Week 26 – June 25 – 26

2008 Mosquito Report: Week 26

Report based on data collected from traps deployed on Wednesday, June 25, 2008 and retrieved on Thursday, June 26, 2008. Report prepared by John Smith, Chan Suom, M.S., and Nate Boonisar.

1. Current mosquito activity/trend

CDC Light Traps:
Generally, activity level for CDC traps declined this week compared to the average with the exception of traps in the towns of Dedham, Holbrook, andNeedham which showed some increase in activity. CDC light traps for this week show a predominance of Ochlerotatus canadensis and Ocherlotatus excrucians. Coquillettidia perturbans were collected in a few traps but the emergence of the adults of this species continues to seem late and in lower numbers relative to the average. Small numbers of Anopheles punctipennis and walkeri continue to be collected. Although Culiseta melanura numbers remain low in those traps which collect them the Holbrook trap showed a spike in Culiseta melanura which is worth noting since this trap has collected mosquitoes positive for EEE in the past.

Gravid Traps:
Mosquito activity in gravid traps has dramatically increased in the towns of Avon, Bellingham, Canton, Dedham, Dover, Milton, Needham, Quincy,Randolph, and Wrentham. The Quincy trap collected more than three times the average for this week. Most of the other gravid trap collections showed increased numbers this week. The trend of higher numbers of Culex pipiens/restuans collected in the eastern (more urban) trap sites continued for this week. In some cases several times higher than their average. This trend most likely will continue especially given the fact that frequent thunderstorms with their accompanying heavy rain and street flooding continues to replenish rain basins and above ground containers. Ocherlotatus japonicus collections seem to be increasing some what most likely for the same reasons as the Culex increases.

2. Current Predominant Species

The predominant species this week were Ocherlotatus canadensis, Ocherlotatus excrucians and Culex pipiens/restuans.

3. Comparison to previous season

Compared to last season, activity of the predominant species Ocherlotatus canadensis in light traps is below average. Above average collections of Culex pipiens/restuans have occurred in gravid traps especially in eastern locations of the county. Coquillettidia perturbans collections seem late and below normal for this year.

4. Weather Summary

The beginning and end of this week featured a very active weather pattern with numerous thunderstorms with torrential rainfall affecting much of eastern Massachusetts. Even though the worst of the rain missed the county some of this affected extreme northern and southern portions. A large swath extending across the center of the county received under 0.5 inches for the week, with Norwood barely receiving any rainfall. The north and east, parts of Needham, Milton, Quincy, and Weymouth received over an inch of rain with portions of Needham approaching two inches from thunderstorms on Monday, Tuesday, and again Friday. In the south (Plainville and Foxboro), slow moving thunderstorms produced 1-2 inches of rain on Tuesday. The remainder of the southern border towns received between one half and one inch of rain. This was not enough to eliminate 60 and 90 day precipitation deficits, but it did halt further drying as deficits remain generally 50-75% of normal. The exception to this is the central part of the county where drying continued, with deficits closer to 50% of normal. The active weather pattern appears to continue for the next couple of weeks with above normal precipitation in the forecast.

Total weekly rainfall: 0.08 inches (-0.56 in.)
Total Monthly rainfall: 1.85 inches (-1.16 in.)
Total Yearly rainfall: 21.90” (+0.83 in.)

5. Number of requests for service

Year to date NCMCP has received 1,556 calls for service as of 6/28/08. This represents a total of 289 calls for the week. This shows a slight increase in calls from last week. Last year at this time the calls for service (year to date) were 2,918.

6. MCP/Commission response

In general our response has been to continue ground ULV applications targeting areas of high public demand. NCMCP continues to treat rain basins in highly urban areas where Culex pipiens/restuans activity is highest based on gravid trap collections.


144 Production Rd, Suite C

Walpole, MA 02081

Office: (781) 762-3681
Fax: (781) 769-6436