Japanese Beetle Control 101

Japanese Beetles can decimate crops above and below ground, leaving huge swaths of land barren and unproductive. These grubs are naturally detritivores (meaning that they eat decomposing materials), but they also feed on plant roots. Once they start to feed on roots, water and nutrient uptake is severely hindered. This results in brown and patchy dead spots in turf, lack of plant vigor and stunted growth. Unfortunately for the grower, this is only part of the plague that is the Japanese Beetle. 

Adult Japanese Beetles skeletonize leaves, strip flower petals and damage developing fruit. While their grubs feast on plant roots, the adults are opportunistic and tend to eat whatever they can get their little (yet voracious) mouth parts on. Some of their favorite host plants include roses, beans, grapes and berries.

Where Are They? Should You Be Worried?

Japanese beetles are found predominately in the eastern part of Unites States, from the Atlantic coast to states that border the west side of the Mississippi river. They have, additionally, been spotted in several Midwestern states, although their numbers and distribution vary in these regions (i.e. Texas is only considered partially infested). Chances are if you live in an area with lawns, prairies or grazing areas, you can expect Japanese beetles to make their way to you, if they haven’t already. 

What Do They Look Like?

Japanese Beetles are often described as iridescent green beetles. Other beetles like the Fig Beetle and False Japanese Beetle are often mistaken because of this. While their heads are a metallic green, their wings are a brown to bronze color with recognizable white tufts around them. Look for the tufts for a positive ID!

How Do We Control Them?

The best way to control Japanese Beetles is by stopping them before there is an infestation through preventative treatments. These treatments include applying beneficial nematodes to kill grubs, using Milky Spore to prevent yearly recurrences and utilizing row covers to limit damage. 

If prevention is not an option or if you have adult beetles making their way in from nearby areas, then direct, spray-on treatments will be your best plan of action. The infective fungus, Beauveria bassiana, kills both grubs and adults while remaining harmless to beneficial insects. It is a fantastic choice for organic growers trying to stay away from conventional pesticides. Surround WP is the next best option to save your plants from damage. Sprayed onto foliage and fruit, it deters beetle feeding and helps shield plants from heat stress.

There are a number of DIY traps we have found online and would love to hear any other ways you have found to control these bad hombres!