Adults may fly up to 2 miles in mating flights. The grubs migrate downward to remain below the frost line. In areas of heavy sod and snow cover, larvae may remain within only a few inches of the surface. Generally, the large European chafer grubs begin feeding a month earlier in the spring and feed a month later in the fall than Japanese beetle larvae. Highest populations are found out to about 75 feet from the trees or structures to which the adults have flown.
Weather conditions govern flight activities.
Adult flights are reduced at temperatures below 66 degrees F or after an afternoon rainstorm. The European chafer is in the prepupal or pupal stage during the flowering period of horse chestnut and Spirea vanhouttei . First flights may occur during the full bloom period of black locust in New York State. For this reason, quarantines are often imposed on the movement of agricultural and other products. In lawns and turf, European chafer larvae may be managed similar to Japanese beetles.