Week 31 – Aug 1-5

2011 MOSQUITO REPORT: WEEK 31

Report based on data collected from traps deployed the week of August 1, 2011 through August 5, 2011. Report prepared by John Smith, Chan Suom, M.S., and Nate Boonisar.

1. CURRENT MOSQUITO ACTIVITY/TREND

CDC Light Traps:
Host-seeking activity throughout Norfolk County continues to decline significantly this week. Almost all towns returned trap collections with lower than average numbers of mosquitoes. Only Holbrook collected higher than average numbers of host-seeking mosquitoes.

Gravid Traps:
Gravid mosquito activity throughout Norfolk County reversed last week’s trend with almost all towns reporting higher than average numbers of mosquitoes collected. Only Braintree and Millis reported lower than average collections.

2. CURRENT PREDOMINANT SPECIES

CDC Light Traps:
Culiseta melanura continues to be very populous in Holbrook and in parts of Sharon. Coquillettidia perturbans are numerous in Norfolk and Canton andAnopheles punctipennis are appearing in high numbers in Holbrook and Medfield.

Gravid Traps:
Gravid Culex pipiens/restuans mosquito populations are very high this week. Oc. japonicus numbers are about average.

3. COMPARISON TO PREVIOUS SEASON

The continued scattered thunderstorms and low overnight temperatures (60’s) during our trapping period had a different effect on our mosquito collections than last week. Host-seeking mosquito populations dropped dramatically whereas gravid mosquito populations increased substantially. It will be hard to make an accurate prediction for the forthcoming week’s mosquito activity.

4. WEATHER SUMMARY

This week started off with above normal temperatures. A cold front on Tuesday brought a return to near normal temperatures along with showers and thunderstorms, mainly in the eastern part of the county. Amounts of over ¼ inch fell northeast of a line from Needham to Holbrook, with amounts over a ½ inch in Milton, Quincy, and Weymouth.

Total weekly rainfall: 0.04 inches (-0.68 in.)
Total Monthly rainfall: 0.04 inches (-0.58 in.)
Total Yearly rainfall: 24.50 inches (-0.46 in.)

5. NUMBER OF REQUESTS FOR SERVICE

NCMCP received 5,643 calls year to date for service as of 8/05/11. NCMCP received 411 calls for service this week.

6. MCP/COMMISSION RESPONSE

NCMCP continues “area wide” ground ULV applications in high request areas and in areas where collection data indicate a need. Rain basin treatments continue with a concentration in urban areas where West Nile virus (WNV) has been collected historically. Rain basin treatments in the eastern areas where gravid traps are showing higher levels of Culex have been prioritized. NCMCP is also prioritizing basin treatments adjacent to areas in Bostonwhere West Nile virus has been identified. ULV applications have been conducted in these adjacent areas due to the high numbers of Culex collected in gravid traps. NCMCP continues some ground larviciding in coastal areas. Due to the positive WNV isolates in mosquitoes collected in Dedham, Needham, Norwood and Quincy, NCMCP has conducted localized (focused) applications of both ULV and rain basin treatments. Boards of Health in all communities have stepped up public outreach using all available local media outlets.

Contact

144 Production Rd, Suite C

Walpole, MA 02081

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