Week 31 – Aug 2 – 6

2010 Mosquito Report: Week 31

Report based on data collected from traps deployed the week of August 2, 2010 through August 6, 2010. Report prepared by John Smith, Chan Suom, M.S., and Nate Boonisar.

1. Current mosquito activity/trend

CDC Light Traps:
Host seeking mosquito activity has remained historically low throughout most of Norfolk County for the past few weeks now. Only the towns of Bellingham, Foxboro, and Needham reported average levels of mosquito activity.

Gravid Traps:
Gravid trap collections have seen a minor boost in mosquito activity, but for the most part, they continue to decline in numbers throughout most towns in NorfolkCounty. Only Quincy reported higher than average gravid mosquito activity, whereas Bellingham, Foxboro, Medfield, Medway, Needham, Norfolk, parts of Sharon, and parts of Walpole have seen activity rise to average levels this week.

2. Current Predominant Species

CDC Light Traps:
The most predominant CDC trapped mosquito in Norfolk County this week was once again Coquillettidia perturbans. Their populations are very low compared to the historical average. Most specimens appear aged, although there were a few collections that contained recently emerged Co. perturbans adults. Culexpipiens/restuans populations continue to be higher than average in Canton and Franklin one again.

Gravid Traps:
Culex pipiens/restuans continue to dominate gravid traps, although their populations remain in decline as seen in recent weeks. Ochlerotatus japonicus populations are also in decline.

3. Comparison to previous season

Host seeking and gravid mosquito activity continue to be on the decline throughout most of Norfolk County. The forecast for outdoor activities is very good with minimal mosquito nuisance. The very low numbers of mosquitoes may provide a false sense of security in the wake of recent, historically high isolations of EEE virus in mosquitoes in southeastern Massachusetts. Precautions should be taken when prolonged outdoor activity is expected.

4. Weather Summary

After a cool and dry start with below normal temperatures, it gradually warmed up and became very humid by mid week. A cold front crossed the area Thursday into Friday bringing thunderstorms to much of the area. The entire county received rainfall of greater than ¼ inch, with the heaviest rain falling in a band from Dover/Needham, east to Quincy/North Weymouth where amounts of 1 – 1.5 inches fell. Cooler and drier weather followed for the weekend.

Total weekly rainfall: 0.31 inches (-0.42 in.)
Total Monthly rainfall: 0.31 inches (-0.42 in.)
Total Yearly rainfall: 31.26 inches (+6.20 in.)

5. Number of requests for service

NCMCP received 5,671 calls year to date for service as of 8/06/10. NCMCP received 524 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 continued in Quincy andNorth Weymouth although only during the normal schedule for these two towns. Although there is residual mosquito activity in the areas mention in the last report the activity has declined as is evidenced by the drop in calls for the Quincy areas affected (Merrymount, Adams Shore, Germantown andHoughs Neck). Due to the heavy rain received in areas noted in the Weather Report (see above) field technicians will be dispatched on Monday of EpiWeek 32 to treat the Broad Meadow area of Quincy and the Neck Street area of North Weymouth. Other locations along the heavy rain ban in the northern part of the county will receive equal scrutiny. Other than these areas the remaining inland wooded wetlands remain dry. Complaint calls are lower than last week but still at an elevated level this week due to the residual sollicitans outbreak in Quincy and North Weymouth and as a response to the media coverage of EEE/WNv activity. NCMCP continues to treat rain basins using a pouch with Bacillus sphaericus as the active ingredients.


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Walpole, MA 02081

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