Cornwall, Ontario, Canada
August 8, 2010
I was taking a little break from the Rachel’s Kids Garden Party and Auction and admiring some of the fine cars parked along the road (pair of black Porche Carreras anyone? One ragtop, one coupe…A Merc or three?) and on my way back in I spotted a little unusual activity on a rose flower. On closer investigation, I saw these beetles were having a wee bun-fight of their own. There was a main block of them in the centre of the rose flower and any interlopers were bulldozed over the edge. Quite entertaining.
On doing a little research (browsing through the Neff’s Bug Book), I found out that these are Japanese beetles. And this was not a good thing!
Thanks to Wikipedia.
The beetle species Popillia japonica is commonly known as the Japanese beetle. It is about 15 millimetres (0.6 in) long and 10 millimetres (0.4 in) wide, with iridescent copper-colored elytra and green thorax and head. It is not very destructive in Japan, where it is controlled by natural enemies, but in America it is a serious pest of about 200 species of plants, including rose bushes, grapes, hops, canna, crape myrtles, and other plants.
It is a clumsy flier, dropping several centimeters when it hits a wall. Japanese beetle traps therefore consist of a pair of crossed walls with a bag underneath, and are baited with floral scent, pheromone, or both. However, studies done at the University of Kentucky suggest that traps attract more beetles than they actually trap, thus causing more damage along the flight path of the beetles and in the vicinity of the trap than may have occurred if the trap was not present.
These insects damage plants by skeletonizing the foliage, that is, consuming only the leaf material between the veins.
As the name suggests, the Japanese beetle is native to Japan. The insect was first found in the United States in 1916 in a nursery near Riverton, New Jersey. It is thought that beetle larvae entered the United States in a shipment of iris bulbs prior to 1912 when inspections of commodities entering the country began. "The first Japanese beetle found in Canada was in a tourist’s car at Yarmouth, arriving in Nova Scotia by ferry from Maine in 1939. During the same year three additional adults were captured at Yarmouth and three at Lacolle in southern Quebec.
The life cycle of the beetle is typically one year in most parts of the United States, but this can be extended in cooler climates; for instance, in its native Japan, the beetle’s life cycle is two years long as a result of the higher latitudes of the grasslands required for the larval stage. During the larval stage the white grubs can be identified by their V-shaped raster pattern.
During the larval stage, the Japanese beetle lives in lawns and other grasslands, where it eats the roots of grass. During that stage, it is susceptible to a fatal disease called milky spore disease, caused by a bacterium called milky spore, Paenibacillus (formerly Bacillus) popilliae. The USDA developed this biological control and it is commercially available in powder form for application to lawn areas. Standard applications (low density across a broad area) take from one to five years to establish maximal protection against larval survival (depending on climate), expanding through the soil through repeated rounds of infection, in-vers can be used to exclude the beetles; however, this may necessitate hand pollination of flowers. Kaolin sprays can also be used as barriers.
Research performed by many US extension service branches has shown that pheromone traps attract more beetles than they catch. Traps are most effective when spread out over an entire community, and downwind and at the borders (ie, as far away as possible, particularly upwind), of managed property containing plants being protected. Natural repellents include catnip, chives, garlic, and tansy, as well as the remains of dead beetles, but these methods have limited effectiveness. Additionally, when present in small numbers, the beetles may be manually controlled using a soap-water spray mixture, shaking a plant in the morning hours and disposing of the fallen beetles, or simply picking them off attractions such as rose flowers, since the presence of beetles attracts more beetles to that plant.
Sony Alpha 700, Sigma 17 to 70 macro at 70 mm
iso 100, spot metered, aperture priority, F8.0, 1/200 second