Week 28 – July 11-15

2011 MOSQUITO REPORT: WEEK 28

Report based on data collected from traps deployed the week of July 11, 2011 through July 15, 2011. Report prepared by John Smith, Chan Suom, M.S., and Nate Boonisar.

1. CURRENT MOSQUITO ACTIVITY/TREND

CDC Light Traps:
Most towns in Norfolk County had lower than average host-seeking mosquito collections. The towns of Bellingham, Medway, Plainville, Stoughton, and Wrentham reported average levels of activity, whereas Canton, Millis, Norfolk, and Quincy reported higher than average mosquito activity.

Gravid Traps:
Gravid mosquito activity was significantly reduced this week in most towns. Only Dedham retained average levels of activity, whereas Bellingham, Dover,Franklin, Medway, Milton, Norwood, Walpole, and Westwood continued with higher than average gravid collections.

2. CURRENT PREDOMINANT SPECIES

CDC Light Traps:
Coquillettidia perturbans are plentiful in Millis and Norfolk. Culiseta melanura are appearing in larger numbers in Sharon and Holbrook. Aedes vexanspopulations are higher than average in Canton and Millis; meanwhile Oc. cantator has literally taken over as the most abundant mosquito in our Quincylocation.

Gravid Traps:
Gravid Culex pipiens/restuans mosquito populations are mixed this week. Oc. japonicus numbers are average to lower than average for the week.

3. COMPARISON TO PREVIOUS SEASON

Wednesday’s evening and overnight thunderstorms have much to do with the low trap collections for host-seeking mosquitoes and the mixed activity levels for gravid collections. It appears Co. perturbans populations are waning, but this could be a false reading based on the storms’ effects on our collections. The following week promises fewer weather disturbances during our trap setting and collecting period.

4. WEATHER SUMMARY

This week started hot and humid, followed by a return to normal or slightly below normal temperatures. A strong cold front moved through Wednesday night into early Thursday bringing two rounds of showers and thunderstorms to the area, some with torrential rain. Rainfall ranged from less than ¼ inch across western sections, to over one inch across eastern sections. Monthly rain remains below normal across most of the county, except for a small strip along the southern border from Foxborough to Weymouth which has above normal rain.

Total weekly rainfall: 0.36 inches (-0.32 in.)
Total Monthly rainfall: 1.19 inches (-0.39 in.)
Total Yearly rainfall: 23.82 inches (+0.96 in.)

5. NUMBER OF REQUESTS FOR SERVICE

NCMCP received 4,325 calls year to date for service as of 7/15/11. NCMCP received 489 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 have begun with a concentration in urban areas where West Nile virus has been collected historically. Rain basin treatments in the eastern areas where gravid traps are showing high levels of Culex have been prioritized. NCMCP is also prioritizing basin treatments adjacent to areas in Boston where 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.

Contact

144 Production Rd, Suite C

Walpole, MA 02081

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