Adult Japanese beetles and southern masked chafers (annual
white grubs) are flying in the Chicago area, according to
Donna Danielson of the Morton Arboretum Scouting Program.
Reports of beetle emergence from central Illinois have been
relatively sporadic. As was indicated in last week’s
newsletter, the cooler-than-normal temperatures this spring
slowed grub development and delayed adult emergence.
Although time of emergence has been sporadic, recent
warm, dry weather and conscientious lawn care practices have
created ideal habitats for egg laying. Lawns that go dormant
in the summer or that receive limited amounts of water are
less attractive for egg laying than lush areas of turf that
have been irrigated. Refer to last week’s newsletter for
turf grub management options.
As Japanese beetles continue to emerge, more damage will
occur from the adults feeding on deciduous plant materials
in infested areas of the state. Perhaps we should adjust our
mindset and think of Japanese beetles as one of the “joys”
of living in Illinois. When purchasing new plant materials,
keep Japanese beetle defoliation in mind and select plant
varieties that are less attractive to the beetle. If you
select plants that are favored by this insect, you should
get used to beetle-damaged plants or expect to treat the
plants weekly with an insecticide when the beetles are
present. University of Kentucky and Purdue University
scientists have been conducting research to identify woody
plant species that are less favored by the Japanese beetle.
We will include a list of such species in next week’s