West Nile virus and to-do list
By John
Fulton
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[June 01, 2013]
West Nile virus has,
unfortunately, become a household phrase. With the extremely wet
weather we have had this year, being outside is not very pleasant
around dusk. The mosquito numbers are very large, and West Nile
virus is of particular concern this year. The virus was first
isolated in Uganda, Africa. It can harm humans, birds and other
animals. It is transmitted by infected mosquitoes, primarily the
northern house mosquito. The mosquito becomes infected after biting
wild birds that are the primary host of the virus. The mosquito is
actually able to transmit the virus after 10-14 days after biting
the infected bird.
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The mosquito life cycle has four life stages: egg, larvae, pupa and
adult. The female mosquito lays eggs on water or moist soil. Most of
the larvae hatch after 48 hours, and the larvae and pupae live in
the water. The females need a blood meal before they can lay eggs,
so only the females bite. They bite every few days during their
adult lives, which may last several weeks. Preventing mosquitoes
is a first step. Homeowners can best accomplish this by eliminating
standing water. Tires and old containers are obvious places to
start. Drill holes in the bottom of recycling containers, clean
clogged gutters, don't allow stagnant water in anything such as
birdbaths, change landscape slopes to eliminate standing water, and
use larvacides in standing water that can't be eliminated. Bt
Israeli is the strain that is effective against mosquito larvae --
not the Bt kurstaki variety commonly used on trees and gardens to
kill larvae of moths and butterflies. The mosquitoes have already
begun hatching, so treatment time is at hand.
Also protect yourself from bites. Mosquitoes can travel up to
three miles from their breeding sites. Make sure that screens and
doors are tight, use proper outside lighting such as fluorescent
lights, stay indoors at dawn and dusk when mosquitoes are most
active, wear long-sleeved shirt and long pants when you must go
outside, and use insect repellents properly applied.
The Centers for Disease Control is currently recommending DEET,
picaridin and oil of lemon eucalyptus (similar to very low DEET
concentrations in repelling mosquitoes). Permethrin for clothing
treatment is also available at stores selling outdoor sports and
camping supplies. Read and follow all label directions. The DEET
percentage affects the length of time mosquitoes will be repelled.
For example, a 4.75 percent DEET lasts about 1½
hours, and 20 percent lasts about four hours.
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To-do list
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Believe it or not,
we're at the proper timing for fall garden plantings. That means
potatoes, kale and some others. Some of the planting dates
overlap this time of year. That basically means plant it, but
you can expect harvest to be closer to fall.
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Keep pruning
flowering shrubs after they complete their blooming. That will
allow for more flower buds next year. The pruning time for
evergreens will be coming up the end of June.
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Bagworm spray time
will be coming up mid-June. We'll try to fine-tune the date as
we get closer. The cool spring has delayed things to this point,
but warm weather could catch us back up to the book timing of
June 15. The key is to have the eggs all hatched out, but not
have the bagworms grow too large.
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Many borers are susceptible to control
at this time throughout the state. Roundheaded appletree borer,
flatheaded appletree borer, peachtree borer and viburnum borers
are all susceptible to control. Products containing imidicloprid
(such as Bayer Advanced Tree and Shrub Insect Control) are
systemic (move throughout the plant), last for about a year and
are generally good on borers from beetles. The caterpillar-type
beetles are better controlled with a more traditional
insecticide such as permethrin or bifenthrin.
[By
JOHN FULTON,
University of Illinois Extension]
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