though specific plant associations have not been definitively established. Many chrysomelid species are specialized feeders on particular plant families or genera, suggesting that S. saucia may have similar host plant specificity. The elevation range and specific vegetation types preferred by this species remain undetermined. The life history and ecology of the red-shouldered leaf beetle are poorly understood. Like other leaf beetles, adults likely feed on foliage of their host plants, while larvae may feed on roots, stems, or leaves depending on the species. Seasonal activity patterns, reproductive timing, and overwintering strategies have not been documented for this species. The number of generations per year and specific developmental requirements remain unknown, representing significant gaps in our biological understanding. Currently, Saxinis saucia holds no federal or state conservation listing status. The species is not included on the IUCN Red List, and its population status remains unassessed. Without baseline population data or trend information, it is difficult to evaluate conservation needs. The lack of comprehensive distributional data and ecological information hampers efforts to assess potential threats or habitat requirements for management purposes. Climate change impacts on this species cannot be evaluated without better understanding of its current distribution and habitat preferences. Scientific documentation for this species remains extremely limited despite searches of federal databases and taxonomic resources. The information presented here is based on available taxonomic records from the U.S. Fish and Wildlife Service and general characteristics of the family Chrysomelidae. Detailed ecological studies, population surveys, and host plant documentation are needed to develop a complete understanding of this beetle's biology and conservation status. We welcome contributions of verified scientific data, photographs, or field observations to enhance this species account.

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, and more.