Mosquito Monitoring
mosquito on a fingertip

Mosquito Monitoring for West Nile Virus

Vector Index Log

The vector index tell us the relative risk of West Nile virus transmission. The vector index is based on the:

  • Total number of Culex Pipien and Culex Tarsalis – the species that carry West Nile virus
  • Number of infected mosquitoes across an area. The vector index is calculated by determining the average number of infected mosquitoes collected per trap in an area.
  • Emergency spraying may be recommended when the vector index is at 0.75 or higher.

Mosquito Monitoring 2019

Zone 1Zone 2Zone 3
Season WeekVector IndexVector IndexVector Index
May 26 - June 1 (Week 22)
June 2 - 8 (Week 23)
June 9 - 15 (Week 24)
June 16 - 22 (Week 25)0.000.000.00
June 23 - 29 (Week 26)0.000.000.00
June 30 - July 6 (Week 27)0.000.000.00
July 7 - 13 (Week 28)0.000.000.00
July 14 - 20 (Week 29)0.000.000.00
July 21 - 27 (Week 30)0.000.110.13
July 28 - August 3 (Week 31)0.000.000.48
August 4 - 10 (Week 32)0.000.380.44
August 11 - 17 (Week 33)0.000.200.19
August 18 - 24 (Week 34)0.000.000.00
August 25 - 31 (Week 35)0.190.000.00
September 1 - 7 (Week 36)
September 8 - 14 (Week 37)

NOTE: “—” indicates a single pool was submitted for that zone that tested positive, therefore we were unable to calculate an infection rate or vector index for that zone.

Sentinel Map

Sentinel Zones for mosquito testing

West Nile Data

Contact Us


Vector Control Program

Main: 303-441-1564
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Location

Boulder
3450 Broadway
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