30 May/June 2015 Landscape and Irrigation www.landscapeirrigation.com
Unfortunately, many municipalities, even
whole states, are banning the use of syn-
thetic pesticides (and in some cases all pes-
ticides) on municipal or school grounds
(which can also apply to the athletic fields).
I'm not going to debate the lack of scien-
tific evidence that this is necessary, as it is
a reality in many locations. However, this
leaves grounds and athletic field manag-
ers asking, "Are there any alternatives that
work?" The short answer is yes, but there
are many qualifications to this.
In many of these restricted environ-
ments, biological, natural and organic
products are allowed. The problem is that
many of the folks who passed these regula-
tions don't really understand these terms,
so managers will likely have to ask whether
any product that is discussed is allowed in
their particular situation.
BIOLOGICAL CONTROL
OR BIOBASED?
There are many true biological controls in
turfgrass habitats — predators, parasites
and diseases. Each one of these completes
its life cycle by capturing and eating prey,
feeding internally on the insect or increas-
ing its population by infecting and kill-
ing a host insect. Common soil-dwelling
ants prey on white grub and sod web-
worm eggs, but they rarely control these
pests when outbreak populations occur.
There are also several parasite wasps and
flies that attack turfgrass insects, but they
usually do so at low levels (below 10%).
When we sample turf insects, we often see
ones with fungal, bacterial or viral infec-
tions, but these also rarely achieve more
than 20 to 25% mortality. So, how can the
efficacy of these biological controls be in-
LANDSCAPE AND TURF MAINTENANCE
Alternate insect controls:
what works and what doesn't?
■ BY DR. DAVID SHETLAR
Above: Northern masked chafers exposed by pulling damaged turf back.
Inset: All white grubs are robust, C-shaped larvae of scarabs that feed on the organic matter in soils, especially thatch in turf.
