Japanese beetles in peak season, damaging gardens

Credit: Purdue Extension Entomology

FORT WAYNE, Ind. (WANE) – Late July into early August is peak season for Japanese beetles.  You have likely seen more of these pests lately in your garden, but there are ways to prevent them or get rid of them once they arrive.  Japanese beetles are very harmful to your garden; you will either see the beetle itself or the damage it does.  The beetles are roughly half an inch long and metallic in appearance, so they are not hard to spot.  Your leaves will either have holes eaten in them or will be only a skeleton of the leaf with most of it having been eaten away.  James Wolff, Ag and Natural Resources Educator at Purdue Extension, Allen County said, “You would see a lot of defoliation to your vegetables, also other ornamental plants you have in your garden.”

“Recommended Insecticides to Kill Adult Japanese Beetles on Plants” (from Purdue Extension)

  • Acephate (Orthene)
  • Bifenthrin (Talstar L&T and other site specific products)
  • Carbaryl (Sevin and others)
  • Cyfluthrin (Tempo, Decathalon, Bayer Lawn & Garden)
  • Deltamethrin (Deltaguard T&O)
  • Fluvalinate (Mavrik)
  • Imidacloprid (Bayer Tree and Shrub)
  • Malathion
  • Permethrin (Astro EC)
  • Spectracide Bug Stop (Eight)

“Landscape Plants Relatively Free of Feeding by Adult Japanese Beetle” (from Purdue Extension)

  • red maple (acer rubrum)
  • silver maple (acer saccharinum)
  • boxwood (buxus sempervirens)
  • shagbark hickory (carya ovata)
  • flowering dogwood (cornus florida)
  • persimmon (diospyros virginiana)
  • euonymus (euonymus species – all species)
  • white ash (fraxinus americana)
  • green ash (fraxinus pennsylvanica)
  • holly (ilex species – all species)
  • butternut (jaglans cinerea)
  • tuliptree (liriodendron tulipifera)
  • American sweetgum (liquidamar styraciflua)
  • magnolia (magnolia species – all species)
  • red mulberry (morus rubra)
  • white poplar (popuus alba)
  • common pear (pyrus communis)
  • white oak (quercus alba)
  • scarlet oak (quercus coccinea)
  • red oak (quercus rubra)
  • common lilac (synga vulgaris)