Sluggin' Along: Asiatic Garden Beetle

The Asiatic Garden Beetle (Maladera castanea) resembles a June Bug (genus Phyllophaga, tribe Melolonthini), but it's not. For one thing, its elytra (wing cases) have regularly spaced striations, whereas the June Bug has smooth ones. However, they both do have an oily sheen or iridescence. The Asiatic Garden Beetle belongs to a different tribe: Sericini. Within that tribe, it most closely resembles members of the genus Serica, but its hind tibiae are wider. Other distinguishing features are the transverse row of spines on abdominal segments 5, 6, and 7, extending the width of each segment ventrally. Also, this beetle has backward-projecting hairs on the top of its head.

I found my specimen at night, which is no wonder, because the Asiatic Garden Beetle feeds at night on the leaves of garden plants. It was attracted to my lantern, and landed just inches from me at the base of our shed. It's a summer beetle, and its larvae are the white grubs you find at shallow depths of the soil. But note that not all white grubs will turn into this species, so it's a good idea to check to see what exactly you have. In this species, the adults cause more damage than the larvae, because unlike other grubs, these larvae feed deeper down on the peripheral roots instead of the main ones. Adults aren't picky; they will feed on any of over 100 plant species, leaves or flowers, and can wreak havoc in large numbers. Once again we have a pest species introduced from Asia for no apparent reason. So far I've only spotted two, perhaps three during my nightly inspections. As I always do with an invasive species, I hope that they won't make an unwitting nuisance of themselves so their beauty can be appreciated.