Week 23 – June 7 – 12

2010 Mosquito Report: Week 23

Report based on data collected from traps deployed the week of June 7, 2010 through June 12, 2010. Report prepared by John Smith, Chan Suom, M.S., and Nate Boonisar.

1. Current mosquito activity/trend

CDC Light Traps:
We have sufficient historical data for Week 23 to make mosquito population comparisons. Most of Norfolk County had average mosquito activity compared to previous years’ data. It appears as though activity has resumed to normal/average levels since early season outbreaks from torrential flooding and a string of uncharacteristically warm days. Landing counts taken during this period exceeded 100 per 10 minute count in several areas especially those residential areas adjacent to large floodplains. Specifically, these areas included the eastern end of the Fowl Meadow (Neponset River flood plain) and the area south of Route 109 in the Noon Hill area of Medfield (the Charles River flood plain).

Gravid Traps:
Gravid traps have not been deployed as of yet and there is very little Culex spp. activity in CDC light traps.

2. Current Predominant Species

CDC Light Traps:
The most predominant CDC trapped mosquitoes in Norfolk County this week were Ochleortatus canadensis and Oc. excrucians, which were common in most towns. We have indications of limited Aedes vexans activity but its population is sparse.

Gravid Traps:
Gravid trap figures are not available thus far.

3. Comparison to previous season

In the town of Sharon, there is a higher than average population of Culiseta melanura for this time of year. Oc. canadensis activity is lower than average in the towns of Bellingham and Needham, although there is an increase in Oc. excrucians activity in Bellingham. Culex pipiens/restuans activity is higher than average inFranklin. The Franklin trap’s collection of Coquillettidia perturbans, which was much higher than average the previous week, plummeted back down to normal this week.

4. Weather Summary

Spring, 2010 featured well above normal rainfall and temperatures. Our area received near record rainfall in March which caused significant river flooding on both the Charles and Neponset Rivers as well as widespread small stream flooding. Rainfall was then below normal in April and May but temperatures continued above normal. This allowed the water in both rivers and wetlands to recede. Rainfall so far in June has been variable across the county due to local thunderstorm activity. Most of the county has received below normal precipitation in June with pockets of near normal, except for the extreme west and north which has averaged above normal. This includes the upper Charles River basin outside the county that has received much above normal precipitation. Ground water levels at the USGS well in the town of Norfolk are showing below normal levels.

Total Monthly rainfall: 1.55” (+0.15 in.)
Total Yearly rainfall: 28.98 inches (+9.42 in.)

5. Number of requests for service

NCMCP received 2,218 calls for service as of 6/11/10. NCMCP received 439 calls for service this week.

6. MCP/Commission response

NCMCP has been conducting “area wide” ground ULV applications when and where necessary although poor weather conditions (cool mornings and rain) have delayed applications in many areas. Large area larval control interventions were conducted using aircraft in mid April and small area larval control has been on going since early April. Most spring “reflood” mosquito larval development has ended which as resulted in a decline in these operations. Larval control operations will shift to salt marsh and rain basin/storm water structure treatments once surveillance indicates activities in these areas.


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Walpole, MA 02081

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