Mosquito Surveillance

The City of Southlake uses six gravid traps to conduct mosquito surveillance. These traps use dirty water to attract female mosquitoes that have just taken a blood meal and need a place to lay eggs. Once the mosquito comes near the dirty water, a small electric fan sucks them into the trap. The trapped mosquitoes are then collected and tested for the presence of West Nile Virus by Tarrant County Public Health.

Surveillance Results


The chart below shows the date that samples were tested, along with the test results. Also shown is the average number of the Culex Quinquefasciatus mosquito (the mosquito primarily responsible for transmitting WNV), as well as the average total of all species of mosquitoes trapped that week. The City monitors these numbers as part of its response to evaluate trends and to determine the effectiveness of larviciding and outreach initiatives.

Southlake Surveillance Results
Date                             Result                    Average Culex  Average # Mosquitoes   
November 4th, 2015 Negative 14 17
October 28th, 2015 Negative 11 26
October 21st, 2015 Negative 46 87
October 14th, 2015 Positive 59 100 
October 7th, 2015 Negative 27 39
September 30th, 2015 Negative 25 38
September 23rd, 2015 Negative 36 63
September 16th, 2015 Negative 42 55
September 9th, 2015 Negative 97 135
September 2nd, 2015 Negative 31 46
August 26th, 2015 Negative   43 48
August 19th, 2015 Negative 
32 49
August 12th, 2015 Negative 
34 41
August 5th, 2015 Negative  48 65
July 29th, 2015 Negative
43 70
July 22nd, 2015 Negative
13 25
July 15th, 2015 Negative
37 45
July 8th, 2015 Negative 28 49
July 1st, 2015 Negative
9 11 
June 24th, 2015 Negative
26 34 
June 17th, 2015 Negative
17 29
June 10th, 2015 Negative  40 53 
June 3rd, 2015 Negative
15 26 
May 27th, 2015 Negative
6 12
May 20th, 2015 Negative
7 10
May 13th, 2015 Negative
48 59 
May 6th, 2015
Negative
55 58 
April 29th, 2015
Negative 50 51
April 22nd, 2015
Negative
21 22
April 15th, 2015
Negative
24 26
April 8th, 2015
Negative
4 4

Trap Locations


The City uses six traps to conduct mosquito surveillance. Five of these traps remain in static locations throughout the year, while one trap roams across the City based on complaints or concerns. By keeping the majority of our traps in a static location, we are able to better track the spread of West Nile Virus across the City. For more information and a map on where sampling has been conducted, visit the Tarrant County Public Health WNV Surveillance map.