Week 30 – July 26 – 30

2010 Mosquito Report: Week 30

Report based on data collected from traps deployed the week of July 26, 2010 through July 30, 2010. Report prepared by John Smith, Chan Suom, M.S., and Nate Boonisar.

1. Current mosquito activity/trend

CDC Light Traps:
This week’s trap collections indicate a continued decline of host-seeking mosquito activity. Only Foxboro, Needham, Plainville, Quincy, and Wrentham maintained average levels of mosquito populations.

Gravid Traps:
Gravid trap collections this week also continue the downward trend in mosquito activity. Only parts of Foxboro, Franklin, Medfield, Norfolk, Norwood, parts ofQuincy, and parts of Walpole report average levels of gravid mosquito activity.

2. Current Predominant Species

CDC Light Traps:
The most predominant CDC trapped mosquitoes in Norfolk County this week was once again Coquillettidia perturbans although their populations have dramatically declined in comparison with their respective town’s averages. Culex pipiens/restuans populations are higher than average in Canton and Franklin. Anophelespunctipennis and An. walkeri populations are higher than usual in Franklin. Aedes vexans populations are minimal to non-existent at this point.

Gravid Traps:
Culex pipiens/restuans continue to dominate gravid traps, although their populations continue to be low following the downward trend in recent weeks. Ochlerotatus japonicus numbers are down from last week as well.

3. Comparison to previous season

Host-seeking and gravid mosquito activities are lower than average throughout most of Norfolk County. There continue to be service requests for parts of Quincyfor what seems to be remnants of the prior Ochlerotatus sollicitans outbreak. These low levels of mosquito activity are in sharp contrast to the current atmosphere of elevated EEE virus activity in the southeastern portion of Massachusetts.

4. Weather Summary

This week was warm and dry for the most part. Humidity was lower than previous weeks, except for Thursday prior to a cold frontal passage. This front brought brief showers to the region, with amounts up to a tenth of an inch. Otherwise, our dry pattern continues with little in the way of rainfall. Precipitation in July was well below normal across the county with amounts between one and two inches (highest amounts in the southwest). Most of the county had between 25-50% of normal rainfall with up to 75% of normal in the southwest.

Total weekly rainfall: 0.04 inches (-0.66 in.)
Total Monthly rainfall: 1.30 inches (-1.76 in.)
Total Yearly rainfall: 30.95 inches (+6.61 in.)

5. Number of requests for service

NCMCP received 5,146 calls year to date for service as of 7/30/10. NCMCP received 665 calls for service this week.

6. MCP/Commission response

NCMCP continues to conduct “scattered and isolated” ground ULV applications when and where necessary. ULV applications in Quincy and North Weymouth have been expended in response to a fairly large emergence of salt marsh mosquitoes from the Broad Meadow area. The adjacent residential areas most affected include Merrymount, Adams Shore, Germantown and Houghs Neck in east Quincy. NCMCP conducted two early morning aerosol applications in this area, Tuesday and then again Thursday morning. Early monitoring results indicate a successful set of applications which reduced the biting population significantly. Other than the recent larval development in Quincy the flood plains and inland wooded wetlands remain “bone” dry. Complaint calls are up again this week due to the Oc. sollicitans outbreak in Quincy and North Weymouth. Calls have also increased in response to the media coverage of EEE/WNv activity. The NCMCP continues to treat rain basins using a pouch with Bacillus sphaericus as the active ingredient.


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Walpole, MA 02081

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