Week 32 – Aug 4-10

2013 MOSQUITO REPORT: WEEK 32

Report based on data collected from traps deployed the week of August 4-10, 2013. Report prepared by Chan Suom, M.S., Dave Lawson, and Nate Boonisar.

1. CURRENT MOSQUITO ACTIVITY/TREND

CDC Light Traps:
CDC light traps collected mostly lower than average numbers of host-seeking mosquitoes. Only Medfield reported a higher than average collection of mosquitoes.

Gravid Traps:
Gravid traps collected an average number of mosquitoes throughout Norfolk County for the week.

 2. CURRENT PREDOMINANT SPECIES

CDC Light Traps:
The most abundant mosquito species this week is Aedes vexans, though this was only represented in Dedham which also reported a lower than average collection. In a smaller capacity, Psorophora ferox continues to be prevalent in Canton.  Ochlerotatus canadensis is still very active in Sharon though their numbers have declined dramatically. A population of Culiseta melanura in Medfield is higher than average and it appears that they are newly emerged.

Gravid Traps:
Culex pipiens/restuans are predominant in these traps and their overall population is average for this time of the season.

3. COMPARISON TO PREVIOUS SEASON

The overall mosquito population for host-seeking mosquitoes in CDC light traps is below average compared to the historical averages for each town. Gravid collections are average. The towns of Quincy and Weymounth still experience the aftermath of a minor outbreak of salt marsh mosquitoes due to the last high tide. Torrential downpours this past Friday and rain expected this week will only create more habitat for flood and salt marsh species in the coming weeks.

4. WEATHER SUMMARY

Temperatures this week averaged slightly below normal with low humidity and cool nights. An area of light showers moved through on Thursday bringing around a tenth of an inch of rain to most areas. Far more significant rains occurred Friday as a large swath of moderate to heavy rain with embedded thunderstorms moved across the area in a 6-hour period. Widespread rainfall of 1.5 – 2.5 inches (heaviest central to east) occurred with local amounts that approached 3 inches. This brought sharp rises on small streams and the Neponset River with some possible inundation onto portions of the flood plain.

Total weekly rainfall: 2.25 inches (+1.51 in.)
Total Monthly rainfall:  2.45 inches (+1.40 in.)
Total Yearly rainfall:  29.69 inches (+4.31 in.)

5. NUMBER OF REQUESTS FOR SERVICE

We received 775 service requests this week, with a total of 8,991 service requests for the year.

6. MCP/COMMISSION RESPONSE

A July 23rd spring high tide over 12 feet high was the source of water for an emergence of Aedes sollicitans like we have not seen for quite a while. Across Weymouth and Quincy shoreline communities, the calls have been desperate as people are unable to venture outside due to the large numbers of mosquitoes. NCMCD is conducting off-schedule ULV applications in Weymouth and Quincy this week to help alleviate this problem. Otherwise calls across the district are declining but still high. ULV applications are being conducted in response. Catch basin treatments continue especially in the more densely populated towns in the eastern part of the district as WNV begins to show up in mosquito pools. Many residents are still requesting ground larviciding as well, but most sites are now drying up; though this may have changed as of last Friday’s torrential rainfall. The NCMCD will monitor the flood plains for larval development and prepare for the next emergence.

Contact

144 Production Rd, Suite C

Walpole, MA 02081

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