Week 31 – July 29-Aug 4

2012 MOSQUITO REPORT: WEEK 31

Report based on data collected from traps deployed the week of July 29, 2012 through August 4, 2012. Report prepared by Chan Suom, M.S., Dave Lawson, and Nate Boonisar.

1. CURRENT MOSQUITO ACTIVITY/TREND

CDC Light Traps:
Host-seeking light traps returned mixed results once more this week. Dedham, Foxborough, Medfield, Sharon, Walpole, and Wrentham collected higher than average numbers of mosquitoes whereas the remainder of the county returned lower than average to average collections.

Gravid Traps:
This trapping interval continues to show a downward population trend of gravid mosquitoes for Norfolk County. Again, only Medfield indicated an increase in Culex pipiens/restuans populations.

 2. CURRENT PREDOMINANT SPECIES

CDC Light Traps:
The most predominant CDC trapped mosquitoes in Norfolk County this week were Coquillettidia perturbans once again, with populations higher than average in Foxborough and Wrentham. Aedes vexans has started to make a noticeable appearance in Canton, Dedham, and Foxborough.  Culex pipiens/restuans numbers are higher than average in Dedham, Plainville, and Walpole. Culiseta melanura is returning in higher than average numbers in Medfield, Plainville, Sharon, and Walpole.

Gravid Traps:
Though their populations are low, Culex pipiens/restuans are the most predominant species in gravid traps throughout Norfolk County.

3. COMPARISON TO PREVIOUS SEASON

The mixed collections for host-seeking mosquitoes and really low abundance of gravid mosquitoes appear to be a factor of low abundance as the phenology would suggest. Overall, mosquito collections returned lower numbers than average. This week’s thunderstorm and rain events may produce a new emergence of flood-dependent mosquito species, of which we should encounter within 2 weeks.

4. WEATHER SUMMARY

Temperatures this week continued to average mainly above normal with increasing humidity towards the end of the week. There were two periods of rainfall.  A small coastal storm on Tuesday evening brought a swath of steady rain to most of the district. Amounts were generally 0.5”-0.75” east of a line from Foxborough to Dover, while amounts west of that rapidly trailed off to a trace at the western border. On Wednesday, a swath of heavy afternoon showers brought 1 – 1.5 inches of rain in about an hour’s time along a narrow corridor from Franklin to Dedham. This caused brief, but sharp rises on the Neponset River; however any inundation onto the floodplain was very brief and unlikely to cause any problems.

Total weekly rainfall: 1.77 inches (+1.06 in.)
Total Monthly rainfall: 2.99 inches (-0.07 in.)
Total Yearly rainfall: 19.09 inches (-5.66 in.)

5. NUMBER OF REQUESTS FOR SERVICE

NCMCD has received 5,947 calls year to date for services as of 8/3/12. The NCMCD received 604 calls for service this week.

6. MCP/COMMISSION RESPONSE

The NCMCD continues to respond to ULV requests by residents. With the recent finding of multiple EEE positive pools of Cq. perturbans in Canton, the District has stepped up additional ULV applications in Canton and Randolph. Basin treatments have been completed in some communities and continue in other municipalities. Very few larvicide requests are being initiated at this time.

Contact

144 Production Rd, Suite C

Walpole, MA 02081

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