Grasshopper season is not here yet, but judging from last
summer’s population in our garden there may be a big crop.
Grasshoppers increase gradually over several years. Then in
favorable conditions they increase in massive numbers. One female
can lay as many as 400 eggs and even if small numbers survive, the
result will be legions of grasshoppers.
There are many species of grasshoppers in Colorado. The most
widespread and the most destructive is the Migratory grasshopper
(Melanoplus sanguinipes). He is about one inch long with a black
patch on the neck. He prefers grains and grasses. But if the food
supplies run out, he will devour anything in his path.
Grasshoppers emerge in mid June to early July when the eggs have
hatched. Most of the grasshoppers in Colorado lay their eggs in
late fall. These eggs remain in the soil all winter and hatch in
spring or early summer and are adults by mid summer. A few species
will lay their egg in the summer. Then in August they hatch and
spend the winter as nymphs, immature grasshoppers. These nymphs
become adults much sooner.
According to Dr. Whitney S. Cranshaw and John L. Capinera,
“Grasshoppers breed and develop each year in dry, undisturbed sites
such as pastures, empty lots and roadsides. As the plants in these
areas dry out or are eaten, the grasshoppers move to the lusher
growth found in yards and gardens. Successful management of
grasshoppers must include the breeding areas.”
Enemies of grasshoppers: Birds, rodents, spiders, skunks, flies
and horsehair worms.
It is possible to slow down the movement of grasshoppers in your
yard, by watering the breeding ground to promote green growth and
by leaving a barrier strip of weeds and grass around your yard to
concentrate the grasshopper population. Treat these strips with
insecticide for greater control.
Highly effective insecticides against grasshoppers can be
purchased at any garden shop. Pick insecticides that are labeled
for grasshoppers and for specific locations, such as rangelands
pastures or specific plants that are in your garden. Remember,
insecticides are poisonous and can be toxic to animals and
beneficial insects. Always read, understand and follow all label
instructions.
The Colorado State University, Colorado Master Gardener Program
volunteer network strives to enhance Coloradans’ quality of life by
extending knowledge-based education throughout Colorado communities
to foster successful gardeners. For information call the CSU
Extension, Elbert County Master Gardener office at 303-621-3162.
Fact Sheet 5.535: Grasshoppers in Field Crops and Fact Sheet 5.536:
Grasshopper Control in Gardens and Small Acreage.
Aija Tobiss is a Colorado Master Gardener.
