The Japanese Beetle is a relatively new invasive species to Idaho. In 1990 the ISDA started deploying traps. There are 200-300 traps that are regularly set out. They are seen at Idaho airports, all UPS/Fedex/USPS flights from regulated states go through other states first. The yellow torpedo looking traps are also found throughout the State of Idaho. They are found in and around nurseries, parks, neighborhoods, and where ever there may be a threat of Japanese Beetles appearing. Even with regulations in place to help prevent invasive species from traveling from state to state there is a possibility of this happening. There have been three incidences where a single Japanese Beetle was found; Ada County in 1992, Gooding County in 1997, and Twin Falls County in 2011. There is not a huge problem when one beetle on its own is found. In July 2012 two male Japanese Beetles where found 5.5 miles apart in Boise. They were found in routinely set traps in the downtown Boise area and at a nursery in west Boise. The Japanese Beetle was also discovered in the Kootenai County, Bannock County and in other locations in Ada County last year.
The Japanese Beetle larvae/grub can be found underground. Here it will destroy whatever turf is above by eating the roots. The grub will feed from April-May and then from August to November. Not only will the grub cause damage by eating the grass roots but it will attract animals like geese and raccoons that will do damage to the turf from above by digging to get to the grubs. The grub is no larger than a quarter, white and can always be found curled up in a C shape.
When the Japanese Beetle morphs into an adult the plants above do not stand a chance. The adult will decimate a shrub leaving only the ribs of the leaves left. The Japanese Beetle like the upper sunlit leaves the best. The damage is so evident because the Japanese Beetle prefers to attack/feed on a plant in hordes. As an adult the beetle is