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Friend or Foe?
A typical garden attracts
hundreds of different species of insects, from beetles
and caterpillars to bees, nematodes
and moths. Only a few of these insects
are pests,
and many of the pests are only a problem during a specific part of their
life cycle. The vast majority of the insects
are "good bugs": predators, pollinators and parasites. The trick is knowing
which ones cause damage and when, and learning ways to minimize that damage.
Japanese
Beetle: (Size=1/2 inch) Where: Leaves, flowers, and fruits of
fruit
trees (apple, cherry, plum),
vegetables
(beans), flowers (roses), ornamentals (apple family); east of the
Mississippi
Controls: Handpicking, milky
spore, neem, nematodes ,
pyrethrins
Still primarily a pest of
the eastern U.S., they turn up west of the Rockies from time to time. They're
a problem for gardeners for their appetite for a wide variety of plants:
Adults feed on just about every kind of flower or vegetable, sometimes
in disturbingly large crowds. They chew out the leaf tissue between the
veins, leaving a lacy skeleton. Prior to pupating, the white, 1-inch long,
C-shaped grubs live in the soil and feed on the roots of most all plants.
Grubs are often a problem in lawns. Bug Mugs provided by NationalGardening.com,
the online publisher of the National Gardening Association. Photography
by Clemson University Department of Entomology, Cooperative Extension Service
Cucumber
Beetle: (Size= 1/4 to 1/2 inch) Don't be confused by the two
different forms of this pest. The striped form is shown above. It's cousin
features a dozen black spots. But whether spotted or striped, both are
the same size and the same, greenish yellow color, and both dine on a wide
variety of cucumber
family vegetables
as well as various ornamentals such as roses
and dahlias. Another well known family member is the corn root worm. They
are more dangerous to their
cucumber
family hosts than many pests because they transmit deadly diseases mosaic
and bacterial wilts. The adults over winter in weeds and plant debris.
They emerge in spring after the last frost and enter gardens once the growing
season is underway. You may first notice them inside squash flowers. They
lay orange eggs at the base of host plants; white larva with legs and brown
heads chew on roots. Short, northern seasons allow just one generation
a year. In the south and mild west, two or more
generations are typical.
Controls: Look for
varieties of cucumbers
and squash
that are resistant to these pests. Cover young plants with floating
row covers .
Knock, shake, or hand pick beetles off plants and out of flowers, and clean
up in the fall to reduce the number of over wintering adults. Dust plants
and flowers with insecticides containing pyrethrins.
Photography by USDA
Colorado
Potato Beetle (Size= 1/3 inch) If you see in your garden a small yellow
beetle with black stripes over its wings and black spots just behind its
head, say hello to the Colorado potato beetle. The humpbacked larva is
equally distinctive: red with a row of black spots along each side. For
years it lived quietly in Colorado feeding on weedy potato relatives. But
at some point after the potato was well established in North America, its
ancestors learned a new trick. It's been the bane of potato growing gardeners
ever since. Potatoes are its first love, but this beetle will eagerly consume
leaves of potato relatives eggplant, ground cherry, peppers, tomato, and
tomatillo. Colorado potato beetle prefer cold winters. While found
as far west as Arizona, Nevada, western Oregon and western Washington,
it is by far more common on the East Coast as far south as
Virginia, then from there to the north west through Wyoming. The adult
beetles over winter in the soil, emerging in the spring to lay clusters
of yellow eggs on leaf undersides. There are one to three generations per
year, depending on the part of the country.
Controls: Bt, handpicking,
neem, early planting, pyrethrins,
row
covers. A thick organic mulch makes it hard for emerging beetles to
reach plants in spring. Surveillance and hand picking remains among the
gardener's best defenses. Examine plants while holding container of soapy
water to dispose of any you find. Natural enemies include birds, spined
soldier bugs, and parasitic nematodes.
Spray Potato Beetle Beater, which is Bacillus thuringiensis tenebrionis
(also known as San Diego strain), while larva are small to manage major
outbreaks. Photography by USDA. Bug photos and information above courtesy
of Gardener's
Supply Company
Pest
and Disease Finder
More
Bugs To learn more about the following bugs......
Aphid, Apple Maggot, Box Elder Bug, Bronze Birch Borer, Cabbage Worm, Carpenter
Ant, Flying
Ants, Carpet Beetle, Cucumber Beetle, Earwig, Eastern Tent Caterpillar,
European Pine Saw Fly, Gypsy Moth, Horn worm, Japanese Beetle, Centipede,
Millipede, Pantry Pests, Peach Tree Borer, Slug, Squash Bug, Squash Vine
Borer, Annual White Grub.
Chinese
Praying
Mantis
Information

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