Japanese Beetle - Popillia japonica
Superfamily Scarabaeoidea / Family Scarabaeidae / Subfamily Rutelinae / Tribe Anomalini / Subtribe Popilliin
Live adult beetles photographed in the wild at Winfield and Wheaton, Illinois, USA..
 

Japanese Beetle - Popillia japonica
Japanese Beetle - Popillia japonica

This photo was used by the Utah Department of Natural Resources in its brochure detailing their battle against this recent invader.

The Japanese Beetle is oval shaped, with a bright metallic green body and pronotum and brown or reddish-orange elytra. White to grayish hair underneath, with five patches of white hair (setae) along each side if the abdomen, and two tufts of white hair at the rear. This is a very distinctive beetle - nothing else looks like it. Males have pointed tibial spurs, the female's are rounded. Habitat and range: The Japanese beetle can be found in gardens, woods, and open meadows. The beetle is slowly spreading across the United States after being accidentally introduced many times in the early 20th century, most notably in 1916 along with roots of imported Iris. [2]

Japanese Beetles Mating

Japanese beetles can feed on about 300 species of plants, ranging from roses to poison ivy. Odor and location in direct sun seem to be very important factors in plant selection. The beetles usually feed in groups, starting at the top of a plant and working downward. While a single beetle doesn't eat much; group feeding by many causes severe damage. Adults feed on the upper surface of foliage, chewing out tissue between the veins. This gives the leaf a characteristic skeletonized appearance. A few beetles on plants, or some moderate damage, will bring in more. Japanese beetles apparently produce aggregation pheromones that will attract more males and females to feed and find potential mates. In addition, volatile odors from damaged plants may attract more beetles.

Japanese Beetle Antennae Detail
Scarab beetle antennae form a club at the last 3-7 segments, flattened into plates (lamellae) that can be expanded or folded together. [1]
Japanese beetles react to a camera flash by flinching and quickly furling their lamellae.
I'm not sure why the male beetle poses with his middle legs outstretched. Wikipedia declares it is a defensive measure against predators, but I'm skeptical of that explanation. The antennae of both sexes are frequently furled and hidden - they open like little flower petals, called lamellae, when an interesting odor or pheromone is detected. This is a lovely but destructive creature.

Japanese Beetle - Popillia japonica

Insecticides for Japanese Beetle Control
Many insecticides are labeled for Japanese beetle control on landscape plants. Examples include acephate (Orthene Turf, Tree & Ornamental Insecticide), carbaryl (Sevin and many other brand names), cyfluthrin (Bayer Advanced Garden Multi-Insect Killer Concentrate), lambda-cyhalothrin (Spectracide® Triazicide® Soil & Turf Insect Killer Concentrate), esfenvalerate (Ortho Bug-B-Gon Garden & Landscape Insect Killer Concentrate), and permethrin (Spectracide® Bug Stop Multi-Purpose Insect Control Concentrate and many other brands). Neem extracts (Bon-Neem) deter Japanese beetle feeding but may not be adequate against high populations.

Direct spray applications of insecticidal soap kills Japanese beetles on contact but does not provide any residual protection.

References
  1. Troy Bartlett et al, Bugguide.net, Family Scarabidae - Scarab Beetles

  2. Line, Les. The Audubon Society Book of Insects. Harry N Abrams, 1983.