Since I have not seen this beetle in Lawrence, I decided to see what's known about its distribution in Kansas. It turns out there is a very nice data base called NAPIS, the National Agricultural Pest Information System. or “Pest Tracker”. Looking up Japanese beetle gives an information link with pictures of the sort of damage the grubs can do to lawns, tips for controlling the insect. They don't mention what we used to do when I was young namely pick the beetles off and plop them in jar of rubbing alcohol.
Alas there doesn't seem to be any quick fixes, but that is typical for most pest species. Instead the suggested approach outlined here is an Integrated Pest Management (IPM) approach. IPM involves monitoring larval and adult populations, cultural practices and yes judicial use of appropriate pesticides and where practical biological control with pathogens that attack the grubs. For the Japanese beetle there are several biological control options including parasitic roundworms, bacteria such as Bt which you can buy locally, and milky spore.
The other thing to check is the distribution map on Pest Tracker. Fortunately this map has just been updated for the Japanese Beetle. Check out the full sized map on the Pest Tracker site.
Notice the beetle is widespread in the East and it appears to be moving into Kansas. In Douglas County, it has been found in surveys but is not widespread. There is one hot area of infestation, namely Wichita and the Kansas Department of Agriculture blames infested nursery stock for this.
So look at the beetle picture carefully. The beetle is easy to identify by the white markings on the side of the abdomen, the greenish metallic thorax and orange wing covers. If you see it collect one for verification, contact the local extension bureau for advice and don't bring uninspected plant material from another area into Kansas.