Japanese Beetle

Japanese Beetle

Description: 

  • Popillia japonica are members of the Scarab Family
  • Grubs are creamy colored, 1 – 1 1/8” long, with a small V of hairs on their rasters
  • Adults are ~ 1/2” long with green metallic heads, have bronze wing covers, & 6 white hair tufts per side

Life Cycle:

  • Japanese Beetles go through one generation per year
  • Larvae are in the soil and feed on roots from August until June
  • Adults emerge in June and continue eating, mating, and laying eggs until late August

Damage:

  • Adults will feed on several hundred different host plants with a fondness for ornamentals and fruit trees
  • Damage lies predominately on the outside edges in both corn and soybean fields with feeding rarely spreading throughout
  • Treatment is warranted at 30% defoliation during the vegetative stages and 15-20% during the reproductive stages in soybeans
  • In cornfields consider treatment if silks are clipped to less than 1/2” and pollination is less than half complete