The rating of the Risk of West Nile virus (WNv) infection continues to be rated at LEVEL 1
(LOW RISK) based on the Centers for Disease Control (CDC) guidelines for a phased
response to WNv surveillance data. Currently NO samples have tested positive for WNv in
Surveillance traps located throughout the Laramie Valley are showing extremely low counts of
vector mosquitoes. Although the trap numbers have dipped below the treatment threshold
there is still a slight risk of infection through mosquito bites and citizens are reminded to
continue to use precautions, especially from dusk to 10pm, when vector mosquitoes are most
On August 15th, fogging for the control of adult mosquitoes was suspended pending the
results of further surveillance. There has been no increase in adult activity signaling that
most of the blood feeding activity has ceased for the season. Based on this assessment, all
fogging has been concluded for the season.
Larval control operations will continue at sites where permanent water may produce more
vector mosquitoes. During the late summer/early fall, female mosquitoes cease blood
feeding and feed exclusively on nectar to prepare for winter hibernation. The mated females
will overwinter in warm places and take a blood meal in the spring to begin the next
generation of offspring. By continuing to do larval control we can help to deplete the
numbers of overwintering females that will be available to start next year’s production. Larval
control crews will continue treatments until freezing conditions eliminate larval activity.
City of Laramie technicians have tested a total of 102 samples of Culex tarsalis mosquitoes
throughout the summer season with NO positive samples for WNv. Two crows have also been
tested with NO positive samples.
Further Wyoming WNv information can be found on line at: the www.badskeeter.org or the
Centers for Disease Control website: http://www.cdc.gov/westnile/index.html.Hotline
information regarding chemical applications on City owned properties will be updated daily at
4pm. Call 721-5056 or click on the Mosquito and Chemical Application hotline tab on the City
of Laramie home page. For further information contact Tyler Shevling, Mosquito Control Crew
Supervisor at 721-5258 or Scott Hunter, Parks Manager at 721-5264.