Mass trapping: A potential organic management option for the Japanese beetle (Coleoptera: Scarabaeidae)

The Japanese beetle, Popillia japonica (Coleoptera: Scarabaeidae), is a highly destructive plant pest of foreign origin. In Missouri, damaged caused by this pest has been increasing as populations continue to become established and expand. Because no truly effective organic management options against this invasive pest are available, this study was then aimed at evaluating the potential of mass trapping as an organic control method in elderberry and blueberry orchards. In 2012, we assessed the effectiveness of commercial and home-made traps baited with either, one or two commercial lures at capturing Japanese beetles in two Lincoln University (LU) farms and in one commercial elderberry farm in central Missouri. The level of damage produced by Japanese beetle to plants was estimated. Over the course of five weeks, approx. 1’550,000 Japanese beetles were captured by traps in the two LU farms, and ca. 1’120,000 beetles were captured in the commercial elderberry farm. The commercial trap baited with one lure proved to be the most cost-effective. Level of damage caused by Japanese beetle averaged 2.5% in elderberry in one LU farm, and it was minimal in the other LU farm. In the commercial elderberry farm, level of damage was minimal in some areas whereas for other areas not well protected by traps damage was greater but within limits acceptable by the farmer given that zero insecticides were applied. Further refinement of this technique is expected to contribute to more effective management of this pest not only in Missouri, but also in other U.S. regions where Japanese beetle is present.