Japanese Beetle

Check out this edition of TTT - this is the 1st video recording for the month of August 2025.

Check out the latest edition of the OSU Turf Team Times.

The latest Turfgrass Team Times (TTT) is out - field days, leaf spot, Japanese beetles and irrigation decisions all on tap!

Here are the links to this week's OSU Turfgrass Team Times. A great 'snap-shot' of what is happening in our lawns, sport fields, and on the golf course. This is an excellent seasonal update to keep Ohioans up on their turfgrass and all of the happenings.

Reports of noticeable numbers of Japanese Beetles (Popillia japonica) were on the rise last week in Ohio. Thus far, population distribution is highly localized. This population pattern has been typical for Japanese beetles in Ohio for many years. A short drive can take you from a location with high numbers to another location with virtually no beetles.

After getting off to a late, slow start this season, Japanese Beetle numbers have risen dramatically with high populations being reported in various parts of the state. However, not everyone is seeing heavy damage. Thus far, the population distribution is remaining highly localized.

Dave Shetlar (OSU Entomology, Professor Emeritus) and I had a conversation early last week about what had become of Japanese beetles this season. Neither of us had yet seen our first adults in central and southwestern Ohio, respectively.

Northern Masked Chafers and Japanese Beetles are on the wing in southern Ohio. These scarabs (family Scarabaeidae) are two of the three most common "white grub producing" beetles found beneath turfgrass in Ohio. The third potential participant in the grub-party are Southern Masked Chafers which have not yet appeared on the scene.

  Japanese beetles on a linden leaf or on a rose leaf or flower - to this we are accustomed. On certain plants though, such as cut-leaf rhamnus or as shown here from Wooster, Ohio on dawnredwood (Metasequoia glyptostroboides); somehow it seems like they do not have enough of a perch or dining area.  Perhaps it is the small-plates phenomenon. At any rate, the chewing-mouthparts damage here is quite familiar and Popillia japonica damage to the turf and ornamental industry is huge. In fact, a 2002 paper by Dan Potter and David Held of the University of Kentucky (Annu. Rev....

One of the challenges of plant problem diagnostics is that Nature is sometimes less tidy than we might wish. Pests do not confine their damage to plants one at a time, and also the different stages of an insect may cause different types of damage (symptoms).  Oak shothole leafminer (Agromyza viridula) adult flies damage oak leaf buds with their ovipositors. The holes from this damage expand as the leaf expands, causing the characteristically parallel holes on either side of the unfolding leaf.  Later larvae of this insect cause leaf-mining damage shown as browned areas in the...