Controlling Chinch Bugs and Grubs the Organic Way
As part of our lawn maintenance programs we will monitor your lawn for the presence of chinch books and grubs and other insect pests and diseases. If we find them, we have orgainc ways of controlling them as well as recommendations for you, the homeowner, to avoid them in the first place. .
Grubs
Grubs live underground and
feed on grass roots. Damage appears as dead grass that can be lifted
like a piece of carpet. Grub damage usually shows up in August and
into September; damage will first occur in the sunniest, driest
locations of the lawn and can spread very quickly during dry
conditions. To check for grubs, cut and turn over 1" section of
grass at the edge of a brown area. Grubs will be found within the
top couple cm of soil. The grubs are milky white with a brown head
and a darker tail. They will be curled up in a C shape and
approximately ¾" long. You may also detect grubs when a hungry
raccoon or skunk discovers them in your
lawn and rolls up the grass to get at them..
Our method of killing grubs
in your lawn organically involves applying beneficial nematodes to
your lawn. Nematodes are microscopic worms that will kill the grubs.
They are harmless to pets, cats, people, plants and anything except
grubs. Nematodes are not selective and therefore attack a wide range
of over 250 different root zones pests.
The Lite Gardener will apply
the nematodes using water. Immediately following application, the
lawn has to be heavily watered to wash the nematodes down into the
soil where they can attack the grubs. The home owner must keep the
soil moist for about three weeks after application because nematodes
need water to survive. Nematodes die in sunlight and so we do the
application early in the morning or early in the evening. We
recommend aerating the lawn before an application of nematodes
since it
will help the nematodes get down into the soil to attack the grubs.
Chinch Bugs and Other
Insects
As part of our lawn
maintenance program we will keep an eye out for surface-feeding
insects called chinch bugs. Adults are approximately ⅛" long and
black with white wings and black triangle where their wings overlap.
Larvae are tiny, bright red and have a white stripe on their back.
The damage will first be noticed in dry sunny areas and spread out
in irregular brown patches. They attack the grass in middle to late
summer usually during dry conditions.
If we spot this kind of
damage we will part the grass and
look for chinch bugs on the soil and in thatch. We will look at how
quickly the chinch bugs move since, earlier chinch stages are less
mobile than later stages.
You can help avoid the chinch
bugs by keeping the lawn watered in the summer. Chinch bugs need hot
dry conditions for survival and reproduction
and they don’t tolerate a
large amount of water.
As always, though, avoid over watering.
If chinch bugs are discovered
early enough, soaking the sod with a
solution of 75ml biodegradable soap mixed with 40 L of water per 5.5
ft², and covering the grass with a flannel sheet will help control
the bugs which will will crawl to the tip of the grass.
If chinch bugs still
continue to be a concern the Lite Gardener would recommend
overseeding the entire lawn with resistant grass seed.
We would over-seed the lawn
with a specially designed perennial ryegrass mixture. Perennial
Ryegrass provides improved resistance to several grass insects and
many grass diseases. Chinch bugs, in particular, do not like to eat
perennial Ryegrass.
As a less preferred
alternative, diatomaceous earth
(DE) is approved for use against chinch
bugs and certain other pests. DE absorbs the waxy layer on insects’
cuticle, causing dehydration and death. It also works abrasively to
rupture insect cuticles, allowing cell sap to leak out and, if
ingested, it disrupts the insect’s breathing, digestion and
reproduction. There are no formal studies on application rates and
effectiveness on chinch bugs. DE should be applied over the effected
are, it takes several weeks or months to control pests. DE is non-
toxic to humans but dust can irritate eyes and lungs so we would have
to wear a mask when using it.