Maladera castanea

Definition

A species of scarab beetle in the family Scarabaeidae, originally described by Arrow in 1913 and now treated as a junior synonym of Maladera formosae (Asiatic garden beetle). Native to East Asia (Japan, China, Taiwan, Korean Peninsula, and Russia), it was introduced to North America in the 1920s and established as a significant pest of turfgrass, ornamental gardens, and agricultural crops. Adults are nocturnal, strongly attracted to light, and feed on leaves and flowers during summer months; larvae damage roots and rhizomes.

Etymology

Latin castanea, chestnut-colored, referring to the typical coloration of the beetle; Maladera from Greek malakos (soft) and dera (neck or throat), a genus name established for certain sericine scarabs.

Example

Specimens identified as Maladera castanea in older North American entomological collections and pest-management literature from the mid-20th century are now reclassified under Maladera formosae, though the name persists in some regulatory and agricultural extension documents.

Synonyms

• Maladera formosae
• Asiatic garden beetle

Related Terms

• Scarabaeidae
• Sericini
• exotic species
• root-feeding scarab
• turf pest
• junior synonym

Usage Notes

The name Maladera castanea appears frequently in historical North American pest-management literature and regulatory quarantine records from the 1920s–1990s, but current taxonomic practice treats it as a synonym of Maladera formosae. Specialists should verify specimen identifications against modern revisions; the two subspecies names Maladera castanea castanea and Maladera castanea koreana (now Maladera formosae koreana) remain in occasional use for regional populations. Not to be confused with the related Japanese beetle (Popillia japonica), with which it shares habitat and pest status but differs in adult size, coloration, and flight behavior.